FirstMerit (FMER) 10-K 23 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 20, 2015	Jun. 30, 2014
Entity Information [Line Items]
Entity Registrant Name	FIRSTMERIT CORP /OH/
Entity Central Index Key	354869
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		165,385,707
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$3,266,512,204

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS
Cash and due from banks	$480,998	$571,171
Interest-bearing deposits in banks	216,426	346,651
Total cash and cash equivalents	697,424	917,822
Investment securities:
Held-to-maturity	2,903,609	2,935,688
Available-for-sale	3,545,288	3,273,174
Other investments	148,654	180,803
Loans held for sale	13,428	11,622
Loans
Loans	15,326,147	14,300,972
Allowance for loan losses	-143,649	-141,252
Net loans	15,182,498	14,159,720
Premises and equipment, net	332,297	327,054
Goodwill	741,740	741,740
Intangible assets	71,020	82,755
Covered other real estate	49,641	65,234
Accrued interest receivable and other assets	1,216,748	1,216,416
Assets	24,902,347	23,912,028
Deposits:
Noninterest-bearing	5,786,662	5,459,029
Interest-bearing	3,028,888	3,026,735
Savings and money market accounts	8,399,612	8,587,167
Certificates and other time deposits	2,289,503	2,460,670
Total deposits	19,504,665	19,533,601
Federal funds purchased and securities sold under agreements to repurchase	1,272,591	851,535
Wholesale borrowings	428,071	200,600
Long-term debt	505,192	324,428
Accrued taxes, expenses and other liabilities	357,547	298,970
Total liabilities	22,068,066	21,209,134
Shareholders' equity:
Capital surplus	1,393,090	1,390,643
Accumulated other comprehensive loss	-71,892	-66,876
Retained earnings	1,404,717	1,277,975
Treasury stock, at cost: December 31, 2014 - 4,793,566 shares; December 31, 2013 - 5,127,332 shares	-122,571	-129,785
Total shareholders' equity	2,834,281	2,702,894
Total liabilities and shareholders' equity	24,902,347	23,912,028
Series A Non-Cumulative Perpetual Preferred Stock
Shareholders' equity:
5.875% Non-Cumulative Perpetual Preferred stock, Series A, without par value: authorized 115,000 shares; 100,000 issued	100,000	100,000
Common stock
Shareholders' equity:
Common stock warrant	3,000	3,000
Common Stock, without par value; authorized 300,000,000 shares; issued: December 31, 2014 - 170,183,540 shares; December 31, 2013 - 170,183,540 shares	127,937	127,937
Fair Value, Inputs, Level 1 [Member]
Investment securities:
Available-for-sale	2,974	3,036
Other investments	0	0
Loans held for sale	0	0
Fair Value, Inputs, Level 2 [Member]
Investment securities:
Available-for-sale	3,203,127	2,922,527
Other investments		180,803
Loans held for sale		$11,622

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets Parenthetical	Dec. 31, 2014	Dec. 31, 2013
Class of Stock [Line Items]
Common Stock, Shares Authorized	300,000,000	300,000,000
Treasury Stock, Shares	4,793,566	5,127,332
Common Stock, Shares, Issued	170,183,540	170,183,540
Preferred Stock, Shares Authorized	7,000,000
Series A Non-Cumulative Perpetual Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	115,000	115,000
Preferred Stock, Shares Outstanding	100,000	100,000

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest income:
Loans and loans held for sale	$682,328	$635,872	$410,299
Investment securities:
Taxable	128,363	108,824	85,030
Tax-exempt	21,807	21,107	15,354
Total investment securities interest	150,170	129,931	100,384
Total interest income	832,498	765,803	510,683
Interest expense:
Interest bearing	2,963	2,543	987
Savings and money market accounts	22,101	24,406	20,563
Certificates and other time deposits	10,844	9,649	11,723
Securities sold under agreements to repurchase	991	1,240	1,157
Wholesale borrowings	6,277	3,893	4,423
Long-term debt	13,754	13,287	0
Total interest expense	56,930	55,018	38,853
Net interest income	775,568	710,785	471,830
Provision for loan losses	52,279	33,684	54,698
Net interest income after provision for loan losses	723,289	677,101	417,132
Noninterest income:
Trust department income	39,949	34,770	23,143
Service charges on deposits	71,457	74,399	57,737
Credit card fees	52,666	50,542	43,569
ATM and other service fees	24,179	19,155	14,792
Bank owned life insurance income	19,177	16,926	12,140
Investment services and insurance	15,145	12,777	8,990
Investment securities gains/(losses), net	166	-2,803	3,786
Loan sales and servicing income	16,044	23,069	27,031
Other operating income	42,741	41,508	32,416
Total noninterest income	281,524	270,343	223,604
Noninterest expense:
Salaries, wages, pension and employee benefits	358,970	354,016	245,192
Net occupancy expense	59,436	49,510	31,754
Equipment expense	48,499	41,875	29,243
Stationery, supplies and postage	15,587	14,199	8,800
Bankcard, loan processing and other costs	45,625	71,929	34,195
Professional services	21,813	40,680	23,480
Amortization of intangibles	11,735	8,392	1,866
FDIC insurance expense	20,481	17,707	10,753
Other operating expense	82,773	85,945	65,654
Total noninterest expense	664,919	684,253	450,937
Income before income tax expense	339,894	263,191	189,799
Income tax expense	101,943	79,507	55,693
Net income	237,951	183,684	134,106
Less: Net income allocated to participating securities	1,930	1,545	0
Preferred Stock dividends	5,876	5,337	0
Net income attributable to common shareholders	$230,145	$176,802	$134,106
Basic earnings per common share	$1.39	$1.18	$1.22
Diluted earnings per common share	$1.39	$1.18	$1.22
Cash dividend per common share	$0.64	$0.64	$0.64
Weighted average number of common shares outstanding - basic	165,296	149,607	109,518
Weighted average number of common shares outstanding - diluted	166,054	150,421	109,518

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Preferred Stock	Common stock	Warrant	Capital Surplus	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
In Thousands, unless otherwise specified
Beginning Balance at Dec. 31, 2011	$1,565,953	$0	$127,937	$0	$479,882	($23,887)	$1,131,203	($149,182)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	134,106	0	0	0	0	0	134,106	0
Other comprehensive income	7,682	0	0	0	0	7,682	0	0
Comprehensive income	141,788	0	0	0	0	7,682	134,106	0
Cash dividends - common stock	-69,459	0	0	0	0	0	-69,459	0
Nonvested (restricted) shares granted	49		0	0	-14,582	0		14,631
Restricted stock activity	-2,389	0	0	0	1,219	0	0	-3,608
Deferred compensation trust	0	0	0	0	200	0	0	-200
Issuance of a Common Stock warrant to the U.S. Treasury for Citizens TARP warrant	0
Share-based compensation	9,260	0	0	0	9,260	0	0	0
Ending Balance at Dec. 31, 2012	1,645,202	0	127,937	0	475,979	-16,205	1,195,850	-138,359
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	183,684	0	0	0	0	0	183,684	0
Other comprehensive income	-50,671	0	0	0	0	-50,671	0	0
Comprehensive income	133,013	0	0	0	0	-50,671	183,684	0
Cash dividends - Preferred Stock	-5,337	0	0	0	0	0	-5,337	0
Cash dividends - common stock	-96,222	0	0	0	0	0	-96,222	0
Nonvested (restricted) shares granted	-6,813			0	-19,790			12,977
Common stock issued in connection with Citizens acquisition	925,272				925,272
Restricted stock activity	-2,708	0	0	0	1,261	0	0	-3,969
Deferred compensation trust	0	0	0	0	434	0	0	-434
Issuance Non-Cumulative Perpetual Preferred Stock, Series A	96,550	100,000			-3,450
Issuance of a Common Stock warrant to the U.S. Treasury for Citizens TARP warrant	3,000			3,000
Share-based compensation	10,937	0	0	0	10,937	0	0	0
Ending Balance at Dec. 31, 2013	2,702,894	100,000	127,937	3,000	1,390,643	-66,876	1,277,975	-129,785
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	237,951	0	0	0	0	0		0
Other comprehensive income	-5,016	0	0	0	0	-5,016	0	0
Comprehensive income	232,935	0	0	0	0	-5,016	237,951	0
Cash dividends - Preferred Stock	-5,876	0	0	0	0	0	-5,876	0
Cash dividends - common stock	-105,333	0	0	0	0	0	-105,333	0
Nonvested (restricted) shares granted	99			0	-13,469		0	13,568
Restricted stock activity	-4,360	0	0	0	1,219	0	0	-5,579
Deferred compensation trust	0	0	0	0	775	0	0	-775
Issuance of a Common Stock warrant to the U.S. Treasury for Citizens TARP warrant	0
Share-based compensation	13,922	0	0	0	13,922	0	0	0
Ending Balance at Dec. 31, 2014	$2,834,281	$100,000	$127,937	$3,000	$1,393,090	($71,892)	$1,404,717	($122,571)

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Shareholders' Equity (parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Cash dividend per common share	$0.64	$0.64	$0.64
Stock Issued During Period, Shares, Restricted Stock Award, Gross	595,906	563,257	596,415
Treasury Stock, Shares, Acquired	262,140	217,674	198,407
Stock Issued During Period, Shares, Treasury Stock Reissued	291,419	198,207	105,850
Stock Issued During Period, Shares, New Issues	0	55,468,283	0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	0

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net income	$237,951	$183,684	$134,106
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	52,279	33,684	54,698
Provision (benefit) for deferred income taxes	44,666	-17,819	4,679
Depreciation and amortization	53,802	38,236	32,486
Benefit attributable to FDIC loss share	2,920	10,790	14,728
Accretion of acquired loans	-136,776	-154,487	-80,506
Amortization and accretion of investment securities, net
Available for sale	11,734	17,274	15,343
Held to maturity	4,800	7,609	2,421
Losses (gains) on sales and calls of available-for-sale investment securities, net	-166	2,803	-3,786
Originations of loans held for sale	-358,301	-550,193	-738,797
Proceeds from sales of loans, primarily mortgage loans sold in the secondary markets	363,732	574,321	757,298
Gains on sales of loans, net	-7,237	-12,067	-12,107
Amortization of intangible assets	11,735	8,392	1,866
Recognition of stock compensation expense	13,922	10,937	9,260
Net decrease (increase) in other assets	-26,707	181,772	88,530
Net increase (decrease) in other liabilities	16,283	-25,570	-99,753
NET CASH PROVIDED BY OPERATING ACTIVITIES	284,637	309,366	180,466
Proceeds from sale of securities
Available for sale	22,463	2,179,728	418,124
Other	32,486	89,554	0
Held to maturity	7,088	897	0
Proceeds from prepayments, calls, and maturities
Available for sale	486,100	699,647	853,179
Held to maturity	390,882	245,259	54,775
Other	0	0	0
Purchases of securities
Available for sale	-754,518	-1,059,130	-1,416,413
Held to maturity	-378,678	-1,832,993	-113,918
Other	-388	-3,098	-42
Net decrease (increase) in loans and leases	-952,518	171,929	-511,914
Purchases of premises and equipment	-69,346	-40,632	-13,073
Sales of premises and equipment	26,509	1,110	1,813
Cash received for acquisition, net of cash paid	0	188,948	0
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	-1,189,920	641,219	-727,469
Financing Activities
Net increase in demand accounts	329,786	835,011	532,924
Net increase (decrease) in savings and money market accounts	-187,555	176,513	162,714
Net decrease in certificates and other time deposits	-171,167	-514,103	-367,822
Net increase (decrease) in securities sold under agreements to repurchase	421,056	-367,995	238,260
Increase (decrease) in long-term debt	180,764	249,930	0
Net increase (decrease) in wholesale borrowings	227,471	-655,603	-66,579
Net proceeds from issuance of preferred stock	0	96,550	0
Cash dividends - common	-105,333	-96,222	-69,459
Cash dividends - preferred	-5,876	-5,337	0
Restricted stock activity	-4,261	-9,521	-2,340
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES	684,885	-290,777	427,698
Increase (decrease) in cash and cash equivalents	-220,398	659,808	-119,305
Cash and cash equivalents at beginning of year	917,822	258,014	377,319
Cash and cash equivalents at end of year	697,424	917,822	258,014
SUPPLEMENTAL DISCLOSURE OF CASH FLOWS INFORMATION:
Non-cash transaction: Common Stock issued in merger with Citizens	0	925,211	0
Non-cash transaction: Consideration from the warrant issued to the Treasury for Citizens TARP	0	3,000	0
Cash paid during the year for:
Interest expense	55,424	50,055	40,252
Federal income taxes	$35,981	$27,662	$45,321

Statement_of_Comprehensive_Inc

Statement of Comprehensive Income Statement (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Income before income tax expense	$339,894	$263,191	$189,799
Total income tax expense	101,943	79,507	55,693
Net income	237,951	183,684	134,106
Changes in unrealized securities' holding gains/(losses), Pre-Tax	38,864	-130,947	-6,668
Changes in unrealized securities' holding gains/(losses), Tax	13,602	-45,833	-2,334
Changes in unrealized securities' holding gains/(losses), After-tax	25,262	-85,114	-4,334
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, Pre-Tax	-2,157	-2,187	13,059
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, Tax	-753	-765	4,571
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, After-tax	-1,404	-1,422	8,488
Net losses/(gains) realized on sale of securities reclassified to noninterest income, Pre-Tax	-166	2,803	-3,786
Net losses/(gains) realized on sale of securities reclassified to noninterest income, Tax	-58	981	-1,325
Net losses/(gains) realized on sale of securities reclassified to noninterest income, After-tax	-108	1,822	-2,461
Net change in unrealized gains/(losses) on securities available for sale, Pre-Tax	36,541	-130,331	2,605
Net change in unrealized gains/(losses) on securities available for sale, Tax	12,791	-45,617	912
Net change in unrealized gains/(losses) on securities available for sale, After-tax	23,750	-84,714	1,693
Net gains/(losses) arising during the period, Pre-Tax	-49,552	47,939	-1,224
Net gains/(losses) arising during the period, Tax	-17,344	16,779	-429
Net gains/(losses) arising during the period, After-tax	-32,208	31,160	-795
Amortization of actuarial gain, Pre-Tax	3,166	4,437	10,517
Amortization of actuarial gain, Tax	1,108	1,553	3,681
Amortization of actuarial gain, After-tax	2,058	2,884	6,836
Amortization of prior service cost reclassified to other noninterest expense, Pre-Tax	2,131	-1	-80
Amortization of prior service cost reclassified to other noninterest expense, Tax	747	0	-28
Amortization of prior service cost reclassified to other noninterest expense, After-tax	1,384	-1	-52
Net change from defined benefit pension plans, Pre-Tax	-44,255	52,375	9,213
Net change from defined benefit pension plans, Tax	-15,489	18,332	3,224
Net change from defined benefit pension plans, After-tax	-28,766	34,043	5,989
Total other comprehensive gains/(losses), Pre-Tax	-7,714	-77,956	11,818
Total other comprehensive gains/(losses), Tax	-2,698	-27,285	4,136
Total other comprehensive gains/(losses), After-tax	-5,016	-50,671	7,682
Comprehensive income, Pre-Tax	332,180	185,235	201,617
Comprehensive income, Tax	99,245	52,222	59,829
Comprehensive income, After-tax	$232,935	$133,013	$141,788

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	The accounting and reporting policies of the Corporation conform to GAAP and to general practices within the financial services industry.
	In preparing these accompanying consolidated financial statements, subsequent events were evaluated through the time the consolidated financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users, or filed with the SEC.
	The following is a description of the Corporation’s significant accounting policies.
	(a) Principles of Consolidation
	The Parent Company is a bank holding company whose principal asset is the common stock of its wholly-owned subsidiary, the Bank. The Parent Company’s other subsidiaries include Citizens Savings Corporation of Stark County, FirstMerit Capital Trust I, and FirstMerit Risk Management, Inc. All significant intercompany balances and transactions have been eliminated in consolidation.
	(b) Use of Estimates
	Management must make certain estimates and assumptions that affect the amounts reported in the financial statements and related notes. If these estimates prove to be inaccurate, actual results could differ from those reported.
	(c) Business Combinations
	Business combinations are accounted for using the acquisition method of accounting. Under this accounting method, the acquired company's net assets are recorded at fair value on the date of acquisition, and the results of operations of the acquired company are combined with the Corporation's results from that date forward. Costs related to the acquisition are expensed as incurred. The difference between the purchase price and the fair value of the net assets acquired (including intangible assets with finite lives) is recorded as goodwill. The accounting policy for goodwill and intangible assets is summarized in this note under the heading "Goodwill and Other Intangible Assets". As discussed in Note 2 (Business Combinations), the Corporation completed the merger with Citizens, a Michigan corporation, during 2013. As of November 18, 2014, the recently issued FASB ASU 2014-17, Pushdown Accounting—a consensus of the FASB Emerging Issues Task Force, provides the Corporation the ability to elect push down accounting in the acquired entities separate financial statements, either in the current reporting period in which a change-in-control event occurs or in a subsequent period. This ASU is summarized in this notes under the heading “Recently Issued Accounting Standards”.
	(d) Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and due from banks, interest bearing deposits in other banks and checks in the process of collection.
	(e) Investment Securities
	Debt securities are classified as held-to-maturity when the Corporation has the positive intent and ability to hold the securities to maturity. These securities are reported at amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity using the effective yield method. This method produces a constant rate of return on the adjusted carrying amount.
	Securities are classified as available-for-sale when the Corporation intends to hold the securities for an indefinite period of time but may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Securities available-for-sale are reported at fair value, with unrealized gains and losses, net of income tax, reported as a separate component of other comprehensive income (loss) in shareholders’ equity.
	In certain situations, Management may elect to transfer certain debt securities from the available-for-sale to the held to maturity classification. In such cases, any unrealized gain or loss included in accumulated other comprehensive income (loss) at the time of transfer is amortized over the remaining life of the security as a yield adjustment such that only the remaining initial discount or premium from the purchase date is recognized in income.
	Interest and dividends on securities, including the amortization of premiums and accretion of discount, are included in interest income. Realized gains or losses on the sales of available-for-sale securities are recorded on the trade date and determined using the specific identification method.
	On at least a quarterly basis, Management evaluates securities that are in an unrealized loss position for OTTI. An investment security is deemed impaired if the fair value of the investment is less than its amortized cost. As part of the impairment evaluation, Management considers the extent and duration of the unrealized loss, and the financial condition and near-term prospects of the issuer. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: 1) OTTI related to credit loss, which must be recognized in earnings, and 2) OTTI related to other factors, such as liquidity conditions in the market or changes in market interest rates, which is recognized in other comprehensive income. The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis. For equity securities, the entire amount of impairment is recognized in earnings.
	Other investments include FHLB and FRB stock. As a member of the FHLB system, the Bank is required to own a certain amount of stock based on the level of borrowings and other factors. The Bank is also a member of its regional FRB. Both FHLB and FRB stock are carried at cost and evaluated for impairment based on the ultimate recovery of par value. Cash and stock dividends received on the stock are reported as interest income in the Consolidated Statement of Income.
	(f) Originated Loans and Loan Income
	Loans originated for investment are stated at their principal amount outstanding adjusted for partial charge-offs, and net deferred loan fees and costs. Interest income on loans is accrued over the term of the loans primarily using the simple-interest method based on the principal balance outstanding. Interest is not accrued on loans where collectability is uncertain. Accrued interest is presented separately in the balance sheet, except for accrued interest on credit card loans, which is included in the outstanding loan balance. Loan origination fees and certain direct costs incurred to extend credit are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield.
	(g) Loans Held for Sale
	Mortgage loans originated and intended for sale in the secondary market are carried at fair value. The election of the fair value option aligns the accounting for these loans with the related economic hedges. Loan origination fees are recorded when earned and related direct loan origination costs are recognized when incurred. Upon their sale, differences between carrying value and sales proceeds realized are recorded to loan sales and servicing income in the Consolidated Statement of Income.
	A discussion of the valuation methodology applied to the Corporation’s loans held for sale is described in Note 18 (Fair Value Measurement).
	(h) Nonperforming Loans
	Loans and leases on which payments are past due for 90 days are placed on nonaccrual, with the exception of certain commercial, credit card and mortgage loans and loans that are fully secured and in process of collection. Credit card loans on which payments are past due for 120 days are placed on nonaccrual status. Interest on mortgage loans is accrued until Management deems it uncollectible based upon the specific identification method.
	Loans are generally written off when deemed uncollectible or when they reach a predetermined number of days past due depending upon loan product, terms, and other factors. When a loan is placed on nonaccrual status, interest deemed uncollectible that had been accrued in prior years is charged against the allowance for loan losses and interest deemed uncollectible accrued in the current year is reversed against interest income. Payments subsequently received on nonaccrual loans are generally applied to principal. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable. This generally requires a sustained period of timely principal and interest payments.
	Under the Corporation’s credit policies and practices, individually impaired loans include all nonaccrual and restructured commercial, agricultural, construction, and commercial real estate loans, but exclude certain aggregated consumer loans, mortgage loans, and leases classified as nonaccrual. Loan impairment for all loans is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate at inception, at the observable market price of the loan, or the fair value of the collateral for certain collateral dependent loans.
	Restructured loans are those on which concessions in terms have been made as a result of deterioration in a borrower’s financial condition. In general, the modification or restructuring of a debt constitutes a troubled debt restructuring if the Corporation for economic or legal reasons related to the borrower’s financial difficulties grants a concession to the borrower that the Corporation would not otherwise consider under current market conditions. Debt restructurings or loan modifications for a borrower do not necessarily constitute troubled debt restructurings. Troubled debt restructurings do not necessarily result in nonaccrual loans. Specific allowances for loan losses are established for certain consumer, commercial and commercial real estate loans whose terms have been modified in a TDR.
	Acquired nonimpaired loans are placed on nonaccrual and considered and reported as nonperforming or past due using the same criteria applied to the originated portfolio. Acquired impaired loans are not classified as nonperforming assets as the loans are considered to be performing under the provisions of ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (“ASC 310-30”). Acquired loans restructured after acquisition are not considered TDRs for purposes of the Corporation’s accounting and disclosure if the loans evidenced credit deterioration as of the acquisition date and are accounted for in pools.
	(i) Allowance for Loan Losses
	The allowance for loan losses is Management’s estimate of the amount of probable credit losses inherent in the loan portfolio at the balance sheet date. Increases to the allowance for loan losses are made by charges to the provisions for loan losses. Loans deemed uncollectible are charged against the allowance for loan losses. Recoveries of previously charged-off amounts are credited to the allowance for loan losses. Management estimates credit losses based on individual loans determined to be impaired and on all other loans grouped based on similar risk characteristics.
	The Corporation’s historical loss component is the most significant of the allowance for loan losses components and is based on historical loss experience by credit-risk grade (for commercial loan pools) and payment status (for mortgage and consumer loan pools). Loans are pooled based on similar risk characteristics supported by observable data. The historical loss experience component of the allowance for loan losses represents the results of migration analysis of historical net charge-offs for portfolios of loans (including groups of commercial loans within each credit-risk grade and groups of consumer loans by payment status). For measuring loss exposure in a pool of loans, the historical net charge-off or migration experience is utilized to estimate expected losses to be realized from the pool of loans.
	Individual commercial loans are assigned credit-risk grades based on an internal assessment of conditions that affect a borrower’s ability to meet its contractual obligation under the loan agreement. The assessment process includes reviewing a borrower’s current financial information, historical payment experience, credit documentation, public information, and other information specific to each individual borrower. Certain commercial loans are reviewed on an annual, quarterly or rotational basis or as Management becomes aware of information affecting a borrower’s ability to fulfill its obligation.
	The credit-risk grading process for commercial loans is summarized as follows:
	“Pass” Loans (Grades 1, 2, 3, 4) are not considered a greater than normal credit risk. Generally, the borrowers have the apparent ability to satisfy obligations to the bank, and the Corporation anticipates insignificant uncollectible amounts based on its individual loan review.
	“Special-Mention” Loans (Grade 5) are commercial loans that have identified potential weaknesses that deserve Management’s close attention. If left uncorrected, these potential weaknesses may result in noticeable deterioration of the repayment prospects for the asset or in the institution’s credit position.
	“Substandard” Loans (Grade 6) are inadequately protected by the current financial condition and paying capacity of the obligor or by any collateral pledged. Loans so classified have a well-defined weakness or weaknesses that may jeopardize the liquidation of the debt pursuant to the contractual principal and interest terms. Such loans are characterized by the distinct possibility that the Corporation may sustain some loss if the deficiencies are not corrected.
	“Doubtful” Loans (Grade 7) have all the weaknesses inherent in those classified as substandard, with the added characteristic that existing facts, conditions, and values make collection or liquidation in full highly improbable. Such loans are currently managed separately to determine the highest recovery alternatives.
	If a nonperforming, substandard loan has an outstanding balance of $0.3 million or greater or if a doubtful loan has an outstanding balance of $0.1 million or greater, as determined by the Corporation’s credit-risk grading process, further analysis is performed to determine the probable loss, if any, and assign a specific allowance to the loan if needed. The allowance for loan losses relating to originated loans that have become impaired is based on either expected cash flows discounted at the loan’s original effective interest rate, the observable market price, or the fair value of the collateral for certain collateral dependent loans. To the extent credit deterioration occurs on purchased loans after the date of acquisition, the Corporation records an allowance for loan losses, net of any expected reimbursement under any FDIC Loss Sharing Agreements.
	Management also considers internal and external factors such as economic conditions, credit quality trends, loan management practices, portfolio monitoring, and other risks, collectively known as qualitative factors, or Q-factors, to estimate credit losses in the loan portfolio. Q-factors are used to reflect changes in the portfolio’s collectability characteristics not captured by historical loss data.
	The Corporation also assesses the credit risk associated with off-balance sheet loan commitments and letters of credit. The liability for off-balance sheet credit exposure related to loan commitments and other credit guarantees is included in other liabilities on the Consolidated Balance Sheet.
	(j) Acquired Loans, Covered Loans and Related Loss Share Receivable
	Acquired loans (nonimpaired and impaired) are initially measured at fair value as of the acquisition date. The fair value estimates for acquired loans are based on the estimate of expected cash flows, both principal and interest and prepayments, discounted at prevailing market interest rates. Credit discounts representing the principal losses expected over the life of the loan are also a component of the initial fair value; therefore, an allowance for loan losses is not recorded at the acquisition date.
	The Corporation evaluates acquired loans for impairment in accordance with the provisions of ASC 310-30. Acquired loans are considered impaired if there is evidence of credit deterioration since origination and if it is probable at time of acquisition that all contractually required payments will not be collected. In determining the acquisition date fair value of acquired impaired loans, and in subsequent accounting, the Corporation generally aggregates impaired loans into pools of loans with common characteristics. Each pool is accounted for as a single asset with one composite interest rate and an aggregate expectation of cash flows. Expected cash flows at the acquisition date in excess of the fair value of the loans is referred to as the accretable yield and recorded as interest income over the life of the loans. Acquired impaired loans are not classified as nonaccrual or nonperforming as they are considered to be accruing loans because their interest income relates to the accretable yield recognized at the pool level and not to contractual interest payments at the loan level. Subsequent to the acquisition date, increases in expected cash flows will generally result in a recovery of any previously recorded ALL, to the extent applicable, and/or a reclassification from the nonaccretable difference to accretable yield, which will be recognized prospectively. The present value of any decreases in expected cash flows after the acquisition date will generally result in an impairment charge recorded as a provision for loan losses, resulting in an increase to the ALL, net of any expected reimbursement under FDIC Loss Share Agreements, to the extent applicable. Revolving loans, including lines of credit and credit cards loans, and leases are excluded from acquired impaired loan accounting.
	For acquired nonimpaired loans, the difference between the acquisition date fair value and the contractual amounts due at the acquisition date represents the fair value adjustment. Fair value adjustments may be discounts (or premiums) to a loan’s cost basis and are accreted (or amortized) to interest income over the the loan’s remaining life using the level yield method. Subsequent to the acquisition date, the method utilized to estimate the required allowance for loan losses for these loans is similar to originated loans, however, the Corporation records an allowance for loan losses only when the required allowance, net of any expected reimbursement under any FDIC Loss Share Agreements, to the extent applicable, exceeds the remaining fair value adjustment. Acquired nonimpaired loans are reported net of the unamortized fair value adjustment. Nonimpaired acquired loans are placed on nonaccrual status and reported as nonperforming or past due using the same criteria applied to the originated portfolio.
	Loans acquired in FDIC assisted transactions and covered under FDIC Loss Share Agreements are referred to as covered loans. Covered loans are recorded at fair value at the date of acquisition exclusive of the FDIC Loss Share Agreements. No allowance for loan losses related to covered loans is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. The covered loans are subsequently valued and accounted for in the same manner as the acquired loans disclosed above.
	A loss share receivable is recorded at the acquisition date which represents the estimated fair value of reimbursement the Corporation expects to receive from the FDIC for incurred losses on certain covered loans. The fair value measurement reflects counterparty credit risk and other uncertainties. The loss share receivable continues to be measured on the same basis as the related indemnified loans. Deterioration in the credit quality of the loans (recorded as an adjustment to the allowance for covered loan losses) would immediately increase the basis of the loss share receivable, with the offset recorded through the consolidated statement of comprehensive income. Increases in the credit quality or cash flows of loans (reflected as an adjustment to yield and accreted into income over the remaining life of the loans) decrease the basis of the loss share receivable, with such decrease being accreted into income over 1) the same period or 2) the life of the loss share agreements, whichever is shorter. Loss assumptions used in the basis of the loss share receivable are consistent with the loss assumptions used to measure the related covered loans.
	Upon the determination of an incurred loss the loss share receivable will be reduced by the amount owed by the FDIC. A corresponding claim receivable is recorded in accrued interest receivable and other assets on the Consolidated Balance Sheet until cash is received from the FDIC.
	An acquired or covered loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the period of resolution of a nonimpaired loan, any remaining unamortized fair value adjustment is recognized as interest income. In the period of resolution of an impaired loan accounted for on an individual basis, the difference between the carrying amount of the loan and the proceeds received is recognized as a gain or loss within noninterest income. The majority of impaired loans are accounted for within a pool of loans which results in any difference between the proceeds received and the loan carrying amount being deferred as part of the carrying amount of the pool. The accretable amount of the pool remains unaffected from the resolution until the subsequent quarterly cash flow re-estimation. Favorable results from removal of the resolved loan from the pool increase the future accretable yield of the pool, while unfavorable results are recorded as impairment in the quarter of the cash flow re-estimation. Acquired or covered impaired loans subject to modification are not removed from a pool even if those loans would otherwise be deemed TDRs as the pool, and not the individual loan, represents the unit of account.
	For further discussion of the Corporation’s acquisitions and loan accounting, see Note 2 (Business Combinations), Note 4 (Loans), and Note 5 (Allowance for Loan Losses).
	(k) Equipment Lease Financing
	The Corporation leases equipment directly to customers. The net investment in financing leases includes the aggregate amount of lease payments to be received and the estimated residual values of the equipment, less unearned income. Income from lease financing is recognized over the lives of the leases on an approximate level rate of return on the unrecovered investment. The residual value represents the estimated fair value of the leased asset at the end of the lease term. Unguaranteed residual values of leased assets are reviewed at least annually for impairment. Declines in residual values determined to be other-than-temporary are recognized in earnings in the period such determinations are made.
	(l) Mortgage Servicing Rights
	The Corporation periodically sells residential real estate loans while retaining the rights and obligations to perform the servicing of such loans. Whenever the Corporation undertakes an obligation to service such loans, Management assesses whether a servicing asset or liability should be recognized. A servicing asset is recognized whenever the compensation for servicing is expected to exceed servicing costs. Likewise, a servicing liability would be recognized in the event that servicing fees to be received are not expected to adequately compensate the Corporation for its expected cost. Servicing assets associated with retained mortgage servicing rights are presented within other assets on the balance sheet. The Corporation does not presently have any servicing liabilities.
	MSRs are initially valued at fair value. Servicing assets and liabilities are subsequently measured using the amortization method which requires servicing rights to be amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Amortization is recorded in loan sales and servicing income in the Consolidated Statement of Income.
	At each reporting period, MSRs are assessed for impairment based on fair value of those rights on a stratum-by-stratum basis. The Corporation stratifies its servicing rights portfolio into tranches based on loan type and interest rate, the predominant risk characteristics of the underlying loans. Any impairment is recognized through a valuation allowance for each impaired stratum through a charge to income. If the Corporation later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income.
	The Corporation also reviews MSRs for OTTI each quarter and recognizes a direct write-down when the recoverability of a recorded allowance for impairment is determined to be remote. Unlike an allowance for impairment, a direct write-down permanently reduces the unamortized cost of the MSR and the allowance for impairment.
	MSRs do not trade in an active open market with readily observable market prices. Although sales of MSRs do occur, the exact terms and conditions may not be available. As a result, the fair value of MSRs is estimated using discounted cash flow modeling techniques which require Management to make assumptions regarding future net servicing income, adjusted for such factors as net servicing income, discount rate and prepayments. The primary assumptions used in determining the current fair value of the Corporation’s MSRs as well as a sensitivity analysis are presented in Note 7 (Mortgage Servicing Rights and Mortgage Servicing Activity).
	The Corporation generally records loan administration fees for servicing loans for investors on the accrual basis of accounting. Servicing fees and late fees related to delinquent loan payments are also recorded on the accrual basis of accounting.
	(m) Depreciation and Amortization
	Premises and equipment are reported at cost less accumulated depreciation and amortization and principally depreciated using the straight-line method over their estimated useful lives. Estimated useful lives for furniture and equipment range from three to 15 years, and depreciable buildings ranges from 10 to 35 years. Amortization of leasehold improvements is computed on the straight-line method based on related lease terms or the estimated useful lives of the assets of up to 15 years, whichever is shorter.
	The Corporation purchases, as well as internally develops and customizes, certain software to enhance or perform internal business functions. Software development costs incurred in the planning and post-development project stages are charged to noninterest expense. Costs associated with designing software configuration and interfaces, installation, coding programs and testing systems are capitalized and amortized using the straight-line method over periods ranging from three to seven years.
	(n) Goodwill and Other Intangible Assets
Goodwill represents the amount by which the cost of net assets acquired in a business combination exceeds their fair value. Goodwill is evaluated for impairment on an annual basis or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The goodwill impairment test is a two-step process. The first step compares the reporting unit’s estimated fair values, including goodwill, to its carrying amount. If the carrying amount exceeds its fair value, then goodwill impairment may be indicated. The second step allocates the reporting units fair value to its assets and liabilities. If the unallocated fair value does not exceed the carrying amount of goodwill then an impairment loss would be recognized as a charge to earnings.
Other intangible assets represent the present value of the future stream of income to be derived from the purchase of core deposits. Other intangible assets are amortized on a straight-line basis over their estimated useful lives. Goodwill and other intangible assets deemed to have indefinite lives are not amortized.
(o) Other Real Estate Owned
Other real estate owned is included in other assets in the consolidated balance sheets and is primarily comprised of property acquired through loan foreclosure proceedings or acceptance of a deed-in-lieu of foreclosures, and loans classified as in-substance foreclosure. Other real estate owned is recorded at the lower of the recorded investment in the loan at the time of transfer or the fair value of the underlying property collateral, less estimated selling costs. Any write-down in the carrying value of a property at the time of acquisition is charged to the allowance for loan losses. Any subsequent write-downs to reflect current fair market value, as well as gains and losses on disposition and revenues and expenses incurred in maintaining such properties, are treated as period costs. Other real estate owned also includes bank premises formerly but no longer used for banking. Banking premises are transferred at the lower of carrying value or estimated fair value, less estimated selling costs.
(p) Derivative Instruments and Hedging Activities
The Corporation uses interest rate swaps, interest rate lock commitments and forward contracts sold to hedge interest rate risk for asset and liability management purposes. All derivatives are recorded as either other assets or other liabilities at fair value. Credit risk associated with derivatives is reflected in the fair values recorded for those positions. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedging relationship, and further, on the type of hedging relationship. For derivatives that are not designated as hedging instruments, the gain or loss is recognized immediately in other operating income. A derivative that is designated and qualifies as a hedging instrument must be designated a fair value hedge, a cash flow hedge or a hedge of a net investment in a foreign operation. The Corporation does not have any cash flow hedges or derivatives that hedge net investments in foreign operations.
Effectiveness measures the extent to which changes in the fair value of a derivative instrument offset changes in the fair value of the hedged item. If the relationship between the change in the fair value of the derivative instrument and the fair value of the hedged item falls within a range considered to be the industry norm, the hedge is considered highly-effective and qualifies for hedge accounting. A hedge is ineffective if the offsetting difference between the fair values falls outside the acceptable range.
A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities and firm commitments caused by changes in interest rates or other economic factors. The Corporation recognizes the gain or loss on these derivatives, as well as the related gain or loss on the underlying hedged item, in earnings during the period in which the fair value changes. If a hedge is perfectly effective, the change in the fair value of the hedged item will be offset, resulting in no net effect on earnings.
A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The effective portion of a gain or loss on any cash flow hedge is reported as a component of accumulated other comprehensive income (loss) and reclassified into other operating income in the same period or periods that the hedged transaction affects earnings. Any ineffective portion of the derivative gain or loss is recognized in other operating income during the current period.
The Corporation enters into commitments to originate mortgage loans whereby the interest rate on the prospective loan is determined prior to funding (rate lock commitments). Rate lock commitments on mortgage loans that are intended to be sold are considered to be derivatives. Accordingly, such commitments, along with any related fees received from potential borrowers, are recorded at fair value as derivative assets or liabilities, with changes in fair value recorded in net gain or loss on sale of mortgage loans.
(q) Income Taxes
Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between the carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized.
A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.
The Corporation follows the asset and liability method of accounting for income taxes. Deferred income taxes are recognized for the tax consequences of “temporary differences” by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. The effect of a change in tax rates is recognized in income in the period of enactment date.
In assessing the realizability of deferred tax assets, Management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Assessing the need for, or the sufficiency of, a valuation allowance requires Management to evaluate all available evidence, both negative and positive, including the recent trend of quarterly earnings. Positive evidence necessary to overcome the negative evidence includes whether future taxable income in sufficient amounts and character within the carryback and carryforward periods is available under the tax law, including the use of tax planning strategies. When negative evidence (e.g., cumulative losses in recent years, history of operating loss or tax credit carryforwards expiring unused) exists, more positive evidence than negative evidence will be necessary.
Additional information regarding income taxes is included in Note 13 (Income Taxes).
(r) Treasury Stock
Treasury stock is accounted for using the cost method in which reacquired shares reduce outstanding Common Stock and capital surplus. At the date of subsequent reissue, the treasury stock account is reduced by the cost of such stock on the last-in, first-out basis.
(s) Per Share Data
Basic net income per common share is calculated using the two-class method to determine income attributable to common shareholders. The two-class method is an earnings allocation formula that determines earnings per share for each share of common stock and participating securities according to dividends declared (distributed earnings) and participation rights in undistributed earnings. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights to receive dividends. Unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are considered participating securities (i.e., nonvested restricted stock). Undistributed net losses are not allocated to nonvested restricted shareholders, as these shareholders do not have a contractual obligation to fund the losses incurred by the Corporation. Net income attributable to Common Stock is then divided by the weighted-average number of Common Stock outstanding during the period.
Diluted net income per common share is calculated under the more dilutive of either the treasury method or two-class method. For the diluted calculation, the weighted-average number of shares of Common Stock outstanding by the assumed conversion of outstanding convertible preferred stock from the beginning of the year or date of issuance, if later, and the number of shares of Common Stock that would be issued assuming the exercise of stock options and warrants using the treasury stock method. The treasury stock method assumes that the Corporation uses the proceeds from a hypothetical exercise of any options and warrants to repurchase Common Stock at the average market price during the period. These adjustments to the weighted-average number of shares of Common Stock outstanding are made only when such adjustments will dilute earnings per common share.
All earnings per share disclosures appearing in these financial statements, related notes and management’s discussion and analysis, are computed assuming dilution unless otherwise indicated. The Corporation’s earnings per share calculations are illustrated in Note 21 (Shareholders' Equity) under the heading “Earnings per Share.”
(t) Trust Department Assets and Income
Property held by the Corporation in a fiduciary or other capacity for trust customers is not included in the accompanying consolidated financial statements, since such items are not assets of the Corporation. Trust department income is reported on the accrual basis of accounting.
(u) Share-Based Compensation
The Corporation’s share-based compensation plans are described in detail in Note 15 (Share-Based Compensation). The Corporation recognizes share-based compensation expense using the straight-line method over the requisite service period for all stock awards, including those with graded vesting. The requisite service period is the period an employee is required to provide service in order to vest in the award, which cannot extend beyond the date at which the employee is no longer required to perform any service to receive the share-based compensation (the retirement-eligible date). Certain awards are contingent upon performance conditions, which affect the number of awards ultimately granted. The Corporation periodically evaluates the probable outcome of the performance conditions and makes cumulative adjustments to compensation expense as appropriate.
(v) Pension and Other Postretirement Plans
Pension and other postretirement costs are based on assumptions concerning future events that will affect the amount and timing of required benefit payments under the Corporation’s plans. These assumptions include demographic assumptions such as retirement age and mortality, a compensation rate increase, a discount rate used to determine the current benefit obligation and a long-term expected rate of return on plan assets. Net periodic benefit cost includes service and interest cost based on the assumed discount rate, an expected return on plan assets based on an actuarially derived market-related value and amortization of prior service cost and net actuarial gains or losses. The amortization of any prior service costs is determined using a straight line amortization of the cost over the average remaining lifetime of participants expected to receive benefits under the plans. Actuarial gains and losses include the impact of plan amendments and various unrecognized gains and losses, which are deferred and amortized over the future service periods of active employees. The overfunded or underfunded status of the plans is recorded as an asset or liability, respectively, in the Consolidated Balance Sheet, with changes in that status recognized through other comprehensive income. Additional information about pension and other postretirement plans is included in Note 14 (Benefit Plans).
(w) Revenue Recognition
The Corporation recognizes revenues as they are earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. The Corporation’s principal source of revenue is interest income, which is recognized on an accrual basis primarily according to nondiscretionary formulas in written contracts, such as loan agreements or securities contracts.
(x) Fair Value Measurement
Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants. It represents an exit price at the measurement date. Market participants are buyers and sellers, who are independent, knowledgeable, and willing and able to transact in the principal (or most advantageous) market for the asset or liability being measured. Current market conditions, including imbalances between supply and demand, are considered in determining fair value. The Corporation values its assets and liabilities in the principal market where it sells the particular asset or transfers the liability with the greatest volume and level of activity. In the absence of a principal market, the valuation is based on the most advantageous market for the asset or liability (i.e., the market where the asset could be sold or the liability transferred at a price that maximizes the amount to be received for the asset or minimizes the amount to be paid to transfer the liability).
In measuring the fair value of an asset, the Corporation assumes the highest and best use of the asset by a market participant to maximize the value of the asset, and does not consider the intended use of the asset.
When measuring the fair value of a liability, the Corporation assumes that the nonperformance risk associated with the liability is the same before and after the transfer. Nonperformance risk is the risk that an obligation will not be satisfied and encompasses not only the Corporation’s own credit risk (i.e., the risk that the Corporation will fail to meet its obligation), but also other risks such as settlement risk. The Corporation considers the effect of its own credit risk on the fair value for any period in which fair value is measured.
There are three acceptable valuation techniques that can be used to measure fair value: the market approach, the income approach and the cost approach. Selection of the appropriate technique for valuing a particular asset or liability takes into consideration the exit market, the nature of the asset or liability being valued, and how a market participant would value the same asset or liability. Ultimately, determination of the appropriate valuation method requires significant judgment, and sufficient knowledge and expertise are required to apply the valuation techniques.
Valuation inputs refer to the assumptions market participants would use in pricing a given asset or liability using one of the three valuation techniques. Inputs can be observable or unobservable. Observable inputs are those assumptions which market participants would use in pricing the particular asset or liability. These inputs are based on market data and are obtained from a source independent of the Corporation. Unobservable inputs are assumptions based on the Corporation’s own information or estimate of assumptions used by market participants in pricing the asset or liability. Unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy which gives the highest ranking to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for assets or liabilities classified as Level 2 are based on one or a combination of the following factors: (i) quoted prices for similar assets; (ii) observable inputs for the asset or liability, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Corporation considers an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability.
Assets and liabilities are considered to be fair valued on a recurring basis if fair value is measured regularly (i.e., daily, weekly, monthly or quarterly). Recurring valuation occurs at a minimum on the measurement date. Assets and liabilities are considered to be fair valued on a nonrecurring basis if the fair value measurement of the instrument does not necessarily result in a change in the amount recorded on the balance sheet. Generally, nonrecurring valuation is the result of the application of other accounting pronouncements which require assets or liabilities to be assessed for impairment or recorded at the lower of cost or fair value. The fair value of assets or liabilities transferred in or out of Level 3 is measured on the transfer date, with any additional changes in fair value subsequent to the transfer considered to be realized or unrealized gains or losses. Additional information regarding fair value measurements is provided in Note 18 (Fair Value Measurement).
(y) Reclassifications
Certain reclassifications of prior years’ amounts have been made to conform to current year presentation. Such reclassifications had no effect on prior year net income or shareholders’ equity.
(z) Recently Adopted Accounting Standards
FASB ASU 2014-01, Accounting for Investments in Qualified Affordable Housing Projects. The amendments in ASU 2014-01 do not change the existing accounting methods, but permit reporting entities to make an accounting policy election to account for their investments in qualified affordable projects using the proportional amortization method, if certain conditions are met. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). The amendments in ASU 2014-01 are effective for annual periods and interim reporting periods within those annual periods, beginning after December 15, 2014, and should be applied retrospectively to all periods presented. The Corporation early adopted ASU 2014-01 in the first quarter of 2014. Amortization of the initial investment cost of qualifying projects is now recorded in the provision for income taxes together with the tax credits and benefits received. Previously, the amortization was recorded as other noninterest expense. All prior period amounts have been restated to reflect the adoption of the amendment, which resulted in an offsetting decrease to other noninterest expense and increase to the provision for income taxes of approximately $3.1 million and $2.7 million for the years ended, December 31, 2013, and December 31, 2012, respectively.
(aa) Recently Issued Accounting Standards
FASB ASU 2015-2, Amendments to the Consolidation Analysis. The amendments in ASU 2015-02 affect reporting entities that are required to evaluate whether they should consolidate certain legal entities. All legal entities are subject to reevaluation under the revised consolidation model. These amendments modify the evaluation of whether limited partnerships and other similar entities are variable interest entities; eliminate the presumption that a general partner should consolidate a limited partnership; affect the consolidation analysis
that are involved with variable interest entities; and provide a scope exception from consolidation for entities that are required to comply or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The amendments are effective for public business entities for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. A reporting entity may apply the amendments using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the fiscal year of adoption. A reporting entity also may apply the amendments retrospectively. The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
FASB ASU 2014-17, Pushdown Accounting—a consensus of the FASB Emerging Issues Task Force. The objective of this update is to provide guidance on whether and at what threshold an acquired entity can apply pushdown accounting in the acquired entities separate financial statements. The amendments in this update provide the acquired entity the option to apply pushdown accounting accounting in the reporting period in which the change-in-control event occurs or in a subsequent reporting period after the change-in-control event occurs. If the election if made in the current reporting period, the entity should disclose information in the current reporting period that enables users of financial statements to evaluate the effect of pushdown accounting. If the election is made after the current period the change-in-control event, it is irrevocable and should be considered a change in accounting principle in accordance with Topic 250, Accounting Changes and Error Corrections. The ASU is effective on November 18, 2014. After the effective date, acquired entities can make the election to future change-in-control events or to its most recent change-in-control event. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
FASB ASU 2014-14, Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure—a consensus of the FASB Emerging Issues Task Force. The objective of this update is to reduce diversity in practice by addressing the classification of certain foreclosed mortgage loans held by creditors that are either fully or partially guaranteed under government programs. The amendments in this update require that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the
following conditions are met: 1) the loan has a government guarantee that is not separable from the
loan before foreclosure; 2) at the time of foreclosure, the creditor has the intent to convey the real
estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim; and 3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. The ASU is effective for interim and annual periods beginning after December 15, 2014. The amendments can be adopted using either a prospective transition method or a modified retrospective transition method. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
FASB ASU 2014–12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved After the Requisite Service Period — a consensus of the FASB Emerging Issues Task Force. The amendments in this update clarify that entities should treat performance targets that can be met after the requisite service period of a share-based payment award as performance conditions that affect vesting. Therefore, an entity would not record compensation expense (measured as of the grant date without taking into account the effect of the performance target) related to an award for which transfer to the employee is contingent on the entity’s satisfaction of a performance target until it becomes probable that the performance target will be met. The ASU does not contain any new disclosure requirements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. In addition, entities will have the option of applying the guidance either prospectively (i.e., only to awards granted or modified on or after the effective date) or retrospectively. Retrospective application would only apply to awards with performance targets outstanding at or after the beginning of the first annual period presented (i.e., the earliest presented comparative period). The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
FASB ASU 2014-11, Transfers and Servicing: Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures. The amendments in this update require entities to account for repurchase-to-maturity transactions as secured borrowings (rather than as sales with forward repurchase agreements), eliminate accounting guidance on linking repurchase financing transactions, and expand disclosure requirements related to certain transfers of financial assets that are accounted for as sales and certain transfers, such as repos, securities lending transactions, and repurchase-to-maturity transactions, accounted for as secured borrowings. The amendments in ASU 2014-11 are effective for the first interim or annual period beginning after December 15, 2014. The amendments must present changes in accounting for transactions outstanding on the effective date as a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. Early application is prohibited. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
FASB ASU 2014-09, Revenue from Contracts with Customers. The amendments in this update supersede virtually all existing GAAP revenue recognition guidance, including most industry-specific revenue recognition guidance. ASU 2014-09 creates a single, principle-based revenue recognition framework and will require entities to apply significantly more judgment and expanded disclosures surrounding revenue recognition. The core principle requires an entity to recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 applies to contracts with customers to provide goods and services, with certain exclusions such as lease contracts, financing arrangements, and financial instruments. The amendments in ASU 2014-09 are effective for fiscal years beginning after December 15, 2016. The amendments can be adopted using either the full retrospective approach or a modified retrospective approach. Early adoption is prohibited. The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
FASB ASU 2014-08, Presentation of Financial Statements and Property, Plant, and Equipment: Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update change the definition of a discontinued operation in ASC 205-20 and require additional disclosures for transactions that meet the definition of a discontinued operation and certain other significant transactions that do not meet the discontinued operations criteria. The amendments in ASU 2014-08 are effective prospectively for all disposals, except disposals classified as held for sale before the adoption date or components initially classified as held for sale in periods beginning on or after December 15, 2014, with early adoption permitted. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
FASB ASU 2014-04, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. ASU 2014-04 amends the guidance in ASC 310-40 by clarifying when an in-substance repossession or foreclosure occurs, and a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan. Additionally, the amendments require interim and annual disclosure of both 1) the amount of foreclosed residential real estate property held by the creditor and 2) the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure according to local requirements of the applicable jurisdiction. The amendments in ASU 2014-04 are effective for annual periods, and interim period within those annual periods, beginning after December 15, 2014. The amendments can either be adopted using a modified retrospective or a prospective transition method. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	Business Combinations
	The Corporation completed the merger with Citizens, a Michigan corporation with approximately $9.6 billion in assets and 219 branches, in the quarter ended June 30, 2013. All of Citizens’ common shareholders received 1.37 shares of the Corporation’s Common Stock in exchange for one share of Citizens’ common stock, resulting in the Corporation issuing 55,468,283 shares of its Common Stock. In conjunction with the completion of the merger, the Corporation fully repurchased the $300 million of Citizens TARP Preferred plus accumulated but unpaid dividends and interest of approximately $55.4 million previously issued to the U.S. Treasury under the Capital Purchase Program. The Corporation used the net proceeds from its February 4, 2013 public offerings, which consisted of $250 million aggregate principal amount of 4.35% subordinated notes due February 4, 2023, and $100 million 5.875% Non-Cumulative Perpetual Preferred Stock, Series A, to repurchase the Citizens TARP Preferred and pay all accrued, accumulated and unpaid dividends and interest. Additionally, a warrant issued by Citizens to the U.S. Treasury to purchase up to 1,757,812.5 shares of Citizens’ common stock has been converted into a warrant issued by the Corporation to the U.S. Treasury to purchase 2,408,203 shares of FirstMerit Common Stock.
	The Citizens transaction was accounted for using the acquisition method of accounting and, as such, assets acquired, liabilities assumed and consideration exchanged were recorded at estimated fair value on the Acquisition Date. Per the applicable accounting guidance for business combinations, these fair values were subject to refinement for up to one year after the closing date of the acquisition as additional information relative to closing date fair values become available. The measurement period ended on March 31, 2014.
	The following table provides the purchase price calculation as of the Acquisition Date and the identifiable assets purchased and the liabilities assumed at their estimated fair value. These fair value measurements are based on third-party valuations.
	(In thousands, except per share amounts)
	Purchase Price:
	FirstMerit shares of Common Stock issued for Citizens' shares						55,468,283
	Closing price per share of the Corporation's Common Stock on April 12, 2013						$	16.68
	Consideration from Common Stock conversion (1.37 ratio)						925,211
	Cash paid to the Treasury for Citizens' TARP Preferred						355,371
	Cash paid in lieu of fractional shares to the former Citizens' shareholders						61
	Consideration from the warrant issued to the Treasury for Citizens' TARP warrant						3,000
	Total purchase price						$	1,283,643
	Statement of Net Assets Acquired at Fair Value:
	ASSETS
	Cash and due from banks		$	544,380
	Investment securities		3,202,575
	Loans		4,617,004
	Premises and equipment		138,536
	Intangible assets		84,774			(1)
	Accrued interest receivable and other assets		681,100
	Total assets		$	9,268,369
	LIABILITIES
	Deposits		$	7,276,754
	Borrowings		908,824
	Accrued taxes, expenses, and other liabilities		80,842
	Total liabilities		$	8,266,420
	Net identifiable assets acquired						1,001,949
	Goodwill						$	281,694
	(1) Intangible assets consist of core deposit intangibles of $70.8 million and trust relationships of approximately $14.0 million. The useful lives for which the core deposit intangible and the trust relationships are being amortized over are 15 years and 12 years, respectively.
	The amount of goodwill recorded reflects the increased market share and related synergies that are expected to result from the acquisition, and represents the excess purchase price over the estimated fair value of the net assets acquired. None of the goodwill is deductible for income tax purposes as the merger is accounted for as a tax-free exchange. The tax-free exchange resulted in a carryover of tax attributes and tax basis to the Corporation's subsequent income tax filings. These carryovers were comprised of DTA of $313.0 million and DTL of $51.3 million for a net DTA carryover of $261.7 million. This net DTA includes $224.8 million of net operating loss and tax credit carryovers. The carryover of these tax attributes is subject to limitation as to the tax period in which they can be used to reduce future tax payments. The amounts recorded are expected to be substantially used by 2016, however, some will continue to carryover until 2032. These tax attribute benefits will also be subject to regulatory capital adjustments until fully utilized. An additional net DTA of $87.6 million was established on the Acquisition Date as a result of the purchase accounting fair value adjustments resulting in a total net DTA on the Acquisition Date of $349.3 million.
	The following table summarizes the final fair value of both acquired impaired and nonimpaired loans by product type as of the Acquisition Date.
	(In thousands)	Acquired Impaired Loans				Acquired Nonimpaired Loans			Acquired Loans Total
	Commercial
	C&I	$	93,735			$	1,660,199		$	1,753,934
	CRE	378,569				359,066			737,635
	Construction	13,399				17,135			30,534
	Total commercial	485,703				2,036,400			2,522,103
	Consumer
	Residential mortgages	232,291				278,404			510,695
	Installment	54,108				1,165,235			1,219,343
	Home equity lines	47,613				317,250			364,863
	Total consumer	334,012				1,760,889			2,094,901
	Total	$	819,715			$	3,797,289		$	4,617,004
	The determination of estimated fair values of the acquired loans required the Corporation to make certain estimates about discount rates, future expected cash flows, market conditions and other future events that are highly subjective in nature. Based on such factors as past due status, nonaccrual status and credit risk ratings, the acquired loans were divided into loans with evidence of credit quality deterioration, which are accounted for under ASC 310-30 (acquired impaired), and loans that do not meet this criteria, which are accounted for under ASC 310-20 (acquired nonimpaired). The acquired loans were further segregated into loan pools designed to facilitate the development of expected cash flows to be used in estimating fair value. Acquired loans were segregated into pools based on characteristics such as loan type, credit risk profiles, contractual interest rate and repayment terms and market area in which originated. Expected cash flows, both principal and interest, were estimated based on key assumptions covering such factors as prepayments, default rates and severity of loss given default. These assumptions were developed using both Citizens’ historical experience and the portfolio characteristics at Acquisition Date as well as available market research. The fair value estimates for acquired loans was based on the amount and timing of expected principal, interest and other cash flows, included expected prepayments, discounted at prevailing market interest rates.
	For acquired nonimpaired loans, the difference between the Acquisition Date fair value and the contractual amounts due at the Acquisition Date represents the fair value adjustment. The fair value adjustment may be a discount (or premium) to an individual loan’s cost basis and is accreted (or amortized) to interest income over the the loan’s remaining life using the level yield method. Acquired nonimpaired loans are reported net of the unamortized fair value adjustment. The fair value adjustment for acquired nonimpaired loans as of the Acquisition Date is presented in the following table.
	(In thousands)	Acquired Nonimpaired Loans
	Outstanding balance	$	4,017,304
	Less: Fair value adjustment	220,015
	Fair value of acquired nonimpaired loans	$	3,797,289
	The table below details contractually required payments, cash flows not expected to be collected and cash flows expected to be collected on acquired nonimpaired loans as of the Acquisition Date.
	(In thousands)	Acquired Nonimpaired Loans
	Contractually required payments including interest (1)	$	4,955,180
	Less: Contractual cash flows not expected to be collected	680,664
	Cash flows expected to be collected	$	4,274,516
	(1) Total undiscounted amounts of all uncollected contractual principal and interest, including any fees and penalties, both past due and scheduled for the future, assuming no loss or prepayment.
	For acquired impaired loans, the excess of cash flows expected over the estimated fair value at the Acquisition Date represents the accretable yield and is recognized as interest income using a level yield method over the remaining life of the pooled impaired loans. Each pool of acquired impaired loans is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Acquired impaired loans in pools with an accretable yield are considered to be accruing and performing even though collection of contractual payments on loans within the pool may be in doubt, because the pool is the unit of accounting and income continues to be accreted on the pool as long as expected cash flows are reasonably estimable.
	Total outstanding acquired impaired loans as of the Acquisition Date were $1.1 billion. A reconciliation of the contractual required payments to the fair value of the acquired impaired loans at the Acquisition Date is as follows:
	(In thousands)	Acquired Impaired Loans
	Contractually required payments including interest (1)	$	1,231,172
	Nonaccretable difference (2)	(279,899		)
	Cash flows expected to be collected (3)	951,273
	Accretable yield (4)	(131,558		)
	Fair value of loans acquired	$	819,715
(1) Total undiscounted amounts of all uncollected contractual principal and interest, including any fees and penalties, both past due and scheduled for the future, assuming no loss or prepayment.
(2) The nonaccretable difference represents, as of the Acquisition Date, the amount of contractually required payments, including interest, that are not expected to be collected based on estimated credit losses and other factors, such as prepayments.
(3) Represents the estimate, at Acquisition Date, of the amount and timing of undiscounted principal, interest, and other cash flows expected to be collected. This estimate includes the effect of anticipated prepayments.
(4) The accretable yield represents the excess of cash flows expected at Acquisition Date over the estimated fair value and is recognized as interest income over the remaining life of the loan using the level yield method.
The fair value of the investment securities acquired was approximately $3.2 billion. Management’s strategy to reduce prepayment and credit risk of the acquired investment securities portfolio resulted in the sale of approximately $2.2 billion in agency MBS, agency CMO, municipal securities and private label MBS investments subsequent to the close of the acquisition. During the second quarter of 2013, Management repurchased approximately $1.5 billion of agency MBS and CMO securities in accordance with the Corporation’s investment polices.
As part of the merger, the Corporation assumed Citizens' FHLB advances with a fair value of $719.3 million. On April 15, 2013, in conjunction with Management’s strategy to de-leverage the acquired Citizens’ balance sheet, the Corporation terminated all but two assumed FHLB advances resulting in cash outlay of $652.5 million, which approximated the fair value. The fair value of the two retained FHLB advances totaled $66.8 million and mature on May 16, 2016. FHLB advances are reflected in the line item “Federal funds purchased and securities sold under agreements to repurchase” on the Consolidated Balance Sheet.
The Corporation also assumed obligations under junior subordinated debentures at fair value in the amount of $74.5 million, payable to two unconsolidated trusts that issued trust preferred securities. The junior subordinated debentures were the sole assets of each trust. The variable interest rate junior subordinated debenture had a maturity date of June 26, 2033, and bare interest at an annual rate equal to the three-month LIBOR plus 3.10% and adjusted on a quarterly basis not to exceed 11.75%. The fixed 7.50% interest rate junior subordinated debenture had a maturity date of September 15, 2066, and was listed on the NYSE (NYSE symbol CTZ-PA). Interest was payable quarterly in arrears and became callable on September 15, 2011. These trust preferred securities junior subordinated debentures, totaling $74.5 million, were redeemed on September 26, 2014.
The Corporation also assumed long-term repurchase agreements with a fair value amount of $115.0 million. On April 15, 2013, in conjunction with Management’s strategy to de-leverage the newly acquired Citizens’ balance sheet, all of these these long-term repurchase agreements were terminated.
There were merger-related charges recorded in the Consolidated Statement of Income of $1.0 million in the year ended December 31, 2014. These costs were primarily composed of professional service fees. In the year ended December 31, 2013, merger-related costs of $75.1 million were recognized and were primarily composed of severance and retention employee benefits, professional services, and fees for early termination of existing agreements assumed from the merger.
The following table provides the unaudited pro forma information for the results of operations for the year ended December 31, 2013, as if the Citizens acquisition had occurred January 1, 2013. These adjustments include the impact of certain purchase accounting adjustments including accretion of loan marks, which makes up the vast majority of the adjustments, followed by intangible assets amortization, investment securities amortization, fixed assets depreciation and deposit accretion. In addition, $75.1 million in merger-related expenses recorded in 2013 are included in the period presented. The unaudited pro forma results are presented for illustrative purposes and are not intended to represent or be indicative of the actual results of operations of the combined corporation that would have been achieved had the acquisition occurred at the beginning of the year of acquisition, nor are they intended to represent or be indicative of future results of operations.
		(Unaudited)
		Year Ended December 31,
(In thousands)				2013
Total revenue, net of interest expense				$	1,096,960
Net income				196,744

Investment_Securities

Investment Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities
	The following tables provide the amortized cost and fair value for the major categories of held-to-maturity and available-for-sale securities. Held-to-maturity securities are carried at amortized cost, which reflects historical cost, adjusted for amortization of premiums and accretion of discounts. Available-for-sale securities are carried at fair value with net unrealized gains or losses reported on an after tax basis as a component of OCI in shareholders' equity.
			December 31, 2014
	(In thousands)		Amortized				Gross Unrealized Gains				Gross Unrealized Losses				Fair
			Cost												Value
	Securities available-for-sale
	Debt securities
		U.S. government agency debentures	$	2,500			$	—			$	(18	)		$	2,482
		U.S. states and political subdivisions	221,052				6,756				(466		)		227,342
		Residential mortgage-backed securities:
		U.S. government agencies	951,839				22,377				(3,218		)		970,998
		Commercial mortgage-backed securities:
		U.S. government agencies	104,176				598				(1,371		)		103,403
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,698,015				4,777				(26,225		)		1,676,567
		Nonagency	7				—				—				7
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	222,876				863				(1,405		)		222,334
		Asset-backed securities:
		Collateralized loan obligations	297,446				11				(9,613		)		287,844
		Corporate debt securities	61,652				—				(10,315		)		51,337
		Total debt securities	3,559,563				35,382				(52,631		)		3,542,314
	Equity securities
		Marketable equity securities	2,974				—				—				2,974
		Total equity securities	2,974				—				—				2,974
		Total securities available for sale	$	3,562,537			$	35,382			$	(52,631	)		$	3,545,288
	Securities held-to-maturity
	Debt securities
		U.S. treasuries	$	5,000			$	—			$	—			$	5,000
		U.S. government agency debentures	25,000				—				(537		)		24,463
		U.S. states and political subdivisions	517,824				12,645				(191		)		530,278
		Residential mortgage-backed securities:
		U.S. government agencies	580,727				7,495				(3,045		)		585,177
		Commercial mortgage-backed securities:
		U.S. government agencies	58,143				281				(329		)		58,095
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,368,534				718				(38,875		)		1,330,377
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	257,642				557				(6,768		)		251,431
		Corporate debt securities	90,739				412				(52		)		91,099
		Total securities held to maturity	$	2,903,609			$	22,108			$	(49,797	)		$	2,875,920
			December 31, 2013
	(In thousands)		Amortized				Gross Unrealized Gains				Gross Unrealized Losses				Fair
			Cost												Value
	Securities available-for-sale
	Debt securities
		U.S. states and political subdivisions	$	258,787			$	7,376			$	(3,796	)		$	262,367
		Residential mortgage-backed securities:
		U.S. government agencies	962,687				21,662				(14,427		)		969,922
		Commercial mortgage-backed securities:
		U.S. government agencies	72,048				7				(2,488		)		69,567
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,566,262				4,199				(52,068		)		1,518,393
		Nonagency	9				—				—				9
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	104,152				273				(2,157		)		102,268
		Asset-backed securities:
		Collateralized loan obligations	297,259				760				(4,332		)		293,687
		Corporate debt securities	61,596				—				(10,952		)		50,644
		Total debt securities	3,322,800				34,277				(90,220		)		3,266,857
	Equity Securities
		Marketable equity securities	3,036				—				—				3,036
		Nonmarketable equity securities	3,281				—				—				3,281
		Total equity securities	6,317				—				—				6,317
	Total securities available for sale	$	3,329,117			$	34,277			$	(90,220	)		$	3,273,174
Securities held-to-maturity
Debt securities
	U.S. treasuries	$	5,000			$	4			$	—			$	5,004
	U.S. government agency debentures	25,000				—				(1,348		)		23,652
	U.S. states and political subdivisions	480,703				5,335				(10,459		)		475,579
	Residential mortgage-backed securities:
	U.S. government agencies	569,960				1,108				(11,617		)		559,451
	Commercial mortgage-backed securities:													—
	U.S. government agencies	56,596				—				(1,190		)		55,406
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,464,732				—				(81,818		)		1,382,914
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	240,069				6				(11,052		)		229,023
	Corporate debt securities	93,628				308				(725		)		93,211
	Total securities held to maturity	$	2,935,688			$	6,761			$	(118,209	)		$	2,824,240
The Corporation’s U.S. states and political subdivisions portfolio is composed of general obligation bonds issued by a highly diversified number of states, cities, counties, and school districts. The amortized cost and fair value of the Corporation’s portfolio of general obligation bonds are summarized by U.S. state in the tables below. As illustrated in the tables below, the aggregate fair value of the Corporation’s general obligation bonds was greater than $10 million in eleven of the thirty-seven U.S. states in which it holds investments.
(Dollars in thousands)	December 31, 2014
U.S. State	# of Issuers			Average Issue Size, Fair Value				Amortized Cost				Fair Value
Ohio	137			$	979			$	130,741			$	134,127
Michigan	169			842				138,325				142,292
Illinois	66			1,897				121,560				125,169
Wisconsin	77			841				62,543				64,776
Texas	64			801				50,307				51,293
Pennsylvania	45			1,000				44,443				45,006
Minnesota	42			674				27,740				28,326
Washington	30			952				27,987				28,558
New Jersey	37			746				26,755				27,612
Missouri	19			1,011				18,764				19,207
New York	19			628				11,659				11,929
Other	120			650				76,849				78,020
Total general obligation bonds	825			$	917			$	737,673			$	756,315
(Dollars in thousands)	December 31, 2013
U.S. State	# of Issuers			Average Issue Size, Fair Value				Amortized Cost				Fair Value
Michigan	166			$	744			$	122,198			$	123,571
Ohio	152			1,048				158,641				159,232
Illinois	75			1,314				96,863				98,521
Texas	69			771				54,295				53,204
Wisconsin	86			648				54,516				55,747
Pennsylvania	50			898				47,835				44,883
Minnesota	45			663				29,840				29,816
Washington	30			930				28,393				27,906
New Jersey	38			722				27,101				27,440
Missouri	20			969				19,253				19,382
New York	22			585				13,064				12,878
California	18			599				10,651				10,788
Other	115			631				74,918				72,572
Total general obligation bonds	886			$	831			$	737,568			$	735,940
The Corporation’s investment policy states that municipal securities purchased are to be investment grade and allows for a 20% maximum portfolio concentration in municipal securities with a combined individual state to total municipal outstanding equal to or less than 25%. A municipal security is investment grade if (1) the security has a low risk of default by the obligor and (2) the full and timely payment of principal and interest is expected over the anticipated life of the instrument. The fact that a municipal security is rated by one nationally recognized credit rating agency is indicative, but not sufficient evidence, that a municipal security is investment grade. In all cases, the Corporation considers and documents within a security pre-purchase analysis factors such as capacity to pay, market and economic data, and such other factors as are available and relevant to the security or issuer. Factors to be considered in the ongoing monitoring of municipal securities and in the pre-purchase analysis include soundness of budgetary position, and sources, strength, and stability of tax or enterprise revenues. The Corporation also considers spreads to U.S. Treasuries on comparable bonds of similar credit quality, in addition to the above analysis, to assess whether municipal securities are investment grade. The Corporation performs a risk analysis for any security that is downgraded below investment grade to determine if the security should be retained or sold. This risk analysis includes, but is not limited to, discussions with the Corporation’s credit department as well as third party municipal credit analysts and review of the nationally recognized credit rating agency’s analysis describing the downgrade.
The Corporation's evaluation of its municipal bond portfolio at December 31, 2014 did not uncover any facts or circumstances resulting in significantly different credit ratings than those assigned by a nationally recognized credit rating agency.
FRB and FHLB stock constitute the majority of other investments on the Consolidated Balance Sheet.
	December 31,
(In thousands)	2014				2013
FRB stock	$	55,681			$	55,294
FHLB stock	92,547				125,032
Other	426				477
Total other investments	$	148,654			$	180,803
FRB and FHLB stock is classified as a restricted investment, carried at cost and valued based on the ultimate recoverability of par value. Cash and stock dividends received on the stock are reported as interest income. There are no identified events or changes in circumstances that may have a significant adverse effect on these investments carried at cost.
Securities with a carrying value of $2.8 billion and $3.2 billion at December 31, 2014 and 2013, respectively, were pledged to secure trust and public deposits and securities sold under agreements to repurchase and for other purposes required or permitted by law.
Realized Gains and Losses
The following table presents the proceeds from sales of available-for-sale securities and the gross realized gains and losses on the sales of those securities that have been included in earnings as a result of those sales. Gains or losses on the sales of available-for-sale securities are recognized upon sale and are determined using the specific identification method.
	Year Ended December 31,
(In thousands)	2014				2013				2012
Realized gains	$	382			$	3,786			$	3,786
Realized losses	(216		)		(6,589		)		—
Net securities (losses)/gains	$	166			$	(2,803	)		$	3,786
Gross Unrealized Losses and Fair Value
The following table presents the gross unrealized losses and fair value of securities by length of time that individual securities had been in a continuous loss position by major categories of available-for-sale and held-to-maturity securities.
		December 31, 2014
		Less than 12 months											12 months or longer							Total
(Dollars in thousands)		Fair Value				Unrealized				Number			Fair Value			Unrealized			Number	Fair Value		Unrealized
						Losses				Impaired						Losses			Impaired			Losses
										Securities									Securities
Securities available-for-sale
	Debt Securities
	U.S. government agency debentures	$	2,482			$	(18	)		1			$	—		$	—		—	$	2,482	$	(18	)
	U.S. states and political subdivisions	5,637				(11		)		11			22,528			(455		)	36	28,165		(466		)
	Residential mortgage-backed securities:
	U.S. government agencies	50,126				(182		)		5			199,773			(3,036		)	14	249,899		(3,218		)
	Commercial mortgage-backed securities:
	U.S. government agencies	12,284				(55		)		2			45,485			(1,316		)	6	57,769		(1,371		)
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	243,970				(906		)		15			905,478			(25,319		)	64	1,149,448		(26,225		)
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	31,375				(229		)		4			67,169			(1,176		)	7	98,544		(1,405		)
	Asset-backed securities:
	Collateralized loan obligations	79,042				(1,406		)		15			193,687			(8,207		)	27	272,729		(9,613		)
	Corporate debt securities	—				—				—			51,338			(10,315		)	8	51,338		(10,315		)
	Total available-for-sale securities	$	424,916			$	(2,807	)		53			$	1,485,458		$	(49,824	)	162	$	1,910,374	$	(52,631	)
Securities held-to-maturity
	Debt Securities
	U.S. government agency debentures	$	—			$	—			—			$	24,463		$	(537	)	1	$	24,463	$	(537	)
	U.S. states and political subdivisions	9,085				(17		)		9			18,371			(174		)	21	27,456		(191		)
	Residential mortgage-backed securities:
	U.S. government agencies	—				—				—			185,361			(3,045		)	10	185,361		(3,045		)
	Commercial mortgage-backed securities:
	U.S. government agencies	9,950				(4		)		2			16,735			(325		)	2	26,685		(329		)
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	28,333				(149		)		3			1,161,297			(38,726		)	58	1,189,630		(38,875		)
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	41,474				(55		)		3			171,570			(6,713		)	16	213,044		(6,768		)
	Corporate debt securities	36,933				(52		)		13			—			—			—	36,933		(52		)
	Total held-to-maturity securities	$	125,775			$	(277	)		30			$	1,577,797		$	(49,520	)	108	$	1,703,572	$	(49,797	)
		December 31, 2013
		Less than 12 months											12 months or longer							Total
(Dollars in thousands)		Fair Value				Unrealized				Number			Fair Value			Unrealized			Number	Fair Value		Unrealized
						Losses				Impaired						Losses			Impaired			Losses
										Securities									Securities
Securities available-for-sale
Debt securities
	U.S. states and political subdivisions	$	38,039			$	(1,996	)		65			$	14,157		$	(1,800	)	25	$	52,196	$	(3,796	)
	Residential mortgage-backed securities:
	U.S. government agencies	434,761				(13,109		)		35			14,890			(1,318		)	2	449,651		(14,427		)
	Commercial mortgage-backed securities:
	U.S. government agencies	33,387				(1,491		)		5			16,944			(997		)	2	50,331		(2,488		)
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,135,151				(44,775		)		74			100,530			(7,293		)	7	1,235,681		(52,068		)
	Nonagency	—				—				—			1			—			1	1		—
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	43,747				(2,055		)		6			2,525			(102		)	1	46,272		(2,157		)
	Asset-backed securities:
	Collateralized loan obligations	223,458				(4,332		)		33			—			—			—	223,458		(4,332		)
	Corporate debt securities	—				—				—			50,644			(10,952		)	8	50,644		(10,952		)
	Total available-for-sale securities	$	1,908,543			$	(67,758	)		218			$	199,691		$	(22,462	)	46	$	2,108,234	$	(90,220	)
Securities held-to-maturity
	Debt securities
	U.S. government agency debentures	$	23,652			$	(1,348	)		1			$	—		$	—		—	$	23,652	$	(1,348	)
	U.S. states and political subdivisions	222,154				(10,276		)		353			2,478			(183		)	6	224,632		(10,459		)
	Residential mortgage-backed securities:
	U.S. government agencies	422,192				(11,617		)		22			—			—			—	422,192		(11,617		)
	Commercial mortgage-backed securities:
	U.S. government agencies	48,831				(1,190		)		8			—			—			—	48,831		(1,190		)
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,382,915				(81,818		)		66			—			—			—	1,382,915		(81,818		)
	Nonagency	—				—				—			—			—			—	—		—
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	208,863				(11,052		)		19			—			—			—	208,863		(11,052		)
	Corporate debt securities	64,541				(725		)		23			—			—			—	64,541		(725		)
	Total held-to-maturity securities	$	2,373,148			$	(118,026	)		492			$	2,478		$	(183	)	6	$	2,375,626	$	(118,209	)
At least quarterly, the Corporation conducts a comprehensive security-level impairment assessment on all securities in an unrealized loss position to determine if OTTI exists. An unrealized loss exists when the current fair value of an individual security is less than its amortized cost basis. An OTTI loss must be recognized for a debt security in an unrealized loss position if the Corporation intends to sell the security or it is more likely than not that the Corporation will be required to sell the security before recovery of its amortized cost basis. In this situation, the amount of loss recognized in income is equal to the difference between the fair value and the amortized cost basis of the security. Even if the Corporation does not expect to sell the security, the Corporation must evaluate the expected cash flows to be received to determine if a credit loss has occurred. In the event of a credit loss, only the amount of impairment associated with the credit loss is recognized in income. The portion of the unrealized loss relating to other factors, such as liquidity conditions in the market or changes in market interest rates, is recorded in OCI. Equity securities are also evaluated to determine whether the unrealized loss is expected to be recoverable based on whether evidence exists to support a realizable value equal to or greater than the amortized cost basis. If it is probable that the Corporation will not recover the amortized cost basis, taking into consideration the estimated recovery period and its ability to hold the equity security until recovery, OTTI is recognized.
The security-level assessment is performed on each security, regardless of the classification of the security as available for sale or held to maturity. The assessments are based on the nature of the securities, the financial condition of the issuer, the extent and duration of the securities, the extent and duration of the loss and the intent and whether Management intends to sell or it is more likely than not that it will be required to sell a security before recovery of its amortized cost basis, which may be maturity. For those securities for which the assessment shows the Corporation will recover the entire cost basis, Management does not intend to sell these securities and it is not more likely than not that the Corporation will be required to sell them before the anticipated recovery of the amortized cost basis, the gross unrealized losses are recognized in OCI, net of tax.
The investment securities portfolio was in a net unrealized loss position of $44.9 million at December 31, 2014, compared to a net unrealized loss position of $167.4 million at December 31, 2013. Gross unrealized losses were $102.4 million as of December 31, 2014, compared to $208.4 million at December 31, 2013. As of December 31, 2014, gross unrealized losses are concentrated within agency MBS, CLOs, and corporate debt securities. The fair values of the agency MBSs have been impacted by the flattening yield curves throughout 2014 in which shorter term rates are higher and longer terms rates are longer than the previous year. The fair value of the CLOs have been impacted by increased supply which has widened spreads. Corporate debt securities are composed of eight, single issuer, trust preferred securities with stated maturities. Such investments are only 1% of the fair value of the entire investment portfolio. None of the corporate issuers have deferred paying dividends on their issued trust preferred shares in which the Corporation is invested. The fair values of these investments have been impacted by the market conditions which have caused risk premiums to increase, resulting in the decline in the fair value of the trust preferred securities.
Management believes the Corporation will fully recover the cost of these agency MBSs, CLOs, and corporate debt securities, and it does not intend to sell these securities and it is not more likely than not that it will be required to sell them before the anticipated recovery of the remaining amortized cost basis, which may be maturity. As a result, Management concluded that these securities were not other-than-temporarily impaired at December 31, 2014 and has recognized the total amount of the impairment in OCI, net of tax.
The Corporation also holds $287.8 million of CLOs with a gross unrealized loss position of $9.6 million as of December 31, 2014. The new Volcker regulations, as originally adopted, may affect the Corporation’s ability to hold these CLOs. Management believes that its holdings of CLOs are not ownership interests in a covered fund prohibited by the Volcker regulations, and, therefore, expect to be able to hold these investments until their stated maturities with no restriction.
Contractual Maturity of Debt Securities
The following table shows the remaining contractual maturities and contractual yields of debt securities held-to-maturity and available-for-sale as of December 31, 2014. Estimated lives on MBSs may differ from contractual maturities as issuers may have the right to call or prepay obligations with or without call or prepayment penalties.

Loans

Loans	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans	Loans
	Loans outstanding as of December 31, 2014 and 2013, net of unearned income, consisted of the following:
	(In thousands)		December 31, 2014				December 31, 2013
	Originated loans
	Commercial		$	7,830,085			$	6,648,279
	Residential mortgage		625,283				529,253
	Installment		2,393,451				1,727,925
	Home equity		1,110,336				920,066
	Credit cards		164,478				148,313
	Leases		370,179				239,551
		Total originated loans	12,493,812				10,213,387
	Allowance for originated loan losses		(95,696		)		(96,484		)
		Net originated loans	$	12,398,116			$	10,116,903
	Acquired loans:
	Commercial		$	1,086,899			$	1,725,970
	Residential mortgage		394,484				470,652
	Installment		764,168				1,004,569
	Home equity		233,629				294,424
		Total acquired loans	2,479,180				3,495,615
	Allowance for acquired loan losses		(7,457		)		(741		)
		Net acquired loans	$	2,471,723			$	3,494,874
	Covered loans:
	Commercial		211,607				375,860
	Residential mortgage		41,276				50,679
	Installment		4,874				6,162
	Home equity		73,365				97,442
	Loss share receivable		22,033				61,827
		Total covered loans	353,155				591,970
	Allowance for covered loan losses		(40,496		)		(44,027		)
		Net covered loans	$	312,659			$	547,943
	Total loans:
	Commercial		$	9,128,591			$	8,750,109
	Residential mortgage		1,061,043				1,050,584
	Installment		3,162,493				2,738,656
	Home equity		1,417,330				1,311,932
	Credit cards		164,478				148,313
	Leases		370,179				239,551
	Loss share receivable		22,033				61,827
		Total loans	15,326,147				14,300,972
	Total allowance for loan losses		(143,649		)		(141,252		)
		Total Net loans	$	15,182,498			$	14,159,720
	The Corporation makes loans to officers on the same terms and conditions as made available to all employees and to directors on substantially the same terms and conditions as transactions with other parties. An analysis of loan activity with related parties for the years ended December 31, 2014, 2013, and 2012 is summarized as follows:
		Year Ended December 31,
	(In thousands)	2014				2013				2012
	Aggregate amount at beginning of year	$	24,536			$	16,578			$	15,629
	New loans	2,534				11,507				3,500
	Repayments	(6,388		)		(4,374		)		(2,739		)
	Changes in directors and their affiliations	—				825				188
	Aggregate amount at end of year	$	20,682			$	24,536			$	16,578
	The following describes the distinction between originated, acquired and covered loan portfolios and certain significant accounting policies relevant to each of these portfolios.
	Originated Loans
	Loans originated for investment are stated at their principal amount outstanding adjusted for partial charge-offs, the ALL, and net deferred loan fees and costs. Interest income on loans is accrued over the term of the loans primarily using the "simple-interest" method based on the principal balance outstanding. Interest is not accrued on loans where collectability is uncertain. Accrued interest is presented separately in the Consolidated Balance Sheet, except for accrued interest on credit card loans, which is included in the outstanding loan balance. Loan origination fees and certain direct costs incurred to extend credit are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield. Net deferred loan origination fees and costs amounted to $5.4 million and $6.6 million at December 31, 2014 and 2013, respectively.
	Acquired Loans
	Acquired loans are those purchased in the Citizens acquisition (See Note 2 (Business Combinations) for further information). These loans were recorded at estimated fair value at the Acquisition Date with no carryover of the related ALL. The acquired loans were segregated as of the Acquisition Date between those considered to be performing (acquired nonimpaired loans) and those with evidence of credit deterioration (acquired impaired loans). Acquired loans are considered impaired if there is evidence of credit deterioration and if it is probable, at acquisition, all contractually required payments will not be collected. Revolving loans, including lines of credit, are excluded from acquired impaired loan accounting.
	Total outstanding acquired impaired loans were $590.9 million and $817.6 million as of December 31, 2014 and 2013. The outstanding balance of these loans is the undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loans, owed at the reporting date, whether or not currently due and whether or not any such amounts have been charged off. Changes in the carrying amount and accretable yield for acquired impaired loans were as follows for the years ended December 31, 2014 and 2013:
		Year Ended
	Acquired Impaired Loans	December 31, 2014								December 31, 2013
	(In thousands)	Accretable Yield				Carrying Amount of Loans				Accretable Yield			Carrying Amount of Loans
	Balance at beginning of period	$	136,646			$	601,000			$	—		$	—
	Additions due to Citizens acquisition on April 12, 2013	—				—				131,558			819,715
	Accretion	(49,271		)		49,271				(27,144		)	27,144
	Net reclassifications from nonaccretable to accretable	45,824				—				46,361			—
	Payments received, net	—				(227,062		)		—			(245,859		)
	Disposals	(13,749		)		—				(14,129		)	—
Balance at end of period	$	119,450			$	423,209			$	136,646		$	601,000
Cash flows expected to be collected on acquired impaired loans are estimated quarterly by incorporating several key assumptions similar to the initial estimate of fair value. These key assumptions include probability of default, and the amount of actual prepayments after the acquisition date. Prepayments affect the estimated life of the loans and could change the amount of interest income, and possibly principal expected to be collected. In reforecasting future estimated cash flows, credit loss expectations are adjusted as necessary.
Improved cash flow expectations for loans or pools that were impaired in prior periods are recorded first as a reversal of previously recorded impairment and then as an increase in prospective yield when all previously recorded impairment has been recaptured. Decreases in expected cash flows are recognized as an impairment through a provision for loan loss and an increase to the allowance for acquired impaired loans.
During the year ended December 31, 2014, there was an overall improvement in cash flow expectations which resulted in the reclassification of $45.8 million from the nonaccretable difference to accretable yield. This reclassification results in prospective yield adjustments on these loan pools.
Covered Loans and Related Loss Share Receivable
The loans purchased in the 2010 FDIC-assisted acquisitions of George Washington and Midwest are covered by loss sharing agreements between the FDIC and the Corporation that afford the Bank significant loss protection. These covered loans were recorded at estimated fair value at the Acquisition Date with no carryover of the related ALL and are accounted for as acquired impaired loans. A loss share receivable was recorded at the Acquisition Date which represents the estimated fair value of reimbursement the Corporation expects to receive from the FDIC for incurred losses on certain covered loans. These expected reimbursements are recorded as part of covered loans in the accompanying Consolidated Balance Sheets.
Changes in the loss share receivable associated with covered loans for the years ended December 31, 2014 and 2013, respectively, were as follows:
Loss Share Receivable	Year Ended
(In thousands)	December 31, 2014				December 31, 2013
Balance at beginning of period	$	61,827			$	113,734
Amortization	(20,943		)		(24,307		)
Increase due to impairment on covered loans	2,920				10,790
FDIC reimbursement	(17,837		)		(27,234		)
Covered loans paid in full	(3,934		)		(11,156		)
Balance at end of period	$	22,033			$	61,827
Total outstanding covered impaired loans were $451.2 million and $756.1 million as of December 31, 2014 and 2013, respectively. The outstanding balance of these loans is the undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loans, owed at the reporting date, whether or not currently due and whether or not any such amounts have been charged off. Changes in the carrying amount and accretable yield for covered impaired loans were as follows for the years ended December 31, 2014 and 2013:
	Year Ended December 31,
Covered Impaired Loans	2014								2013
(In thousands)	Accretable				Carrying				Accretable			Carrying
	Yield				Amount of				Yield			Amount of
					Loans							Loans
Balance at beginning of period	$	67,282			$	403,692			$	113,288		$	762,386
Accretion	(42,161		)		42,161				(64,528		)	64,528
Net reclassifications from nonaccretable to accretable	16,841				—				34,965			—
Payments received, net	—				(213,401		)		—			(423,222		)
Disposals	(4,451		)		—				(16,443		)	—
Balance at end of period	$	37,511			$	232,452			$	67,282		$	403,692
The cash flows expected to be collected on covered impaired loans are estimated quarterly in a similar manner as described above for acquired impaired loans. During the year ended December 31, 2014, the overall improvement in the cash flow expectations resulted in the reclassification of $16.8 million from the nonaccretable difference to accretable yield. This reclassification results in prospective yield adjustments on the loan pools.
Credit Quality Disclosures
The credit quality of the Corporation’s loan portfolios is assessed as a function of net credit losses, levels of nonperforming assets and delinquencies, and credit quality ratings as defined by the Corporation. These credit quality ratings are an important part of the Corporation’s overall credit risk management process and evaluation of the allowance for credit losses.
Generally loans, except for certain commercial, credit card and mortgage loans, and leases on which payments are past due for 90 days are placed on nonaccrual status, unless those loans are in the process of collection and, in Management’s opinion, are fully secured. Credit card loans on which payments are past due for 120 days are placed on nonaccrual status. Acquired and covered impaired loans are considered to be accruing and performing even though collection of contractual payments may be in doubt because income continues to be accreted on the loan pool as long as expected cash flows are reasonably estimable.
When a loan is placed on nonaccrual status, interest deemed uncollectible which had been accrued in prior years is charged against the ALL and interest deemed uncollectible accrued in the current year is reversed against interest income. Interest on mortgage loans is accrued until Management deems it uncollectible based upon the specific identification method. Payments subsequently received on nonaccrual loans are generally applied to principal. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable. This generally requires timely principal and interest payments for a minimum of six consecutive payment cycles. Loans are generally written off when deemed uncollectible or when they reach a predetermined number of days past due depending upon loan product, terms and other factors.
The following tables provide a summary of loans by portfolio type, including the delinquency status of those loans that continue to accrue interest and those loans that are nonaccrual:
As of December 31, 2014
(In thousands)																			≥ 90 Days
Originated Loans	Days Past Due											Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (1)		Loans
Commercial
C&I	$	2,212			$	1,162			$	2,670		$	6,044		$	5,169,157	$	5,175,201	$	1,547	$	6,114
CRE	2,155				1,460				8,864			12,479			2,104,639		2,117,118		1,696		11,033
Construction	—				—				—			—			537,766		537,766		—		—
Leases	—				—				—			—			370,179		370,179		—		—
Consumer
Installment	14,621				3,647				4,716			22,984			2,370,467		2,393,451		3,695		3,268
Home equity lines	1,357				587				1,206			3,150			1,107,186		1,110,336		569		1,654
Credit cards	668				516				860			2,044			162,434		164,478		407		596
Residential mortgages	12,086				2,744				8,013			22,843			602,440		625,283		4,242		11,952
Total	$	33,099			$	10,116			$	26,329		$	69,544		$	12,424,268	$	12,493,812	$	12,156	$	34,617
																			≥ 90 Days
Acquired Loans												Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing		Loans
Commercial
C&I	$	92			$	234			$	4,791		$	5,117		$	444,137	$	449,254	$	—	$	787
CRE	3,479				3,398				23,509			30,386			600,288		630,674		44		4,171
Construction	—				—				685			685			6,286		6,971		—		—
Consumer
Installment	6,204				2,029				1,861			10,094			754,074		764,168		615		1,218
Home equity lines	2,819				2,123				2,333			7,275			226,354		233,629		1,519		631
Residential mortgages	13,062				1,648				7,089			21,799			372,685		394,484		1,293		1,249
Total	$	25,656			$	9,432			$	40,268		$	75,356		$	2,403,824	$	2,479,180	$	3,471	$	8,056
																			≥ 90 Days
Covered Loans (2)	Days Past Due											Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (3)		Loans (3)
Commercial
C&I	$	58			$	—			$	6,041		$	6,099		$	42,738	$	48,837	n/a		n/a
CRE	234				1,517				47,233			48,984			104,524		153,508		n/a		n/a
Construction	—				—				6,064			6,064			3,198		9,262		n/a		n/a
Consumer
Installment	23				—				34			57			4,817		4,874		n/a		n/a
Home equity lines	1,395				870				3,859			6,124			67,241		73,365		n/a		n/a
Residential mortgages	6,205				91				3,572			9,868			31,408		41,276		n/a		n/a
Total	$	7,915			$	2,478			$	66,803		$	77,196		$	253,926	$	331,122	n/a		n/a
(1) Installment loans 90 days or more past due and accruing include $2.4 million of loans guaranteed by the U.S. government as of December 31, 2014.
(2) Excludes loss share receivable of $22.0 million as of December 31, 2014.
(3) Acquired impaired loans were not classified as nonperforming assets at December 31, 2014 as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cash flows, is being recognized on all acquired impaired loans. These asset quality disclosures are, therefore, not applicable to acquired impaired loans.
As of December 31, 2013
(In thousands)																			≥ 90 Days
Originated Loans	Days Past Due											Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (1)		Loans
Commercial
C&I	$	8,941			$	994			$	10,622		$	20,557		$	4,119,010	$	4,139,567	$	151	$	11,323
CRE	4,507				2,400				9,688			16,595			2,153,192		2,169,787		460		14,229
Construction	351				21				66			438			338,487		338,925		—		122
Leases	902				—				—			902			238,649		239,551		—		—
Consumer
Installment	15,433				4,050				4,462			23,945			1,703,980		1,727,925		3,735		3,681
Home equity lines	1,864				918				965			3,747			916,319		920,066		418		1,819
Credit cards	729				471				735			1,935			146,378		148,313		404		558
Residential mortgages	19,858				2,072				9,350			31,280			497,973		529,253		6,008		10,471
Total	$	52,585			$	10,926			$	35,888		$	99,399		$	10,113,988	$	10,213,387	$	11,176	$	42,203
																			≥ 90 Days
Acquired Loans												Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing		Loans
Commercial	$	1,295			$	862			$	3,744		$	5,901		$	788,178	$	794,079	$	40	$	795
C&I	5,603				5,281				26,366			37,250			881,395		918,645		403		651
CRE	2,675				—				—			2,675			10,571		13,246		—		—
Construction
Consumer	14,528				4,076				3,354			21,958			982,611		1,004,569		2,263		679
Installment	4,774				1,933				3,606			10,313			284,111		294,424		1,039		1,300
Home equity lines	3,918				1,426				8,063			13,407			457,245		470,652		403		582
Residential mortgages	$	32,793			$	13,578			$	45,133		$	91,504		$	3,404,111	$	3,495,615	$	4,148	$	4,007
Total
Covered Loans (2)	Days Past Due											Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (3)		Loans (3)
Commercial
C&I	$	836			$	1,489			$	12,957		$	15,282		$	60,955	$	76,237	n/a		n/a
CRE	2,855				3,443				103,077			109,375			164,219		273,594		n/a		n/a
Construction	2,191				1,917				20,388			24,496			1,533		26,029		n/a		n/a
Consumer
Installment	33				—				—			33			6,130		6,163		n/a		n/a
Home equity lines	544				1,467				1,651			3,662			93,780		97,442		n/a		n/a
Residential mortgages	7,463				1,565				5,165			14,193			36,485		50,678		n/a		n/a
Total	$	13,922			$	9,881			$	143,238		$	167,041		$	363,102	$	530,143	n/a		n/a
(1) Installment loans 90 days or more past due and accruing include $2.1 million of loans guaranteed by the U.S. government as of December 31, 2013.
(2) Excludes loss share receivable of $61.8 million as of December 31, 2013.
(3) Acquired impaired loans were not classified as nonperforming assets at December 31, 2013 as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cash flows, is being recognized on all acquired impaired loans. These asset quality disclosures are, therefore, not applicable to acquired impaired loans.
Individual commercial loans are assigned credit risk grades based on an internal assessment of conditions that affect a borrower’s ability to meet its contractual obligation under the loan agreement. The assessment process includes reviewing a borrower’s current financial information, historical payment experience, credit documentation, public information, and other information specific to each borrower. Commercial loans are reviewed on an annual, quarterly or rotational basis or as Management becomes aware of information during a borrower’s ability to fulfill its obligation. For consumer loans, Management evaluates credit quality based on the aging status of the loan as well as by payment activity, which is presented in the above tables.
The credit-risk grading process for commercial loans is summarized as follows:
“Pass” Loans (Grades 1, 2, 3, 4) are not considered a greater than normal credit risk. Generally, the borrowers have the apparent ability to satisfy obligations to the bank, and the Corporation anticipates insignificant uncollectible amounts based on its individual loan review.
“Special-Mention” Loans (Grade 5) are commercial loans that have identified potential weaknesses that deserve Management’s close attention. If left uncorrected, these potential weaknesses may result in noticeable deterioration of the repayment prospects for the asset or in the institution’s credit position.
“Substandard” Loans (Grade 6) are inadequately protected by the current financial condition and paying capacity of the obligor or by any collateral pledged. Loans so classified have a well-defined weakness or weaknesses that may jeopardize the liquidation of the debt pursuant to the contractual principal and interest terms. Such loans are characterized by the distinct possibility that the Corporation may sustain some loss if the deficiencies are not corrected.
“Doubtful” Loans (Grade 7) have all the weaknesses inherent in those classified as substandard, with the added characteristic that existing facts, conditions, and values make collection or liquidation in full highly improbable. Such loans are currently managed separately to determine the highest recovery alternatives.
“Loss” Loans (Grade 8) are considered uncollectible and of such little value that their continuance as bankable assets is not warranted. These loans are charged off when loss is identified.
The following tables provide a summary of commercial loans by portfolio type and the Corporation’s internal credit quality rating:
As of December 31, 2014
(In thousands)
Originated Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	52,676			$	683			$	678		$	4,451		$	58,488
Grade 2	186,278				3,454				—			14,959			204,691
Grade 3	1,340,100				294,281				46,074			71,908			1,752,363
Grade 4	3,413,446				1,745,470				490,757			277,277			5,926,950
Grade 5	139,083				29,990				257			1,389			170,719
Grade 6	43,618				43,240				—			195			87,053
Grade 7	—				—				—			—			—
Total	$	5,175,201			$	2,117,118			$	537,766		$	370,179		$	8,200,264
Acquired Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	1,076			$	—			$	—		$	—		$	1,076
Grade 2	—				—				—			—			—
Grade 3	20,891				24,867				—			—			45,758
Grade 4	376,129				532,447				6,286			—			914,862
Grade 5	23,268				28,382				685			—			52,335
Grade 6	27,890				44,978				—			—			72,868
Grade 7	—				—				—			—			—
Total	$	449,254			$	630,674			$	6,971		$	—		$	1,086,899
Covered Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	—			$	—			$	—		$	—		$	—
Grade 2	1,347				—				—			—			1,347
Grade 3	—				—				—			—			—
Grade 4	36,406				86,779				823			—			124,008
Grade 5	167				3,401				—			—			3,568
Grade 6	10,917				63,328				8,248			—			82,493
Grade 7	—				—				191			—			191
Total	$	48,837			$	153,508			$	9,262		$	—		$	211,607
As of December 31, 2013
(In thousands)
Originated Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	34,909			$	241			$	—		$	9,271		$	44,421
Grade 2	108,709				3,730				—			2,900			115,339
Grade 3	802,624				315,150				25,632			54,446			1,197,852
Grade 4	3,083,458				1,759,383				306,795			167,022			5,316,658
Grade 5	71,857				34,969				267			5,750			112,843
Grade 6	38,010				56,314				6,231			162			100,717
Grade 7	—				—				—			—			—
Total	$	4,139,567			$	2,169,787			$	338,925		$	239,551		$	6,887,830
Acquired Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	—			$	—			$	—		$	—		$	—
Grade 2	1,741				703				—			—			2,444
Grade 3	79,634				29,224				—			—			108,858
Grade 4	643,495				722,307				13,246			—			1,379,048
Grade 5	46,807				93,499				—			—			140,306
Grade 6	22,402				72,912				—			—			95,314
Grade 7	—				—				—			—			—
Total	$	794,079			$	918,645			$	13,246		$	—		$	1,725,970
Covered Loans	Commercial
	C&I				CRE				Construction			Leases			Total
Grade 1	$	—			$	—			$	—		$	—		$	—
Grade 2	968				—				—			—			968
Grade 3	—				—				—			—			—
Grade 4	41,115				113,863				601			—			155,579
Grade 5	427				6,219				—			—			6,646
Grade 6	31,621				153,318				23,208			—			208,147
Grade 7	2,106				194				2,220			—			4,520
Total	$	76,237			$	273,594			$	26,029		$	—		$	375,860

Allowance_for_Loan_and_Lease_L

Allowance for Loan and Lease Losses	12 Months Ended
	Dec. 31, 2014
Allowance for Loan and Lease Losses [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses
	The Corporation’s Credit Policy Division manages credit risk by establishing common credit policies for its subsidiary bank, participating in approval of its loans, conducting reviews of loan portfolios, providing centralized consumer underwriting, collections and loan operation services, and overseeing loan workouts. The Corporation’s objective is to minimize losses from its commercial lending activities and to maintain consumer losses at acceptable levels that are stable and consistent with growth and profitability objectives.
	The ALL is Management’s estimate of the amount of probable credit losses inherent in a loan portfolio at the balance sheet date. The following describes the distinctions in methodology used to estimate the ALL of originated, acquired and covered loan portfolios as well as certain significant accounting policies relevant to each category.
	Allowance for Originated Loan Losses
	Management estimates credit losses based on originated individual loans determined to be impaired and on all other loans grouped based on similar risk characteristics. Management also considers internal and external factors such as economic conditions, loan management practices, portfolio monitoring, and other risks, collectively known as qualitative factors, or Q-factors, to estimate credit losses in the loan portfolio. Q-factors are used to reflect changes in the portfolio’s collectability characteristics not captured by historical loss data.
	The Corporation’s historical loss component is the most significant of the ALL components and is based on historical loss experience by credit-risk grade (for commercial loan pools) and payment status (for mortgage and consumer loan pools). The historical loss experience component of the ALL represents the results of migration analysis of historical net charge-offs for portfolios of loans (including groups of commercial loans within each credit-risk grade and groups of consumer loans by payment status). For measuring loss exposure in a pool of loans, the historical net charge-off or migration experience is utilized to estimate expected losses to be realized from the pool of loans.
	If a nonperforming, substandard loan has an outstanding balance of $0.3 million or greater or if a doubtful loan has an outstanding balance of $0.1 million or greater, as determined by the Corporation’s credit-risk grading process, further analysis is performed to determine the probable loss content and assign a specific allowance to the loan, if deemed appropriate. The ALL relating to originated loans that have become impaired is based on either expected cash flows discounted using the original effective interest rate, the observable market price, or the fair value of the collateral for certain collateral dependent loans.
	The following tables show activity in the originated ALL, by portfolio segment for the years ended December 31, 2014, 2013 and 2012, as well as the corresponding recorded investment in originated loans at the end of the period:
	As of December 31, 2014
	(In thousands)
	Originated Loans		C&I				CRE				Construction				Leases				Installment				Home Equity Lines				Credit Cards				Residential Mortgages			Total
	Year ended
	Allowance for originated loan losses, beginning balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Charge-offs		(9,617		)		(3,512		)		—				—				(20,328		)		(4,831		)		(4,604		)		(2,031		)	(44,923		)
	Recoveries		3,872				515				39				379				11,185				2,940				1,716				318			20,964
	Provision for loan losses		139				1,224				(647		)		(786		)		10,126				8,315				3,114				1,686			23,171
	Allowance for originated loan losses, ending balance		$	37,375			$	10,492			$	2,202			$	674			$	12,918			$	19,324			$	7,966			$	4,745		$	95,696
	Ending allowance for originated loan losses balance attributable to loans:
		Individually evaluated for impairment	$	72			$	2,914			$	—			$	—			$	1,178			$	207			$	296			$	1,283		$	5,950
		Collectively evaluated for impairment	37,303				7,578				2,202				674				11,740				19,117				7,670				3,462			89,746
	Total ending allowance for originated loan losses balance		$	37,375			$	10,492			$	2,202			$	674			$	12,918			$	19,324			$	7,966			$	4,745		$	95,696
	Originated loans:
		Originated loans individually evaluated for impairment	$	11,759			$	23,300			$	—			$	—			$	24,905			$	7,379			$	854			$	25,251		$	93,448
		Originated loans collectively evaluated for impairment	5,163,442				2,093,818				537,766				370,179				2,368,546				1,102,957				163,624				600,032			12,400,364
	Total ending originated loan balance		$	5,175,201			$	2,117,118			$	537,766			$	370,179			$	2,393,451			$	1,110,336			$	164,478			$	625,283		$	12,493,812
	As of December 31, 2013
	(In thousands)
	Originated Loans		C&I				CRE				Construction				Leases				Installment				Home Equity Lines				Credit Cards				Residential Mortgages			Total
	Year ended
	Allowance for originated loan losses, beginning balance		$	36,209			$	20,126			$	3,821			$	639			$	11,154			$	13,724			$	7,384			$	5,885		$	98,942
	Charge-offs		(5,840		)		(1,281		)		(516		)		(1,237		)		(16,683		)		(7,172		)		(5,541		)		(1,903		)	(40,173		)
	Recoveries		7,981				524				507				100				10,519				2,979				1,841				230			24,681
	Provision for loan losses		4,631				(7,104		)		(1,002		)		1,579				6,945				3,369				4,056				560			13,034
	Allowance for originated loan losses, ending balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Ending allowance for originated loan losses balance attributable to loans:
		Individually evaluated for impairment	$	3,235			$	229			$	—			$	—			$	1,014			$	223			$	312			$	1,133		$	6,146
		Collectively evaluated for impairment	39,746				12,036				2,810				1,081				10,921				12,677				7,428				3,639			90,338
	Total ending allowance for originated loan losses balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Originated loans:
		Originated loans individually evaluated for impairment	$	8,053			$	20,616			$	906			$	—			$	27,285			$	6,726			$	1,112			$	23,066		$	87,764
		Originated loans collectively evaluated for impairment	4,131,514				2,149,171				338,019				239,551				1,700,640				913,340				147,201				506,187			10,125,623
	Total ending originated loan balance		$	4,139,567			$	2,169,787			$	338,925			$	239,551			$	1,727,925			$	920,066			$	148,313			$	529,253		$	10,213,387
	As of December 31, 2012
	(In thousands)
	Originated Loans		C&I				CRE				Construction				Leases				Installment				Home Equity Lines				Credit Cards				Residential Mortgages			Total
	Year ended
	Allowance for originated loan losses, beginning balance		$	32,363			$	31,857			$	5,173			$	341			$	17,981			$	6,766			$	7,369			$	5,849		$	107,699
	Charge-offs		(22,639		)		(5,312		)		(697		)		(144		)		(18,029		)		(8,949		)		(6,171		)		(3,964		)	(65,905		)
	Recoveries		4,266				911				449				38				11,694				3,441				2,138				235			23,172
	Provision for loan losses		22,219				(7,330		)		(1,104		)		404				(492		)		12,466				4,048				3,765			33,976
	Allowance for originated loan losses, ending balance		$	36,209			$	20,126			$	3,821			$	639			$	11,154			$	13,724			$	7,384			$	5,885		$	98,942
	Ending allowance for originated loan losses balance attributable to loans:
		Individually evaluated for impairment	$	577			$	913			$	105			$	—			$	1,526			$	34			$	127			$	1,722		$	5,004
		Collectively evaluated for impairment	35,632				19,213				3,716				639				9,628				13,690				7,257				4,163			93,938
	Total ending allowance for originated loan losses balance		$	36,209			$	20,126			$	3,821			$	639			$	11,154			$	13,724			$	7,384			$	5,885		$	98,942
	Originated loans:
		Originated loans individually evaluated for impairment	$	6,187			$	24,007			$	3,405			$	—			$	30,870			$	6,281			$	1,612			$	24,009		$	96,371
		Originated loans collectively evaluated for impairment	3,300,339				2,200,409				332,142				139,236				1,297,388				799,797				144,775				421,202			8,635,288
	Total ending originated loan balance		$	3,306,526			$	2,224,416			$	335,547			$	139,236			$	1,328,258			$	806,078			$	146,387			$	445,211		$	8,731,659
	Allowance for Acquired Loan Losses
	The Citizens’ loans were recorded at their fair value as of the Acquisition Date and the prior ALL was eliminated. An ALL for acquired nonimpaired loans is estimated using a methodology similar to that used for originated loans. The allowance determined for each acquired nonimpaired loan is compared to the remaining fair value adjustment for that loan. If the computed allowance is greater, the excess is added to the allowance through a provision for loan losses. If the computed allowance is less, no additional allowance is recognized. As of December 31, 2014 and 2013, the computed ALL was less than the remaining fair value discount; therefore, no allowance for acquired nonimpaired loan losses was recorded.
	Charge-offs and actual losses on an acquired nonimpaired loan first reduce any remaining fair value
	discount for that loan. Once a loan’s discount is depleted, charge-offs and actual losses are applied against
	the acquired ALL. During the years ended December 31, 2014 and 2013, provision for loan losses, equal to net charge-offs, of $14.7 million and $6.8 million was recorded, respectively. Charge-offs on acquired nonimpaired loans were mainly related to consumer loans that were written off in accordance with the Corporation’s credit policies based on a predetermined number of days past due.
The ALL for acquired impaired loans is determined by comparing the present value of the cash flows expected to be collected to the carrying amount for a given pool of loans. Management reforecasts the estimated cash flows expected to be collected on acquired impaired loans on a quarterly basis. If the present value of expected cash flows for a pool is less than its carrying value, impairment is recognized by an increase in the ALL and a charge to the provision for loan losses. If the present value of expected cash flows for a pool is greater than its carrying value, any previously established ALL is reversed and any remaining difference increases the accretable yield which will be taken into interest income over the remaining life of the loan pool. See Note 4 (Loans) for further information on changes in accretable yield.
The following table presents activity in the allowance for acquired impaired loan losses for the years ended December 31, 2014 and 2013:
Allowance for Acquired Impaired Loan Losses		Year Ended December 31,
(In thousands)		2014				2013
Balance at beginning of the period		$	741			$	—
Charge-offs		—				—
Recoveries		—				—
Provision for loan losses		6,716				741
Balance at end of the period		$	7,457			$	741
Allowance for Covered Loan Losses
The ALL for covered loans is estimated similar to acquired loans as described above except any increase to the allowance and provision for loan losses is partially offset by an increase in the loss share receivable for the portion of the losses recoverable under the loss sharing agreements with the FDIC. As of December 31, 2014 and 2013, the computed ALL was less than the remaining fair value discount, therefore, no ALL for covered nonimpaired loans was recorded.
The following table presents activity in the allowance for covered impaired loan losses for the years ended December 31, 2014, 2013, and 2012:
Allowance for Covered Impaired Loan Losses		Year Ended December 31,
(In thousands)		2014				2013				2012
Balance at beginning of the period		$	44,027			$	43,255			$	36,417
	Net provision for loan losses before benefit attributable to FDIC loss share agreements	10,568				23,892				35,450
	Net benefit attributable to FDIC loss share agreements	(2,920		)		(10,790		)		(14,728		)
Net provision for loan losses		7,648				13,102				20,722
Increase in loss share receivable		2,920				10,790				14,728
Loans charged-off		(14,099		)		(23,120		)		(28,612		)
Balance at end of the period		$	40,496			$	44,027			$	43,255
An acquired or covered loan may be resolved either through receipt of payment (in full or in part)from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the period of resolution of a nonimpaired loan, any remaining unamortized fair value adjustment is recognized as interest income. In the period of resolution of an impaired loan accounted for on an individual basis, the difference between the carrying amount of the loan and the proceeds received is recognized as a gain or loss within noninterest income. The majority of impaired loans are accounted for within a pool of loans which results in any difference between the proceeds received and the loan carrying amount being deferred as part of the carrying amount of the pool. The accretable amount of the pool remains unaffected from the resolution until the subsequent quarterly cash flow re-estimation. Favorable results from removal of the resolved loan from the pool increase the future accretable yield of the pool, while unfavorable results are recorded as impairment in the quarter of the cash flow re-estimation. Acquired or covered impaired loans subject to modification are not removed from a pool even if those loans would otherwise be deemed TDRs as the pool, and not the individual loan, represents the unit of account.
Credit Quality
A loan is considered to be impaired when, based on current events or information, it is probable the Corporation will be unable to collect all amounts due (principal and interest) per the contractual terms of the loan agreement.
Interest income recognized on impaired loans was $0.9 million, $1.3 million, and $1.3 million during the years ended 2014, 2013 and 2012, respectively. Interest income which would have been earned in accordance with the original terms was $2.8 million, $5.5 million, and $3.2 million during the years ended 2014, 2013, and 2012, respectively.
Loan impairment is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate, at the observable market price of the loan, or the fair value of the collateral for certain collateral dependent loans. Impaired loans include all nonaccrual commercial, agricultural, construction, and commercial real estate loans, and loans modified as a TDR, regardless of nonperforming status. Acquired and covered impaired loans are not considered or reported as impaired loans. Nonimpaired acquired loans that are subsequently placed on nonaccrual status are reported as impaired loans and included in the tables below. Acquired loans restructured after acquisition are not considered or reported as TDRs if the loans evidenced credit deterioration as of the date of acquisition and are accounted for in pools.
The following tables provide further detail on impaired loans individually evaluated for impairment and the associated ALL. Certain impaired loans do not have a related ALL as the valuation of these impaired loans exceeded the recorded investment.
As of December 31, 2014
Originated Loans						Unpaid								Average
		Recorded				Principal				Related				Recorded
(In thousands)		Investment				Balance				Allowance				Investment
Impaired loans with no related allowance
Commercial
	C&I	$	11,451			$	18,207			$	—			$	14,193
	CRE	16,874				22,696				—				18,027
	Construction	—				—				—				—
Consumer
	Installment	4,460				4,584				—				4,272
	Home equity line	1,723				1,754				—				1,792
	Credit card	16				16				—				32
	Residential mortgages	12,204				15,119				—				12,425
Subtotal		46,728				62,376				—				50,741
Impaired loans with a related allowance
Commercial
	C&I	308				344				72				326
	CRE	6,426				6,440				2,914				4,497
	Construction	—				—				—				—
Consumer
	Installment	20,445				21,024				1,178				19,513
	Home equity line	5,656				5,875				207				5,944
	Credit card	838				838				296				966
	Residential mortgages	13,047				13,158				1,283				13,121
Subtotal		46,720				47,679				5,950				44,367
	Total impaired loans	$	93,448			$	110,055			$	5,950			$	95,108
Note 1: These tables exclude loans fully charged off.
Note 2: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
As of December 31, 2013
Originated Loans						Unpaid								Average
		Recorded				Principal				Related				Recorded
(In thousands)		Investment				Balance				Allowance				Investment
Impaired loans with no related allowance
Commercial
	C&I	$	2,503			$	6,679			$	—			$	7,256
	CRE	17,871				23,709				—				18,639
	Construction	906				1,179				—				1,035
Consumer
	Installment	2,813				3,978				—				3,338
	Home equity line	1,018				1,347				—				1,079
	Credit card	49				49				—				91
	Residential mortgages	10,250				12,778				—				10,258
Subtotal		35,410				49,719				—				41,696
Impaired loans with a related allowance
Commercial
	C&I	5,551				7,428				3,235				5,009
	CRE	2,744				2,870				229				2,836
	Construction	—				—				—				—
Consumer
	Installment	24,472				24,558				1,014				24,985
	Home equity line	5,707				5,707				223				5,874
	Credit card	1,064				1,064				312				1,238
	Residential mortgages	12,816				12,898				1,133				12,064
Subtotal		52,354				54,525				6,146				52,006
	Total impaired loans	$	87,764			$	104,244			$	6,146			$	93,702
Note 1: These tables exclude loans fully charged off.
Note 2: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
Troubled Debt Restructurings
In certain circumstances, the Corporation may modify the terms of a loan to maximize the collection of amounts due when a borrower is experiencing financial difficulties or is expected to experience difficulties in the near term. In most cases the modification is either a concessionary reduction in interest rate, extension of the maturity date or modification of the adjustable rate provisions of the loan that would otherwise not be considered; however, forgiveness of principal is rarely granted. Concessionary modifications are classified as TDRs unless the modification is short-term, typically less than 90 days. TDRs accrue interest if the borrower complies with the revised terms and conditions and has demonstrated repayment performance at a level commensurate with the modified terms for a minimum of six consecutive payment cycles after the restructuring date. Acquired loans restructured after acquisition are not considered or reported as TDRs if the loans evidenced credit deterioration as of the Acquisition Date and are accounted for in pools.
The substantial majority of the Corporation’s residential mortgage TDRs involve reducing the client’s loan payment through an interest rate reduction for a set period of time based on the borrower’s ability to service the modified loan payment. Modifications of mortgages retained in portfolio are handled using proprietary modification guidelines, or the FDIC’s Modification Program for residential first mortgages covered by loss share agreements (agreements between the Bank and the FDIC that afford the Bank significant protection against future losses). The Corporation participates in the U.S. Treasury’s Home Affordable Modification Program for originated mortgages sold to and serviced for FNMA and FHLMC.
Commercial and industrial loans modified in a TDR often involve temporary interest-only payments, term extensions and converting revolving credit lines to term loans. Additional collateral, a co-borrower, or a guarantor is often requested. Commercial real estate and construction loans modified in a TDR often involve reducing the interest rate for the remaining term of the loan, extending the maturity date at an interest rate lower than the current market rate for new debt with similar risk, or substituting or adding a new borrower or guarantor. Construction loans modified in a TDR may also involve extending the interest-only payment period. The Corporation has modified certain loans according to provisions in loss share agreements. Losses associated with modifications on these loans, including the economic impact of interest rate reductions, are generally eligible for reimbursement under the loss share agreements.
The following tables provide the number of loans modified in a TDR and the recorded investment and unpaid principal balance by loan portfolio as of December 31, 2014, and 2013.
			As of December 31, 2014
(Dollars in thousands)			Number of Loans			Recorded Investment				Unpaid Principal Balance
Originated loans
	Commercial
		C&I	41			$	7,123			$	13,887
		CRE	67			17,607				22,645
		Construction	31			—				—
		Total originated commercial	139			24,730				36,532
	Consumer
		Installment	1,205			24,905				25,608
		Home equity lines	270			7,379				7,629
		Credit card	238			854				854
		Residential mortgages	315			25,251				28,277
		Total originated consumer	2,028			58,389				62,368
Total originated loans			2,167			$	83,119			$	98,900
Acquired Loans
	Commercial
		C&I	2			$	18			$	19
		CRE	3			2,542				2,595
		Total acquired commercial	5			2,560				2,614
	Consumer
		Installment	40			975				1,054
		Home equity lines	145			6,932				6,983
		Residential mortgages	26			1,633				1,823
		Total acquired consumer	211			9,540				9,860
Total acquired loans			216			$	12,100			$	12,474
Covered loans
	Commercial
		C&I	8			$	177			$	1,589
		CRE	24			25,499				42,226
		Construction	9			339				9,552
		Total covered commercial	41			26,015				53,367
	Consumer
		Home equity lines	68			8,890				8,901
		Residential mortgages	2			334				334
		Total covered consumer	70			9,224				9,235
Total covered loans			111			$	35,239			$	62,602
Total loans
	Commercial
		C&I	51			$	7,318			$	15,495
		CRE	94			45,648				67,466
		Construction	40			339				9,552
		Total commercial	185			53,305				92,513
	Consumer
		Installment	1,245			25,880				26,662
		Home equity lines	483			23,201				23,513
		Credit card	238			854				854
		Residential mortgages	343			27,218				30,434
		Total consumer	2,309			77,153				81,463
Total loans			2,494			$	130,458			$	173,976
Note 1: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
			As of December 31, 2013
(Dollars in thousands)			Number of Loans			Recorded Investment				Unpaid Principal Balance
Originated loans
	Commercial
		C&I	35			$	4,449			$	7,660
		CRE	52			15,932				20,569
		Construction	30			905				1,179
		Total originated commercial	117			21,286				29,408
	Consumer
		Installment	1,553			27,285				28,536
		Home equity lines	231			6,725				7,054
		Credit card	307			1,113				1,113
		Residential mortgages	301			23,067				25,676
		Total originated consumer	2,392			58,190				62,379
Total originated loans			2,509			$	79,476			$	91,787
Acquired Loans
	Commercial
		C&I	1			$	6			$	5
		CRE	1			1,730				1,730
		Total acquired commercial	2			1,736				1,735
	Consumer
		Installment	12			505				542
		Home equity lines	8			245				270
		Residential mortgages	7			431				502
		Total acquired consumer	27			1,181				1,314
Total acquired loans			29			$	2,917			$	3,049
Covered loans
	Commercial
		C&I	4			$	1,104			$	2,331
		CRE	24			39,995				57,008
		Construction	10			4,144				24,547
		Total covered commercial	38			45,243				83,886
	Consumer
		Home equity lines	47			5,401				5,421
		Residential Mortgages	1			150				150
		Total covered consumer	48			5,551				5,571
Total covered loans			86			$	50,794			$	89,457
Total loans
	Commercial
		C&I	40			$	5,559			$	9,996
		CRE	77			57,657				79,307
		Construction	40			5,049				25,726
		Total commercial	157			68,265				115,029
	Consumer
		Installment	1,565			27,790				29,078
		Home equity lines	286			12,371				12,745
		Credit card	307			1,113				1,113
		Residential mortgages	309			23,648				26,328
		Total consumer	2,467			64,922				69,264
Total loans			2,624			$	133,187			$	184,293
Note 1: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
The pre-modification and post-modification outstanding recorded investments of loans modified as TDRs during the years ended December 31, 2014 and 2013 were not materially different. Post-modification balances may include capitalization of unpaid accrued interest and fees associated with the modification as well as forgiveness of principal. Loans modified as TDRs during the years ended December 31, 2014, 2013 and 2012 did not involve the forgiveness of principal, accordingly, the Corporation did not record a charge-off at the modification date. Additionally, capitalization of any unpaid accrued interest and fees assessed to loans modified in the years ended December 31, 2014, 2013 and 2012 were not material to the accompanying consolidated financial statements. Specific allowances for loan losses are established for loans whose terms have been modified in a TDR. Specific reserve allocations are generally assessed prior to loans being modified in a TDR, as most of these loans migrate from the Corporation’s internal watch list and have been specifically allocated for as part of the Corporation’s normal loan loss provisioning methodology. At December 31, 2014, the Corporation had $0.2 million in commitments to lend additional funds to debtors owing receivables whose terms have been modified in a TDR.
The following tables provide a summary of the delinquency status of TDRs along with the specific allowance for loan loss, by loan type, as of December 31, 2014 and 2013, including TDRs that continue to accrue interest and TDRs included in nonperforming assets.
As of December 31, 2014
	Accruing TDRs												Nonaccruing TDRs												Total				Total
(In thousands)	Current				Delinquent				Total				Current				Delinquent				Total				TDRs				Allowance
Originated loans
Commercial
C&I	$	6,740			$	—			$	6,740			$	—			$	383			$	383			$	7,123			$	72
CRE	12,885				952				13,837				394				3,376				3,770				17,607				159
Construction	—				—				—				—				—				—				—				—
Total originated commercial	19,625				952				20,577				394				3,759				4,153				24,730				231
Consumer
Installment	22,254				726				22,980				1,663				262				1,925				24,905				1,178
Home equity lines	6,239				269				6,508				871				—				871				7,379				207
Credit card	775				60				835				15				4				19				854				296
Residential mortgages	13,440				3,538				16,978				5,006				3,267				8,273				25,251				1,283
Total originated consumer	42,708				4,593				47,301				7,555				3,533				11,088				58,389				2,964
Total originated TDRs	$	62,333			$	5,545			$	67,878			$	7,949			$	7,292			$	15,241			$	83,119			$	3,195
Acquired loans
Commercial
C&I	$	15			$	—			$	15			$	3			$	—			$	3			$	18			$	18
CRE	—				—				—				978				1,564				2,542				2,542				134
Total acquired commercial	15				—				15				981				1,564				2,545				2,560				152
Consumer
Installment	841				87				928				24				23				47				975				65
Home equity lines	6,186				607				6,793				139				—				139				6,932				9
Residential mortgages	868				—				868				470				295				765				1,633				2
Total acquired consumer	7,895				694				8,589				633				318				951				9,540				76
Total acquired TDRs	$	7,910			$	694			$	8,604			$	1,614			$	1,882			$	3,496			$	12,100			$	228
Covered loans
Commercial
C&I	$	—			$	177			$	177			$	—			$	—			$	—			$	177			$	—
CRE	5,123				20,376				25,499				—				—				—				25,499				2,879
Construction	339				—				339				—				—				—				339				295
Total covered commercial	5,462				20,553				26,015				—				—				—				26,015				3,174
Consumer
Home equity lines	8,561				—				8,561				329				—				329				8,890				27
Residential mortgages	334				—				334				—				—				—				334				21
Total covered consumer	8,895				—				8,895				329				—				329				9,224				48
Total covered TDRs	$	14,357			$	20,553			$	34,910			$	329			$	—			$	329			$	35,239			$	3,222
Total loans
Commercial
C&I	$	6,755			$	177			$	6,932			$	3			$	383			$	386			$	7,318			$	90
CRE	18,008				21,328				39,336				1,372				4,940				6,312				45,648				3,172
Construction	339				—				339				—				—				—				339				295
Total commercial	25,102				21,505				46,607				1,375				5,323				6,698				53,305				3,557
Consumer
Installment	23,095				813				23,908				1,687				285				1,972				25,880				1,243
Home equity lines	20,986				876				21,862				1,339				—				1,339				23,201				243
Credit card	775				60				835				15				4				19				854				296
Residential mortgages	14,642				3,538				18,180				5,476				3,562				9,038				27,218				1,306
Total consumer	59,498				5,287				64,785				8,517				3,851				12,368				77,153				3,088
Total TDRs	$	84,600			$	26,792			$	111,392			$	9,892			$	9,174			$	19,066			$	130,458			$	6,645
As of December 31, 2013
	Accruing TDRs												Nonaccruing TDRs												Total				Total
(In thousands)	Current				Delinquent				Total				Current				Delinquent				Total				TDRs				Allowance
Originated loans
Commercial
C&I	$	1,438			$	879			$	2,317			$	177			$	1,955			$	2,132			$	4,449			$	665
CRE	10,442				382				10,824				1,208				3,900				5,108				15,932				32
Construction	848				—				848				—				57				57				905				—
Total originated commercial	12,728				1,261				13,989				1,385				5,912				7,297				21,286				697
Consumer
Installment	23,342				1,238				24,580				2,483				222				2,705				27,285				1,014
Home equity lines	5,313				194				5,507				1,206				12				1,218				6,725				223
Credit card	1,046				66				1,112				—				1				1				1,113				312
Residential mortgages	12,276				3,327				15,603				4,360				3,104				7,464				23,067				1,133
Total originated consumer	41,977				4,825				46,802				8,049				3,339				11,388				58,190				2,682
Total originated TDRs	$	54,705			$	6,086			$	60,791			$	9,434			$	9,251			$	18,685			$	79,476			$	3,379
Acquired loans
Commercial
C&I	$	—			$	—			$	—			$	6			$	—			$	6			$	6			$	—
CRE	1,730				—				1,730				—				—				—				1,730				—
Total acquired commercial	1,730				—				1,730				6				—				6				1,736				—
Consumer
Installment	369				136				505				—				—				—				505				—
Home equity lines	182				—				182				63				—				63				245				—
Residential mortgages	245				—				245				32				154				186				431				—
Total acquired consumer	796				136				932				95				154				249				1,181				—
Total acquired TDRs	$	2,526			$	136			$	2,662			$	101			$	154			$	255			$	2,917			$	—
Covered loans
Commercial
C&I	$	362			$	742			$	1,104			$	—			$	—			$	—			$	1,104			$	—
CRE	5,259				34,736				39,995				—				—				—				39,995				3,022
Construction	698				3,446				4,144				—				—				—				4,144				800
Total covered commercial	6,319				38,924				45,243				—				—				—				45,243				3,822
Consumer
Home equity lines	5,377				24				5,401				—				—				—				5,401				—
Residential mortgages	150				—				150				—				—				—				150				—
Total covered consumer	5,527				24				5,551				—				—				—				5,551				—
Total covered TDRs	$	11,846			$	38,948			$	50,794			$	—			$	—			$	—			$	50,794			$	3,822
Total loans
Commercial
C&I	$	1,800			$	1,621			$	3,421			$	183			$	1,955			$	2,138			$	5,559			$	665
CRE	17,431				35,118				52,549				1,208				3,900				5,108				57,657				3,054
Construction	1,546				3,446				4,992				—				57				57				5,049				800
Total commercial	20,777				40,185				60,962				1,391				5,912				7,303				68,265				4,519
Consumer
Installment	23,711				1,374				25,085				2,483				222				2,705				27,790				1,014
Home equity lines	10,872				218				11,090				1,269				12				1,281				12,371				223
Credit card	1,046				66				1,112				—				1				1				1,113				312
Residential mortgages	12,671				3,327				15,998				4,392				3,258				7,650				23,648				1,133
Total consumer	48,300				4,985				53,285				8,144				3,493				11,637				64,922				2,682
Total TDRs	$	69,077			$	45,170			$	114,247			$	9,535			$	9,405			$	18,940			$	133,187			$	7,201
Loans modified in a TDR are closely monitored for delinquency as an early indicator of possible future default. If loans modified in a TDR subsequently default, the Corporation evaluates the loan for possible further impairment. The ALL may be increased, adjustments may be made in the allocation of the ALL, or partial charge-offs may be taken to further write-down the carrying value of the loan.
On an ongoing basis, the Corporation monitors the performance of modified loans to their restructured terms. In the event of a subsequent default, the ALL continues to be reassessed on the basis of an individual evaluation of the loan.
The following table provides the number of loans modified in a TDR during the previous 12 months that subsequently defaulted during the year ended December 31, 2014 and 2013, as well as the amount defaulted in these restructured loans as of December 31, 2014 and 2013.
	As of December 31, 2014
(Dollars in thousands)	Number of Loans			Amount Defaulted
Originated loans
Commercial
C&I	3			$	4,930
CRE	1			363
Construction	—			—
Total originated commercial	4			5,293
Consumer
Installment	11			40
Home equity lines	1			29
Credit card	28			140
Residential mortgages	3			183
Total originated consumer	43			$	392
Covered loans
Commercial
C&I	1			$	427
CRE	—			—
Construction	—			—
Total covered commercial	1			$	427
Acquired loans
Consumer
Installment	2			$	165
Home equity lines	1			61
Residential mortgages	—			—
Total acquired consumer	3			$	226
Total loans
Commercial
C&I	4			$	5,357
CRE	1			363
Construction	—			—
Total commercial	5			5,720
Consumer
Installment	13			205
Home equity lines	2			90
Credit card	28			140
Residential mortgages	3			183
Total consumer	46			618
Total	51			$	6,338
	As of December 31, 2013
(Dollars in thousands)	Number of Loans			Amount Defaulted
Originated loans
Commercial
C&I	4			$	1,773
CRE	6			3,101
Construction	1			231
Total originated commercial	11			5,105
Consumer
Installment	17			170
Home equity lines	—			—
Credit card	33			245
Residential mortgages	1			75
Total originated consumer	51			$	490
Covered loans
Commercial
C&I	—			$	—
CRE	1			—
Construction	1			45
Total covered commercial	2			$	45
Total loans
Commercial
C&I	4			$	1,773
CRE	7			3,101
Construction	2			276
Total commercial	13			5,150
Consumer
Installment	17			170
Home equity lines	—			—
Credit card	33			245
Residential mortgages	1			75
Total consumer	51			490
Total	64			$	5,640

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets
	Goodwill
	Goodwill totaled $741.7 million as of December 31, 2014 and 2013. The following table shows goodwill allocated by business segment.
	(In thousands)	Commercial		Retail			Wealth		Total
	Balance at December 31, 2013	$	527,406	$	193,961		$	20,373	$	741,740
	Balance at December 31, 2014	$	527,406	$	193,961		$	20,373	$	741,740
	The Corporation performed its annual impairment test of goodwill as of November 30, 2014 and determined that no impairment of goodwill had been incurred. Key changes in the market and our operations were monitored from our impairment test date of November 30th to year end in order to identify circumstances necessitating further testing of impairment. No such changes were noted for 2014. It is possible that a future conclusion could be reached that all or a portion of the Corporation’s goodwill may be impaired, in which case a noncash charge for the amount of such impairment would be recorded in earnings.
	Other Intangible Assets
	The following tables show the gross carrying amount and the amount of accumulated amortization of intangible assets subject to amortization.
		December 31, 2014
		Gross Carrying		Accumulated			Net Carrying
	(In thousands)	Amount		Amortization			Amount
	Core deposit intangibles (1)	$	82,323	$	(19,996	)	$	62,327
	Lease intangible	238		(176		)	62
	Trust relationships (2)	14,000		(5,369		)	8,631
	Total intangibles	$	96,561	$	(25,541	)	$	71,020
		December 31, 2013
		Gross Carrying		Accumulated			Net Carrying
	(In thousands)	Amount		Amortization			Amount
	Core deposit intangibles (1)	$	87,533	$	(16,065	)	$	71,468
	Noncompete covenant	102		(102		)	—
	Lease intangible	238		(140		)	98
	Trust relationships (2)	14,000		(2,811		)	11,189
	Total intangibles	$	101,873	$	(19,118	)	$	82,755
	(1) Core deposit intangibles are amortized on an accelerated basis over their estimated useful lives, which range from 10-15 years.
	(2) Trust relationship intangibles are amortized on an accelerated basis on their estimated useful lives of 12 years.
	Amortization expense for intangible assets was $11.7 million in 2014, $8.4 million in 2013, and $1.9 million in 2012.
	The following table shows the estimated future amortization expense for intangible assets subject to amortization as of December 31, 2014.
	(In thousands)
	For the years ended:
	December 31, 2015	$	10,391
	December 31, 2016	9,209
	December 31, 2017	8,161
	December 31, 2018	7,273
	December 31, 2019	6,500
	Total estimated future amortization	$	41,534

Mortgage_Servicing_Rights_and_

Mortgage Servicing Rights and Mortgage Servicing Activity	12 Months Ended
	Dec. 31, 2014
Transfers and Servicing [Abstract]
Mortgage Servicing Rights and Mortgage Servicing Activity	Mortgage Servicing Rights and Mortgage Servicing Activity
	In the years ended December 31, 2014 and 2013, the Corporation sold residential mortgage loans from the held for sale portfolio with unpaid principal balances of $356.5 million and $562.3 million, respectively, and recognized pretax gains of $7.2 million and $12.1 million, respectively, which are included as a component of loan sales and servicing income. As of December 31, 2014 and 2013, the Corporation retained the related MSRs, for which it receives servicing fees, on $314.4 million and $514.6 million, respectively, of the loans sold.
	The Corporation serviced for third parties approximately $2.6 billion of residential mortgage loans at December 31, 2014, and $2.7 billion at December 31, 2013. Loan servicing fees, not including valuation changes on MSRs included in loan sales and servicing income, were $6.6 million, $6.4 million, and $5.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Servicing rights are presented within other assets on the accompanying Consolidated Balance Sheet. The retained servicing rights are initially valued at fair value. Since MSRs do not trade in an active market with readily observable prices, the Corporation relies primarily on a discounted cash flow analysis model to estimate the fair value of its mortgage servicing rights. Additional information can be found in Note 18 (Fair Value Measurement). MSRs are subsequently measured using the amortization method. Accordingly, the MSRs are amortized over the period of, and in proportion to, the estimated net servicing income and the related amortization is recorded in loan sales and servicing income.
	Changes in the carrying amount of MSRs and the MSR valuation allowance are as follows:
		Year Ended December 31,
	(In thousands)	2014			2013			2012
	Balance at beginning of period	$	22,760		$	21,316		$	21,179
	Addition of Citizens’ MSRs on Acquisition Date	—			1,065			—
	Additions	3,049			4,952			5,876
	Amortization	(3,798		)	(4,573		)	(5,739		)
	Balance at end of period	22,011			22,760			21,316
	Valuation allowance at beginning of period	(282		)	(2,564		)	(3,539		)
	Recoveries (Additions)	(673		)	2,282			975
	Valuation Allowance at end of period	(955		)	(282		)	(2,564		)
	MSRs, net carrying balance	$	21,056		$	22,478		$	18,752
	Fair value at end of period	$	21,228		$	23,041		$	18,833
	On a quarterly basis, the Corporation assesses its capitalized servicing rights for impairment based on their current fair value. For purposes of the impairment, the servicing rights are disaggregated based on loan type and interest rate which are the predominant risk characteristics of the underlying loans. A valuation allowance is established through a charge to earnings to the extent the amortized cost of the MSRs exceeds the estimated fair value by stratification. If it is later determined that all or a portion of the temporary impairment no longer exists for the stratification, the valuation is reduced through a recovery to earnings. No permanent impairment losses were written off against the allowance during the years ended December 31, 2014, 2013, and 2012.
	Key economic assumptions and the sensitivity of the current fair value of the MSRS related to immediate 10% and 25% adverse changes in those assumptions at December 31, 2014, are presented in the following table below. These sensitivities are hypothetical and should be used with caution. As the figures indicate, changes in the fair value based on 10% variation in the prepayment speed assumption generally cannot be extrapolated because the relationship of the change in the prepayment speed assumption to the change in fair value may not be linear. Also, in the below table, the effect of a variation in the discount rate assumption on the fair value of the MSRs is calculated independently without changing any other assumption. In reality, changes in one factor may result in changes in another (for example, changes in prepayment speed estimates could result in changes in the discount rates), which might magnify or counteract the sensitivities.
	(Dollars in thousands)
	Prepayment speed assumption (annual CPR)	11.79		%
	Decrease in fair value from 10% adverse change	$	767
	Decrease in fair value from 25% adverse change	$	1,837
	Discount rate assumption	9.89		%
	Decrease in fair value from 100 basis point adverse change	$	660
	Decrease in fair value from 200 basis point adverse change	$	1,277
	Expected weighted-average life (in months)	96.9
	The following table shows the estimated future amortization for net MSRs as of December 31, 2014:
	(In thousands)
	Year Ended December 31,
	2015	$	3,562
	2016	3,128
	2017	2,610
	2018	2,189
	2019	1,836
	more than 5 years	7,731
	Total estimated future amortization	$	21,056

Restrictions_on_Cash_and_Divid

Restrictions on Cash and Dividends	12 Months Ended
	Dec. 31, 2014
Restrictions on Cash and Dividends [Abstract]
Restrictions on Cash and Dividends	Restrictions on Cash and Dividends
	The average balance on deposit with the FRB or other governing bodies to satisfy reserve requirements amounted to $5.9 million and $41.8 million during 2014 and 2013, respectively. The level of this balance is based upon amounts and types of customers’ deposits held by the banking subsidiary of the Corporation. In addition, deposits are maintained with other banks at levels determined by Management based upon the volumes of activity and prevailing interest rates to compensate for check-clearing, safekeeping, collection and other bank services performed by these banks. At December 31, 2014, cash and due from banks included $0.1 million deposited with the FRB and other banks for these reasons.
	Dividends paid by the subsidiaries are the principal source of funds to enable the payment of dividends by the Corporation to its shareholders. These payments by the subsidiaries in 2014 were restricted, by the regulatory agencies, principally to the total of 2014 net income plus undistributed net income of the previous two calendar years. Regulatory approval must be obtained for the payment of dividends of any greater amount.

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment
	The components of premises and equipment are as follows:
		As of December 31,				Estimated
	(In thousands)	2014		2013		useful lives
	Land	$	60,397	$	64,810	-
	Buildings	308,144		310,345		10-35 yrs
	Equipment	176,906		156,521		3-15 yrs
	Leasehold improvements	25,151		23,872		1-20 yrs
	Software	103,782		83,989		3-7 yrs
		674,380		639,537
	Less accumulated depreciation and amortization	342,083		312,483
	Total premises and equipment	$	332,297	$	327,054
	Amounts included in noninterest expense in the accompanying Consolidated Statement of Income for depreciation and amortization aggregated $37.6 million, $32.2 million, and $23.1 million for the years ended 2014, 2013, and 2012, respectively.

Certificates_and_Other_Time_De

Certificates and Other Time Deposits	12 Months Ended
	Dec. 31, 2014
Time Deposits [Abstract]
Certificates and Other Time Deposits	Certificates and Other Time Deposits
	The aggregate amounts of certificates and other time deposits of $100 thousand and over at December 31, 2014, 2013, and 2012, were $716.5 million, $882.4 million, and $489.9 million respectively. Interest expense on these certificates and time deposits amounted to $3.8 million, $4.5 million, and $3.8 million in 2014, 2013, and 2012, respectively.
	Maturities of certificates and other time deposits as of December 31, 2014 are as follows:
	(In thousands)
	For the year ended December 31,
	2015	$	1,627,788
	2016	341,135
	2017	101,325
	2018	109,896
	2019	105,632
	2020 and after	3,727
	Total certificates and other time deposits	$	2,289,503

Federal_Funds_Purchased_and_Se

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	12 Months Ended
	Dec. 31, 2014
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal Funds Purchased And Securities Sold Under Agreements to Repurchase	Federal Funds Purchased and Securities Sold under Agreements to Repurchase
	The following table presents federal funds purchased and securities sold under agreements to repurchase as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	Federal funds purchased and securities sold under agreements to repurchase		$	1,272,591		$	851,535
	Securities sold under agreements to repurchase are secured by securities with a carrying value of $888.4 million and $1.0 billion at December 31, 2014 and 2013, respectively. Securities sold under agreements to repurchase have an overnight maturity at December 31, 2014.
	Selected financial statement information pertaining to the securities sold under agreements to repurchase is as follows:
		As of December 31,
	(Dollars in thousands)	2014			2013			2012
	Average balance during the year	$	1,084,532		$	949,068		$	949,756
	Weighted-average annual interest rate during the year	0.09		%	0.13		%	0.12		%
	Maximum month-end balance	$	1,289,460		$	1,123,795		$	1,104,525

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	Income tax expense is comprised of the following:
		Year Ended December 31,
	(In thousands)	2014				2013				2012
	Taxes currently payable
	Federal	$	52,514			$	24,426			$	48,359
	State	4,763				3,496				2,655
	Deferred expense (benefit)	44,666				51,585				4,679
	Total income tax expense	$	101,943			$	79,507			$	55,693
	The actual income tax rate differs from the statutory tax rate as shown in the following table:
			Year Ended December 31,
			2014			2013			2012
	Statutory rate		35	%		35	%		35	%
	Increase (decrease) in rate due to:
		Interest on tax-exempt securities and tax-free loans, net	(2.77	)		(3.16	)		(3.23	)
		Merger expenses at acquisition	—			0.54			—
		Reduction in excess tax reserves	—			0.11			—
		Bank owned life insurance	(2.10	)		(2.53	)		(3.10	)
		State income tax (net)	0.91			0.87			0.94
		Tax credits	(0.96	)		(1.06	)		(1.14	)
		ESOP Dividends	(0.13	)		(0.14	)		(0.21	)
		Nondeductible meals and entertainment	0.22			0.27			0.25
		Other	(0.18	)		0.31			0.83
	Effective tax rates		29.99	%		30.21	%		29.34	%
	Income tax expense as reflected in the previous table excludes net worth-based taxes, which are assessed on financial institutions in lieu of income tax in Ohio, Pennsylvania and Michigan. These taxes are $8.2 million, $9.9 million, and $7.8 million in 2014, 2013, and 2012, respectively, and are recorded in other operating expense in the accompanying Consolidated Statement of Income.
	Principal components of the Corporation’s net deferred tax asset are summarized as follows:
			Year Ended
			December 31,
	(In thousands)		2014				2013
	Deferred tax assets:
		Allowance for credit losses	$	35,760			$	37,857
		Employee benefits	51,584				33,676
		Real Estate Mortgage Investment Credit	4,831				5,645
		Acquired liabilities	6,296				14,768
		Acquired loans	51,701				62,993
		Available for sale securities	3,862				16,819
		Loan fees and expenses	—				2,777
		Federal NOL carryforwards	131,195				190,350
		Alternative minimum tax credit carryforward	83,428				41,882
		General business tax credit carryforward	1,982				5,715
		State income tax (net of federal benefit)	1,970				4,728
		Other	467				—
		Total deferred tax assets	373,076				417,210
	Deferred tax liabilities:
		Leased assets and depreciation	(24,699		)		(25,818		)
		FHLB stock	(18,165		)		(24,401		)
		Loan fees and expenses	(2,537		)		—
		Goodwill	(16,580		)		(7,129		)
		Core deposit intangibles	(22,013		)		(25,302		)
		Other	—				(3,510		)
		Total deferred tax liabilities	(83,994		)		(86,160		)
	Total net deferred tax asset		$	289,082			$	331,050
	At December 31, 2014 and 2013, there was no valuation allowance for deferred tax assets.
	At December 31, 2014, the Corporation had gross federal loss carryforwards of $374.8 million that expire in 2028 through 2032, general business credits of $2.0 million that expire in 2028, and $83.4 million of federal alternative minimum tax credits with an indefinite life. In addition, future state income taxes are expected to be reduced by $2.3 million resulting from state non-operating losses at various levels in various states. This benefit is expected to be fully used during the expiration period of 2014 through 2027.
	The period change in deferred taxes recorded both directly to shareholders’ equity and as a part of the income tax expense is summarized as follows:
			Year Ended December 31,
	(In thousands)		2014				2013
	Deferred tax changes reflected in other comprehensive income		$	(2,698	)		$	(27,285	)
	Deferred tax changes reflected in Federal income tax expense		44,666				51,585
	Deferred tax changes reflected in acquired net assets		—				(348,239		)
		Net decrease/(increase) in DTA	$	41,968			$	(323,939	)
	Income tax benefits are recognized in the financial statements for a tax position only if it is considered “more likely than not” of being sustained on audit based solely on the technical merits of the income tax position. If the recognition criteria are met, the amount of income tax benefits to be recognized is measured based on the largest income tax benefit that is more than 50 percent likely to be realized on ultimate resolution of the tax position.
	A reconciliation of the change in the reserve for uncertain tax positions for 2014 and 2013 is as follows:
	(In thousands)	Federal and				Accrued				Gross Unrecognized Income Tax Benefits
State Tax			Interest and
			Penalties
Balance as of January 1, 2014	$	1,003			$	262			$	1,265
Additions for tax provisions related to prior year	798				14				812
Reduction for tax positions related to prior year due closed tax years	(31		)		(3		)		(34		)
Reduction for tax positions related to prior tax years	(1,465		)		(254		)		(1,719		)
Balance at December 31, 2014	$	305			$	19			$	324
Components of Reserve:
State income tax exposure	$	305			$	19			$	324
Balance at December 31, 2014	$	305			$	19			$	324
(In thousands)	Federal and				Accrued				Gross Unrecognized Income Tax Benefits
	State Tax				Interest and
					Penalties
Balance as of January 1, 2013	$	953			$	854			$	1,807
Additions for tax provisions related to prior year	77				72				149
Reduction for tax positions related to prior tax years	(27		)		(664		)		(691		)
Balance at December 31, 2013	$	1,003			$	262			$	1,265
Components of Reserve:
Potential adjustment to nondeductible interest expense	$	30			$	5			$	35
State income tax exposure	973				257				1,230
Balance at December 31, 2013	$	1,003			$	262			$	1,265
The Corporation recognized accrued interest and penalties, as appropriate, related to UTBs, in the effective tax rate. The balance of accrued interest and penalties at the reporting periods is presented in the table above. The reserve of uncertain tax positions is recorded in accrued taxes, expenses and other liabilities on the Consolidated Balance Sheet.
The Corporation is routinely examined by various taxing authorities. With few exceptions, the Corporation is no longer subject to federal, state and local tax examinations by tax authorities for years before 2011. The expiration of statutes of limitation for various jurisdictions is expected to reduce the UTB balance by approximately $0.05 million within the next twelve months. Management anticipates that the UTB balance will increase by $0.2 million as a result of the 2014 tax filings in the next twelve months. If the total amount of UTBs were recognized the effective tax rate would decrease by 9 basis points to 29.90% at December 31, 2014.
Management monitors changes in tax statutes and regulations and the issuance of judicial decisions to determine the potential impact to uncertain income tax positions. As of December 31, 2014, Management had identified no other potential U.S. Treasury regulations or legislative initiatives that could have a significant impact on the UTB balance within the next twelve months.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	Benefit Plans
	Pension plans. The Corporation had a noncontributory qualified defined benefit pension plan that covered all eligible legacy FirstMerit employees vested in the pension plan as of December 31, 2006 (“FirstMerit Pension Plan”). The FirstMerit Pension Plan was frozen for nonvested employees and closed to new entrants after December 31, 2006. Effective December 31, 2012, the FirstMerit Pension Plan was frozen for vested employees resulting in no benefits accruing after December 31, 2012. Employees will have an accrued benefit which will be paid upon retirement.
	Certain former Citizens’ employees were covered by a cash balance defined benefit pension plan after the Acquisition Date through December 31, 2013 (“Citizens Pension Plan”). Effective December 31, 2006, the Citizens Pension Plan was frozen, preserving prior earned benefits but discontinuing the accrual of future benefits.
	As of December 31, 2013, the Corporation adopted one noncontributory qualified defined pension plan covering all eligible FirstMerit and former Citizens employees, with the FirstMerit Pension Plan being the surviving plan. The Citizens Pension Plan ceased to exist after December 31, 2013. The plan assets of the FirstMerit Pension Plan and the Citizens Pension Plan were combined and invested in a single trust as of December 31, 2013. Benefits remain frozen in the combined plan with the unique benefit structure under each of the FirstMerit and Citizens Pension Plans retained in the combined plan.
	A supplemental nonqualified, nonfunded pension plan for certain officers is also maintained and is being provided for by charges to earnings sufficient to meet the projected benefit obligation. The pension cost for this plan is based on substantially the same actuarial methods and economic assumptions as those used for the FirstMerit Pension Plan. On December 18, 2013, the FirstMerit Corporation Amended and Restated Supplemental Executive Retirement Plan was amended to freeze the benefit payable to the Corporation’s Chairman, President and Chief Executive Officer (“CEO”) at the level of the benefit accrued by the CEO under the plan as of November 30, 2013. Subsequent increases or decreases in the CEO’s compensation nor any changes in circumstances will cause any increase or decrease in the amount payable to the CEO under this plan.
	Postretirement medical and life insurance plan. The Corporation also sponsors a benefit plan that provided postretirement medical and life insurance for retired employees (“FirstMerit Postretirement Plan”). The Corporation’s medical contribution was limited to 200% of the 1993 level for employees who retire after January 1, 1993.
	Effective March 1, 2009, the Corporation discontinued the subsidy for retiree medical for current eligible active employees. Eligible employees who retired on or prior to March 1, 2009, were offered subsidized retiree medical coverage until age 65. Employees who retired after March 1, 2009, do not receive a Corporation subsidy toward retiree medical coverage.
	Effective January 1, 2012, the FirstMerit Postretirement Plan was amended to cap the Corporation’s subsidy on retiree medical costs. Any cost incurred over the cap will be the responsibility of the retiree.
	Postretirement medical and life insurance plans were also maintained for certain former Citizens employees after the Acquisition Date through December 31, 2013, (“Citizens Postretirement Plan”). Citizens’ Postretirement Plan provided postretirement health and dental care to full-time employees who retired with eligibility for coverage based on historical plan terms.
	As of December 31, 2013, the Corporation adopted one postretirement plan covering all eligible FirstMerit and former Citizens employees, with the FirstMerit Postretirement Plan being the surviving plan. The Citizens Postretirement Plan ceased to exist after December 31, 2013, and future benefits to the existing participants of the Citizens Postretirement Plan Plan will be provided under the FirstMerit Postretirement Plan. The Corporation reserves the right to terminate or amend the FirstMerit Postretirement Plan at any time.
	Other employee benefits. FirstMerit’s Amended and Restated Executive Deferred Compensation Plan (“FirstMerit Deferred Compensation Plan”) allows participating executives to elect to receive incentive compensation payable with respect to any year in whole Common Stock or cash, or to elect to defer receipt of any incentive compensation otherwise payable with respect to any year in increments of 1%. An account is maintained in the name of each participant and is credited with cash or Common Stock equal to the number of shares that could have been purchased with the amount of any compensation so deferred, at the closing price of the Common Stock on the day as of which the share account is so credited. The deferred compensation liability at December 31, 2014, and 2013, was $19.0 million and $19.2 million, respectively, and is included in accrued taxes, expenses and other liabilities on the accompanying Consolidated Balance Sheet.
	Savings plans. The Corporation maintains a retirement savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended, covering substantially all full-time and part-time employees beginning in the quarter following three months of continuous employment (“FirstMerit 401(k) Plan”). For the years ended December 31, 2014 and 2013, the employer’s matching contribution to the FirstMerit 401(k) Plan was 100% on the first 3% and then 50% on the next 2% of the employee’s qualifying salary. For the year ended December 31, 2012, the employer’s matching contribution was $0.50 of each $1.00 up to 1% of employee’s qualifying salary. Contributions made by the Corporation to the FirstMerit 401(k) Plan were $7.7 million for 2014, $4.4 million in 2013, and $0.6 million in 2012. Matching contributions vest in accordance with plan specifications.
	From the Acquisition Date through the close of business December 31, 2013, eligible Citizens employees who were employed by the Corporation continued to be covered by an employee savings plan under Section 401(k) ("Citizens 401(k) Plan"). Contributions to the Citizens 401(k) Plan were matched 50% on the first 2% of salary deferred and 25% on the next 6% deferred. The Corporation contributed $1.1 million to the Citizens 401(k) Plan from Acquisition Date through December 31, 2013. The Citizens 401(k) Plan was merged with the FirstMerit 401(k) Plan as of close of business December 31, 2013. The plan terms of the merged plans are substantially the same as the FirstMerit 401(k) Plan.
	The Corporation maintained a qualified defined contribution plan known as Retirement Investment Plan through December 31, 2012. Effective with the termination of this plan as of January 1, 2013, the Corporation will provide, for a five-year period, a transition contribution equal to 3% of an employee’s qualifying salary to all eligible plan participants that have earned 60 age-plus-service points, as of December 31, 2012. This transition contribution totaled $0.7 million and $1.1 million for the years ended December 31, 2014 and December 31, 2013, respectively.
	The combined components of net periodic pension and postretirement benefits and other amounts recognized in AOCI for the Corporation's pension and postretirement benefit plans as of December 31, 2014, 2013 and 2012, are as follows:
		Pension Benefits											Postretirement Benefits
	(In thousands)	2014				2013				2012			2014			2013			2012
	Net periodic cost consists of:
	Service cost	$	728			$	2,339			$	7,194		$	65		$	99		$	77
	Interest cost	14,337				12,814				11,862			655			563			697
	Expected return on plan assets	(16,035		)		(14,938		)		(12,136		)	—			—			—
	Amortization of prior service cost/(credit)	2,599				467				388			(468		)	(468		)	(468		)
	Amortization of actuarial (gains)/losses	2,930				4,693				10,371			236			268			288
	Settlement / curtailment income	—				(524		)		(142		)	—			—			—
	Net periodic cost (benefit)	4,559				4,851				17,537			488			462			594
	Other changes in plan assets and benefit obligations recognized in Other comprehensive income:
	Current year actuarial losses/(gains)	49,488				(47,257		)		1,281			64			(682		)	(57		)
	Amortization of actuarial gains/(losses)	(2,930		)		(4,169		)		(10,229		)	(236		)	(268		)	(288		)
	Amortization of prior service (cost)/credit	(2,599		)		(467		)		(388		)	468			468			468
	Total recognized in AOCI, before income taxes	43,959				(51,893		)		(9,336		)	296			(482		)	123
	Total recognized in net periodic cost and AOCI	$	48,518			$	(47,042	)		$	8,201		$	784		$	(20	)	$	717
	A measurement date of December 31 is used for plan assets and benefit obligations. The following table sets forth a reconciliation of the changes in the projected benefit obligation for the Corporation’s pension and postretirement benefit plans as of December 31, 2014, and 2013, as well as the change in plan assets for the Corporation’s qualified pension plans:
		Pension Benefits								Postretirement Benefits
	(In thousands)	2014				2013				2014			2013
	Accumulated benefit obligation, end of year	$	354,402			$	307,739
	Change in projected benefit obligation:
	Projected benefit obligation, beginning of year	308,834				259,428				$	15,544		$	14,771
	Citizens acquisition	—				85,483				—			2,062
	Service cost	728				2,339				65			99
	Interest cost	14,337				12,814				655			563
	Plan amendments	—				3,927				(1,979		)	—
	Participant contributions	—				—				1,851			1,538
	Actuarial (gains)/losses and change in assumptions	50,115				(35,984		)		2,046			(682		)
	Benefits paid	(18,372		)		(19,172		)		(3,018		)	(2,808		)
	Projected benefit obligation, end of year	$	355,642			$	308,834			$	15,164		$	15,544
	Change in plan assets, at fair value:
	Fair value of plan assets, beginning of year	$	257,510			$	174,385			$	—		$	—
	Citizens acquisition	—				68,304				—			—
	Actual return on plan assets	16,663				30,298				—			—
	Participant contributions	—				—				1,851			1,538
	Employer contributions	1,554				3,695				1,167			1,270
	Benefits paid	(18,372		)		(19,172		)		(3,018		)	(2,808		)
	Fair value of plan assets, end of year	$	257,355			$	257,510			$	—		$	—
	Funded status (1)	(98,287		)		(51,324		)		(15,164		)	(15,544		)
	Amounts recognized in AOCI before income taxes:
	Prior service cost (credit)	$	2,587			$	5,121			$	(5,370	)	$	(3,858	)
	Net actuarial loss	99,715				53,061				5,138			3,329
	Amount recognized in AOCI	$	102,302			$	58,182			$	(232	)	$	(529	)
	(1) The Corporation recognizes the underfunded status of the plans in accrued taxes, expenses and other liabilities on the Consolidated Balance Sheet.
	As indicated in the table above, the benefit obligation and accumulated benefit obligation for all of the Corporation’s pension plans were in excess of the fair value of plan assets.
	Actuarial assumptions. The actuarial assumptions used to determine year end obligations for the Corporation’s pension and postretirement plans were as follows:
	Weighted-average assumptions for year end obligations	2014			2013			2012
	Discount rate
	Qualified pensions	4.19	%		4.99	%		4.21	%
Nonqualified pensions	3.61	%		4.12	%		4.21	%
Postretirement medical benefits, FirstMerit’s plan	3.5	%		4.01	%		3.18	%
Postretirement medical benefits, Citizens’ plan	3.61	%		3.98	%		na
Postretirement life insurance benefits	4.36	%		5.08	%		4.3	%
Expected long-term rate of return	6.5	%		6.75	%		7	%
Rate of compensation increase
Qualified pensions	na			na			na
Nonqualified pensions	3.75	%		3.75	%		3.75	%
Assumed health care cost trend rate, pre-65 (1)
Initial trend	7	%		7.5	%		8	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2019			2019			2019
Assumed health care cost trend rate, post-65 (1)
Initial trend	11	%		11.5	%		12	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2027			2027			2027
Prescription Drugs
Initial trend	7	%		7.5	%		8	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2019			2019			2019
(1) The health care cost trend assumptions relate only to the postretirement benefit plans. Increasing or decreasing the assumed health care cost trend rates by one percentage point each future year would not have a material impact on total service and interest cost or the year end benefit obligation.
The actuarial assumptions used as of the beginning of the year to determine the net periodic costs for the Corporation’s pension and postretirement plans were as follows:
Weighted-average assumptions for benefit cost at beginning of year	2014			2013			2012
Discount rate
Qualified pension	4.99	%		4.21	%		5.04	%
Nonqualified pensions	4.12	%		4.21	%		5.04	%
Postretirement medical benefits	4.01	%		3.18	%		4.23	%
Postretirement life insurance benefits	5.08	%		4.3	%		5.03	%
Expected long-term rate of return	6.75	%		7	%		7.25	%
Rate of compensation increase
Qualified pension	na			na			5.22	%
Nonqualified pensions	3.75	%		3.75	%		3.75	%
Assumed health care cost trend rate, pre-65 (1)
Initial trend	7.5	%		8	%		8.5	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2019			2019			2019
Assumed health care cost trend rate, post-65 (1)
Initial trend	11.5	%		12	%		12.5	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2027			2027			2027
Prescription Drugs
Initial trend	7.5	%		8	%		8.5	%
Ultimate trend	5	%		5	%		5	%
Year ultimate trend reached	2019			2019			2019
(1) The health care cost trend assumptions relate only to the postretirement benefit plans. Increasing or decreasing the assumed health care cost trend rates by one percentage point each future year would not have a material impact on total service and interest cost or the year end benefit obligation
The discount rates are determined independently for each plan and reflect the market rate for high-quality fixed income debt instruments, that are rated double-A or higher by a recognized ratings agency.
The rate of return on plan assets is a long-term assumption established by considering historic plan asset returns and anticipated returns of the asset classes invested in by the pension plan and the allocation strategy currently in place among those classes. The expected return on equities was computed using a valuation framework, which projected future returns based on current equity valuations rather than historical returns. Due to active management of the plan’s assets, the return on the plan equity investments historically has exceeded market averages. Management estimated the rate by which the plan assets would outperform the market in the future based on historical experience adjusted for changes in asset allocation and expectations for overall future returns on equities compared to past periods.
The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 introduced a prescription drug benefit under Medicare, and provides a federal subsidy to sponsors of retiree healthcare benefit plans that offer “actuarially equivalent” prescription drug coverage to retirees. For the years ended December 31, 2014, 2013, and 2012, these subsidies did not have a material effect on the APBO and net postretirement benefit cost for the Corporation.
Net unrecognized actuarial gains or losses and prior service costs are recognized as an adjustment to accumulated other comprehensive income, net of tax, in the period they arise and, subsequently, recognized as a component of net periodic benefit cost over the average remaining service period of the active employees. The amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost (credit) during the next fiscal year are as follows:
(In thousands)	Pension				Postretirement				Total
Prior service cost/(credit)	$	2,279			$	(639	)		$	1,640
Actuarial net loss	4,224				325				4,549
At December 31, 2014, the FirstMerit Pension Plan was sufficiently funded under the requirements of ERISA, consequently, the Corporation was not required to make a minimum contribution to that plan in 2014. The Corporation also does not expect to make any significant discretionary contributions during 2015.
At December 31, 2014, the following table shows when benefit payments were expected to be paid. The expected benefits were estimated using the same assumptions as those used to calculate the benefit obligations in the preceding tables and includes benefits attributable to estimated future employee service.
(In thousands)	Pension				Postretirement
2015	$	26,555			$	1,247
2016	26,420				1,137
2017	22,162				1,063
2018	21,858				1,004
2019	20,239				951
2020 through 2024	93,104				4,331
FirstMerit Pension Plan Investment Policy and Strategy. The FirstMerit Pension Plan invests in equities and other return-seeking assets such as real assets, as well as liability-hedging assets, primarily fixed income.  The Investment Policy recognizes that the plan’s asset return requirements and risk tolerances will change over time.  The Corporation utilizes a dynamic investment policy, whereby the allocation to return-seeking assets and liability-hedging assets is determined by comparing plan assets to the plan liabilities. As the plan’s funded ratio status improves, the allocation to liability-hedging assets will increase.
Dynamic Investment Policy Schedule
Return-Seeking (and Diversification) Allocation Strategy
Funded Ratio	Minimum	Target	Maximum
≤97%	36%	40%	44%
98%	34%	38%	42%
99%	31%	35%	39%
100%	30%	33%	36%
101%	28%	31%	34%
102%	26%	29%	32%
103%	23%	26%	29%
104%	21%	24%	27%
105%	18%	21%	24%
106%	16%	18%	20%
107%	12%	14%	16%
≥108%	8%	10%	12%
The weighted-average allocations for the FirstMerit Pension Plan as of December 31, 2014 and 2013, by asset category, are as follows:
		Percentage of
		Plan Assets on
		Measurement Date
		December 31,
Asset Category		2014			2013
Cash and domestic money market funds		1.49	%		1.92	%
U.S. Treasury obligations		1.97	%		1.76	%
U.S. Government agencies		1.12	%		0.95	%
Corporate bonds		2.79	%		3.12	%
Common stocks		13.54	%		11.24	%
Equity mutual funds		18.85	%		27.62	%
Fixed income mutual funds		50.11	%		36.56	%
Foreign mutual funds		10.13	%		16.83	%
		100	%		100	%
The following is a description of the valuation methodologies used to measure assets held by the FirstMerit Pension Plans at fair value.
•	Domestic and foreign money market funds: Valued at quoted prices as reported on the active market in which the money market funds are traded.
•	United States government securities, United States government agency issues and corporate bonds: Valued using independent evaluated prices which are based on observable inputs, such as available trade information, spreads, bids and offers, and United States Treasury curves.
•	Common stocks: Valued at the closing price reported on the active market in which the individual securities are traded.
•	Registered equity, fixed income and foreign mutual funds: Valued at quoted prices as reported on the active market in which the securities are traded.
The preceding methods described may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Corporation believes its valuation method is appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of financial instruments could result in a different fair value measurement at the reporting date.
The following table sets forth by level, within the fair value hierarchy, the FirstMerit Pension Plan’s assets at fair value as of December 31, 2014:
(In thousands)	Level 1				Level 2				Level 3			Total
Domestic money market funds	$	3,836			$	—			$	—		$	3,836
United States government securities	—				5,067				—			5,067
United States government agency issues	—				2,897				—			2,897
Corporate bonds	—				7,177				—			7,177
Common stocks	34,835				—				—			34,835
Equity mutual funds	48,518				—				—			48,518
Fixed income mutual funds	128,951				—				—			128,951
Foreign mutual funds	26,074				—				—			26,074
Total assets at fair value	$	242,214			$	15,141			$	—		$	257,355

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Share-Based Compensation	Share-Based Compensation
	The Corporation’s 2002, 2006 and 2011 Stock and Equity Plans, and the Citizens Republic Bancorp, Inc. Stock Compensation plan, and the Republic Bancorp, Inc 1998 Stock Option Plan that were assumed by the Corporation in connection with the Citizens acquisition (the “Plans”), provide stock options and restricted stock awards available to grant to employees for up to 5,769,655 shares of Common Stock of the Corporation. The Plans also provide for the granting of nonqualified stock options and nonvested (restricted) shares to certain nonemployee directors of the Corporation. Outstanding options under these Plans are generally not exercisable for twelve months from date of grant. The total share-based compensation expense recognized during the years ended December 31, 2014, 2013, and 2012, was $13.9 million, $10.9 million, and $9.3 million, respectively, and the related tax benefit was $4.9 million, $3.8 million, and $3.3 million, respectively. Share-based compensation expense related to awards granted to employees as well as awards granted to directors is recorded in salaries, wages, pension and employee benefits in the accompanying Consolidated Statements of Income.
	Certain of the Corporation’s share-based award grants contain terms that provide for a graded vesting schedule whereby portions of the award vest in increments over the requisite service period. The Corporation has elected to recognize compensation expense for awards with graded vesting schedule on a straight-line basis over the service period for the entire award. Compensation expense is recognized based on the estimated number of stock options and awards for which service is to be rendered. Upon stock option exercise or stock unit conversion, it is the policy of the Corporation to issue shares from treasury stock. No open market repurchases of Common Stock are planned in the upcoming calendar year. The Corporation has the authority to issue shares well in excess of the total number of stock option and restricted stock awards available for grant.
	In accordance with the Corporation’s stock option and nonvested (restricted) shares plans, employee participants that are 55 or older and have fifteen years of service are eligible to retire. Prior to the Plans’ amendments during 2007, which eliminated post retirement vesting, all unvested awards at the time of retirement continued to vest. The Corporation accelerates the recognition of compensation costs for share-based awards granted or modified to retirement-eligible employees and employees who become retirement-eligible. The compensation cost of these awards is recognized over the period up to the date the employee first becomes eligible to retire.
	Stock Option Awards
	Options under these Plans are granted with an exercise price equal to the market price of the Corporation’s shares at the date of grant; those option awards generally vest based on three years of continuous service and have a 10-year contractual term. Options granted as incentive stock options must be exercised within ten years and options granted as nonqualified stock options have terms established by the Compensation Committee of the Board and approved by the nonemployee directors of the Board. Upon termination, options are cancelable within defined periods based upon the reason for termination of employment.
	The Black-Scholes option pricing model was used to estimate the fair market value of the options at the date of grant. This model was originally developed for use in estimating the fair value of traded options which have different characteristics from the Corporation’s employee stock options. Because of these differences, the Black-Scholes model is not a perfect indicator of value of an employee stock option, but it is commonly used for this purpose.
	A summary of stock option activity under the Plans as of December 31, 2014, 2013, and 2012, and changes during the years then ended is as follows:
	Options	Shares (000’s)		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate InstrinsicValue (000’s)
	Outstanding at January 1, 2012	2,077		$	25.15	1.85	—
	Exercised	—		—
	Forfeited	(71	)	25.85
	Expired	(186	)	25.97
	Outstanding at December 31, 2012	1,820		$	24.73	1.82	$	—
	Acquired	63		218.01
	Exercised	—		—
	Forfeited	(8	)	23.93
	Expired	(479	)	36.64
	Outstanding at December 31, 2013	1,396		$	28.84	1.14	$	87
	Exercised	—		—
	Forfeited	—		—
	Expired	(558	)	31.91
	Outstanding at December 31, 2014	838		$	26.64	0.62	$	—
	Exercisable at December 31, 2014	838		$	26.64	0.62	$	—
	There were no options granted in the years ended December 31, 2014, 2013, and 2012. During the years ended December 31, 2014, 2013, and 2012, no options were exercised.
	At December 31, 2014, there was no unrecognized compensation costs related to stock options granted to be realized under the Plans.
	Nonvested (Restricted) Stock Awards
	The market price of the Corporation’s Common Stock at the date of grant is used to estimate the fair value of nonvested (restricted) stock awards. A summary of the status of the Corporation’s nonvested shares as of December 31, 2014, 2013, and 2012, and changes during the years then ended, is as follows:
				Weighted-Average
				Grant Date
	Nonvested (restricted) Stock Awards	Shares (000’s)		Fair Value
	Nonvested at January 1, 2012	1,026		$	18.26
	Granted	596		16.06
	Vested	(493	)	18.29
	Forfeited or expired	(50	)	18.94
	Nonvested at December 31, 2012	1,079		$	17
	Granted	823		16.47
	Vested	(508	)	17.9
	Forfeited or expired	(52	)	16.89
	Nonvested at December 31, 2013	1,342		$	16.34
	Granted	777		19.67
	Vested	(664	)	16.3
	Forfeited or expired	(42	)	18.16
	Nonvested at December 31, 2014	1,413		$	18.16
	At December 31, 2014, there was $14.6 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements granted under the Plans. That cost is expected to be recognized over a weighted-average period of 1.65 years. The total fair value of shares vested during the year ended December 31, 2014, 2013, and 2012, was $10.8 million, $9.1 million, and $9.0 million, respectively.

Parent_Company

Parent Company	12 Months Ended
	Dec. 31, 2014
Parent Company [Abstract]
Parent Company	Parent Company
	Condensed financial information of FirstMerit Corporation (Parent Company only) is as follows:
	(In thousands)			As of December 31,
	Condensed Balance Sheet			2014				2013
		Assets:
			Cash and due from banks	$	142,950			$	125,032
			Investment securities	1,553				2,253
			Investment in subsidiaries, at equity in underlying value of their net assets	2,936,865				2,863,473
			Other assets	20,479				77,674
			Total Assets	$	3,101,847			$	3,068,432
		Liabilities and Shareholders’ Equity:
			Long-term debt	$	249,935			$	324,428
			Accrued and other liabilities	17,631				41,110
			Shareholders’ equity	2,834,281				2,702,894
			Total Liabilities and Shareholders’ Equity	$	3,101,847			$	3,068,432
	(In thousands)			Year Ended December 31,
	Condensed Statement of Income			2014				2013				2012
		Income:
			Cash dividends from subsidiaries	$	82,642			$	81,715			$	155,493
			Noninterest income	437				483				309
			Total income	83,079				82,198				155,802
		Interest and other expenses		30,613				29,684				10,799
		Income before income tax benefit and equity in undistributed income of subsidiaries		52,466				52,514				145,003
		Income tax benefit		(10,324		)		(9,341		)		(2,004		)
			Income before equity in undistributed net income of subsidiaries	62,790				61,855				147,007
		Equity in undistributed income of subsidiaries		175,161				121,829				(12,901		)
		Net income		$	237,951			$	183,684			$	134,106
	(In thousands)				Year Ended December 31,
	Condensed Statement of Cash Flows				2014				2013				2012
	Operating activities:
			Net income		$	237,951			$	183,684			$	134,106
			Adjustments to reconcile net income to net cash provided by operating activities
			Equity in undistributed income of subsidiaries		(175,161		)		(121,829		)		12,901
			Decrease (increase) in Federal income tax receivable		35,672				(30,399		)		(4,446		)
			(Increase) decrease in deferred Federal tax asset		(1,449		)		27,032				106
			Increase in interest payable		—				4,618				—
			Other		(552		)		924				738
			Net cash provided by operating activities		96,461				64,030				143,405
	Investing activities:
			Loans or advances to subsidiaries		—				(50		)		—
			Repayment of loans to or investment in subsidiaries		110,675				—				—
			Cash paid for acquisition, net of cash received		—				(315,069		)		—
			Sale of investments in subsidiaries		—				—				7,827
			Sale of investment securities		784				—				—
			Purchases of investment securities		(81		)		(215		)		(44		)
			Net cash provided (used) by investing activities		111,378				(315,334		)		7,783
	Financing activities:
			Proceeds from issuance of subordinated debt		—				249,927				—
			Proceeds from issuance of preferred stock		—				96,550				—
			Repayment of long-term debt		(74,451		)		—				—
			Cash dividends-common stock		(105,333		)		(96,222		)		(69,459		)
			Cash dividends-preferred stock		(5,876		)		(5,337		)		—
			Purchase of treasury shares		(4,261		)		(9,521		)		(2,389		)
			Net cash (used) provided by financing activities		(189,921		)		235,397				(71,848		)
	Increase (decrease) in cash and cash equivalents				17,918				(15,907		)		79,340
	Cash and cash equivalents at beginning of year				125,032				140,939				61,599
	Cash and cash equivalents at end of year				$	142,950			$	125,032			$	140,939

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	Segment Information
	Management monitors the Corporation’s results by an internal performance measurement system, which provides lines of business results and key performance measures. The profitability measurement system is based on internal financial management practices designed to produce consistent results and reflect the underlying economics of the businesses. The development and application of these methodologies is a dynamic process. Accordingly, these measurement tools and assumptions may be revised periodically to reflect methodological, product, and/or management organizational changes. Further, these tools measure financial results that support the strategic objectives and internal organizational structure of the Corporation. Consequently, the information presented is not necessarily comparable with similar information for other financial institutions.
	A description of each business, selected financial performance, and the methodologies used to measure financial performance are presented below.
	•	Commercial – The commercial line of business provides a full range of lending, depository, and related financial services to middle-market corporate, industrial, financial, core business banking, public entities, and leasing clients. Commercial also includes personal business from commercial loan clients in coordination with the Wealth Management segment. Products and services offered include commercial term loans, revolving credit arrangements, asset-based lending, leasing, commercial mortgages, real estate construction lending, letters of credit, treasury management, government banking, international banking, merchant card and other depository products and services.
	•	Retail – The retail line of business includes consumer lending and deposit gathering, residential mortgage loan origination and servicing, and branch-based small business banking (formerly known as the “micro business” line). Retail offers a variety of retail financial products and services including consumer direct and indirect installment loans, debit and credit cards, debit gift cards, residential mortgage loans, home equity loans and lines of credit, deposit products, fixed and variable annuities and ATM network services. Deposit products include checking, savings, money market accounts and certificates of deposit.
	•	Wealth – The wealth line of business offers a broad array of asset management, private banking, financial planning, estate settlement and administration, credit and deposit products and services. Trust and investment services include personal trust and planning, investment management, estate settlement and administration services. Retirement plan services focus on investment management and fiduciary activities. Brokerage and insurance delivers retail mutual funds, other securities, variable and fixed annuities, personal disability and life insurance products and brokerage services. Private banking provides credit, deposit and asset management solutions for affluent clients.
	•	Other – The other line of business includes activities that are not directly attributable to one of the three principal lines of business. Included in the Other category are the parent company, eliminations companies, community development operations, the treasury group, which includes the securities portfolio, wholesale funding and asset liability management activities, and the economic impact of certain assets, capital and support functions not specifically identifiable with the three primary lines of business.
	The accounting policies of the lines of businesses are the same as those of the Corporation described in Note 1 (Summary of Significant Accounting Policies). Funds transfer pricing is used in the determination of net interest income by assigning a cost for funds used or credit for funds provided to assets and liabilities within each business unit. In the first quarter of 2014, Management changed the estimate regarding the funds transfer pricing crediting rate provided on non-maturity deposits, including amounts for 2013. The same crediting rate estimate for 2012 did not need to be changed. Assets and liabilities are match-funded based on their maturity, prepayment and/or repricing characteristics. As a result, the three primary lines of business are generally insulated from changes in interest rates. Changes in net interest income due to changes in rates are reported in Other by the treasury group. Capital has been allocated on an economic risk basis. Loans and lines of credit have been allocated capital based upon their respective credit risk. Asset management holdings in the Wealth segment have been allocated capital based upon their respective market risk related to assets under management. Normal business operating risk has been allocated to each line of business by the level of noninterest expense. Mismatch between asset and liability cash flow as well as interest rate risk for mortgage servicing rights and the origination business franchise value have been allocated capital based upon their respective asset/liability management risk. The provision for loan loss is allocated based upon the actual net charge-offs of each respective line of business, adjusted for loan growth and changes in risk profile. Noninterest income and expenses directly attributable to a line of business are assigned to that line of business. Expenses for centrally provided services are allocated to the business line by various activity based cost formulas.
	Substantially all of the Corporation’s business is conducted in the United States of America. The following tables present a summary of financial results as of and for the years ended December 31, 2014, 2013, and 2012:
	(In thousands)															FirstMerit
	December 31, 2014	Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)	$	421,136		$	378,597		$	19,836			$	(44,001	)		$	775,568
	Provision for loan losses	2,898			39,618			1,895				7,868				52,279
	Noninterest income	91,483			106,356			55,800				27,885				281,524
	Noninterest expense	240,142			354,305			51,269				19,203				664,919
	Net income/(loss)	175,227			59,169			14,606				(11,051		)		237,951
	AVERAGES:
	Assets	9,265,088			5,632,881			271,975				9,248,267				24,418,211
	Loans	9,262,224			5,305,513			261,321				62,257				14,891,315
	Earnings assets	9,549,341			5,328,548			261,321				6,363,537				21,502,747
	Deposits	6,679,007			11,484,769			1,089,068				275,591				19,528,435
	Economic capital	743,071			353,098			58,106				1,635,864				2,790,139
	(In thousands)																FirstMerit
	December 31, 2013		Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)		$	408,006		$	349,433		$	17,192			$	(63,846	)		$	710,785
	Provision for loan losses		17,072			16,151			(692		)		1,153				33,684
	Noninterest income		83,933			114,679			48,289				23,442				270,343
	Noninterest expense		209,936			330,875			54,196				89,246				684,253
	Net income/(loss)		172,206			76,105			7,784				(72,411		)		183,684
	AVERAGES:
	Assets		8,397,357			4,746,277			259,601				8,086,540				21,489,775
	Loans		8,292,805			4,367,701			226,152				62,008				12,948,666
	Earnings assets		8,480,005			4,392,937			226,179				5,393,874				18,492,995
	Deposits		5,572,287			10,749,725			826,794				152,782				17,301,588
	Economic capital		602,561			256,362			72,244				1,477,698				2,408,865
	(In thousands)																FirstMerit
	December 31, 2012		Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)		$	258,575		$	207,907		$	17,444			$	(12,096	)		$	471,830
	Provision for loan losses		32,319			10,008			(626		)		12,997				54,698
	Noninterest income		67,606			103,279			32,996				19,723				223,604
	Noninterest expense		159,525			221,297			39,296				30,819				450,937
	Net income/(loss)		87,318			51,922			7,650				(12,784		)		134,106
	AVERAGES:
	Assets		6,424,226			2,952,280			238,805				5,005,316				14,620,627
	Loans		6,391,189			2,674,997			225,018				65,876				9,357,080
	Earnings assets		6,493,713			2,707,632			225,044				3,646,302				13,072,691
	Deposits		3,284,722			7,416,982			709,786				142,308				11,553,798
	Economic capital		404,005			212,409			49,313				942,381				1,608,108

Fair_Value_Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurement	18.     Fair Value Measurement
	As defined in ASC 820, Fair Value Measurements and Disclosures, fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market or most advantageous market for the asset or liability. Fair value is based on quoted market prices, when available, for identical or similar assets or liabilities. In the absence of quoted market prices, Management determines the fair value of the Corporation’s assets and liabilities using valuation models or third-party pricing services. Both of these approaches rely on market-based parameters when available, such as interest rate yield curves, option volatilities and credit spreads, or unobservable inputs. Unobservable inputs may be based on Management’s judgment, assumptions and estimates related to credit quality, liquidity, interest rates and other relevant inputs.
	GAAP establishes a three-level valuation hierarchy for determining fair value that is based on the transparency of the inputs used in the valuation process. The inputs used in determining fair value in each of the three levels of the hierarchy, highest ranking to lowest, are as follows:
	•	Level 1 — Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date.
	•	Level 2 — Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.
	•	Level 3 — Significant unobservable inputs that reflect a company’s own assumptions about the assumptions that market participants would use in pricing an asset or liability.
	The level in the fair value hierarchy ascribed to a fair value measurement in its entirety is based on the lowest level input that is significant to the overall fair value measurement.
	Valuation adjustments, such as those pertaining to counterparty and the Corporation's own credit quality and liquidity, may be necessary to ensure that assets and liabilities are recorded at fair value.  Credit valuation adjustments are made when market pricing does not accurately reflect the counterparty's credit quality.  As determined by Management, liquidity valuation adjustments may be made to the fair value of certain assets to reflect the uncertainty in the pricing and trading of the instruments when Management is unable to observe recent market transactions for identical or similar instruments. Liquidity valuation adjustments are based on the following factors:
	•	the amount of time since the last relevant valuation;
	•	whether there is an actual trade or relevant external quote available at the measurement date; and
	•	volatility associated with the primary pricing components.
	Management ensures that fair value measurements are accurate and appropriate by relying upon various controls, including:
	•	an independent review and approval of valuation models;
	•	recurring detailed reviews of profit and loss; and
	•	a validation of valuation model components against benchmark data and similar products, where possible.
	Management reviews any changes to its valuation methodologies to ensure they are appropriate and justified, and refines valuation methodologies as more market-based data becomes available.  Transfers between levels of the fair value hierarchy are recognized at the end of the reporting period.
	Additional information regarding the Corporation's accounting policies for determining fair value is provided in Note 1 (Summary of Significant Accounting Policies) under the heading “Fair Value Measurements.”
	The following tables present the balance of assets and liabilities measured at fair value on a recurring and nonrecurring basis at December 31, 2014 and 2013:
					Fair Value by Hierarchy
	(In thousands)	31-Dec-14			Level 1			Level 2			Level 3
	Recurring fair value measurement
	Available-for-sale securities:
	Marketable equity securities	$	2,974		$	2,974		$	—		$	—
	U.S. government agency debentures	2,482			—			2,482			—
	U.S. States and political subdivisions	227,342			—			227,342			—
	Residential mortgage-backed securities:
	U.S. government agencies	970,998			—			970,998			—
	Commercial mortgage-backed securities:
	U.S. government agencies	103,403			—			103,403			—
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,676,567			—			1,676,567			—
	Nonagency	7			—			1			6
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	222,334			—			222,334			—
	Corporate debt securities	51,337			—			—			51,337
	Asset-backed securities:
	Collateralized loan obligations, nonagency issued	287,844			—			—			287,844
	Total available-for-sale securities	3,545,288			2,974			3,203,127			339,187
	Residential loans held for sale	13,428			—			13,428			—
	Derivative assets:
	Interest rate swaps - fair value hedges	5,256			—			5,256			—
	Interest rate swaps - nondesignated	48,366			—			48,366			—
	Mortgage loan commitments	1,408			—			1,408			—
	Foreign exchange	167			—			167			—
	Total derivative assets	55,197			—			55,197			—
	Total fair value of assets (1)	$	3,613,913		$	2,974		$	3,271,752		$	339,187
	Derivative liabilities:
	Interest rate swaps - fair value hedges	6,683			—			6,683			—
	Interest rate swaps - nondesignated	48,366			—			48,366			—
	Forward sales contracts	272			—			272			—
	Foreign exchange	118			—			118			—
	Total derivative liabilities	55,439			—			55,439			—
	True-up liability	13,294			—			—			13,294
	Total fair value of liabilities (1)	$	68,733		$	—		$	55,439		$	13,294
	Nonrecurring fair value measurement
	Mortgage servicing rights (2)	$	21,228		$	—		$	—		$	21,228
	Impaired loans (3)	56,041			—			—			56,041
	Other property (4)	12,510			—			—			12,510
	Other real estate covered by loss share (5)	3,614			—			—			3,614
	Total fair value	$	93,393		$	—		$	—		$	93,393
	(1) There were no transfers between levels 1, 2, or 3 of the fair value hierarchy during the year ended December 31, 2014.
	(2) MSRs with a recorded investment of $22.0 million were reduced by a specific valuation allowance totaling $1.0 million to a reported carrying value of $21.1 million resulting in a recovery of previously recognized expense of $0.7 million included in loans sales and servicing income in the year ended December 31, 2014.
	(3) Collateral dependent impaired loans with a recorded investment of $60.3 million were reduced by specific valuation allowance allocations totaling $4.3 million to a reported net carrying value of $56.0 million.
	(4) Amounts do not include assets held at cost at December 31, 2014. During the year ended December 31, 2014, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $2.6 million included in noninterest expense.
(5) Amounts do not include assets held at cost at December 31, 2014. During the year ended December 31, 2014, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.2 million included in noninterest expense.
				Fair Value by Hierarchy
(In thousands)	31-Dec-13			Level 1			Level 2			Level 3
Recurring fair value measurement
Available-for-sale securities:
Marketable equity securities	$	3,036		$	3,036		$	—		$	—
Nonmarketable equity securities	3,281			—			10			3,271
U.S. States and political subdivisions	262,367			—			262,367			—
Residential mortgage-backed securities:
U.S. government agencies	969,922			—			969,922			—
Commercial mortgage-backed securities:
U.S. government agencies	69,567			—			69,567			—
Residential collateralized mortgage-backed securities:
U.S. government agencies	1,518,393			—			1,518,393			—
Nonagency	9			—			—			9
Commercial collateralized mortgage-backed securities:
U.S. government agencies	102,268			—			102,268			—
Corporate debt securities	50,644			—			—			50,644
Asset-backed securities:
Collateralized loan obligations, nonagency issued	293,687			—			—			293,687
Total available-for-sale securities	3,273,174			3,036			2,922,527			347,611
Residential loans held for sale	11,622			—			11,622			—
Derivative assets:
Interest rate swaps - nondesignated	46,577			—			46,577			—
Mortgage loan commitments	891			—			891			—
Forward sale contracts	384			—			384			—
Foreign exchange	50			—			50			—
Total derivative assets	47,902			—			47,902			—
Total fair value of assets (1)	$	3,332,698		$	3,036		$	2,982,051		$	347,611
Derivative liabilities:
Interest rate swaps - fair value hedges	11,574			—			11,574			—
Interest rate swaps - nondesignated	46,577			—			46,577			—
Foreign exchange	50			—			50			—
Total derivative liabilities	58,201			—			58,201			—
True-up liability	11,463			—			—			11,463
Total fair value of liabilities (1)	$	69,664		$	—		$	58,201		$	11,463
Nonrecurring fair value measurement
Mortgage servicing rights (2)	$	23,041		$	—		$	—		$	23,041
Impaired loans (3)	47,870			—			—			47,870
Other property (4)	10,018			—			—			10,018
Other real estate covered by loss share (5)	8,754			—			—			8,754
Total fair value	$	89,683		$	—		$	—		$	89,683
(1) There were no transfers between levels 1, 2, or 3 of the fair value hierarchy during the year ended December 31, 2013.
(2) MSRs with a recorded investment of $22.8 million were reduced by a specific valuation allowance totaling $0.3 million to a reported carrying value of $22.5 million resulting in the recovery of previously recognized expense of $2.3 million included in loan sales and servicing income in the year ended December 31, 2013.
(3) Collateral dependent impaired loans with a recorded investment of $52.6 million were reduced by specific valuation allowance allocations totaling $4.8 million to a reported net carrying value of $47.9 million.
(4) Amounts do not include assets held at cost at December 31, 2013. During the year ended December 31, 2013, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.4 million included in noninterest expense.
(5) Amounts do not include assets held at cost at December 31, 2013. During the year ended December 31, 2013, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.0 million included in noninterest expense.
The following section describes the valuation methodologies used by the Corporation to measure financial assets and liabilities at fair value. During years ended December 31, 2014 and 2013, there were no significant changes to the valuation techniques used by the Corporation to measure fair value.
Available-for-sale securities. When quoted prices are available in an active market, securities are valued using the quoted price and are classified as Level 1. The quoted prices are not adjusted. Level 1 instruments include money market mutual funds.
Securities are classified as Level 2 if quoted prices for identical securities are not available, and fair value is determined using pricing models by a third-party pricing service.   Approximately 90% of the available-for-sale portfolio is Level 2. For the majority of available-for sale securities, the Corporation obtains fair value measurements from an independent third party pricing service. These instruments include: municipal bonds; bonds backed by the U.S. government; corporate bonds; MBS; securities issued by the U.S. Treasury; and certain agency and corporate CMO.  The independent pricing service uses industry-standard models to price U.S. Government agencies and MBS that consider various assumptions, including time value, yield curves, volatility factors, prepayment speeds, default rates, loss severity, current market and contractual prices for the underlying financial instruments, as well as other relevant economic measures. Obligations of state and political subdivisions are valued using a matrix, or grid, pricing in which securities are benchmarked against the treasury rate based on credit rating. For collateralized mortgage securities, depending on the characteristics of a given tranche, a volatility driven multidimensional static model or Option-Adjusted Spread model is generally used. Substantially all assumptions used by the independent pricing service for securities classified as Level 2 are observable in the marketplace, can be derived from observable data, or are supported by observable levels at which transactions are executed in the marketplace.
Securities are classified as Level 3 when there is limited activity in the market for a particular instrument and fair value is determined by obtaining broker quotes. As of December 31, 2014, approximately 10% of the available-for-sale portfolio is Level 3, which consists of single issuer trust preferred securities and CLOs.
The single issuer trust preferred securities are measured at unadjusted prices obtained from the independent pricing service. The independent pricing service prices these instruments through a broker quote when sufficient information, such as cash flows or other security structure or market information, is not available to produce an evaluation. Broker-quoted securities are adjusted by the independent pricing service based solely on the receipt of updated quotes from market makers or broker-dealers recognized as market participants. A list of such issues is compiled by the independent pricing service daily. For broker-quoted issues, the independent pricing service applies a zero spread relationship to the bid-side valuation, resulting in the same values for the mean and ask.
CLOs are securitized products where payments from multiple middle sized and large business loans are pooled together and segregated into different classes of bonds with payments on these bonds based on their priority within the overall deal structure. The markets for such securities are generally characterized by low trading volumes and wide bid-ask spreads, all driven by limited market participants. Although estimated prices are generally obtained for such securities, the level of market observable assumptions used is limited in the valuation. Specifically, market assumptions regarding credit adjusted cash flows and liquidity influences on discount rates were difficult to observe at the individual bond level. Accordingly, the securities are currently valued by a third party that primarily utilizes dealer or pricing service prices and, subsequently, verifies this pricing through a disciplined process to ensure proper valuations and to highlight differences in cash flow modeling or other risks to determine if the market perception of the risk of a CLO is beginning to deviate from other similar tranches.  This is done by establishing ranges for appropriate pricing yields for each CLO tranche and, using a standardized cash flow scenario, ensuring yields are consistent with expectations.
On a monthly basis, Management validates the pricing methodologies utilized by our independent pricing service to ensure the fair value determination is consistent with the applicable accounting guidance and that the investments are properly classified in the fair value hierarchy. Management substantiates the fair values determined for a sample of securities held in portfolio by reviewing the key assumptions used by the independent pricing service to value the securities and comparing the fair values to prices from other independent sources for the same and similar securities. Management analyzes variances and conducts additional research with the independent pricing service, if necessary, and takes appropriate action based on its findings.
Loans held for sale. These loans are regularly traded in active markets through programs offered by FHLMC and FNMA, and observable pricing information is available from market participants. The prices are adjusted as necessary to include any embedded servicing value in the loans and to take into consideration the specific characteristics of certain loans. These adjustments represent unobservable inputs to the valuation but are not considered significant to the fair value of the loans. Accordingly, residential real estate loans held for sale are classified as Level 2.
Impaired loans. Certain impaired collateral dependent loans are reported at fair value less costs to sell the collateral. Collateral values are estimated using Level 3 inputs, consisting of third-party appraisals or price opinions and internal adjustments necessary in the judgment of Management to reflect current market conditions and current operating results for the specific collateral. Collateral may be in the form of real estate or personal property including equipment and inventory. The vast majority of the collateral is real estate. When impaired collateral dependent loans are individually re-measured and reported at fair value of the collateral, less costs to sell, a direct loan charge off to the ALL and/or a specific valuation allowance allocation is recorded.
Other Property. Certain other property which consists of foreclosed assets and properties securing residential and commercial loans, upon initial recognition and transfer from loans, are re-measured and reported at fair value less costs to sell to the property through a charge-off to the ALL based on the fair value of the foreclosed assets. The fair value of a foreclosed asset, upon initial recognition, is estimated using Level 3 inputs, consisting of third party appraisals or price opinions and internal adjustments necessary in the judgment of Management to reflect current market conditions and current operating results for the specific collateral. Subsequent to foreclosure, valuations are updated periodically, and the assets may be written down further through a charge to noninterest expense.
Mortgage Servicing Rights. The Corporation carries its MSRs at lower of cost or fair value, and, therefore, they are subject to fair value measurements on a nonrecurring basis. Since sales of MSRs tend to occur in private transactions and the precise terms and conditions of the sales are typically not readily available, there is a limited market to refer to in determining the fair value of mortgage servicing rights. As such, like other participants in the mortgage banking business, the Corporation relies primarily on a discounted cash flow model, incorporating assumptions about loan prepayment rates, discount rates, servicing costs and other economic factors, to estimate the fair value of its MSRs. Since the valuation model uses significant unobservable inputs, the Corporation classifies mortgage servicing rights within Level 3.
The Corporation utilizes a third-party vendor to perform the modeling to estimate the fair value of its MSRs. The Corporation reviews the estimated fair values and assumptions used by the third party in the model on a quarterly basis. The Corporation also compares the estimates of fair value and assumptions to recent market activity and against its own experience. See Note 7 (Mortgage Servicing Rights and Mortgage Servicing Activity) for further information on MSRs valuation assumptions.
Derivatives. The Corporation’s derivatives include interest rate swaps and written loan commitments and forward sales contracts related to residential mortgage loan origination activity. Valuations for interest rate swaps are derived from third-party models whose significant inputs are readily observable market parameters, primarily yield curves, with appropriate adjustments for liquidity and credit risk. These fair value measurements are classified as Level 2. The fair values of written loan commitments and forward sales contracts on the associated loans are based on quoted prices for similar loans in the secondary market, consistent with the valuation of residential mortgage loans held for sale. Expected net future cash flows related to loan servicing activities are included in the fair value measurement of written loan commitments. A written loan commitment does not bind the potential borrower to entering into the loan, nor does it guarantee that the Corporation will approve the potential borrower for the loan. Therefore, when determining fair value, the Corporation makes estimates of expected “fallout” (interest rate locked pipeline loans not expected to close), using models, which consider cumulative historical fallout rates and other factors. Fallout can occur for a variety of reasons including falling rate environments when a borrower will abandon a fixed rate loan commitment at one lender and enter into a new lower fixed rate loan commitment at another, when a borrower is not approved as an acceptable credit risk by the lender or for a variety of other noneconomic reasons. Fallout is not a significant input to the fair value of the written loan commitments in their entirety. These measurements are classified as Level 2.
Derivative assets are typically secured through securities with financial counterparties or cross collateralization with a borrowing customer. Derivative liabilities are typically secured through the Corporation pledging securities to financial counterparties or, in the case of a borrowing customer, by the right of setoff. The Corporation considers factors such as the likelihood of default by itself and its counterparties, right of setoff, and remaining maturities in determining the appropriate fair value adjustments. All derivative counterparties approved by the Bank's Board are regularly reviewed, and appropriate business action is taken to adjust the exposure to certain counterparties, as necessary. Counterparty exposure is evaluated by netting positions that are subject to master netting agreements, as well as considering the amount of marketable collateral securing the position. This approach used to estimate impacted exposures to counterparties is also used by the Corporation to estimate its own credit risk on derivative liability positions. To date, no material losses have been incurred due to a counterparty's inability to pay any uncollateralized position. There was no significant change in value of derivative assets and liabilities attributed to credit risk in the year ended December 31, 2014.
True-up liability. In connection with the George Washington and Midwest acquisitions in 2010, the Bank has agreed to pay the FDIC should the estimated losses on the acquired loan portfolios as well as servicing fees earned on the acquired loan portfolios not meet thresholds as stated in the loss sharing agreements (the “true-up liability”). This contingent consideration is classified as a liability within accrued taxes, expenses and other liabilities on the Consolidated Balance Sheet and is remeasured at fair value each reporting date until the contingency is resolved. The changes in fair value are recognized in earnings in the current period.
An expected value methodology is used as a starting point for determining the fair value of the true-up liability based on the contractual terms prescribed in the loss sharing agreements. The resulting values under both calculations are discounted over 10 years (the period defined in the loss sharing agreements) to reflect the uncertainty in the timing and payment of the true-up liability by the Bank to arrive at a net present value. The discount rate used to value the true-up liability was 3.36% and 3.69% as of December 31, 2014 and 2013, respectively. Increasing or decreasing the discount rate by one percentage point would change the liability by approximately $0.7 million and $1.3 million, respectively, as of December 31, 2014.
In accordance with the loss sharing agreements governing the Midwest acquisition, on July 15, 2020 (the “Midwest True-Up Measurement Date”), the Bank has agreed to pay to the FDIC half of the amount, if positive, calculated as: (1) 20% of the intrinsic loss estimate of the FDIC (approximately $152 million); minus (2) the sum of (A) 25% of the asset premium paid in connection with the Midwest acquisition (approximately $21 million); plus (B) 25% of the cumulative shared-loss payments (as defined below) plus (C) the cumulative servicing amount (as defined below). The fair value of the true-up liability associated with the Midwest acquisition was $8.5 million and $7.1 million as of December 31, 2014, and December 31, 2013, respectively.
In accordance with the loss sharing agreements governing the George Washington acquisition, on April 14, 2020 (the “George Washington True-Up Measurement Date”), the Bank has agreed to pay to the FDIC 50% of the excess, if any, of (1) 20% of the stated threshold (approximately $34.4 million) less (2) the sum of (A) 25% of the asset discount (approximately $12 million) received in connection with the George Washington acquisition plus (B) 25% of the cumulative shared-loss payments (as defined below) plus (C) the cumulative servicing amount (as defined below). The fair value of the true-up liability associated with the George Washington acquisition was $4.8 million and $4.3 million as of December 31, 2014, and December 31, 2013, respectively.
For the purposes of the above calculations, cumulative shared-loss payments means: (i) the aggregate of all of the payments made or payable to the Bank under the loss sharing agreements minus (ii) the aggregate of all of the payments made or payable to the FDIC. The cumulative servicing amount means the period servicing amounts (as defined in the loss sharing agreements) for every consecutive twelve-month period prior to and ending on the Midwest and George Washington True-Up Measurement Dates. The cumulative loss share payments and cumulative service amounts components of the true-up calculations are estimated each period end based on the expected amount and timing of cash flows of the acquired loan portfolios. See Note 4 (Loans) and Note 5 (Allowance for Loan Losses) for additional information on the estimated cash flows of the acquired loan portfolios.
The changes in Level 3 assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2014 and 2013 are summarized as follows:
	Year Ended
	December 31, 2014						December 31, 2013
(In thousands)	Available-for-sale securities			True-up liability			Available-for-sale securities			True-up liability
Balance at beginning of period	$	347,611		$	11,463		$	49,661		$	12,259
Fair value of assets acquired	—			—			3,271			—
(Gains) losses included in earnings (1)	—			1,831			—			(796		)
Unrealized gains (losses) (2)	(6,030		)	—			(2,635		)	—
Purchases	—			—			297,232			—
Settlements	(2,394		)	—			82			—
Balance at ending of period	$	339,187		$	13,294		$	347,611		$	11,463
(1) Reported in noninterest expense
(2) Reported in other comprehensive income (loss)
Fair Value Option
Residential mortgage loans held for sale are recorded at fair value under fair value option accounting guidance. The election of the fair value option aligns the accounting for these loans with the related hedges. It also eliminates the requirements of the hedge accounting under GAAP.
Interest income on loans held for sale is accrued on the principal outstanding primarily using the “simple-interest” method. None of these loans were 90 days or more past due, nor were any on nonaccrual as of December 31, 2014 and 2013. The aggregate fair value, contractual balance, and gain or loss on loans held for sale was as follows:
(In thousands)		December 31, 2014			December 31, 2013
Aggregate fair value carrying amount		$	14,389		$	11,622
Aggregate unpaid principal / contractual balance		13,873			11,438
Carrying amount over aggregate unpaid principal (1)		$	516		$	184
(1) These changes are included in loan sales and servicing income in the Consolidated Statement of Income.
Disclosures about Fair Value of Financial Instruments
The carrying amount and estimated fair value of the Corporation’s financial instruments that are carried at either fair value or cost as of December 31, 2014, and 2013, are shown in the tables below.
	December 31, 2014
	Carrying			Fair Value
(In thousands)	Amount			Total			Level 1			Level 2			Level 3
Financial assets:
Cash and due from banks	$	697,424		$	697,424		$	697,424		$	—		$	—
Available-for-sale securities	3,545,288			3,545,288			2,974			3,203,127			339,187
Held-to-maturity securities	2,903,609			2,875,920			—			2,875,920			—
Other securities	148,654			148,654			—			148,654			—
Loans held for sale	13,428			13,428			—			13,428			—
Net originated loans	12,398,116			12,235,530			—			—			12,235,530
Net acquired loans	2,471,723			2,564,842			—			—			2,564,842
Net covered loans and loss share receivable	312,659			312,659			—			—			312,659
Accrued interest receivable	63,657			63,657			—			63,657			—
Derivatives	55,197			55,197			—			55,197			—
Financial liabilities:
Deposits	$	19,504,665		$	19,510,192		$	—		$	19,510,192		$	—
Federal funds purchased and securities sold under agreements to repurchase	1,272,591			1,272,591			—			1,272,591			—
Wholesale borrowings	428,071			430,676			—			430,676			—
Long-term debt	505,192			516,476			—			516,476			—
Accrued interest payable	9,820			9,820			—			9,820			—
Derivatives	55,439			55,439			—			55,439			—
	December 31, 2013
	Carrying			Fair Value
(In thousands)	Amount			Total			Level 1			Level 2			Level 3
Financial assets:
Cash and due from banks	$	917,822		$	917,822		$	917,822		$	—		$	—
Available for sale securities	3,273,174			3,273,174			3,036			2,922,527			347,611
Held to maturity securities	2,935,688			2,824,240			—			2,824,240			—
Other securities	180,803			180,803			—			180,803			—
Loans held for sale	11,622			11,622			—			11,622			—
Net originated loans	10,116,903			10,017,722			—			—			10,017,722
Net acquired loans	3,494,874			3,627,275			—			—			3,627,275
Net covered loans and loss share receivable	547,943			547,943			—			—			547,943
Accrued interest receivable	52,929			52,929			—			52,929			—
Derivatives	47,902			47,902			—			47,902			—
Financial liabilities:
Deposits	$	19,533,601		$	19,532,368		$	—		$	19,532,368		$	—
Federal funds purchased and securities sold under agreements to repurchase	851,535			851,535			—			851,535			—
Wholesale borrowings	200,600			204,124			—			204,124			—
Long-term debt	324,428			319,711			—			319,711			—
Accrued interest payable	9,339			9,339			—			9,339			—
Derivatives	58,201			58,201			—			58,201			—
The following methods and assumptions were used to estimate the fair values of each class of financial instrument presented:
Cash and cash equivalents – For these short-term instruments, the carrying amount is considered a reasonable estimate of fair value.
Investment securities – See Financial Instruments Measured at Fair Value above.
Loans held for sale – The majority of loans held for sale are residential mortgage loans which are recorded at fair value. All other loans held for sale are recorded at the lower of cost or market, less costs to sell. See Financial Instruments Measured at Fair Value above.
Net originated loans – The originated loan portfolio was segmented based on loan type and repricing characteristics. Carrying values are used to estimate fair values of variable rate loans. A discounted cash flow method was used to estimate the fair value of fixed-rate loans. Discounting was based on the contractual cash flows, and discount rates are based on the year-end yield curve plus a spread that reflects current pricing on loans with similar characteristics. If applicable, prepayment assumptions are factored into the fair value determination based on historical experience and current economic conditions.
Net acquired and covered loans – Fair values for acquired and covered loans were estimated based on a discounted projected cash flow methodology that considered factors including the type of loan and related collateral, classification status, fixed or variable interest rate, term of loan and whether or not the loan was amortizing, and current discount rates. Loans were grouped together according to similar characteristics and were treated in the aggregate when applying various valuation techniques. The discount rates used for loans are based on current market rates for new originations of comparable loans and include adjustments for liquidity concerns. The discount rate does not include a factor for credit losses as that has been included in the estimated cash flows.
Loss share receivable – This loss sharing asset is measured separately from the related covered assets as it is not contractually embedded in the covered assets and is not transferable with the covered assets should the Bank choose to dispose of them. Fair value was estimated using discounted projected cash flows related to the FDIC loss share agreements based on the expected reimbursements for losses and the applicable loss sharing percentages. These cash flows were discounted to reflect the uncertainty of the timing and receipt from the FDIC.
Accrued interest receivable – The carrying amount is considered a reasonable estimate of fair value.
Mortgage servicing rights – See Financial Instruments Measured at Fair Value above.
Deposits – The estimated fair value of deposits with no stated maturity, which includes demand deposits, money market accounts and other savings accounts, are established at carrying value because of the customers’ ability to withdraw funds immediately. A discounted cash flow method is used to estimate the fair value of fixed rate time deposits. Discounting was based on the contractual cash flows and the current rates at which similar deposits with similar remaining maturities would be issued.
Federal funds purchased and securities sold under agreements to repurchase, wholesale borrowings and long-term debt – The carrying amount of variable rate borrowings including federal funds purchased is considered to be their fair value. Quoted market prices or the discounted cash flow method was used to estimate the fair value of the Corporation’s long-term debt. Discounting was based on the contractual cash flows and the current rate at which debt with similar terms could be issued.
Accrued interest payable – The carrying amount is considered a reasonable estimate of fair value.
Derivative assets and liabilities – See Financial Instruments Measured at Fair Value above.
True-up liability – See Financial Instruments Measured at Fair Value above.

Derivatives_and_Hedging_Activi

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activity
	The Corporation, through its mortgage banking and risk management operations, is party to various derivative instruments that are used for asset and liability management and customers’ financing needs. Derivative instruments are contracts between two or more parties that have a notional amount and underlying variable, require no net investment and allow for the net settlement of positions. The notional amount serves as the basis for the payment provision of the contract and takes the form of units, such as shares or dollars. The underlying variable represents a specified interest rate, index or other component. The interaction between the notional amount and the underlying variable determines the number of units to be exchanged between the parties and influences the market value of the derivative contract.
	The predominant derivative and hedging activities include interest rate swaps and certain mortgage banking activities. Generally, these instruments help the Corporation manage exposure to market risk, and meet customer financing needs. Market risk represents the possibility that economic value or net interest income will be adversely affected by fluctuations in external factors, such as interest rates, market-driven rates and prices or other economic factors. Foreign exchange contracts are entered into to accommodate the needs of customers.
	Derivatives Designated in Hedge Relationships
	The Corporation’s fixed rate loans result in exposure to losses in value as interest rates change. The risk management objective for hedging fixed rate loans is to convert the fixed rate received to a floating rate. The Corporation hedges exposure to changes in the fair value of fixed rate loans through the use of swaps. For a qualifying fair value hedge, changes in the value of the derivatives that have been highly effective as hedges are recognized in current period earnings along with the corresponding changes in the fair value of the designated hedged item attributable to the risk being hedged.
	At December 31, 2014 and 2013, the notional values or contractual amounts and fair value of the Corporation’s derivatives designated in hedge relationships were as follows:
		Asset Derivatives													Liability Derivatives
		December 31, 2014						December 31, 2013							December 31, 2014					December 31, 2013
	(In thousands)	Notional/ Contract Amount			Fair			Notional/ Contract Amount			Fair				Notional/ Contract Amount			Fair		Notional/ Contract Amount		Fair
					Value (1)						Value (1)							Value (2)				Value (2)
	Interest rate swaps:
	Fair value hedges	$	250,000		$	5,256		$	—		$	—			$	93,313		$	6,683	$	126,637	$	11,574
	(1) Included in Other Assets on the Consolidated Balance Sheet
	(2) Included in Other Liabilities on the Consolidated Balance Sheet
	Fair Value Hedges. Prior to 2009, the Corporation entered into interest rate swaps with dealer
	counterparties to convert certain fixed rate loans to variable rate instruments over the terms of the loans (termed
	by the Corporation as the FRAP Program). These interest rate swaps are designated as fair value hedges and meet the criteria to qualify for the short cut method of accounting. Based on this shortcut method of accounting
	treatment, no ineffectiveness is assumed. The Corporation discontinued originating interest rate swaps under the
	FRAP Program in February 2008.
	During the fourth quarter of 2014, the Corporation entered into a $250.0 million interest rate swap simultaneously with its long-term debt issuance for interest rate risk management purposes. This interest rate swap effectively modifies the receipt of fixed-rate interest amounts in exchange for floating-rate interest payments over the life of the swap, without an exchange of the underlying principal amount. This interest rate swap was designated as a fair value hedge, and through application of the “short cut method of accounting”, there is an assumption that the hedge is effective in offsetting changes in the fair value of the long-term debt due to changes in the U.S. LIBOR swap rate (the designated benchmark interest rate).
	Derivatives Not Designated in Hedge Relationships
	As of December 31, 2014 and 2013, the notional values or contractual amounts and fair value of the Corporation’s derivatives not designated in hedge relationships were as follows:
		Asset Derivatives													Liability Derivatives
		December 31, 2014						December 31, 2013							December 31, 2014					December 31, 2013
	(In thousands)	Notional/ Contract Amount			Fair			Notional/ Contract Amount			Fair				Notional/ Contract Amount			Fair		Notional/ Contract Amount		Fair
					Value (1)						Value (1)							Value (2)				Value (2)
	Interest rate swaps	$	1,673,012		$	48,366		$	1,622,525		$	46,577			$	1,673,012		$	48,366	$	1,622,531	$	46,577
	Mortgage loan commitments	102,523			1,408			90,541			891				—			—		—		—
	Forward sales contracts	47,657			—			40,906			384				—			272		—		—
	Credit contracts	10,001			—			—			—				69,227			—		49,914		—
	Foreign exchange	22,406			167			6,478			50				6,580			118		6,893		50
	Equity swap	—			—			—			—				75,138			—		63,813		—
	Total	$	1,855,599		$	49,941		$	1,760,450		$	47,902			$	1,823,957		$	48,756	$	1,743,151	$	46,627
	(1) Included in Other Assets on the Consolidated Balance Sheet
	(2) Included in Other Liabilities on the Consolidated Balance Sheet
	Interest Rate Swaps. The Corporation’s Back-to-Back Program is an interest rate swap program for commercial loan customers that provides the customer with a fixed rate loan while creating a variable rate asset for the Corporation through the customer entering into an interest rate swap with the Corporation on terms that match the loan. The Corporation offsets its risk exposure by entering into an offsetting interest rate swap with a dealer counterparty. These swaps do not qualify as designated hedges; therefore, each swap is accounted for as a stand-alone derivative.
	Mortgage banking. In the normal course of business, the Corporation sells originated mortgage loans into the secondary mortgage loan markets. During the period of loan origination and prior to the sale of the loans in the secondary market, the Corporation has exposure to movements in interest rates associated with mortgage loans that are in the “mortgage pipeline” and the “mortgage warehouse”. A pipeline loan is one in which the Corporation has entered into a written mortgage loan commitment with a potential borrower that will be held for resale. Once a mortgage loan is closed and funded, it is included within the mortgage warehouse of loans awaiting sale and delivery into the secondary market.
	Written loan commitments that relate to the origination of mortgage loans that will be held for resale are considered free-standing derivatives and do not qualify for hedge accounting. Written loan commitments generally have a term of up to 60 days before the closing of the loan. The loan commitment does not bind the potential borrower to entering into the loan, nor does it guarantee that the Corporation will approve the potential borrower for the loan. Therefore, when determining fair value, the Corporation makes estimates of expected “fallout” (loan commitments not expected to close), using models which consider cumulative historical fallout rates and other factors. In addition, expected net future cash flows related to loan servicing activities are included in the fair value measurement of a written loan commitment.
	Written loan commitments in which the borrower has locked in an interest rate results in market risk to the Corporation to the extent market interest rates change from the rate quoted to the borrower. The Corporation economically hedges the risk of changing interest rates associated with its interest rate lock commitments by entering into forward sales contracts.
	The Corporation’s warehouse (mortgage loans held for sale) is subject to changes in fair value, due to fluctuations in interest rates from the loan’s closing date through the date of sale of the loan into the secondary market. Typically, the fair value of the warehouse declines in value when interest rates increase and rises in value when interest rates decrease. To mitigate this risk, the Corporation enters into forward sales contracts on a significant portion of the warehouse to provide an economic hedge against those changes in fair value. Mortgage loans held for sale and the forward sales contracts were recorded at fair value with ineffective changes in value recorded in current earnings as Loan sales and servicing income.
	Credit contracts. The Corporation has bought and sold credit protection in the form of participations in interest rate swaps (swap participations). These swap participations, which meet the definition of credit derivatives, were entered into in the ordinary course of business. Credit derivatives, whereby the Corporation has purchased credit protection, entitles the Corporation to receive a payment from the counterparty when the customer fails to make payment on any amounts due to the Corporation. Swap participations whereby the Corporation has purchased credit protection have maturities that range between three to nine years. For swap participations where the Corporation sold credit protection, the Corporation has guaranteed payment in the event that the counterparty experiences a loss on the swap due to a failure to pay by the Corporation’s commercial loan customer. The Corporation simultaneously entered into reimbursement agreements with the commercial loan customers obligating the customers to reimburse the Corporation for any payments it makes under the swap participations. The Corporation monitors its payment risk on its swap participations by monitoring the creditworthiness of its commercial loan customers, which is based on the normal credit review process the Corporation would have performed had it entered into these derivative instruments directly with the commercial loan customers. Credit derivatives whereby the Corporation has sold credit protection have maturities ranging from less than one to ten years. The Corporation’s maximum estimated exposure to sold swap participations, as measured by projecting a maximum value of the guaranteed derivative instruments based on interest rate curve simulations and assuming 100% default by all obligors on the maximum values, was approximately $5.0 million as of December 31, 2014. The fair values of the written swap participations were not material at December 31, 2014 or 2013.
	Gains and losses recognized in income on nondesignated hedging instruments for the years ended December 31, 2014, 2013 and 2012, are as follows:
	(In thousands)
	Derivatives not		Location of Gain/(Loss)	Amount of Gain / (Loss) Recognized
	designated as hedging		Recognized	in Income on Derivatives
	instruments		in Income on	Year Ended December 31,
			Derivative	2014			2013			2012
	Mortgage loan commitments		Other operating income	$	517		$	(3,509	)	$	(559	)
	Forward sales contracts		Other operating income	(656		)	446			1,737
	Foreign exchange contracts		Other operating income	(193		)	(116		)	189
	Other		Other operating expense	—			—			—
	Total			$	(332	)	$	(3,179	)	$	1,367
	Counterparty Credit Risk
	Like other financial instruments, derivatives contain an element of “credit risk” or the possibility that the Corporation will incur a loss because a counterparty, which may be a bank, a broker-dealer or a customer, fails to meet its contractual obligations. This risk is measured as the expected positive replacement value of contracts. All derivative contracts may be executed only with exchanges or counterparties approved by the Corporation’s ALCO, and only within the Corporation’s Board of Directors Credit Committee approved credit exposure limits. Where contracts have been created for customers, the Corporation enters into derivatives with dealers to offset its risk exposure. To manage the credit exposure to exchanges and counterparties, the Corporation generally enters into bilateral collateral agreements using standard forms published by the ISDA. These agreements are to include thresholds of credit exposure or the maximum amount of unsecured credit exposure that the Corporation is willing to assume. Beyond the threshold levels, collateral in the form of securities made available from the investment portfolio or other forms of collateral acceptable under the bilateral collateral agreements are provided. The threshold levels for each counterparty are established by the Corporation’s ALCO. The Corporation generally posts collateral in the form of highly rated Government Agency issued bonds or MBS. Collateral posted against derivative liabilities was $53.5 million and $70.5 million as of December 31, 2014 and 2013, respectively.
	Derivative assets and liabilities are recorded at fair value on the balance sheet and do not take into account the effects of master netting agreements the Corporation has with its financial institution counterparties. These master netting agreements allow the Corporation to settle all derivative contracts held with a single financial institution counterparty on a net basis, and to offset net derivative positions with related collateral, where applicable. Collateral, usually in the form of investment securities, is posted by the counterparty with net liability position in accordance with contract thresholds. The following tables illustrate the potential effect of the Corporation’s derivative master netting arrangements, by type of financial instrument, on the Corporation’s statement of financial position as of December 31, 2014 and 2013. The swap agreements the Corporation has in place with its commercial customers are not subject to enforceable master netting arrangements, and, therefore, are excluded from these tables.
		As of December 31, 2014
		Gross amounts recognized			Gross amounts offset in the consolidated balance sheet			Net amounts presented in the consolidated balance sheet			Gross amounts not offset in the consolidated balance sheet						Net amount
	(In thousands)										Financial instruments (1)			Collateral (2)
	Derivative Assets
	Interest rate swaps - designated	$	5,256		$	—		$	5,256		$	—		$	—		$	5,256
	Interest rate swaps - nondesignated	352			—			352			(352		)	—			—
	Total derivative assets	$	5,608		$	—		$	5,608		$	(352	)	$	—		$	5,256
		Gross amounts of recognized liabilities			Gross amounts offset in the statement of financial position			Net amounts of liabilities presented in the statement of financial position			Gross amounts of financial instruments not offset in the statement of financial position						Net amount
											Netting adjustment per applicable master netting agreements			Fair value of financial collateral
Derivative Liabilities
Interest rate swaps - designated	$	6,683		$	—		$	6,683		$	—		$	(6,683	)	$	—
Interest rate swaps - nondesignated	48,014			—			48,014			(352		)	(47,662		)	—
Total derivative liabilities	$	54,697		$	—		$	54,697		$	(352	)	$	(54,345	)	$	—
	As of December 31, 2013
	Gross amounts recognized			Gross amounts offset in the consolidated balance sheet			Net amounts presented in the consolidated balance sheet			Gross amounts not offset in the consolidated balance sheet						Net amount
(In thousands)										Financial instruments (1)			Collateral (2)
Derivative Assets
Interest rate swaps - nondesignated	$	4,791		$	—		$	4,791		$	(4,791	)	$	—		$	—
Foreign exchange	4			—			4			(46		)	42			—
Total derivative assets	$	4,795		$	—		$	4,795		$	(4,837	)	$	42		$	—
	Gross amounts of recognized liabilities			Gross amounts offset in the statement of financial position			Net amounts of liabilities presented in the statement of financial position			Gross amounts of financial instruments not offset in the statement of financial position						Net amount
										Netting adjustment per applicable master netting agreements			Fair value of financial collateral
Derivative Liabilities
Interest rate swaps - designated	$	11,574		$	—		$	11,574		$	—		$	(11,574	)	$	—
Interest rate swaps - nondesignated	41,787			—			41,787			(4,791		)	(36,996		)	—
Foreign exchange	46			—			46			(46		)	—			—
Total derivative liabilities	$	53,407		$	—		$	53,407		$	(4,837	)	$	(48,570	)	$	—
(1) For derivative assets, this includes any derivative liability fair values that could be offset in the event of counterparty default. For derivative liabilities, this includes any derivative asset fair values that could be offset in the event of counterparty default.
(2) For derivate assets, this includes the fair value of collateral received by the Corporation from the counterparty. Securities received as collateral are not included in the Consolidated Balance Sheet unless the counterparty defaults. For derivative liabilities, this includes the fair value of securities pledged by the Corporation to the counterparty. These securities are included in the Consolidated Balance Sheet unless the Corporation defaults

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Obligations Under Noncancelable Leases
	The Corporation is obligated under various noncancelable operating leases on branch offices. Minimum future rental payments under noncancelable operating leases at December 31, 2014 are as follows:
	(In thousands)
	Year Ended December 31,		Lease
			Commitments
	2015		$	13,598
	2016		11,167
	2017		9,841
	2018		8,426
	2019		6,459
	2020-2031		21,999
	Total minimum future rental payments		$	71,490
	Commitments to Extend Credit
	Commitments to extend credit are agreements to lend to a customer provided there is no violation of any condition established in the contract. Loan commitments to originate residential mortgage loans held for sale and forward commitments to sell residential mortgage loans are considered derivative instruments, and the fair value of these commitments is recorded on the consolidated balance sheets. Additional information is provided in Note 18 (Fair Value Measurement). Commitments generally are extended at the then-prevailing interest rates, have fixed expiration dates or other termination clauses and may require payment of a fee. Since many of the commitments are expected to expire without being drawn upon the total commitment amounts do not necessarily represent future cash requirements. Loan commitments involve credit risk not reflected on the balance sheet. The Corporation mitigates exposure to credit risk with internal controls that guide how applications for credit are reviewed and approved, how credit limits are established and, when necessary, how demands for collateral are made. Collateral held varies but may include accounts receivable, inventory, property, plant and equipment, and income-producing commercial properties. Management evaluates the creditworthiness of each prospective borrower on a case-by-case basis and, when appropriate, adjusts the allowance for probable credit losses inherent in all commitments. The allowance for unfunded lending commitments at December 31, 2014, was $5.8 million, compared with $7.9 million at December 31, 2013. Additional information pertaining to this allowance is included in Note 5 (Allowance for Loan Losses) and under the heading “Allowance for Originated Loan Losses and Reserve For Unfunded Lending Commitments” within Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operation” of this report.
	The following table shows the remaining contractual amount of each class of commitments to extend credit as of December 31, 2014 and 2013. This amount represents the Corporation’s maximum exposure to loss if the customer were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan.
			At December 31,
	(In thousands)		2014			2013
	Loan Commitments
		Commercial	$	3,748,690		$	3,367,625
		Consumer	2,387,623			2,179,010
		Total loan commitments	$	6,136,313		$	5,546,635
	Guarantees
	The Corporation is a guarantor in certain agreements with third parties. The following table shows the types of guarantees the Corporation had outstanding as of December 31, 2014, and 2013.
			At December 31,
	(In thousands)		2014			2013
	Financial guarantees
		Standby letters of credit	$	242,390		$	196,400
		Loans sold with recourse	45,071			45,082
		Total financial guarantees	$	287,461		$	241,482
	Standby letters of credit obligate the Corporation to pay a specified third party when a customer fails to repay an outstanding loan or debt instrument, or fails to perform some contractual nonfinancial obligation. The credit risk involved in issuing letters of credit is essentially the same as involved in extending loan facilities to customers. Collateral held varies, but may include marketable securities, equipment and real estate. Any amounts drawn under standby letters of credit are treated as loans; they bear interest and pose the same credit risk to the Corporation as a loan. Except for short-term guarantees of $176.4 million at December 31, 2014, the remaining guarantees extend in varying amounts through 2019.
	Asset Sales
	The Corporation regularly sells residential mortgage loans service retained to GSEs as part of its mortgage banking activities. The Corporation provides customary representation and warranties to the GSEs in conjunction with these sales. These representations and warranties generally require the Corporation to repurchase assets if it is subsequently determined that a loan did not meet specified criteria, such as a documentation deficiency or rescission of mortgage insurance. If the Corporation is unable to cure or refute a repurchase request, the Corporation is generally obligated to repurchase the loan or otherwise reimburse the counterparty for losses. The Corporation also sells residential mortgage loans serviced released to other investors which contain early payment default recourse provisions. As of December 31, 2014 and 2013, the Corporation had sold $38.1 million and $34.6 million, respectively, of outstanding residential mortgage loans to GSEs and other investors with recourse provisions. The Corporation had reserved $7.3 million and $8.7 million as of December 31, 2014 and 2013, respectively, for estimated losses from representation and warranty obligations and early payment default recourse provisions.
	Due to prior acquisitions, as of December 31, 2014, the Corporation continued to service approximately $3.7 million in manufactured housing loans that were sold with recourse compared to $6.4 million as of December 31, 2013. The Corporation had reserved $1.1 million for estimated losses from these manufactured housing loans at December 31, 2014 and 2013.
	The total reserve associated with loans sold with recourse was approximately $8.4 million and $9.9 million as of December 31, 2014 and 2013, respectively, and is included in accrued taxes, expenses and other liabilities on the consolidated balance sheet. As a result of the merger with Citizens, $6.0 million was recorded as a contingent liability to reflect the fair value of the liability associated with the expected commitment to repurchase mortgage loans previously sold by Citizens subject to recourse provisions. The Corporation’s reserve reflects management’s best estimate of losses. The Corporation’s reserving methodology uses current information about investor repurchase requests, and assumptions about repurchase mix and loss severity, based upon the Corporation’s most recent loss trends. The Corporation also considers qualitative factors that may result in anticipated losses differing from historical loss trends, such as loan vintage, underwriting characteristics and macroeconomic trends.
	Changes in the amount of the repurchase reserve for the years ended December 31, 2014, and 2013, are as follows:
		Year Ended December 31, 2014
	(In thousands)	Reserve on residential mortgage loans			Reserve on manufactured housing loans			Total repurchased reserve
	Balance at beginning of period	$	8,737		$	1,114		$	9,851
	Net realized losses	(4,528		)	—			(4,528		)
	Net increase (decrease) to reserve	3,041			10			3,051
	Balance at end of period	$	7,250		$	1,124		$	8,374
		Year Ended December 31, 2013
	(In thousands)	Reserve on residential mortgage loans			Reserve on manufactured housing loans			Total repurchased reserve
	Balance at beginning of period	$	1,500		$	1,167		$	2,667
	Assumed Obligation	6,000			—			6,000
	Net realized losses	(5,818		)	—			(5,818		)
	Net increase (decrease) to reserve	7,055			(53		)	7,002
	Balance at end of period	$	8,737		$	1,114		$	9,851

Litigation

Litigation	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Litigation	Litigation
	In the normal course of business, the Corporation and its subsidiaries are at all times subject to pending and threatened legal actions, some for which the relief or damages sought are substantial. Although the Corporation is not able to predict the outcome of such actions, after reviewing pending and threatened actions with counsel, Management believes that based on the information currently available the outcome of such actions, individually or in the aggregate, will not have a material adverse effect on the results of operations or shareholders' equity of the Corporation. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the results of operations in a particular future period as the time and amount of any resolution of such actions and its relationship to the future results of operations are not known.
	Reserves are established for legal claims only when losses associated with the claims are judged to be probable, and the loss can be reasonably estimated. In many lawsuits and arbitrations, including almost all of the class action lawsuits, it is not possible to determine whether a liability will be incurred or to estimate the ultimate or minimum amount of that liability until the case is close to resolution, in which case a reserve will not be recognized until that time.
	Overdraft Litigation
	Commencing in December 2010, two separate lawsuits were filed in the Summit County Court of Common Pleas and the Lake County Court of Common Pleas against the Corporation and the Bank. The complaints were brought as putative class actions on behalf of Ohio residents who maintained a checking account at the Bank and who incurred one or more overdraft fees as a result of the alleged re-sequencing of debit transactions. The lawsuit that had been filed in Summit County Court of Common Pleas was dismissed without prejudice on July 11, 2011. The remaining suit in Lake County seeks actual damages, disgorgement of overdraft fees, punitive damages, interest, injunctive relief and attorney fees. In December 2012, the trial court issued an order certifying a proposed class and the Bank and Corporation appealed the order to the Eleventh District Court of Appeals. In September 2013, the Eleventh District Court of Appeals affirmed in part and reversed in part the trial court’s class certification order, and remanded the case back to the trial court for further consideration, in particular with respect to the class definition. On October 9, 2013, the Bank and Corporation filed with the Eleventh District Court of Appeals an application for reconsideration and application for consideration en banc. On November 20, 2013, the Eleventh District denied those applications. On December 4, 2013, the Bank and Corporation filed a notice of appeal with the Ohio Supreme Court, and on January 3, 2014, they filed with the Ohio Supreme Court a memorandum in support of the Court’s exercising its jurisdiction and accepting the appeal. The plaintiffs filed an opposition, and, on April 24, 2014, the Ohio Supreme Court declined to accept jurisdiction. On August 6, 2014, the Bank and Corporation filed a motion asking the trial court to stay the lawsuit pending arbitration of claims subject to an arbitration agreement. That motion has been fully briefed and is awaiting a decision by the court. On August 25, 2014, the parties stipulated to a revised class definition (without affecting the pending motion to stay), and an order approving that stipulation is awaiting court approval.
	Merger Litigation
	Between September 17, 2012 and October 5, 2012, alleged shareholders of Citizens filed six purported class action lawsuits in the Circuit Court of Genesee County, Michigan, relating to the proposed merger between Citizens and FirstMerit, which merger closed in April 2013. The lawsuits were consolidated under the caption In re Citizens Republic Bancorp, Inc. Shareholder Litigation, Case No. 12-99027-CK (the “Lawsuit”). The consolidated complaint in the Lawsuit alleges that the former directors of Citizens breached their fiduciary duties by failing to obtain the best available price in the merger and by not providing Citizens shareholders with all material information related to the merger, and that FirstMerit and Citizens aided and abetted those alleged breaches of fiduciary duty.  The Complaint sought declaratory and injunctive relief to prevent the consummation of the merger, rescissory damages and other equitable relief.
	The plaintiffs and defendants have entered into a settlement of the Lawsuit, and the court approved the settlement on September 20, 2013. Under the settlement, the defendants amended the joint proxy statement/prospectus relating to the merger to include certain supplemental disclosures to shareholders of Citizens and agreed to pay attorneys’ fees and expenses as awarded by the court. An alleged former shareholder of Citizens objected to the settlement and has filed an appeal of the court’s approval of the settlement; the settlement will not become final until that appeal has been resolved.
	CRBC 401(k) Litigation
	Participants in the Citizens Republic Bancorp 401(k) Plan filed a lawsuit in the United States Court for the Eastern District of Michigan in 2011, alleging that Citizens and certain of its officers and directors violated the Employee Retirement Income Security Act by offering Citizens common stock as an investment alternative in the Plan during periods when it was imprudent to do so and by failing to adequately monitor fiduciaries responsible for administering the Plan. The lawsuit, captioned Kidd v. Citizens Republic Bancorp, Inc. et al., Case No. 2:11-cv-11709, asserts claims for monetary and injunctive relief on behalf of a purported class of participants and beneficiaries in the Plan who held Citizens stock in their Plan accounts during the period from April 17, 2008 to “the present.” In April 2014, the court denied the defendants’ motion to dismiss the second amended complaint.
	Based on information currently available, consultation with counsel, available insurance coverage and established reserves, Management believes that the eventual outcome of all claims against the Corporation and its subsidiaries will not, individually or in the aggregate, have a material adverse effect on its consolidated financial position or results of operations. However, it is possible that the ultimate resolution of these matters, if unfavorable, may be material to the results of operations for a particular period. The Corporation has not established any reserves with respect to any of this disclosed litigation because it is not possible to determine (i) whether a liability has been incurred; or (ii) an estimate of the ultimate or minimum amount of such liability.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Shareholders' Equity [Abstract]
Stockholders' Equity	Shareholders' Equity
	Common Stock Warrant
	The Corporation has an outstanding warrant previously issued by Citizen’s to the U.S. Treasury to initially purchase 2,408,203 shares of FirstMerit Common Stock. Due to a dividend protection clause, the strike price is reduced by an amount equivalent to the dividend as a percentage of the closing market price on the day prior to the ex-dividend date. The adjusted shares are calculated by dividing the original proceeds by the adjusted strike price. At December 31, 2014, the adjusted strike price is $17.65 with a corresponding adjusted number of shares of 2,549,702 issuable upon exercise of the warrant issued to the U.S. Treasury and currently available for purchase.
	Preferred Stock
	The Corporation has 7,000,000 shares of authorized Preferred Stock and has designated 115,000 shares of its Preferred Stock as 5.875% Non-Cumulative Perpetual Preferred Stock, Series A. On February 4, 2013, the Corporation issued 100,000 shares of its 5.875% Non-Cumulative Perpetual Preferred Stock, Series A, which began paying cash dividends on May 4, 2013, quarterly in arrears on the 4th day of February, May, August and November.
	Earnings per Share
	Basic net income per common share is calculated using the two-class method to determine income
	attributable to common shareholders. Net income attributable to Common Stock is then divided by the
	weighted-average number of Common Stock outstanding during the period.
	Diluted net income per common share is calculated under the more dilutive of either the treasury method
	or two-class method. Adjustments to the weighted-average number of shares of Common Stock outstanding are
	made only when such adjustments will dilute earnings per common share. Net income attributable to Common
	Stock is then divided by the weighted-average number of Common Stock and Common Stock equivalents
	outstanding during the period.
	The reconciliation between basic and diluted EPS using the two-class method and treasury stock method is presented as follows:
		Year Ended December 31,
	(In thousands, except per share amounts)	2014		2013		2012
	Basic EPS:
	Net income	$	237,951	$	183,684	$	134,106
	Less:
	Cash dividends on 5.875% non-cumulative perpetual series A, preferred stock	5,876		5,337		—
	Income allocated to participating securities	1,930		1,545		—
	Net income attributable to common shareholders	$	230,145	$	176,802	$	134,106
	Weighted average Common Stock outstanding used in basic EPS	165,296		149,607		109,518
	Basic net income per common share	$	1.39	$	1.18	$	1.22
	Diluted EPS:
	Income used in diluted earnings per share calculation	$	230,145	$	176,802	$	134,106
	Weighted average Common Stock outstanding used in basic EPS	165,296		149,607		109,518
	Add: Common Stock equivalents:
	Warrant and stock plans	758		814		—
	Weighted average Common and Common Stock equivalent shares outstanding	166,054		150,421		109,518
	Diluted net income per common share	$	1.39	$	1.18	$	1.22
	Common Stock equivalents consist of employee stock award plans and the Common Stock warrant. These Common Stock equivalents do not enter into the calculation of diluted EPS if the impact would be anti-dilutive, that is, increase EPS or reduce a loss per share. There were $0.8 million antidilutive Common Stock equivalents for the year ended December 31, 2014, and $1.4 million and $3.4 million antidilutive Common Stock equivalents for the years ended December 31, 2013 and 2012, respectively.

Changes_and_Reclassifications_

Changes and Reclassifications Out of Other Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2014
Changes and Reclassifications Out of Other Comprehensive Income [Abstract]
Changes and Reclassifications Out of Accumulated Other Comprehensive Income	Changes and Reclassifications Out of Accumulated Other Comprehensive Income
	The following table presents the changes in AOCI by components of comprehensive income for the years ended December 31, 2014 and 2013:
		Year Ended December 31, 2014
	(In thousands)	Pre-tax			Tax			After-tax
	Unrealized and realized securities gains and losses:
	Balance at the beginning of the period	$	(45,072	)	$	(15,776	)	$	(29,296	)
	Changes in unrealized securities’ holding gains/(losses)	38,864			13,602			25,262
	Changes in unrealized securities’ holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity	(2,157		)	(753		)	(1,404		)
	Net losses/(gains) realized on sale of securities reclassified to noninterest income	(166		)	(58		)	(108		)
	Balance at the end of the period	(8,531		)	(2,985		)	(5,546		)
	Pension plans and other postretirement benefits:
	Balance at the beginning and end of the period	(57,813		)	(20,233		)	(37,580		)
	Current year actual gains/(losses)	(49,552		)	(17,344		)	(32,208		)
	Amortization of actuarial losses/(gains)	3,166			1,108			2,058
	Amortization of prior service cost reclassified to other noninterest expense	2,131			747			1,384
	Balance at the end of the period	(102,068		)	(35,722		)	(66,346		)
	Total Accumulated Other Comprehensive Income	$	(110,599	)	$	(38,707	)	$	(71,892	)
		Year Ended December 31, 2013
	(In thousands)	Pre-tax			Tax			After-tax
	Unrealized and realized securities gains and losses:
	Balance at the beginning of the period	$	85,259		$	29,841		$	55,418
	Changes in unrealized securities’ holding gains/(losses)	(130,947		)	(45,833		)	(85,114		)
	Changes in unrealized securities’ holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity	(2,187		)	(765		)	(1,422		)
	Net losses/(gains) realized on sale of securities reclassified to noninterest income	2,803			981			1,822
	Balance at the end of the period	(45,072		)	(15,776		)	(29,296		)
	Pension plans and other postretirement benefits:
	Balance at the beginning and end of the period	(110,188		)	(38,565		)	(71,623		)
	Current year actual gains/(losses)	47,939			16,779			31,160
	Amortization of actuarial losses/(gains)	4,437			1,553			2,884
	Amortization of prior service cost reclassified to other noninterest expense	(1		)	—			(1		)
	Balance at the end of the period	(57,813		)	(20,233		)	(37,580		)
	Total Accumulated Other Comprehensive Income	$	(102,885	)	$	(36,009	)	$	(66,876	)
	The following table presents current period reclassifications out of AOCI by component of comprehensive income for the years ended December 31, 2014 and 2013:
	(In thousands)	Year Ended December 31, 2014			Statement of Income line item presentation
	Realized (gains) losses on sale of securities	$	(166	)	Investment securities losses (gains), net
	Tax expense (benefit) (35%)	(58		)	Income tax expense (benefit)
	Reclassified amount, net of tax	$	(108	)
	(In thousands)	Year Ended December 31, 2013			Statement of Income line item presentation
	Realized (gains) losses on sale of securities	$	2,803		Investment securities losses (gains), net
	Tax expense (benefit) (35%)	981			Income tax expense (benefit)
	Reclassified amount, net of tax	$	1,822

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2014
Regulatory Capital Requirements [Abstract]
Regulatory Matters	Regulatory Matters
	The Corporation is subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory – and possibly additional discretionary – actions by regulators that, if undertaken, could have a material effect on the Corporation’s financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Corporation must meet specific capital guidelines that involve quantitative measures of the Corporation’s assets, liabilities, and certain off-balance-sheet items as calculated under regulatory accounting practices. The Corporation’s capital amounts and classification are also subject to quantitative judgments by regulators about components, risk weightings, and other factors.
	Quantitative measures established by regulation to ensure capital adequacy require the Corporation to maintain minimum amounts and ratios (set forth in the following table) of total and Tier I capital to risk-weighted assets, and of Tier I capital to average assets. At December 31, 2014 and 2013, Management believes the Corporation meets all capital adequacy requirements to which it is subject. The capital terms used in this note to the consolidated financial statements are defined in the regulations as well as in the “Capital Resources” section of Management’s Discussion and Analysis of Financial Condition and Results of Operations.
	(Dollars in thousands)	Consolidated
		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2014	Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)	$	2,653,893		15.26	%	>	$	1,391,282		8	%	>	$	1,739,102		10	%
	Tier I Capital
	(to Risk Weighted Assets)	$	2,004,461		11.53	%	>	$	695,641		4	%	>	$	1,043,461		6	%
	Tier I Capital
	(to Average Assets)	$	2,004,461		8.43	%	>	$	951,430		4	%	>	$	1,189,287		5	%
	(Dollars in thousands)	Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2013	Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)	$	2,279,891		13.97	%	>	$	1,305,667		8	%	>	$	1,632,083		10	%
	Tier I Capital
	(to Risk Weighted Assets)	$	1,880,804		11.52	%	>	$	652,833		4	%	>	$	979,250		6	%
	Tier I Capital
	(to Average Assets)	$	1,880,804		8.14	%	>	$	923,887		4	%	>	$	1,154,858		5	%
	At December 31, 2014 and 2013, the most recent notification from the OCC categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well-capitalized the Bank must maintain minimum total risk-based, Tier I risk-based, and Tier I leverage ratios as set forth in the table. In Management’s opinion, there are no conditions or events since the OCC’s notification that have changed the Bank’s categorization as “well-capitalized.”
			Bank Only
	(Dollars in thousands)		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2014		Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)		$	2,521,412		14.49	%	>	$	1,391,988		8	%	>	$	1,739,986		10	%
	Tier I Capital
	(to Risk Weighted Assets)		$	2,127,065		12.22	%	>	$	695,994		4	%	>	$	1,043,991		6	%
	Tier I Capital
	(to Average Assets)		$	2,127,065		8.94	%	>	$	951,455		4	%	>	$	1,189,319		5	%
	(Dollars in thousands)		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2013		Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)		$	2,122,124		13.02	%	>	$	1,303,579		8	%	>	$	1,629,473		10	%
	Tier I Capital
	(to Risk Weighted Assets)		$	1,978,140		12.14	%	>	$	651,789		4	%	>	$	977,684		6	%
	Tier I Capital
	(to Average Assets)		$	1,978,140		8.58	%	>	$	922,312		4	%	>	$	1,152,890		5	%
	FirstMerit Mortgage Corporation, a subsidiary of the Corporation, is subject to net worth requirements issued by the U.S. Department of Housing and Urban Development (HUD). Failure to meet minimum capital requirements of HUD can result in certain mandatory and possibly additional discretionary actions that, if undertaken, could have a direct material effect on FirstMerit Mortgage Corporation's operations.
	The minimum net worth requirement of HUD at December 31, 2014, and 2013, was $1.0 million. FirstMerit Mortgage Corporations’ net worth significantly exceeded the HUD requirements at December 31, 2014, and 2013.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	In preparing these financial statements, subsequent events were evaluated through the time the financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users, or filed with the SEC. In accordance with applicable accounting standards, all material subsequent events have been either recognized in the financial statements or disclosed in the notes to the financial statements.

Borrowed_Funds_Notes

Borrowed Funds (Notes)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Borrowed Funds	Borrowed Funds
	The following table presents wholesale borrowings and long-term debt as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	FHLB advances		$	427,857		$	200,323
	Subordinated debentures		505,192			249,928
	Fixed and variable junior subordinated deferral debentures		—			74,500
	Other		214			277
	Total borrowed funds		$	933,263		$	525,028
	FHLB advances were secured by a lien on residential and other real estate-related loans totaling $5.1 billion at December 31, 2014, and $2.4 billion at December 31, 2013. The FHLB advances have interest rates that range from 1.11% to 4.12% as of December 31, 2014.
	On November 25, 2014, the Bank issued $250 million in aggregate principal of subordinated notes, due November 25, 2026, and bearing interest at an annual rate of 4.27% payable semi-annually in arrears on May 25 and November 25 of each year. The net proceeds were used to initially pay down existing federal funds purchased and securities sold under repurchase agreements, general corporate purposes, and as capital to support the Bank’s growth. The subordinated notes are not redeemable by the Bank or callable by the holders prior to maturity.
	On February 4, 2013, the Corporation issued $250 million in aggregate principal of subordinated notes, due February 4, 2023, and bearing interest at an annual rate of 4.35% payable semi-annually in arrears on February 4 and August 4 of each year. The net proceeds were used to fund the Citizens acquisition.
	As part of the merger with Citizens, the Corporation assumed two active wholly owned trusts formed for the purpose of issuing securities. Each of the two active trusts had issued separate offerings of trust preferred securities to investors in 2006 and 2003. In accordance with GAAP, the financial statements of the Trusts were not included in the Corporation's consolidated financial statements. In conjunction with these trusts, the Corporation assumed a variable rate junior subordinated deferrable debenture in an aggregate principal amount approximating $25.8 million. This debenture bore interest at an annual rate equal to three-month LIBOR plus 3.10%, payable quarterly. Interest was adjusted on a quarterly basis not exceeding 11.75%. The Corporation assumed a 7.50% junior subordinated debenture in an aggregate principal amount approximating $48.7 million. These trust preferred securities and the junior subordinated debentures, totaling $74.5 million, were redeemed on September 26, 2014 and the associated debentures were paid off.
	Selected financial statement information pertaining to the Corporation’s borrowed funds is as follows:
		As of December 31,
	(Dollars in thousands)	2014			2013			2012
	Average balance during the year	$	715,383		$	474,473		$	175,989
	Weighted-average annual interest rate during the year	2.8		%	3.62		%	2.51		%
	Maximum month-end balance	$	973,453		$	527,155		$	178,489
	The following table illustrates the contractual maturities of the Corporation's borrowed funds at December 31, 2014:
			One Year			One to			Three to		Over Five
	(In thousands)		or Less			Three Years			Five Years		Years		Total
	FHLB advances		$	189,808		$	212,495		$	202	$	25,352	$	427,857
	Subordinated debentures		—			—			—		505,192		505,192
	Other		67			147			—		—		214
	Total borrowed funds		$	189,875		$	212,642		$	202	$	530,544	$	933,263

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation
Basis of Accounting	The accounting and reporting policies of the Corporation conform to GAAP and to general practices within the financial services industry.
	In preparing these accompanying consolidated financial statements, subsequent events were evaluated through the time the consolidated financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users, or filed with the SEC.
	The following is a description of the Corporation’s significant accounting policies.
Principles of Consolidation	Principles of Consolidation
	The Parent Company is a bank holding company whose principal asset is the common stock of its wholly-owned subsidiary, the Bank. The Parent Company’s other subsidiaries include Citizens Savings Corporation of Stark County, FirstMerit Capital Trust I, and FirstMerit Risk Management, Inc. All significant intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates
	Management must make certain estimates and assumptions that affect the amounts reported in the financial statements and related notes. If these estimates prove to be inaccurate, actual results could differ from those reported.
Business Combinations	Business Combinations
	Business combinations are accounted for using the acquisition method of accounting. Under this accounting method, the acquired company's net assets are recorded at fair value on the date of acquisition, and the results of operations of the acquired company are combined with the Corporation's results from that date forward. Costs related to the acquisition are expensed as incurred. The difference between the purchase price and the fair value of the net assets acquired (including intangible assets with finite lives) is recorded as goodwill. The accounting policy for goodwill and intangible assets is summarized in this note under the heading "Goodwill and Other Intangible Assets". As discussed in Note 2 (Business Combinations), the Corporation completed the merger with Citizens, a Michigan corporation, during 2013. As of November 18, 2014, the recently issued FASB ASU 2014-17, Pushdown Accounting—a consensus of the FASB Emerging Issues Task Force, provides the Corporation the ability to elect push down accounting in the acquired entities separate financial statements, either in the current reporting period in which a change-in-control event occurs or in a subsequent period. This ASU is summarized in this notes under the heading “Recently Issued Accounting Standards”.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash and due from banks, interest bearing deposits in other banks and checks in the process of collection.
Investment Securities	Investment Securities
	Debt securities are classified as held-to-maturity when the Corporation has the positive intent and ability to hold the securities to maturity. These securities are reported at amortized cost, adjusted for amortization of premiums and accretion of discounts to maturity using the effective yield method. This method produces a constant rate of return on the adjusted carrying amount.
	Securities are classified as available-for-sale when the Corporation intends to hold the securities for an indefinite period of time but may be sold in response to changes in interest rates, prepayment risk, liquidity needs or other factors. Securities available-for-sale are reported at fair value, with unrealized gains and losses, net of income tax, reported as a separate component of other comprehensive income (loss) in shareholders’ equity.
	In certain situations, Management may elect to transfer certain debt securities from the available-for-sale to the held to maturity classification. In such cases, any unrealized gain or loss included in accumulated other comprehensive income (loss) at the time of transfer is amortized over the remaining life of the security as a yield adjustment such that only the remaining initial discount or premium from the purchase date is recognized in income.
	Interest and dividends on securities, including the amortization of premiums and accretion of discount, are included in interest income. Realized gains or losses on the sales of available-for-sale securities are recorded on the trade date and determined using the specific identification method.
	On at least a quarterly basis, Management evaluates securities that are in an unrealized loss position for OTTI. An investment security is deemed impaired if the fair value of the investment is less than its amortized cost. As part of the impairment evaluation, Management considers the extent and duration of the unrealized loss, and the financial condition and near-term prospects of the issuer. Management also assesses whether it intends to sell, or it is more likely than not that it will be required to sell, a security in an unrealized loss position before recovery of its amortized cost. If either of the criteria regarding intent or requirement to sell is met, the entire difference between amortized cost and fair value is recognized as impairment through earnings. For debt securities that do not meet the aforementioned criteria, the amount of impairment is split into two components as follows: 1) OTTI related to credit loss, which must be recognized in earnings, and 2) OTTI related to other factors, such as liquidity conditions in the market or changes in market interest rates, which is recognized in other comprehensive income. The credit loss is defined as the difference between the present value of the cash flows expected to be collected and the amortized cost basis. For equity securities, the entire amount of impairment is recognized in earnings.
	Other investments include FHLB and FRB stock. As a member of the FHLB system, the Bank is required to own a certain amount of stock based on the level of borrowings and other factors. The Bank is also a member of its regional FRB. Both FHLB and FRB stock are carried at cost and evaluated for impairment based on the ultimate recovery of par value. Cash and stock dividends received on the stock are reported as interest income in the Consolidated Statement of Income.
Originated Loans and Loan Income	Originated Loans and Loan Income
	Loans originated for investment are stated at their principal amount outstanding adjusted for partial charge-offs, and net deferred loan fees and costs. Interest income on loans is accrued over the term of the loans primarily using the simple-interest method based on the principal balance outstanding. Interest is not accrued on loans where collectability is uncertain. Accrued interest is presented separately in the balance sheet, except for accrued interest on credit card loans, which is included in the outstanding loan balance. Loan origination fees and certain direct costs incurred to extend credit are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield.
Loans Held for Sale	Loans Held for Sale
	Mortgage loans originated and intended for sale in the secondary market are carried at fair value. The election of the fair value option aligns the accounting for these loans with the related economic hedges. Loan origination fees are recorded when earned and related direct loan origination costs are recognized when incurred. Upon their sale, differences between carrying value and sales proceeds realized are recorded to loan sales and servicing income in the Consolidated Statement of Income.
	A discussion of the valuation methodology applied to the Corporation’s loans held for sale is described in Note 18 (Fair Value Measurement).
Nonperforming Loans	Nonperforming Loans
	Loans and leases on which payments are past due for 90 days are placed on nonaccrual, with the exception of certain commercial, credit card and mortgage loans and loans that are fully secured and in process of collection. Credit card loans on which payments are past due for 120 days are placed on nonaccrual status. Interest on mortgage loans is accrued until Management deems it uncollectible based upon the specific identification method.
	Loans are generally written off when deemed uncollectible or when they reach a predetermined number of days past due depending upon loan product, terms, and other factors. When a loan is placed on nonaccrual status, interest deemed uncollectible that had been accrued in prior years is charged against the allowance for loan losses and interest deemed uncollectible accrued in the current year is reversed against interest income. Payments subsequently received on nonaccrual loans are generally applied to principal. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable. This generally requires a sustained period of timely principal and interest payments.
	Under the Corporation’s credit policies and practices, individually impaired loans include all nonaccrual and restructured commercial, agricultural, construction, and commercial real estate loans, but exclude certain aggregated consumer loans, mortgage loans, and leases classified as nonaccrual. Loan impairment for all loans is measured based on either the present value of expected future cash flows discounted at the loan’s effective interest rate at inception, at the observable market price of the loan, or the fair value of the collateral for certain collateral dependent loans.
	Restructured loans are those on which concessions in terms have been made as a result of deterioration in a borrower’s financial condition. In general, the modification or restructuring of a debt constitutes a troubled debt restructuring if the Corporation for economic or legal reasons related to the borrower’s financial difficulties grants a concession to the borrower that the Corporation would not otherwise consider under current market conditions. Debt restructurings or loan modifications for a borrower do not necessarily constitute troubled debt restructurings. Troubled debt restructurings do not necessarily result in nonaccrual loans. Specific allowances for loan losses are established for certain consumer, commercial and commercial real estate loans whose terms have been modified in a TDR.
	Acquired nonimpaired loans are placed on nonaccrual and considered and reported as nonperforming or past due using the same criteria applied to the originated portfolio. Acquired impaired loans are not classified as nonperforming assets as the loans are considered to be performing under the provisions of ASC 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality (“ASC 310-30”). Acquired loans restructured after acquisition are not considered TDRs for purposes of the Corporation’s accounting and disclosure if the loans evidenced credit deterioration as of the acquisition date and are accounted for in pools.
Allowance for Loan Losses	Allowance for Loan Losses
	The allowance for loan losses is Management’s estimate of the amount of probable credit losses inherent in the loan portfolio at the balance sheet date. Increases to the allowance for loan losses are made by charges to the provisions for loan losses. Loans deemed uncollectible are charged against the allowance for loan losses. Recoveries of previously charged-off amounts are credited to the allowance for loan losses. Management estimates credit losses based on individual loans determined to be impaired and on all other loans grouped based on similar risk characteristics.
	The Corporation’s historical loss component is the most significant of the allowance for loan losses components and is based on historical loss experience by credit-risk grade (for commercial loan pools) and payment status (for mortgage and consumer loan pools). Loans are pooled based on similar risk characteristics supported by observable data. The historical loss experience component of the allowance for loan losses represents the results of migration analysis of historical net charge-offs for portfolios of loans (including groups of commercial loans within each credit-risk grade and groups of consumer loans by payment status). For measuring loss exposure in a pool of loans, the historical net charge-off or migration experience is utilized to estimate expected losses to be realized from the pool of loans.
	Individual commercial loans are assigned credit-risk grades based on an internal assessment of conditions that affect a borrower’s ability to meet its contractual obligation under the loan agreement. The assessment process includes reviewing a borrower’s current financial information, historical payment experience, credit documentation, public information, and other information specific to each individual borrower. Certain commercial loans are reviewed on an annual, quarterly or rotational basis or as Management becomes aware of information affecting a borrower’s ability to fulfill its obligation.
	The credit-risk grading process for commercial loans is summarized as follows:
	“Pass” Loans (Grades 1, 2, 3, 4) are not considered a greater than normal credit risk. Generally, the borrowers have the apparent ability to satisfy obligations to the bank, and the Corporation anticipates insignificant uncollectible amounts based on its individual loan review.
	“Special-Mention” Loans (Grade 5) are commercial loans that have identified potential weaknesses that deserve Management’s close attention. If left uncorrected, these potential weaknesses may result in noticeable deterioration of the repayment prospects for the asset or in the institution’s credit position.
	“Substandard” Loans (Grade 6) are inadequately protected by the current financial condition and paying capacity of the obligor or by any collateral pledged. Loans so classified have a well-defined weakness or weaknesses that may jeopardize the liquidation of the debt pursuant to the contractual principal and interest terms. Such loans are characterized by the distinct possibility that the Corporation may sustain some loss if the deficiencies are not corrected.
	“Doubtful” Loans (Grade 7) have all the weaknesses inherent in those classified as substandard, with the added characteristic that existing facts, conditions, and values make collection or liquidation in full highly improbable. Such loans are currently managed separately to determine the highest recovery alternatives.
	If a nonperforming, substandard loan has an outstanding balance of $0.3 million or greater or if a doubtful loan has an outstanding balance of $0.1 million or greater, as determined by the Corporation’s credit-risk grading process, further analysis is performed to determine the probable loss, if any, and assign a specific allowance to the loan if needed. The allowance for loan losses relating to originated loans that have become impaired is based on either expected cash flows discounted at the loan’s original effective interest rate, the observable market price, or the fair value of the collateral for certain collateral dependent loans. To the extent credit deterioration occurs on purchased loans after the date of acquisition, the Corporation records an allowance for loan losses, net of any expected reimbursement under any FDIC Loss Sharing Agreements.
	Management also considers internal and external factors such as economic conditions, credit quality trends, loan management practices, portfolio monitoring, and other risks, collectively known as qualitative factors, or Q-factors, to estimate credit losses in the loan portfolio. Q-factors are used to reflect changes in the portfolio’s collectability characteristics not captured by historical loss data.
	The Corporation also assesses the credit risk associated with off-balance sheet loan commitments and letters of credit. The liability for off-balance sheet credit exposure related to loan commitments and other credit guarantees is included in other liabilities on the Consolidated Balance Sheet.
Acquired Loans, Covered Loans and Related Loss Share Receivable	Acquired Loans, Covered Loans and Related Loss Share Receivable
	Acquired loans (nonimpaired and impaired) are initially measured at fair value as of the acquisition date. The fair value estimates for acquired loans are based on the estimate of expected cash flows, both principal and interest and prepayments, discounted at prevailing market interest rates. Credit discounts representing the principal losses expected over the life of the loan are also a component of the initial fair value; therefore, an allowance for loan losses is not recorded at the acquisition date.
	The Corporation evaluates acquired loans for impairment in accordance with the provisions of ASC 310-30. Acquired loans are considered impaired if there is evidence of credit deterioration since origination and if it is probable at time of acquisition that all contractually required payments will not be collected. In determining the acquisition date fair value of acquired impaired loans, and in subsequent accounting, the Corporation generally aggregates impaired loans into pools of loans with common characteristics. Each pool is accounted for as a single asset with one composite interest rate and an aggregate expectation of cash flows. Expected cash flows at the acquisition date in excess of the fair value of the loans is referred to as the accretable yield and recorded as interest income over the life of the loans. Acquired impaired loans are not classified as nonaccrual or nonperforming as they are considered to be accruing loans because their interest income relates to the accretable yield recognized at the pool level and not to contractual interest payments at the loan level. Subsequent to the acquisition date, increases in expected cash flows will generally result in a recovery of any previously recorded ALL, to the extent applicable, and/or a reclassification from the nonaccretable difference to accretable yield, which will be recognized prospectively. The present value of any decreases in expected cash flows after the acquisition date will generally result in an impairment charge recorded as a provision for loan losses, resulting in an increase to the ALL, net of any expected reimbursement under FDIC Loss Share Agreements, to the extent applicable. Revolving loans, including lines of credit and credit cards loans, and leases are excluded from acquired impaired loan accounting.
	For acquired nonimpaired loans, the difference between the acquisition date fair value and the contractual amounts due at the acquisition date represents the fair value adjustment. Fair value adjustments may be discounts (or premiums) to a loan’s cost basis and are accreted (or amortized) to interest income over the the loan’s remaining life using the level yield method. Subsequent to the acquisition date, the method utilized to estimate the required allowance for loan losses for these loans is similar to originated loans, however, the Corporation records an allowance for loan losses only when the required allowance, net of any expected reimbursement under any FDIC Loss Share Agreements, to the extent applicable, exceeds the remaining fair value adjustment. Acquired nonimpaired loans are reported net of the unamortized fair value adjustment. Nonimpaired acquired loans are placed on nonaccrual status and reported as nonperforming or past due using the same criteria applied to the originated portfolio.
	Loans acquired in FDIC assisted transactions and covered under FDIC Loss Share Agreements are referred to as covered loans. Covered loans are recorded at fair value at the date of acquisition exclusive of the FDIC Loss Share Agreements. No allowance for loan losses related to covered loans is recorded on the acquisition date as the fair value of the loans acquired incorporates assumptions regarding credit risk. The covered loans are subsequently valued and accounted for in the same manner as the acquired loans disclosed above.
	A loss share receivable is recorded at the acquisition date which represents the estimated fair value of reimbursement the Corporation expects to receive from the FDIC for incurred losses on certain covered loans. The fair value measurement reflects counterparty credit risk and other uncertainties. The loss share receivable continues to be measured on the same basis as the related indemnified loans. Deterioration in the credit quality of the loans (recorded as an adjustment to the allowance for covered loan losses) would immediately increase the basis of the loss share receivable, with the offset recorded through the consolidated statement of comprehensive income. Increases in the credit quality or cash flows of loans (reflected as an adjustment to yield and accreted into income over the remaining life of the loans) decrease the basis of the loss share receivable, with such decrease being accreted into income over 1) the same period or 2) the life of the loss share agreements, whichever is shorter. Loss assumptions used in the basis of the loss share receivable are consistent with the loss assumptions used to measure the related covered loans.
	Upon the determination of an incurred loss the loss share receivable will be reduced by the amount owed by the FDIC. A corresponding claim receivable is recorded in accrued interest receivable and other assets on the Consolidated Balance Sheet until cash is received from the FDIC.
	An acquired or covered loan may be resolved either through receipt of payment (in full or in part) from the borrower, the sale of the loan to a third party, or foreclosure of the collateral. In the period of resolution of a nonimpaired loan, any remaining unamortized fair value adjustment is recognized as interest income. In the period of resolution of an impaired loan accounted for on an individual basis, the difference between the carrying amount of the loan and the proceeds received is recognized as a gain or loss within noninterest income. The majority of impaired loans are accounted for within a pool of loans which results in any difference between the proceeds received and the loan carrying amount being deferred as part of the carrying amount of the pool. The accretable amount of the pool remains unaffected from the resolution until the subsequent quarterly cash flow re-estimation. Favorable results from removal of the resolved loan from the pool increase the future accretable yield of the pool, while unfavorable results are recorded as impairment in the quarter of the cash flow re-estimation. Acquired or covered impaired loans subject to modification are not removed from a pool even if those loans would otherwise be deemed TDRs as the pool, and not the individual loan, represents the unit of account.
	For further discussion of the Corporation’s acquisitions and loan accounting, see Note 2 (Business Combinations), Note 4 (Loans), and Note 5 (Allowance for Loan Losses).
Equipment Lease Financing	Equipment Lease Financing
	The Corporation leases equipment directly to customers. The net investment in financing leases includes the aggregate amount of lease payments to be received and the estimated residual values of the equipment, less unearned income. Income from lease financing is recognized over the lives of the leases on an approximate level rate of return on the unrecovered investment. The residual value represents the estimated fair value of the leased asset at the end of the lease term. Unguaranteed residual values of leased assets are reviewed at least annually for impairment. Declines in residual values determined to be other-than-temporary are recognized in earnings in the period such determinations are made.
Mortgage Servicing Rights	Mortgage Servicing Rights
	The Corporation periodically sells residential real estate loans while retaining the rights and obligations to perform the servicing of such loans. Whenever the Corporation undertakes an obligation to service such loans, Management assesses whether a servicing asset or liability should be recognized. A servicing asset is recognized whenever the compensation for servicing is expected to exceed servicing costs. Likewise, a servicing liability would be recognized in the event that servicing fees to be received are not expected to adequately compensate the Corporation for its expected cost. Servicing assets associated with retained mortgage servicing rights are presented within other assets on the balance sheet. The Corporation does not presently have any servicing liabilities.
	MSRs are initially valued at fair value. Servicing assets and liabilities are subsequently measured using the amortization method which requires servicing rights to be amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying loans. Amortization is recorded in loan sales and servicing income in the Consolidated Statement of Income.
	At each reporting period, MSRs are assessed for impairment based on fair value of those rights on a stratum-by-stratum basis. The Corporation stratifies its servicing rights portfolio into tranches based on loan type and interest rate, the predominant risk characteristics of the underlying loans. Any impairment is recognized through a valuation allowance for each impaired stratum through a charge to income. If the Corporation later determines that all or a portion of the impairment no longer exists for a particular grouping, a reduction of the allowance may be recorded as an increase to income.
	The Corporation also reviews MSRs for OTTI each quarter and recognizes a direct write-down when the recoverability of a recorded allowance for impairment is determined to be remote. Unlike an allowance for impairment, a direct write-down permanently reduces the unamortized cost of the MSR and the allowance for impairment.
	MSRs do not trade in an active open market with readily observable market prices. Although sales of MSRs do occur, the exact terms and conditions may not be available. As a result, the fair value of MSRs is estimated using discounted cash flow modeling techniques which require Management to make assumptions regarding future net servicing income, adjusted for such factors as net servicing income, discount rate and prepayments. The primary assumptions used in determining the current fair value of the Corporation’s MSRs as well as a sensitivity analysis are presented in Note 7 (Mortgage Servicing Rights and Mortgage Servicing Activity).
	The Corporation generally records loan administration fees for servicing loans for investors on the accrual basis of accounting. Servicing fees and late fees related to delinquent loan payments are also recorded on the accrual basis of accounting.
Depreciation and Amortization	Depreciation and Amortization
	Premises and equipment are reported at cost less accumulated depreciation and amortization and principally depreciated using the straight-line method over their estimated useful lives. Estimated useful lives for furniture and equipment range from three to 15 years, and depreciable buildings ranges from 10 to 35 years. Amortization of leasehold improvements is computed on the straight-line method based on related lease terms or the estimated useful lives of the assets of up to 15 years, whichever is shorter.
	The Corporation purchases, as well as internally develops and customizes, certain software to enhance or perform internal business functions. Software development costs incurred in the planning and post-development project stages are charged to noninterest expense. Costs associated with designing software configuration and interfaces, installation, coding programs and testing systems are capitalized and amortized using the straight-line method over periods ranging from three to seven years.
Goodwill and Intangible Assets	Goodwill and Other Intangible Assets
	Goodwill represents the amount by which the cost of net assets acquired in a business combination exceeds their fair value. Goodwill is evaluated for impairment on an annual basis or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The goodwill impairment test is a two-step process. The first step compares the reporting unit’s estimated fair values, including goodwill, to its carrying amount. If the carrying amount exceeds its fair value, then goodwill impairment may be indicated. The second step allocates the reporting units fair value to its assets and liabilities. If the unallocated fair value does not exceed the carrying amount of goodwill then an impairment loss would be recognized as a charge to earnings.
	Other intangible assets represent the present value of the future stream of income to be derived from the purchase of core deposits. Other intangible assets are amortized on a straight-line basis over their estimated useful lives. Goodwill and other intangible assets deemed to have indefinite lives are not amortized.
Other Real Estate Owned	Other Real Estate Owned
	Other real estate owned is included in other assets in the consolidated balance sheets and is primarily comprised of property acquired through loan foreclosure proceedings or acceptance of a deed-in-lieu of foreclosures, and loans classified as in-substance foreclosure. Other real estate owned is recorded at the lower of the recorded investment in the loan at the time of transfer or the fair value of the underlying property collateral, less estimated selling costs. Any write-down in the carrying value of a property at the time of acquisition is charged to the allowance for loan losses. Any subsequent write-downs to reflect current fair market value, as well as gains and losses on disposition and revenues and expenses incurred in maintaining such properties, are treated as period costs. Other real estate owned also includes bank premises formerly but no longer used for banking. Banking premises are transferred at the lower of carrying value or estimated fair value, less estimated selling costs.
Derivative Instruments and Hedging Activites	Derivative Instruments and Hedging Activities
	The Corporation uses interest rate swaps, interest rate lock commitments and forward contracts sold to hedge interest rate risk for asset and liability management purposes. All derivatives are recorded as either other assets or other liabilities at fair value. Credit risk associated with derivatives is reflected in the fair values recorded for those positions. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedging relationship, and further, on the type of hedging relationship. For derivatives that are not designated as hedging instruments, the gain or loss is recognized immediately in other operating income. A derivative that is designated and qualifies as a hedging instrument must be designated a fair value hedge, a cash flow hedge or a hedge of a net investment in a foreign operation. The Corporation does not have any cash flow hedges or derivatives that hedge net investments in foreign operations.
	Effectiveness measures the extent to which changes in the fair value of a derivative instrument offset changes in the fair value of the hedged item. If the relationship between the change in the fair value of the derivative instrument and the fair value of the hedged item falls within a range considered to be the industry norm, the hedge is considered highly-effective and qualifies for hedge accounting. A hedge is ineffective if the offsetting difference between the fair values falls outside the acceptable range.
	A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities and firm commitments caused by changes in interest rates or other economic factors. The Corporation recognizes the gain or loss on these derivatives, as well as the related gain or loss on the underlying hedged item, in earnings during the period in which the fair value changes. If a hedge is perfectly effective, the change in the fair value of the hedged item will be offset, resulting in no net effect on earnings.
	A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The effective portion of a gain or loss on any cash flow hedge is reported as a component of accumulated other comprehensive income (loss) and reclassified into other operating income in the same period or periods that the hedged transaction affects earnings. Any ineffective portion of the derivative gain or loss is recognized in other operating income during the current period.
	The Corporation enters into commitments to originate mortgage loans whereby the interest rate on the prospective loan is determined prior to funding (rate lock commitments). Rate lock commitments on mortgage loans that are intended to be sold are considered to be derivatives. Accordingly, such commitments, along with any related fees received from potential borrowers, are recorded at fair value as derivative assets or liabilities, with changes in fair value recorded in net gain or loss on sale of mortgage loans.
Income Taxes	Income Taxes
	Income tax expense is the total of the current year income tax due or refundable and the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are the expected future tax amounts for the temporary differences between the carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates. A valuation allowance, if needed, reduces deferred tax assets to the amount expected to be realized.
	A tax position is recognized as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax being presumed to occur. The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.
	The Corporation follows the asset and liability method of accounting for income taxes. Deferred income taxes are recognized for the tax consequences of “temporary differences” by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts and the tax bases of existing assets and liabilities. The effect of a change in tax rates is recognized in income in the period of enactment date.
	In assessing the realizability of deferred tax assets, Management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Assessing the need for, or the sufficiency of, a valuation allowance requires Management to evaluate all available evidence, both negative and positive, including the recent trend of quarterly earnings. Positive evidence necessary to overcome the negative evidence includes whether future taxable income in sufficient amounts and character within the carryback and carryforward periods is available under the tax law, including the use of tax planning strategies. When negative evidence (e.g., cumulative losses in recent years, history of operating loss or tax credit carryforwards expiring unused) exists, more positive evidence than negative evidence will be necessary.
	Additional information regarding income taxes is included in Note 13 (Income Taxes).
Treasury Stock	Treasury Stock
	Treasury stock is accounted for using the cost method in which reacquired shares reduce outstanding Common Stock and capital surplus. At the date of subsequent reissue, the treasury stock account is reduced by the cost of such stock on the last-in, first-out basis.
Per Share Data	Per Share Data
	Basic net income per common share is calculated using the two-class method to determine income attributable to common shareholders. The two-class method is an earnings allocation formula that determines earnings per share for each share of common stock and participating securities according to dividends declared (distributed earnings) and participation rights in undistributed earnings. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights to receive dividends. Unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are considered participating securities (i.e., nonvested restricted stock). Undistributed net losses are not allocated to nonvested restricted shareholders, as these shareholders do not have a contractual obligation to fund the losses incurred by the Corporation. Net income attributable to Common Stock is then divided by the weighted-average number of Common Stock outstanding during the period.
	Diluted net income per common share is calculated under the more dilutive of either the treasury method or two-class method. For the diluted calculation, the weighted-average number of shares of Common Stock outstanding by the assumed conversion of outstanding convertible preferred stock from the beginning of the year or date of issuance, if later, and the number of shares of Common Stock that would be issued assuming the exercise of stock options and warrants using the treasury stock method. The treasury stock method assumes that the Corporation uses the proceeds from a hypothetical exercise of any options and warrants to repurchase Common Stock at the average market price during the period. These adjustments to the weighted-average number of shares of Common Stock outstanding are made only when such adjustments will dilute earnings per common share.
	All earnings per share disclosures appearing in these financial statements, related notes and management’s discussion and analysis, are computed assuming dilution unless otherwise indicated. The Corporation’s earnings per share calculations are illustrated in Note 21 (Shareholders' Equity) under the heading “Earnings per Share.
Trust Department Assets and Income	Trust Department Assets and Income
	Property held by the Corporation in a fiduciary or other capacity for trust customers is not included in the accompanying consolidated financial statements, since such items are not assets of the Corporation. Trust department income is reported on the accrual basis of accounting.
Share-Based Compensation	Share-Based Compensation
	The Corporation’s share-based compensation plans are described in detail in Note 15 (Share-Based Compensation). The Corporation recognizes share-based compensation expense using the straight-line method over the requisite service period for all stock awards, including those with graded vesting. The requisite service period is the period an employee is required to provide service in order to vest in the award, which cannot extend beyond the date at which the employee is no longer required to perform any service to receive the share-based compensation (the retirement-eligible date). Certain awards are contingent upon performance conditions, which affect the number of awards ultimately granted. The Corporation periodically evaluates the probable outcome of the performance conditions and makes cumulative adjustments to compensation expense as appropriate.
Pension and Other Postretirement Plans	Pension and Other Postretirement Plans
	Pension and other postretirement costs are based on assumptions concerning future events that will affect the amount and timing of required benefit payments under the Corporation’s plans. These assumptions include demographic assumptions such as retirement age and mortality, a compensation rate increase, a discount rate used to determine the current benefit obligation and a long-term expected rate of return on plan assets. Net periodic benefit cost includes service and interest cost based on the assumed discount rate, an expected return on plan assets based on an actuarially derived market-related value and amortization of prior service cost and net actuarial gains or losses. The amortization of any prior service costs is determined using a straight line amortization of the cost over the average remaining lifetime of participants expected to receive benefits under the plans. Actuarial gains and losses include the impact of plan amendments and various unrecognized gains and losses, which are deferred and amortized over the future service periods of active employees. The overfunded or underfunded status of the plans is recorded as an asset or liability, respectively, in the Consolidated Balance Sheet, with changes in that status recognized through other comprehensive income. Additional information about pension and other postretirement plans is included in Note 14 (Benefit Plans).
Revenue Recognition	Revenue Recognition
	The Corporation recognizes revenues as they are earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. The Corporation’s principal source of revenue is interest income, which is recognized on an accrual basis primarily according to nondiscretionary formulas in written contracts, such as loan agreements or securities contracts.
Fair Value Measurement	Fair Value Measurement
	Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants. It represents an exit price at the measurement date. Market participants are buyers and sellers, who are independent, knowledgeable, and willing and able to transact in the principal (or most advantageous) market for the asset or liability being measured. Current market conditions, including imbalances between supply and demand, are considered in determining fair value. The Corporation values its assets and liabilities in the principal market where it sells the particular asset or transfers the liability with the greatest volume and level of activity. In the absence of a principal market, the valuation is based on the most advantageous market for the asset or liability (i.e., the market where the asset could be sold or the liability transferred at a price that maximizes the amount to be received for the asset or minimizes the amount to be paid to transfer the liability).
	In measuring the fair value of an asset, the Corporation assumes the highest and best use of the asset by a market participant to maximize the value of the asset, and does not consider the intended use of the asset.
	When measuring the fair value of a liability, the Corporation assumes that the nonperformance risk associated with the liability is the same before and after the transfer. Nonperformance risk is the risk that an obligation will not be satisfied and encompasses not only the Corporation’s own credit risk (i.e., the risk that the Corporation will fail to meet its obligation), but also other risks such as settlement risk. The Corporation considers the effect of its own credit risk on the fair value for any period in which fair value is measured.
	There are three acceptable valuation techniques that can be used to measure fair value: the market approach, the income approach and the cost approach. Selection of the appropriate technique for valuing a particular asset or liability takes into consideration the exit market, the nature of the asset or liability being valued, and how a market participant would value the same asset or liability. Ultimately, determination of the appropriate valuation method requires significant judgment, and sufficient knowledge and expertise are required to apply the valuation techniques.
	Valuation inputs refer to the assumptions market participants would use in pricing a given asset or liability using one of the three valuation techniques. Inputs can be observable or unobservable. Observable inputs are those assumptions which market participants would use in pricing the particular asset or liability. These inputs are based on market data and are obtained from a source independent of the Corporation. Unobservable inputs are assumptions based on the Corporation’s own information or estimate of assumptions used by market participants in pricing the asset or liability. Unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy which gives the highest ranking to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for assets or liabilities classified as Level 2 are based on one or a combination of the following factors: (i) quoted prices for similar assets; (ii) observable inputs for the asset or liability, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Corporation considers an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability.
	Assets and liabilities are considered to be fair valued on a recurring basis if fair value is measured regularly (i.e., daily, weekly, monthly or quarterly). Recurring valuation occurs at a minimum on the measurement date. Assets and liabilities are considered to be fair valued on a nonrecurring basis if the fair value measurement of the instrument does not necessarily result in a change in the amount recorded on the balance sheet. Generally, nonrecurring valuation is the result of the application of other accounting pronouncements which require assets or liabilities to be assessed for impairment or recorded at the lower of cost or fair value. The fair value of assets or liabilities transferred in or out of Level 3 is measured on the transfer date, with any additional changes in fair value subsequent to the transfer considered to be realized or unrealized gains or losses. Additional information regarding fair value measurements is provided in Note 18 (Fair Value Measurement).
Reclassifications	Reclassifications
	Certain reclassifications of prior years’ amounts have been made to conform to current year presentation. Such reclassifications had no effect on prior year net income or shareholders’ equity.
New Accounting Pronouncements and Changes in Accounting Principles
New Accounting Pronouncements, Policy	) Recently Adopted Accounting Standards
	FASB ASU 2014-01, Accounting for Investments in Qualified Affordable Housing Projects. The amendments in ASU 2014-01 do not change the existing accounting methods, but permit reporting entities to make an accounting policy election to account for their investments in qualified affordable projects using the proportional amortization method, if certain conditions are met. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as a component of income tax expense (benefit). The amendments in ASU 2014-01 are effective for annual periods and interim reporting periods within those annual periods, beginning after December 15, 2014, and should be applied retrospectively to all periods presented. The Corporation early adopted ASU 2014-01 in the first quarter of 2014. Amortization of the initial investment cost of qualifying projects is now recorded in the provision for income taxes together with the tax credits and benefits received. Previously, the amortization was recorded as other noninterest expense. All prior period amounts have been restated to reflect the adoption of the amendment, which resulted in an offsetting decrease to other noninterest expense and increase to the provision for income taxes of approximately $3.1 million and $2.7 million for the years ended, December 31, 2013, and December 31, 2012, respectively.
	(aa) Recently Issued Accounting Standards
	FASB ASU 2015-2, Amendments to the Consolidation Analysis. The amendments in ASU 2015-02 affect reporting entities that are required to evaluate whether they should consolidate certain legal entities. All legal entities are subject to reevaluation under the revised consolidation model. These amendments modify the evaluation of whether limited partnerships and other similar entities are variable interest entities; eliminate the presumption that a general partner should consolidate a limited partnership; affect the consolidation analysis
	that are involved with variable interest entities; and provide a scope exception from consolidation for entities that are required to comply or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The amendments are effective for public business entities for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption in an interim period. If an entity early adopts the amendments in an interim period, any adjustments should be reflected as of the beginning of the fiscal year that includes that interim period. A reporting entity may apply the amendments using a modified retrospective approach by recording a cumulative-effect adjustment to equity as of the beginning of the fiscal year of adoption. A reporting entity also may apply the amendments retrospectively. The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
	FASB ASU 2014-17, Pushdown Accounting—a consensus of the FASB Emerging Issues Task Force. The objective of this update is to provide guidance on whether and at what threshold an acquired entity can apply pushdown accounting in the acquired entities separate financial statements. The amendments in this update provide the acquired entity the option to apply pushdown accounting accounting in the reporting period in which the change-in-control event occurs or in a subsequent reporting period after the change-in-control event occurs. If the election if made in the current reporting period, the entity should disclose information in the current reporting period that enables users of financial statements to evaluate the effect of pushdown accounting. If the election is made after the current period the change-in-control event, it is irrevocable and should be considered a change in accounting principle in accordance with Topic 250, Accounting Changes and Error Corrections. The ASU is effective on November 18, 2014. After the effective date, acquired entities can make the election to future change-in-control events or to its most recent change-in-control event. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
	FASB ASU 2014-14, Classification of Certain Government-Guaranteed Mortgage Loans upon Foreclosure—a consensus of the FASB Emerging Issues Task Force. The objective of this update is to reduce diversity in practice by addressing the classification of certain foreclosed mortgage loans held by creditors that are either fully or partially guaranteed under government programs. The amendments in this update require that a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the
	following conditions are met: 1) the loan has a government guarantee that is not separable from the
	loan before foreclosure; 2) at the time of foreclosure, the creditor has the intent to convey the real
	estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim; and 3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal and interest) expected to be recovered from the guarantor. The ASU is effective for interim and annual periods beginning after December 15, 2014. The amendments can be adopted using either a prospective transition method or a modified retrospective transition method. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
	FASB ASU 2014–12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved After the Requisite Service Period — a consensus of the FASB Emerging Issues Task Force. The amendments in this update clarify that entities should treat performance targets that can be met after the requisite service period of a share-based payment award as performance conditions that affect vesting. Therefore, an entity would not record compensation expense (measured as of the grant date without taking into account the effect of the performance target) related to an award for which transfer to the employee is contingent on the entity’s satisfaction of a performance target until it becomes probable that the performance target will be met. The ASU does not contain any new disclosure requirements. The ASU is effective for interim and annual reporting periods beginning after December 15, 2015. Early adoption is permitted. In addition, entities will have the option of applying the guidance either prospectively (i.e., only to awards granted or modified on or after the effective date) or retrospectively. Retrospective application would only apply to awards with performance targets outstanding at or after the beginning of the first annual period presented (i.e., the earliest presented comparative period). The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
	FASB ASU 2014-11, Transfers and Servicing: Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures. The amendments in this update require entities to account for repurchase-to-maturity transactions as secured borrowings (rather than as sales with forward repurchase agreements), eliminate accounting guidance on linking repurchase financing transactions, and expand disclosure requirements related to certain transfers of financial assets that are accounted for as sales and certain transfers, such as repos, securities lending transactions, and repurchase-to-maturity transactions, accounted for as secured borrowings. The amendments in ASU 2014-11 are effective for the first interim or annual period beginning after December 15, 2014. The amendments must present changes in accounting for transactions outstanding on the effective date as a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. Early application is prohibited. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
	FASB ASU 2014-09, Revenue from Contracts with Customers. The amendments in this update supersede virtually all existing GAAP revenue recognition guidance, including most industry-specific revenue recognition guidance. ASU 2014-09 creates a single, principle-based revenue recognition framework and will require entities to apply significantly more judgment and expanded disclosures surrounding revenue recognition. The core principle requires an entity to recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 applies to contracts with customers to provide goods and services, with certain exclusions such as lease contracts, financing arrangements, and financial instruments. The amendments in ASU 2014-09 are effective for fiscal years beginning after December 15, 2016. The amendments can be adopted using either the full retrospective approach or a modified retrospective approach. Early adoption is prohibited. The Corporation is in process of assessing the potential impact the adoption of this guidance will have on its consolidated financial statements.
	FASB ASU 2014-08, Presentation of Financial Statements and Property, Plant, and Equipment: Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. The amendments in this update change the definition of a discontinued operation in ASC 205-20 and require additional disclosures for transactions that meet the definition of a discontinued operation and certain other significant transactions that do not meet the discontinued operations criteria. The amendments in ASU 2014-08 are effective prospectively for all disposals, except disposals classified as held for sale before the adoption date or components initially classified as held for sale in periods beginning on or after December 15, 2014, with early adoption permitted. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.
	FASB ASU 2014-04, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. ASU 2014-04 amends the guidance in ASC 310-40 by clarifying when an in-substance repossession or foreclosure occurs, and a creditor is considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan. Additionally, the amendments require interim and annual disclosure of both 1) the amount of foreclosed residential real estate property held by the creditor and 2) the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure according to local requirements of the applicable jurisdiction. The amendments in ASU 2014-04 are effective for annual periods, and interim period within those annual periods, beginning after December 15, 2014. The amendments can either be adopted using a modified retrospective or a prospective transition method. The adoption of this accounting guidance is not expected to have a material effect on the Corporation’s financial position or results of operations.

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The Citizens transaction was accounted for using the acquisition method of accounting and, as such, assets acquired, liabilities assumed and consideration exchanged were recorded at estimated fair value on the Acquisition Date. Per the applicable accounting guidance for business combinations, these fair values were subject to refinement for up to one year after the closing date of the acquisition as additional information relative to closing date fair values become available. The measurement period ended on March 31, 2014.
	The following table provides the purchase price calculation as of the Acquisition Date and the identifiable assets purchased and the liabilities assumed at their estimated fair value. These fair value measurements are based on third-party valuations.
	(In thousands, except per share amounts)
	Purchase Price:
	FirstMerit shares of Common Stock issued for Citizens' shares						55,468,283
	Closing price per share of the Corporation's Common Stock on April 12, 2013						$	16.68
	Consideration from Common Stock conversion (1.37 ratio)						925,211
	Cash paid to the Treasury for Citizens' TARP Preferred						355,371
	Cash paid in lieu of fractional shares to the former Citizens' shareholders						61
	Consideration from the warrant issued to the Treasury for Citizens' TARP warrant						3,000
	Total purchase price						$	1,283,643
	Statement of Net Assets Acquired at Fair Value:
	ASSETS
	Cash and due from banks		$	544,380
	Investment securities		3,202,575
	Loans		4,617,004
	Premises and equipment		138,536
	Intangible assets		84,774			(1)
	Accrued interest receivable and other assets		681,100
	Total assets		$	9,268,369
	LIABILITIES
	Deposits		$	7,276,754
	Borrowings		908,824
	Accrued taxes, expenses, and other liabilities		80,842
	Total liabilities		$	8,266,420
	Net identifiable assets acquired						1,001,949
	Goodwill						$	281,694
	(1) Intangible assets consist of core deposit intangibles of $70.8 million and trust relationships of approximately $14.0 million. The useful lives for which the core deposit intangible and the trust relationships are being amortized over are 15 years and 12 years, respectively.
Acquired Impaired and Non-Impaired Loans at Acquisition Date	The following table summarizes the final fair value of both acquired impaired and nonimpaired loans by product type as of the Acquisition Date.
	(In thousands)	Acquired Impaired Loans				Acquired Nonimpaired Loans			Acquired Loans Total
	Commercial
	C&I	$	93,735			$	1,660,199		$	1,753,934
	CRE	378,569				359,066			737,635
	Construction	13,399				17,135			30,534
	Total commercial	485,703				2,036,400			2,522,103
	Consumer
	Residential mortgages	232,291				278,404			510,695
	Installment	54,108				1,165,235			1,219,343
	Home equity lines	47,613				317,250			364,863
	Total consumer	334,012				1,760,889			2,094,901
	Total	$	819,715			$	3,797,289		$	4,617,004
Acquired Non-impaired Loans Fair Value at Acquisition Date	For acquired nonimpaired loans, the difference between the Acquisition Date fair value and the contractual amounts due at the Acquisition Date represents the fair value adjustment. The fair value adjustment may be a discount (or premium) to an individual loan’s cost basis and is accreted (or amortized) to interest income over the the loan’s remaining life using the level yield method. Acquired nonimpaired loans are reported net of the unamortized fair value adjustment. The fair value adjustment for acquired nonimpaired loans as of the Acquisition Date is presented in the following table.
	(In thousands)	Acquired Nonimpaired Loans
	Outstanding balance	$	4,017,304
	Less: Fair value adjustment	220,015
	Fair value of acquired nonimpaired loans	$	3,797,289
Nonimpaired Loans Cash Flows Reconciliation at Acquisition Date	The table below details contractually required payments, cash flows not expected to be collected and cash flows expected to be collected on acquired nonimpaired loans as of the Acquisition Date.
	(In thousands)	Acquired Nonimpaired Loans
	Contractually required payments including interest (1)	$	4,955,180
	Less: Contractual cash flows not expected to be collected	680,664
	Cash flows expected to be collected	$	4,274,516
	(1) Total undiscounted amounts of all uncollected contractual principal and interest, including any fees and penalties, both past due and scheduled for the future, assuming no loss or prepayment.
Reconciliation of Carrying Amount of Acquired Impaired Loans	A reconciliation of the contractual required payments to the fair value of the acquired impaired loans at the Acquisition Date is as follows:
	(In thousands)	Acquired Impaired Loans
	Contractually required payments including interest (1)	$	1,231,172
	Nonaccretable difference (2)	(279,899		)
	Cash flows expected to be collected (3)	951,273
	Accretable yield (4)	(131,558		)
	Fair value of loans acquired	$	819,715
	(1) Total undiscounted amounts of all uncollected contractual principal and interest, including any fees and penalties, both past due and scheduled for the future, assuming no loss or prepayment.
	(2) The nonaccretable difference represents, as of the Acquisition Date, the amount of contractually required payments, including interest, that are not expected to be collected based on estimated credit losses and other factors, such as prepayments.
	(3) Represents the estimate, at Acquisition Date, of the amount and timing of undiscounted principal, interest, and other cash flows expected to be collected. This estimate includes the effect of anticipated prepayments.
	(4) The accretable yield represents the excess of cash flows expected at Acquisition Date over the estimated fair value and is recognized as interest income over the remaining life of the loan using the level yield method.
Business Acquisition, Pro Forma Information	The following table provides the unaudited pro forma information for the results of operations for the year ended December 31, 2013, as if the Citizens acquisition had occurred January 1, 2013. These adjustments include the impact of certain purchase accounting adjustments including accretion of loan marks, which makes up the vast majority of the adjustments, followed by intangible assets amortization, investment securities amortization, fixed assets depreciation and deposit accretion. In addition, $75.1 million in merger-related expenses recorded in 2013 are included in the period presented. The unaudited pro forma results are presented for illustrative purposes and are not intended to represent or be indicative of the actual results of operations of the combined corporation that would have been achieved had the acquisition occurred at the beginning of the year of acquisition, nor are they intended to represent or be indicative of future results of operations.
			(Unaudited)
			Year Ended December 31,
	(In thousands)				2013
	Total revenue, net of interest expense				$	1,096,960
	Net income				196,744

Investment_Securities_Tables

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Amortized cost and fair value for the major categories of held-to-maturity and available-for-sale securities	The following tables provide the amortized cost and fair value for the major categories of held-to-maturity and available-for-sale securities. Held-to-maturity securities are carried at amortized cost, which reflects historical cost, adjusted for amortization of premiums and accretion of discounts. Available-for-sale securities are carried at fair value with net unrealized gains or losses reported on an after tax basis as a component of OCI in shareholders' equity.
			December 31, 2014
	(In thousands)		Amortized				Gross Unrealized Gains				Gross Unrealized Losses				Fair
			Cost												Value
	Securities available-for-sale
	Debt securities
		U.S. government agency debentures	$	2,500			$	—			$	(18	)		$	2,482
		U.S. states and political subdivisions	221,052				6,756				(466		)		227,342
		Residential mortgage-backed securities:
		U.S. government agencies	951,839				22,377				(3,218		)		970,998
		Commercial mortgage-backed securities:
		U.S. government agencies	104,176				598				(1,371		)		103,403
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,698,015				4,777				(26,225		)		1,676,567
		Nonagency	7				—				—				7
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	222,876				863				(1,405		)		222,334
		Asset-backed securities:
		Collateralized loan obligations	297,446				11				(9,613		)		287,844
		Corporate debt securities	61,652				—				(10,315		)		51,337
		Total debt securities	3,559,563				35,382				(52,631		)		3,542,314
	Equity securities
		Marketable equity securities	2,974				—				—				2,974
		Total equity securities	2,974				—				—				2,974
		Total securities available for sale	$	3,562,537			$	35,382			$	(52,631	)		$	3,545,288
	Securities held-to-maturity
	Debt securities
		U.S. treasuries	$	5,000			$	—			$	—			$	5,000
		U.S. government agency debentures	25,000				—				(537		)		24,463
		U.S. states and political subdivisions	517,824				12,645				(191		)		530,278
		Residential mortgage-backed securities:
		U.S. government agencies	580,727				7,495				(3,045		)		585,177
		Commercial mortgage-backed securities:
		U.S. government agencies	58,143				281				(329		)		58,095
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,368,534				718				(38,875		)		1,330,377
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	257,642				557				(6,768		)		251,431
		Corporate debt securities	90,739				412				(52		)		91,099
		Total securities held to maturity	$	2,903,609			$	22,108			$	(49,797	)		$	2,875,920
			December 31, 2013
	(In thousands)		Amortized				Gross Unrealized Gains				Gross Unrealized Losses				Fair
			Cost												Value
	Securities available-for-sale
	Debt securities
		U.S. states and political subdivisions	$	258,787			$	7,376			$	(3,796	)		$	262,367
		Residential mortgage-backed securities:
		U.S. government agencies	962,687				21,662				(14,427		)		969,922
		Commercial mortgage-backed securities:
		U.S. government agencies	72,048				7				(2,488		)		69,567
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,566,262				4,199				(52,068		)		1,518,393
		Nonagency	9				—				—				9
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	104,152				273				(2,157		)		102,268
		Asset-backed securities:
		Collateralized loan obligations	297,259				760				(4,332		)		293,687
		Corporate debt securities	61,596				—				(10,952		)		50,644
		Total debt securities	3,322,800				34,277				(90,220		)		3,266,857
	Equity Securities
		Marketable equity securities	3,036				—				—				3,036
		Nonmarketable equity securities	3,281				—				—				3,281
		Total equity securities	6,317				—				—				6,317
		Total securities available for sale	$	3,329,117			$	34,277			$	(90,220	)		$	3,273,174
Securities held-to-maturity
Debt securities
	U.S. treasuries	$	5,000			$	4			$	—			$	5,004
	U.S. government agency debentures	25,000				—				(1,348		)		23,652
	U.S. states and political subdivisions	480,703				5,335				(10,459		)		475,579
	Residential mortgage-backed securities:
	U.S. government agencies	569,960				1,108				(11,617		)		559,451
	Commercial mortgage-backed securities:													—
	U.S. government agencies	56,596				—				(1,190		)		55,406
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,464,732				—				(81,818		)		1,382,914
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	240,069				6				(11,052		)		229,023
	Corporate debt securities	93,628				308				(725		)		93,211
	Total securities held to maturity	$	2,935,688			$	6,761			$	(118,209	)		$	2,824,240
Schedule of general obligation bonds	The Corporation’s U.S. states and political subdivisions portfolio is composed of general obligation bonds issued by a highly diversified number of states, cities, counties, and school districts. The amortized cost and fair value of the Corporation’s portfolio of general obligation bonds are summarized by U.S. state in the tables below. As illustrated in the tables below, the aggregate fair value of the Corporation’s general obligation bonds was greater than $10 million in eleven of the thirty-seven U.S. states in which it holds investments.
	(Dollars in thousands)	December 31, 2014
	U.S. State	# of Issuers			Average Issue Size, Fair Value				Amortized Cost				Fair Value
	Ohio	137			$	979			$	130,741			$	134,127
	Michigan	169			842				138,325				142,292
	Illinois	66			1,897				121,560				125,169
	Wisconsin	77			841				62,543				64,776
	Texas	64			801				50,307				51,293
	Pennsylvania	45			1,000				44,443				45,006
	Minnesota	42			674				27,740				28,326
	Washington	30			952				27,987				28,558
	New Jersey	37			746				26,755				27,612
	Missouri	19			1,011				18,764				19,207
	New York	19			628				11,659				11,929
	Other	120			650				76,849				78,020
	Total general obligation bonds	825			$	917			$	737,673			$	756,315
	(Dollars in thousands)	December 31, 2013
	U.S. State	# of Issuers			Average Issue Size, Fair Value				Amortized Cost				Fair Value
	Michigan	166			$	744			$	122,198			$	123,571
	Ohio	152			1,048				158,641				159,232
	Illinois	75			1,314				96,863				98,521
	Texas	69			771				54,295				53,204
	Wisconsin	86			648				54,516				55,747
	Pennsylvania	50			898				47,835				44,883
	Minnesota	45			663				29,840				29,816
	Washington	30			930				28,393				27,906
	New Jersey	38			722				27,101				27,440
	Missouri	20			969				19,253				19,382
	New York	22			585				13,064				12,878
	California	18			599				10,651				10,788
	Other	115			631				74,918				72,572
	Total general obligation bonds	886			$	831			$	737,568			$	735,940
Schedule of other investments	FRB and FHLB stock constitute the majority of other investments on the Consolidated Balance Sheet.
		December 31,
	(In thousands)	2014				2013
	FRB stock	$	55,681			$	55,294
	FHLB stock	92,547				125,032
	Other	426				477
	Total other investments	$	148,654			$	180,803
Schedule of Realized Gain (Loss)	Realized Gains and Losses
	The following table presents the proceeds from sales of available-for-sale securities and the gross realized gains and losses on the sales of those securities that have been included in earnings as a result of those sales. Gains or losses on the sales of available-for-sale securities are recognized upon sale and are determined using the specific identification method.
		Year Ended December 31,
	(In thousands)	2014				2013				2012
	Realized gains	$	382			$	3,786			$	3,786
	Realized losses	(216		)		(6,589		)		—
	Net securities (losses)/gains	$	166			$	(2,803	)		$	3,786
Unrealized Gain (Loss) on Investments	The following table presents the gross unrealized losses and fair value of securities by length of time that individual securities had been in a continuous loss position by major categories of available-for-sale and held-to-maturity securities.
			December 31, 2014
			Less than 12 months											12 months or longer											Total
	(Dollars in thousands)		Fair Value				Unrealized				Number			Fair Value				Unrealized				Number			Fair Value				Unrealized
							Losses				Impaired							Losses				Impaired							Losses
											Securities											Securities
	Securities available-for-sale
		Debt Securities
		U.S. government agency debentures	$	2,482			$	(18	)		1			$	—			$	—			—			$	2,482			$	(18	)
		U.S. states and political subdivisions	5,637				(11		)		11			22,528				(455		)		36			28,165				(466		)
		Residential mortgage-backed securities:
		U.S. government agencies	50,126				(182		)		5			199,773				(3,036		)		14			249,899				(3,218		)
		Commercial mortgage-backed securities:
		U.S. government agencies	12,284				(55		)		2			45,485				(1,316		)		6			57,769				(1,371		)
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	243,970				(906		)		15			905,478				(25,319		)		64			1,149,448				(26,225		)
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	31,375				(229		)		4			67,169				(1,176		)		7			98,544				(1,405		)
		Asset-backed securities:
		Collateralized loan obligations	79,042				(1,406		)		15			193,687				(8,207		)		27			272,729				(9,613		)
		Corporate debt securities	—				—				—			51,338				(10,315		)		8			51,338				(10,315		)
		Total available-for-sale securities	$	424,916			$	(2,807	)		53			$	1,485,458			$	(49,824	)		162			$	1,910,374			$	(52,631	)
	Securities held-to-maturity
		Debt Securities
		U.S. government agency debentures	$	—			$	—			—			$	24,463			$	(537	)		1			$	24,463			$	(537	)
		U.S. states and political subdivisions	9,085				(17		)		9			18,371				(174		)		21			27,456				(191		)
		Residential mortgage-backed securities:
		U.S. government agencies	—				—				—			185,361				(3,045		)		10			185,361				(3,045		)
		Commercial mortgage-backed securities:
		U.S. government agencies	9,950				(4		)		2			16,735				(325		)		2			26,685				(329		)
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	28,333				(149		)		3			1,161,297				(38,726		)		58			1,189,630				(38,875		)
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	41,474				(55		)		3			171,570				(6,713		)		16			213,044				(6,768		)
		Corporate debt securities	36,933				(52		)		13			—				—				—			36,933				(52		)
		Total held-to-maturity securities	$	125,775			$	(277	)		30			$	1,577,797			$	(49,520	)		108			$	1,703,572			$	(49,797	)
			December 31, 2013
			Less than 12 months											12 months or longer											Total
	(Dollars in thousands)		Fair Value				Unrealized				Number			Fair Value				Unrealized				Number			Fair Value				Unrealized
							Losses				Impaired							Losses				Impaired							Losses
											Securities											Securities
	Securities available-for-sale
	Debt securities
		U.S. states and political subdivisions	$	38,039			$	(1,996	)		65			$	14,157			$	(1,800	)		25			$	52,196			$	(3,796	)
		Residential mortgage-backed securities:
		U.S. government agencies	434,761				(13,109		)		35			14,890				(1,318		)		2			449,651				(14,427		)
		Commercial mortgage-backed securities:
		U.S. government agencies	33,387				(1,491		)		5			16,944				(997		)		2			50,331				(2,488		)
		Residential collateralized mortgage-backed securities:
		U.S. government agencies	1,135,151				(44,775		)		74			100,530				(7,293		)		7			1,235,681				(52,068		)
		Nonagency	—				—				—			1				—				1			1				—
		Commercial collateralized mortgage-backed securities:
		U.S. government agencies	43,747				(2,055		)		6			2,525				(102		)		1			46,272				(2,157		)
		Asset-backed securities:
		Collateralized loan obligations	223,458				(4,332		)		33			—				—				—			223,458				(4,332		)
		Corporate debt securities	—				—				—			50,644				(10,952		)		8			50,644				(10,952		)
		Total available-for-sale securities	$	1,908,543			$	(67,758	)		218			$	199,691			$	(22,462	)		46			$	2,108,234			$	(90,220	)
	Securities held-to-maturity
		Debt securities
		U.S. government agency debentures	$	23,652			$	(1,348	)		1			$	—			$	—			—			$	23,652			$	(1,348	)
		U.S. states and political subdivisions	222,154				(10,276		)		353			2,478				(183		)		6			224,632				(10,459		)
		Residential mortgage-backed securities:
		U.S. government agencies	422,192				(11,617		)		22			—				—				—			422,192				(11,617		)
		Commercial mortgage-backed securities:
	U.S. government agencies	48,831				(1,190		)		8			—				—				—			48,831				(1,190		)
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,382,915				(81,818		)		66			—				—				—			1,382,915				(81,818		)
	Nonagency	—				—				—			—				—				—			—				—
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	208,863				(11,052		)		19			—				—				—			208,863				(11,052		)
	Corporate debt securities	64,541				(725		)		23			—				—				—			64,541				(725		)
	Total held-to-maturity securities	$	2,373,148			$	(118,026	)		492			$	2,478			$	(183	)		6			$	2,375,626			$	(118,209	)
Investment Securities Maturities
	(Dollars in thousands)		U.S. Government agency debentures				U.S. Treasuries				U.S. States and political subdivisions obligations				Residential mortgage-backed securities - U.S. govt. agency obligations				Commercial mortgage-backed securities - U.S. govt. agency obligations				Residential collateralized mortgage obligations - U.S. govt. agency obligations				Residential collateralized mortgage obligations - non- U.S. govt. agency issued				Commercial collateralized mortgage obligations - U.S. govt. agency obligations			Collateralized loan obligations			Corporate debt securities			Total			Weighted Average Yield
	Securities Available for Sale
	Remaining maturity:
	One year or less		$	—			$	—			$	12,365			$	2,777			$	16,850			$	8,248			$	—			$	—		$	7,500		$	—		$	47,740		3.72	%
	Over one year through five years		—				—				70,589				791,641				44,030				1,579,527				7				151,025			—			—			2,636,819			2.22	%
	Over five years through ten years		2,482				—				115,140				176,580				42,523				88,792				—				71,309			280,344			—			777,170			2.92	%
	Over ten years		—				—				29,248				—				—				—				—				—			—			51,337			80,585			1.94	%
	Fair Value		$	2,482			$	—			$	227,342			$	970,998			$	103,403			$	1,676,567			$	7			$	222,334		$	287,844		$	51,337		$	3,542,314		2.38	%
	Amortized Cost		$	2,500			$	—			$	221,052			$	951,839			$	104,176			$	1,698,015			$	7			$	222,876		$	297,446		$	61,652		$	3,559,563
	Weighted-Average Yield		1.25		%		—		%		5.23		%		2.6		%		2.28		%		1.96		%		3.35		%		1.97		%	2.67		%	0.96		%	2.38		%
	Weighted-Average Maturity (in years)		3.42				—				6				3.81				4.16				3.68				2				4.01			6.06			12.81			4.25
	Securities Held to Maturity
	Remaining maturity:
	One year or less		$	—			$	5,000			$	64,719			$	—			$	16,305			$	—			$	—			$	—		$	—		$	—		$	86,024		1.93	%
	Over one year through five years		—				—				78,522				468,348				22,119				1,307,203				—				159,587			—			91,099			2,126,878			1.88	%
	Over five years through ten years		24,463				—				199,054				116,829				19,671				23,174				—				91,844			—			—			475,035			3.04	%
	Over ten years		—				—				187,983				—				—				—				—				—			—			—			187,983			5.51	%
	Fair Value		$	24,463			$	5,000			$	530,278			$	585,177			$	58,095			$	1,330,377			$	—			$	251,431		$	—		$	91,099		$	2,875,920		2.3	%
	Amortized Cost		$	25,000			$	5,000			$	517,824			$	580,727			$	58,143			$	1,368,534			$	—			$	257,642		$	—		$	90,739		$	2,903,609
	Weighted-Average Yield		1.33		%		0.26		%		4.68		%		2.16		%		2.12		%		1.61		%		—		%		2.28		%	—		%	2.25		%	2.3		%
	Weighted-Average Maturity (in years)		4.83				0.08				9.4				4.27				3.51				3.91				—				4.61			—			3.03			4.76

Loans_Tables

Loans (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Total originated, acquired and covered loans outstanding table	Loans outstanding as of December 31, 2014 and 2013, net of unearned income, consisted of the following:
	(In thousands)		December 31, 2014				December 31, 2013
	Originated loans
	Commercial		$	7,830,085			$	6,648,279
	Residential mortgage		625,283				529,253
	Installment		2,393,451				1,727,925
	Home equity		1,110,336				920,066
	Credit cards		164,478				148,313
	Leases		370,179				239,551
		Total originated loans	12,493,812				10,213,387
	Allowance for originated loan losses		(95,696		)		(96,484		)
		Net originated loans	$	12,398,116			$	10,116,903
	Acquired loans:
	Commercial		$	1,086,899			$	1,725,970
	Residential mortgage		394,484				470,652
	Installment		764,168				1,004,569
	Home equity		233,629				294,424
		Total acquired loans	2,479,180				3,495,615
	Allowance for acquired loan losses		(7,457		)		(741		)
		Net acquired loans	$	2,471,723			$	3,494,874
	Covered loans:
	Commercial		211,607				375,860
	Residential mortgage		41,276				50,679
	Installment		4,874				6,162
	Home equity		73,365				97,442
	Loss share receivable		22,033				61,827
		Total covered loans	353,155				591,970
	Allowance for covered loan losses		(40,496		)		(44,027		)
		Net covered loans	$	312,659			$	547,943
	Total loans:
	Commercial		$	9,128,591			$	8,750,109
	Residential mortgage		1,061,043				1,050,584
	Installment		3,162,493				2,738,656
	Home equity		1,417,330				1,311,932
	Credit cards		164,478				148,313
	Leases		370,179				239,551
	Loss share receivable		22,033				61,827
		Total loans	15,326,147				14,300,972
	Total allowance for loan losses		(143,649		)		(141,252		)
		Total Net loans	$	15,182,498			$	14,159,720
Summary of loans to related parties table	An analysis of loan activity with related parties for the years ended December 31, 2014, 2013, and 2012 is summarized as follows:
		Year Ended December 31,
	(In thousands)	2014				2013				2012
	Aggregate amount at beginning of year	$	24,536			$	16,578			$	15,629
	New loans	2,534				11,507				3,500
	Repayments	(6,388		)		(4,374		)		(2,739		)
	Changes in directors and their affiliations	—				825				188
	Aggregate amount at end of year	$	20,682			$	24,536			$	16,578
Changes in the Carrying Amount of Accretable Yield for Acquired Impaired Loans [Table Text Block]	Total outstanding acquired impaired loans were $590.9 million and $817.6 million as of December 31, 2014 and 2013. The outstanding balance of these loans is the undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loans, owed at the reporting date, whether or not currently due and whether or not any such amounts have been charged off. Changes in the carrying amount and accretable yield for acquired impaired loans were as follows for the years ended December 31, 2014 and 2013:
		Year Ended
	Acquired Impaired Loans	December 31, 2014								December 31, 2013
	(In thousands)	Accretable Yield				Carrying Amount of Loans				Accretable Yield			Carrying Amount of Loans
	Balance at beginning of period	$	136,646			$	601,000			$	—		$	—
	Additions due to Citizens acquisition on April 12, 2013	—				—				131,558			819,715
	Accretion	(49,271		)		49,271				(27,144		)	27,144
	Net reclassifications from nonaccretable to accretable	45,824				—				46,361			—
	Payments received, net	—				(227,062		)		—			(245,859		)
	Disposals	(13,749		)		—				(14,129		)	—
	Balance at end of period	$	119,450			$	423,209			$	136,646		$	601,000
	Cash flows expected to be collected on acquired impaired loans are estimated quarterly by incorporating several key assumptions similar to the initial estimate of fair value. These key assumptions include probability of default, and the amount of actual prepayments after the acquisition date. Prepayments affect the estimated life of the loans and could change the amount of interest income, and possibly principal expected to be collected. In reforecasting future estimated cash flows, credit loss expectations are adjusted as necessary.
	Improved cash flow expectations for loans or pools that were impaired in prior periods are recorded first as a reversal of previously recorded impairment and then as an increase in prospective yield when all previously recorded impairment has been recaptured. Decreases in expected cash flows are recognized as an impairment through a provision for loan loss and an increase to the allowance for acquired impaired loans.
	During the year ended December 31, 2014, there was an overall improvement in cash flow expectations which resulted in the reclassification of $45.8 million from the nonaccretable difference to accretable yield. This reclassification results in prospective yield adjustments on these loan pools.
Changes in Loss Share Receivable Associated with Covered Loans	Changes in the loss share receivable associated with covered loans for the years ended December 31, 2014 and 2013, respectively, were as follows:
	Loss Share Receivable	Year Ended
	(In thousands)	December 31, 2014				December 31, 2013
	Balance at beginning of period	$	61,827			$	113,734
	Amortization	(20,943		)		(24,307		)
	Increase due to impairment on covered loans	2,920				10,790
	FDIC reimbursement	(17,837		)		(27,234		)
	Covered loans paid in full	(3,934		)		(11,156		)
	Balance at end of period	$	22,033			$	61,827
Changes in Carrying Amount of Accretable Yield for Covered Impaired Loans	Changes in the carrying amount and accretable yield for covered impaired loans were as follows for the years ended December 31, 2014 and 2013:
		Year Ended December 31,
	Covered Impaired Loans	2014								2013
	(In thousands)	Accretable				Carrying				Accretable			Carrying
		Yield				Amount of				Yield			Amount of
						Loans							Loans
	Balance at beginning of period	$	67,282			$	403,692			$	113,288		$	762,386
	Accretion	(42,161		)		42,161				(64,528		)	64,528
	Net reclassifications from nonaccretable to accretable	16,841				—				34,965			—
	Payments received, net	—				(213,401		)		—			(423,222		)
	Disposals	(4,451		)		—				(16,443		)	—
	Balance at end of period	$	37,511			$	232,452			$	67,282		$	403,692
	The cash flows expected to be collected on covered impaired loans are estimated quarterly in a similar manner as described above for acquired impaired loans. During the year ended December 31, 2014, the overall improvement in the cash flow expectations resulted in the reclassification of $16.8 million from the nonaccretable difference to accretable yield. This reclassification results in prospective yield adjustments on the loan pools.
Past Due Financing Receivables	The following tables provide a summary of loans by portfolio type, including the delinquency status of those loans that continue to accrue interest and those loans that are nonaccrual:
	As of December 31, 2014
	(In thousands)																			≥ 90 Days
	Originated Loans	Days Past Due											Total					Total		Past Due and		Nonaccrual
		30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (1)		Loans
	Commercial
	C&I	$	2,212			$	1,162			$	2,670		$	6,044		$	5,169,157	$	5,175,201	$	1,547	$	6,114
	CRE	2,155				1,460				8,864			12,479			2,104,639		2,117,118		1,696		11,033
	Construction	—				—				—			—			537,766		537,766		—		—
	Leases	—				—				—			—			370,179		370,179		—		—
	Consumer
	Installment	14,621				3,647				4,716			22,984			2,370,467		2,393,451		3,695		3,268
	Home equity lines	1,357				587				1,206			3,150			1,107,186		1,110,336		569		1,654
	Credit cards	668				516				860			2,044			162,434		164,478		407		596
	Residential mortgages	12,086				2,744				8,013			22,843			602,440		625,283		4,242		11,952
	Total	$	33,099			$	10,116			$	26,329		$	69,544		$	12,424,268	$	12,493,812	$	12,156	$	34,617
																				≥ 90 Days
	Acquired Loans												Total					Total		Past Due and		Nonaccrual
		30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing		Loans
	Commercial
	C&I	$	92			$	234			$	4,791		$	5,117		$	444,137	$	449,254	$	—	$	787
	CRE	3,479				3,398				23,509			30,386			600,288		630,674		44		4,171
	Construction	—				—				685			685			6,286		6,971		—		—
	Consumer
	Installment	6,204				2,029				1,861			10,094			754,074		764,168		615		1,218
	Home equity lines	2,819				2,123				2,333			7,275			226,354		233,629		1,519		631
	Residential mortgages	13,062				1,648				7,089			21,799			372,685		394,484		1,293		1,249
	Total	$	25,656			$	9,432			$	40,268		$	75,356		$	2,403,824	$	2,479,180	$	3,471	$	8,056
																				≥ 90 Days
	Covered Loans (2)	Days Past Due											Total					Total		Past Due and		Nonaccrual
		30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (3)		Loans (3)
	Commercial
	C&I	$	58			$	—			$	6,041		$	6,099		$	42,738	$	48,837	n/a		n/a
	CRE	234				1,517				47,233			48,984			104,524		153,508		n/a		n/a
	Construction	—				—				6,064			6,064			3,198		9,262		n/a		n/a
	Consumer
	Installment	23				—				34			57			4,817		4,874		n/a		n/a
	Home equity lines	1,395				870				3,859			6,124			67,241		73,365		n/a		n/a
	Residential mortgages	6,205				91				3,572			9,868			31,408		41,276		n/a		n/a
	Total	$	7,915			$	2,478			$	66,803		$	77,196		$	253,926	$	331,122	n/a		n/a
	(1) Installment loans 90 days or more past due and accruing include $2.4 million of loans guaranteed by the U.S. government as of December 31, 2014.
	(2) Excludes loss share receivable of $22.0 million as of December 31, 2014.
	(3) Acquired impaired loans were not classified as nonperforming assets at December 31, 2014 as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cash flows, is being recognized on all acquired impaired loans. These asset quality disclosures are, therefore, not applicable to acquired impaired loans.
	As of December 31, 2013
	(In thousands)																			≥ 90 Days
	Originated Loans	Days Past Due											Total					Total		Past Due and		Nonaccrual
		30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (1)		Loans
	Commercial
	C&I	$	8,941			$	994			$	10,622		$	20,557		$	4,119,010	$	4,139,567	$	151	$	11,323
	CRE	4,507				2,400				9,688			16,595			2,153,192		2,169,787		460		14,229
	Construction	351				21				66			438			338,487		338,925		—		122
	Leases	902				—				—			902			238,649		239,551		—		—
	Consumer
	Installment	15,433				4,050				4,462			23,945			1,703,980		1,727,925		3,735		3,681
	Home equity lines	1,864				918				965			3,747			916,319		920,066		418		1,819
	Credit cards	729				471				735			1,935			146,378		148,313		404		558
	Residential mortgages	19,858				2,072				9,350			31,280			497,973		529,253		6,008		10,471
	Total	$	52,585			$	10,926			$	35,888		$	99,399		$	10,113,988	$	10,213,387	$	11,176	$	42,203
																				≥ 90 Days
	Acquired Loans												Total					Total		Past Due and		Nonaccrual
		30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing		Loans
	Commercial	$	1,295			$	862			$	3,744		$	5,901		$	788,178	$	794,079	$	40	$	795
	C&I	5,603				5,281				26,366			37,250			881,395		918,645		403		651
	CRE	2,675				—				—			2,675			10,571		13,246		—		—
Construction
Consumer	14,528				4,076				3,354			21,958			982,611		1,004,569		2,263		679
Installment	4,774				1,933				3,606			10,313			284,111		294,424		1,039		1,300
Home equity lines	3,918				1,426				8,063			13,407			457,245		470,652		403		582
Residential mortgages	$	32,793			$	13,578			$	45,133		$	91,504		$	3,404,111	$	3,495,615	$	4,148	$	4,007
Total
Covered Loans (2)	Days Past Due											Total					Total		Past Due and		Nonaccrual
	30-59				60-89				≥ 90			Past Due			Current		Loans		Accruing (3)		Loans (3)
Commercial
C&I	$	836			$	1,489			$	12,957		$	15,282		$	60,955	$	76,237	n/a		n/a
CRE	2,855				3,443				103,077			109,375			164,219		273,594		n/a		n/a
Construction	2,191				1,917				20,388			24,496			1,533		26,029		n/a		n/a
Consumer
Installment	33				—				—			33			6,130		6,163		n/a		n/a
Home equity lines	544				1,467				1,651			3,662			93,780		97,442		n/a		n/a
Residential mortgages	7,463				1,565				5,165			14,193			36,485		50,678		n/a		n/a
Total	$	13,922			$	9,881			$	143,238		$	167,041		$	363,102	$	530,143	n/a		n/a
(1) Installment loans 90 days or more past due and accruing include $2.1 million of loans guaranteed by the U.S. government as of December 31, 2013.
(2) Excludes loss share receivable of $61.8 million as of December 31, 2013.
(3) Acquired impaired loans were not classified as nonperforming assets at December 31, 2013 as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cash flows, is being recognized on all acquired impaired loans. These asset quality disclosures are, therefore, not applicable to acquired impaired loans
Financing Receivable Credit Quality Indicators	The following tables provide a summary of commercial loans by portfolio type and the Corporation’s internal credit quality rating:
	As of December 31, 2014
	(In thousands)
	Originated Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	52,676			$	683			$	678		$	4,451		$	58,488
	Grade 2	186,278				3,454				—			14,959			204,691
	Grade 3	1,340,100				294,281				46,074			71,908			1,752,363
	Grade 4	3,413,446				1,745,470				490,757			277,277			5,926,950
	Grade 5	139,083				29,990				257			1,389			170,719
	Grade 6	43,618				43,240				—			195			87,053
	Grade 7	—				—				—			—			—
	Total	$	5,175,201			$	2,117,118			$	537,766		$	370,179		$	8,200,264
	Acquired Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	1,076			$	—			$	—		$	—		$	1,076
	Grade 2	—				—				—			—			—
	Grade 3	20,891				24,867				—			—			45,758
	Grade 4	376,129				532,447				6,286			—			914,862
	Grade 5	23,268				28,382				685			—			52,335
	Grade 6	27,890				44,978				—			—			72,868
	Grade 7	—				—				—			—			—
	Total	$	449,254			$	630,674			$	6,971		$	—		$	1,086,899
	Covered Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	—			$	—			$	—		$	—		$	—
	Grade 2	1,347				—				—			—			1,347
	Grade 3	—				—				—			—			—
	Grade 4	36,406				86,779				823			—			124,008
	Grade 5	167				3,401				—			—			3,568
	Grade 6	10,917				63,328				8,248			—			82,493
	Grade 7	—				—				191			—			191
	Total	$	48,837			$	153,508			$	9,262		$	—		$	211,607
	As of December 31, 2013
	(In thousands)
	Originated Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	34,909			$	241			$	—		$	9,271		$	44,421
	Grade 2	108,709				3,730				—			2,900			115,339
	Grade 3	802,624				315,150				25,632			54,446			1,197,852
	Grade 4	3,083,458				1,759,383				306,795			167,022			5,316,658
	Grade 5	71,857				34,969				267			5,750			112,843
	Grade 6	38,010				56,314				6,231			162			100,717
	Grade 7	—				—				—			—			—
	Total	$	4,139,567			$	2,169,787			$	338,925		$	239,551		$	6,887,830
	Acquired Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	—			$	—			$	—		$	—		$	—
	Grade 2	1,741				703				—			—			2,444
	Grade 3	79,634				29,224				—			—			108,858
	Grade 4	643,495				722,307				13,246			—			1,379,048
	Grade 5	46,807				93,499				—			—			140,306
	Grade 6	22,402				72,912				—			—			95,314
	Grade 7	—				—				—			—			—
	Total	$	794,079			$	918,645			$	13,246		$	—		$	1,725,970
	Covered Loans	Commercial
		C&I				CRE				Construction			Leases			Total
	Grade 1	$	—			$	—			$	—		$	—		$	—
	Grade 2	968				—				—			—			968
	Grade 3	—				—				—			—			—
	Grade 4	41,115				113,863				601			—			155,579
	Grade 5	427				6,219				—			—			6,646
	Grade 6	31,621				153,318				23,208			—			208,147
	Grade 7	2,106				194				2,220			—			4,520
Total	$	76,237			$	273,594			$	26,029		$	—		$	375,860

Allowance_for_Loan_Losses_Tabl

Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2014
Allowance for Loan and Lease Losses [Abstract]
Schedule of Credit Losses Related to Financing Receivables, Current and Non-Current	The following tables show activity in the originated ALL, by portfolio segment for the years ended December 31, 2014, 2013 and 2012, as well as the corresponding recorded investment in originated loans at the end of the period:
	As of December 31, 2014
	(In thousands)
	Originated Loans		C&I				CRE				Construction				Leases				Installment				Home Equity Lines				Credit Cards				Residential Mortgages			Total
	Year ended
	Allowance for originated loan losses, beginning balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Charge-offs		(9,617		)		(3,512		)		—				—				(20,328		)		(4,831		)		(4,604		)		(2,031		)	(44,923		)
	Recoveries		3,872				515				39				379				11,185				2,940				1,716				318			20,964
	Provision for loan losses		139				1,224				(647		)		(786		)		10,126				8,315				3,114				1,686			23,171
	Allowance for originated loan losses, ending balance		$	37,375			$	10,492			$	2,202			$	674			$	12,918			$	19,324			$	7,966			$	4,745		$	95,696
	Ending allowance for originated loan losses balance attributable to loans:
		Individually evaluated for impairment	$	72			$	2,914			$	—			$	—			$	1,178			$	207			$	296			$	1,283		$	5,950
		Collectively evaluated for impairment	37,303				7,578				2,202				674				11,740				19,117				7,670				3,462			89,746
	Total ending allowance for originated loan losses balance		$	37,375			$	10,492			$	2,202			$	674			$	12,918			$	19,324			$	7,966			$	4,745		$	95,696
	Originated loans:
		Originated loans individually evaluated for impairment	$	11,759			$	23,300			$	—			$	—			$	24,905			$	7,379			$	854			$	25,251		$	93,448
		Originated loans collectively evaluated for impairment	5,163,442				2,093,818				537,766				370,179				2,368,546				1,102,957				163,624				600,032			12,400,364
	Total ending originated loan balance		$	5,175,201			$	2,117,118			$	537,766			$	370,179			$	2,393,451			$	1,110,336			$	164,478			$	625,283		$	12,493,812
	As of December 31, 2013
	(In thousands)
	Originated Loans		C&I				CRE				Construction				Leases				Installment				Home Equity Lines				Credit Cards				Residential Mortgages			Total
	Year ended
	Allowance for originated loan losses, beginning balance		$	36,209			$	20,126			$	3,821			$	639			$	11,154			$	13,724			$	7,384			$	5,885		$	98,942
	Charge-offs		(5,840		)		(1,281		)		(516		)		(1,237		)		(16,683		)		(7,172		)		(5,541		)		(1,903		)	(40,173		)
	Recoveries		7,981				524				507				100				10,519				2,979				1,841				230			24,681
	Provision for loan losses		4,631				(7,104		)		(1,002		)		1,579				6,945				3,369				4,056				560			13,034
	Allowance for originated loan losses, ending balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Ending allowance for originated loan losses balance attributable to loans:
		Individually evaluated for impairment	$	3,235			$	229			$	—			$	—			$	1,014			$	223			$	312			$	1,133		$	6,146
		Collectively evaluated for impairment	39,746				12,036				2,810				1,081				10,921				12,677				7,428				3,639			90,338
	Total ending allowance for originated loan losses balance		$	42,981			$	12,265			$	2,810			$	1,081			$	11,935			$	12,900			$	7,740			$	4,772		$	96,484
	Originated loans:
		Originated loans individually evaluated for impairment	$	8,053			$	20,616			$	906			$	—			$	27,285			$	6,726			$	1,112			$	23,066		$	87,764
		Originated loans collectively evaluated for impairment	4,131,514				2,149,171				338,019				239,551				1,700,640				913,340				147,201				506,187			10,125,623
	Total ending originated loan balance		$	4,139,567			$	2,169,787			$	338,925			$	239,551			$	1,727,925			$	920,066			$	148,313			$	529,253		$	10,213,387
Schedule of Credit Losses Financing Receivables Acquired Loans	The following table presents activity in the allowance for acquired impaired loan losses for the years ended December 31, 2014 and 2013:
	Allowance for Acquired Impaired Loan Losses		Year Ended December 31,
	(In thousands)		2014				2013
	Balance at beginning of the period		$	741			$	—
	Charge-offs		—				—
	Recoveries		—				—
	Provision for loan losses		6,716				741
	Balance at end of the period		$	7,457			$	741
Schedule of Credit Losses Related to Covered FInancing Receivables, Current	The following table presents activity in the allowance for covered impaired loan losses for the years ended December 31, 2014, 2013, and 2012:
	Allowance for Covered Impaired Loan Losses		Year Ended December 31,
	(In thousands)		2014				2013				2012
	Balance at beginning of the period		$	44,027			$	43,255			$	36,417
		Net provision for loan losses before benefit attributable to FDIC loss share agreements	10,568				23,892				35,450
		Net benefit attributable to FDIC loss share agreements	(2,920		)		(10,790		)		(14,728		)
	Net provision for loan losses		7,648				13,102				20,722
	Increase in loss share receivable		2,920				10,790				14,728
	Loans charged-off		(14,099		)		(23,120		)		(28,612		)
	Balance at end of the period		$	40,496			$	44,027			$	43,255
Impaired Financing Receivables	The following tables provide further detail on impaired loans individually evaluated for impairment and the associated ALL. Certain impaired loans do not have a related ALL as the valuation of these impaired loans exceeded the recorded investment.
	As of December 31, 2014
	Originated Loans						Unpaid								Average
			Recorded				Principal				Related				Recorded
	(In thousands)		Investment				Balance				Allowance				Investment
	Impaired loans with no related allowance
	Commercial
		C&I	$	11,451			$	18,207			$	—			$	14,193
		CRE	16,874				22,696				—				18,027
		Construction	—				—				—				—
	Consumer
		Installment	4,460				4,584				—				4,272
		Home equity line	1,723				1,754				—				1,792
		Credit card	16				16				—				32
		Residential mortgages	12,204				15,119				—				12,425
	Subtotal		46,728				62,376				—				50,741
	Impaired loans with a related allowance
	Commercial
		C&I	308				344				72				326
		CRE	6,426				6,440				2,914				4,497
		Construction	—				—				—				—
	Consumer
		Installment	20,445				21,024				1,178				19,513
		Home equity line	5,656				5,875				207				5,944
		Credit card	838				838				296				966
		Residential mortgages	13,047				13,158				1,283				13,121
	Subtotal		46,720				47,679				5,950				44,367
		Total impaired loans	$	93,448			$	110,055			$	5,950			$	95,108
	Note 1: These tables exclude loans fully charged off.
	Note 2: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
	As of December 31, 2013
	Originated Loans						Unpaid								Average
			Recorded				Principal				Related				Recorded
	(In thousands)		Investment				Balance				Allowance				Investment
	Impaired loans with no related allowance
	Commercial
		C&I	$	2,503			$	6,679			$	—			$	7,256
		CRE	17,871				23,709				—				18,639
		Construction	906				1,179				—				1,035
	Consumer
		Installment	2,813				3,978				—				3,338
		Home equity line	1,018				1,347				—				1,079
		Credit card	49				49				—				91
		Residential mortgages	10,250				12,778				—				10,258
	Subtotal		35,410				49,719				—				41,696
	Impaired loans with a related allowance
	Commercial
		C&I	5,551				7,428				3,235				5,009
		CRE	2,744				2,870				229				2,836
		Construction	—				—				—				—
	Consumer
		Installment	24,472				24,558				1,014				24,985
		Home equity line	5,707				5,707				223				5,874
		Credit card	1,064				1,064				312				1,238
		Residential mortgages	12,816				12,898				1,133				12,064
	Subtotal		52,354				54,525				6,146				52,006
		Total impaired loans	$	87,764			$	104,244			$	6,146			$	93,702
	Note 1: These tables exclude loans fully charged off.
	Note 2: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
Troubled Debt Restructurings on Financing Receivables	The following tables provide the number of loans modified in a TDR and the recorded investment and unpaid principal balance by loan portfolio as of December 31, 2014, and 2013.
				As of December 31, 2014
	(Dollars in thousands)			Number of Loans			Recorded Investment				Unpaid Principal Balance
	Originated loans
		Commercial
			C&I	41			$	7,123			$	13,887
			CRE	67			17,607				22,645
			Construction	31			—				—
			Total originated commercial	139			24,730				36,532
		Consumer
			Installment	1,205			24,905				25,608
			Home equity lines	270			7,379				7,629
			Credit card	238			854				854
			Residential mortgages	315			25,251				28,277
			Total originated consumer	2,028			58,389				62,368
	Total originated loans			2,167			$	83,119			$	98,900
	Acquired Loans
		Commercial
			C&I	2			$	18			$	19
			CRE	3			2,542				2,595
			Total acquired commercial	5			2,560				2,614
		Consumer
			Installment	40			975				1,054
			Home equity lines	145			6,932				6,983
			Residential mortgages	26			1,633				1,823
			Total acquired consumer	211			9,540				9,860
	Total acquired loans			216			$	12,100			$	12,474
	Covered loans
		Commercial
			C&I	8			$	177			$	1,589
			CRE	24			25,499				42,226
			Construction	9			339				9,552
			Total covered commercial	41			26,015				53,367
		Consumer
			Home equity lines	68			8,890				8,901
			Residential mortgages	2			334				334
			Total covered consumer	70			9,224				9,235
	Total covered loans			111			$	35,239			$	62,602
	Total loans
		Commercial
			C&I	51			$	7,318			$	15,495
			CRE	94			45,648				67,466
			Construction	40			339				9,552
			Total commercial	185			53,305				92,513
		Consumer
			Installment	1,245			25,880				26,662
			Home equity lines	483			23,201				23,513
			Credit card	238			854				854
			Residential mortgages	343			27,218				30,434
			Total consumer	2,309			77,153				81,463
	Total loans			2,494			$	130,458			$	173,976
	Note 1: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
				As of December 31, 2013
	(Dollars in thousands)			Number of Loans			Recorded Investment				Unpaid Principal Balance
	Originated loans
		Commercial
			C&I	35			$	4,449			$	7,660
			CRE	52			15,932				20,569
			Construction	30			905				1,179
			Total originated commercial	117			21,286				29,408
		Consumer
			Installment	1,553			27,285				28,536
			Home equity lines	231			6,725				7,054
			Credit card	307			1,113				1,113
		Residential mortgages	301			23,067				25,676
		Total originated consumer	2,392			58,190				62,379
Total originated loans			2,509			$	79,476			$	91,787
Acquired Loans
	Commercial
		C&I	1			$	6			$	5
		CRE	1			1,730				1,730
		Total acquired commercial	2			1,736				1,735
	Consumer
		Installment	12			505				542
		Home equity lines	8			245				270
		Residential mortgages	7			431				502
		Total acquired consumer	27			1,181				1,314
Total acquired loans			29			$	2,917			$	3,049
Covered loans
	Commercial
		C&I	4			$	1,104			$	2,331
		CRE	24			39,995				57,008
		Construction	10			4,144				24,547
		Total covered commercial	38			45,243				83,886
	Consumer
		Home equity lines	47			5,401				5,421
		Residential Mortgages	1			150				150
		Total covered consumer	48			5,551				5,571
Total covered loans			86			$	50,794			$	89,457
Total loans
	Commercial
		C&I	40			$	5,559			$	9,996
		CRE	77			57,657				79,307
		Construction	40			5,049				25,726
		Total commercial	157			68,265				115,029
	Consumer
		Installment	1,565			27,790				29,078
		Home equity lines	286			12,371				12,745
		Credit card	307			1,113				1,113
		Residential mortgages	309			23,648				26,328
		Total consumer	2,467			64,922				69,264
Total loans			2,624			$	133,187			$	184,293
Note 1: The differences between the recorded investment and unpaid principal balance amounts represent partial charge offs.
Accruing and Nonaccruing Troubled Debt Restructurings	The following tables provide a summary of the delinquency status of TDRs along with the specific allowance for loan loss, by loan type, as of December 31, 2014 and 2013, including TDRs that continue to accrue interest and TDRs included in nonperforming assets.
	As of December 31, 2014
		Accruing TDRs												Nonaccruing TDRs												Total				Total
	(In thousands)	Current				Delinquent				Total				Current				Delinquent				Total				TDRs				Allowance
	Originated loans
	Commercial
	C&I	$	6,740			$	—			$	6,740			$	—			$	383			$	383			$	7,123			$	72
	CRE	12,885				952				13,837				394				3,376				3,770				17,607				159
	Construction	—				—				—				—				—				—				—				—
	Total originated commercial	19,625				952				20,577				394				3,759				4,153				24,730				231
	Consumer
	Installment	22,254				726				22,980				1,663				262				1,925				24,905				1,178
	Home equity lines	6,239				269				6,508				871				—				871				7,379				207
	Credit card	775				60				835				15				4				19				854				296
	Residential mortgages	13,440				3,538				16,978				5,006				3,267				8,273				25,251				1,283
	Total originated consumer	42,708				4,593				47,301				7,555				3,533				11,088				58,389				2,964
	Total originated TDRs	$	62,333			$	5,545			$	67,878			$	7,949			$	7,292			$	15,241			$	83,119			$	3,195
	Acquired loans
	Commercial
	C&I	$	15			$	—			$	15			$	3			$	—			$	3			$	18			$	18
	CRE	—				—				—				978				1,564				2,542				2,542				134
	Total acquired commercial	15				—				15				981				1,564				2,545				2,560				152
	Consumer
	Installment	841				87				928				24				23				47				975				65
	Home equity lines	6,186				607				6,793				139				—				139				6,932				9
	Residential mortgages	868				—				868				470				295				765				1,633				2
	Total acquired consumer	7,895				694				8,589				633				318				951				9,540				76
	Total acquired TDRs	$	7,910			$	694			$	8,604			$	1,614			$	1,882			$	3,496			$	12,100			$	228
	Covered loans
	Commercial
	C&I	$	—			$	177			$	177			$	—			$	—			$	—			$	177			$	—
	CRE	5,123				20,376				25,499				—				—				—				25,499				2,879
	Construction	339				—				339				—				—				—				339				295
	Total covered commercial	5,462				20,553				26,015				—				—				—				26,015				3,174
	Consumer
	Home equity lines	8,561				—				8,561				329				—				329				8,890				27
	Residential mortgages	334				—				334				—				—				—				334				21
	Total covered consumer	8,895				—				8,895				329				—				329				9,224				48
	Total covered TDRs	$	14,357			$	20,553			$	34,910			$	329			$	—			$	329			$	35,239			$	3,222
	Total loans
	Commercial
	C&I	$	6,755			$	177			$	6,932			$	3			$	383			$	386			$	7,318			$	90
	CRE	18,008				21,328				39,336				1,372				4,940				6,312				45,648				3,172
	Construction	339				—				339				—				—				—				339				295
	Total commercial	25,102				21,505				46,607				1,375				5,323				6,698				53,305				3,557
	Consumer
	Installment	23,095				813				23,908				1,687				285				1,972				25,880				1,243
	Home equity lines	20,986				876				21,862				1,339				—				1,339				23,201				243
	Credit card	775				60				835				15				4				19				854				296
	Residential mortgages	14,642				3,538				18,180				5,476				3,562				9,038				27,218				1,306
	Total consumer	59,498				5,287				64,785				8,517				3,851				12,368				77,153				3,088
	Total TDRs	$	84,600			$	26,792			$	111,392			$	9,892			$	9,174			$	19,066			$	130,458			$	6,645
	As of December 31, 2013
		Accruing TDRs												Nonaccruing TDRs												Total				Total
	(In thousands)	Current				Delinquent				Total				Current				Delinquent				Total				TDRs				Allowance
	Originated loans
	Commercial
	C&I	$	1,438			$	879			$	2,317			$	177			$	1,955			$	2,132			$	4,449			$	665
	CRE	10,442				382				10,824				1,208				3,900				5,108				15,932				32
	Construction	848				—				848				—				57				57				905				—
	Total originated commercial	12,728				1,261				13,989				1,385				5,912				7,297				21,286				697
	Consumer
	Installment	23,342				1,238				24,580				2,483				222				2,705				27,285				1,014
	Home equity lines	5,313				194				5,507				1,206				12				1,218				6,725				223
Credit card	1,046				66				1,112				—				1				1				1,113				312
Residential mortgages	12,276				3,327				15,603				4,360				3,104				7,464				23,067				1,133
Total originated consumer	41,977				4,825				46,802				8,049				3,339				11,388				58,190				2,682
Total originated TDRs	$	54,705			$	6,086			$	60,791			$	9,434			$	9,251			$	18,685			$	79,476			$	3,379
Acquired loans
Commercial
C&I	$	—			$	—			$	—			$	6			$	—			$	6			$	6			$	—
CRE	1,730				—				1,730				—				—				—				1,730				—
Total acquired commercial	1,730				—				1,730				6				—				6				1,736				—
Consumer
Installment	369				136				505				—				—				—				505				—
Home equity lines	182				—				182				63				—				63				245				—
Residential mortgages	245				—				245				32				154				186				431				—
Total acquired consumer	796				136				932				95				154				249				1,181				—
Total acquired TDRs	$	2,526			$	136			$	2,662			$	101			$	154			$	255			$	2,917			$	—
Covered loans
Commercial
C&I	$	362			$	742			$	1,104			$	—			$	—			$	—			$	1,104			$	—
CRE	5,259				34,736				39,995				—				—				—				39,995				3,022
Construction	698				3,446				4,144				—				—				—				4,144				800
Total covered commercial	6,319				38,924				45,243				—				—				—				45,243				3,822
Consumer
Home equity lines	5,377				24				5,401				—				—				—				5,401				—
Residential mortgages	150				—				150				—				—				—				150				—
Total covered consumer	5,527				24				5,551				—				—				—				5,551				—
Total covered TDRs	$	11,846			$	38,948			$	50,794			$	—			$	—			$	—			$	50,794			$	3,822
Total loans
Commercial
C&I	$	1,800			$	1,621			$	3,421			$	183			$	1,955			$	2,138			$	5,559			$	665
CRE	17,431				35,118				52,549				1,208				3,900				5,108				57,657				3,054
Construction	1,546				3,446				4,992				—				57				57				5,049				800
Total commercial	20,777				40,185				60,962				1,391				5,912				7,303				68,265				4,519
Consumer
Installment	23,711				1,374				25,085				2,483				222				2,705				27,790				1,014
Home equity lines	10,872				218				11,090				1,269				12				1,281				12,371				223
Credit card	1,046				66				1,112				—				1				1				1,113				312
Residential mortgages	12,671				3,327				15,998				4,392				3,258				7,650				23,648				1,133
Total consumer	48,300				4,985				53,285				8,144				3,493				11,637				64,922				2,682
Total TDRs	$	69,077			$	45,170			$	114,247			$	9,535			$	9,405			$	18,940			$	133,187			$	7,201
Schedule of Debtor Troubled Debt Restructuring, Current Period	The following table provides the number of loans modified in a TDR during the previous 12 months that subsequently defaulted during the year ended December 31, 2014 and 2013, as well as the amount defaulted in these restructured loans as of December 31, 2014 and 2013.
		As of December 31, 2014
	(Dollars in thousands)	Number of Loans			Amount Defaulted
	Originated loans
	Commercial
	C&I	3			$	4,930
	CRE	1			363
	Construction	—			—
	Total originated commercial	4			5,293
	Consumer
	Installment	11			40
	Home equity lines	1			29
	Credit card	28			140
	Residential mortgages	3			183
	Total originated consumer	43			$	392
	Covered loans
	Commercial
	C&I	1			$	427
	CRE	—			—
	Construction	—			—
	Total covered commercial	1			$	427
	Acquired loans
	Consumer
	Installment	2			$	165
	Home equity lines	1			61
	Residential mortgages	—			—
	Total acquired consumer	3			$	226
	Total loans
	Commercial
	C&I	4			$	5,357
	CRE	1			363
	Construction	—			—
	Total commercial	5			5,720
	Consumer
	Installment	13			205
	Home equity lines	2			90
	Credit card	28			140
	Residential mortgages	3			183
	Total consumer	46			618
	Total	51			$	6,338
		As of December 31, 2013
	(Dollars in thousands)	Number of Loans			Amount Defaulted
	Originated loans
	Commercial
	C&I	4			$	1,773
	CRE	6			3,101
	Construction	1			231
	Total originated commercial	11			5,105
	Consumer
	Installment	17			170
	Home equity lines	—			—
	Credit card	33			245
	Residential mortgages	1			75
	Total originated consumer	51			$	490
	Covered loans
	Commercial
	C&I	—			$	—
	CRE	1			—
	Construction	1			45
	Total covered commercial	2			$	45
	Total loans
	Commercial
	C&I	4			$	1,773
	CRE	7			3,101
Construction	2			276
Total commercial	13			5,150
Consumer
Installment	17			170
Home equity lines	—			—
Credit card	33			245
Residential mortgages	1			75
Total consumer	51			490
Total	64			$	5,640

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill
	(In thousands)	Commercial		Retail			Wealth		Total
	Balance at December 31, 2013	$	527,406	$	193,961		$	20,373	$	741,740
	Balance at December 31, 2014	$	527,406	$	193,961		$	20,373	$	741,740
Schedule of Finite-Lived Intangible Assets	The following tables show the gross carrying amount and the amount of accumulated amortization of intangible assets subject to amortization.
		December 31, 2014
		Gross Carrying		Accumulated			Net Carrying
	(In thousands)	Amount		Amortization			Amount
	Core deposit intangibles (1)	$	82,323	$	(19,996	)	$	62,327
	Lease intangible	238		(176		)	62
	Trust relationships (2)	14,000		(5,369		)	8,631
	Total intangibles	$	96,561	$	(25,541	)	$	71,020
		December 31, 2013
		Gross Carrying		Accumulated			Net Carrying
	(In thousands)	Amount		Amortization			Amount
	Core deposit intangibles (1)	$	87,533	$	(16,065	)	$	71,468
	Noncompete covenant	102		(102		)	—
	Lease intangible	238		(140		)	98
	Trust relationships (2)	14,000		(2,811		)	11,189
	Total intangibles	$	101,873	$	(19,118	)	$	82,755
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table shows the estimated future amortization expense for intangible assets subject to amortization as of December 31, 2014.
	(In thousands)
	For the years ended:
	December 31, 2015	$	10,391
	December 31, 2016	9,209
	December 31, 2017	8,161
	December 31, 2018	7,273
	December 31, 2019	6,500
	Total estimated future amortization	$	41,534

Mortgage_Servicing_Rights_and_1

Mortgage Servicing Rights and Mortgage Servicing Activity (Tables)	12 Months Ended
	Dec. 31, 2014
Transfers and Servicing [Abstract]
Changes in the carrying amount of mortgage servicing rights	Changes in the carrying amount of MSRs and the MSR valuation allowance are as follows:
		Year Ended December 31,
	(In thousands)	2014			2013			2012
	Balance at beginning of period	$	22,760		$	21,316		$	21,179
	Addition of Citizens’ MSRs on Acquisition Date	—			1,065			—
	Additions	3,049			4,952			5,876
	Amortization	(3,798		)	(4,573		)	(5,739		)
	Balance at end of period	22,011			22,760			21,316
	Valuation allowance at beginning of period	(282		)	(2,564		)	(3,539		)
	Recoveries (Additions)	(673		)	2,282			975
	Valuation Allowance at end of period	(955		)	(282		)	(2,564		)
	MSRs, net carrying balance	$	21,056		$	22,478		$	18,752
	Fair value at end of period	$	21,228		$	23,041		$	18,833
Changes in Key economics assumptions	Key economic assumptions and the sensitivity of the current fair value of the MSRS related to immediate 10% and 25% adverse changes in those assumptions at December 31, 2014, are presented in the following table below. These sensitivities are hypothetical and should be used with caution. As the figures indicate, changes in the fair value based on 10% variation in the prepayment speed assumption generally cannot be extrapolated because the relationship of the change in the prepayment speed assumption to the change in fair value may not be linear. Also, in the below table, the effect of a variation in the discount rate assumption on the fair value of the MSRs is calculated independently without changing any other assumption. In reality, changes in one factor may result in changes in another (for example, changes in prepayment speed estimates could result in changes in the discount rates), which might magnify or counteract the sensitivities.
	(Dollars in thousands)
	Prepayment speed assumption (annual CPR)	11.79		%
	Decrease in fair value from 10% adverse change	$	767
	Decrease in fair value from 25% adverse change	$	1,837
	Discount rate assumption	9.89		%
	Decrease in fair value from 100 basis point adverse change	$	660
	Decrease in fair value from 200 basis point adverse change	$	1,277
	Expected weighted-average life (in months)	96.9
Estimated amortization expense for mortgage servicing rights	The following table shows the estimated future amortization for net MSRs as of December 31, 2014:
	(In thousands)
	Year Ended December 31,
	2015	$	3,562
	2016	3,128
	2017	2,610
	2018	2,189
	2019	1,836
	more than 5 years	7,731
	Total estimated future amortization	$	21,056

Premises_and_Equipment_Tables

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of Premises and Equipment	The components of premises and equipment are as follows:
		As of December 31,				Estimated
	(In thousands)	2014		2013		useful lives
	Land	$	60,397	$	64,810	-
	Buildings	308,144		310,345		10-35 yrs
	Equipment	176,906		156,521		3-15 yrs
	Leasehold improvements	25,151		23,872		1-20 yrs
	Software	103,782		83,989		3-7 yrs
		674,380		639,537
	Less accumulated depreciation and amortization	342,083		312,483
	Total premises and equipment	$	332,297	$	327,054

Certificates_and_Other_Time_De1

Certificates and Other Time Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Time Deposits [Abstract]
Maturities of Certificates and Other Time Deposits	Maturities of certificates and other time deposits as of December 31, 2014 are as follows:
	(In thousands)
	For the year ended December 31,
	2015	$	1,627,788
	2016	341,135
	2017	101,325
	2018	109,896
	2019	105,632
	2020 and after	3,727
	Total certificates and other time deposits	$	2,289,503

Federal_Funds_Purchased_and_Se1

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Tables)	12 Months Ended
	Dec. 31, 2014
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Schedule Of Federal Funds Purchased And Securities Sold Under Agreements To Repurchase And Wholesale Borrowings	The following table presents federal funds purchased and securities sold under agreements to repurchase as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	Federal funds purchased and securities sold under agreements to repurchase		$	1,272,591		$	851,535
	The following table presents wholesale borrowings and long-term debt as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	FHLB advances		$	427,857		$	200,323
	Subordinated debentures		505,192			249,928
	Fixed and variable junior subordinated deferral debentures		—			74,500
	Other		214			277
	Total borrowed funds		$	933,263		$	525,028
Schedule Of Select Financial Data Federal Funds Purchased And Securities Sold Under Agreements To Repurchase And Wholesale Borrowings	Selected financial statement information pertaining to the securities sold under agreements to repurchase is as follows:
		As of December 31,
	(Dollars in thousands)	2014			2013			2012
	Average balance during the year	$	1,084,532		$	949,068		$	949,756
	Weighted-average annual interest rate during the year	0.09		%	0.13		%	0.12		%
	Maximum month-end balance	$	1,289,460		$	1,123,795		$	1,104,525

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Income tax expense is comprised of the following:
		Year Ended December 31,
	(In thousands)	2014				2013				2012
	Taxes currently payable
	Federal	$	52,514			$	24,426			$	48,359
	State	4,763				3,496				2,655
	Deferred expense (benefit)	44,666				51,585				4,679
	Total income tax expense	$	101,943			$	79,507			$	55,693
Schedule of Effective Income Tax Rate Reconciliation	The actual income tax rate differs from the statutory tax rate as shown in the following table:
			Year Ended December 31,
			2014			2013			2012
	Statutory rate		35	%		35	%		35	%
	Increase (decrease) in rate due to:
		Interest on tax-exempt securities and tax-free loans, net	(2.77	)		(3.16	)		(3.23	)
		Merger expenses at acquisition	—			0.54			—
		Reduction in excess tax reserves	—			0.11			—
		Bank owned life insurance	(2.10	)		(2.53	)		(3.10	)
		State income tax (net)	0.91			0.87			0.94
		Tax credits	(0.96	)		(1.06	)		(1.14	)
		ESOP Dividends	(0.13	)		(0.14	)		(0.21	)
		Nondeductible meals and entertainment	0.22			0.27			0.25
		Other	(0.18	)		0.31			0.83
	Effective tax rates		29.99	%		30.21	%		29.34	%
Schedule of Deferred Tax Assets and Liabilities	Principal components of the Corporation’s net deferred tax asset are summarized as follows:
			Year Ended
			December 31,
	(In thousands)		2014				2013
	Deferred tax assets:
		Allowance for credit losses	$	35,760			$	37,857
		Employee benefits	51,584				33,676
		Real Estate Mortgage Investment Credit	4,831				5,645
		Acquired liabilities	6,296				14,768
		Acquired loans	51,701				62,993
		Available for sale securities	3,862				16,819
		Loan fees and expenses	—				2,777
		Federal NOL carryforwards	131,195				190,350
		Alternative minimum tax credit carryforward	83,428				41,882
		General business tax credit carryforward	1,982				5,715
		State income tax (net of federal benefit)	1,970				4,728
		Other	467				—
		Total deferred tax assets	373,076				417,210
	Deferred tax liabilities:
		Leased assets and depreciation	(24,699		)		(25,818		)
		FHLB stock	(18,165		)		(24,401		)
		Loan fees and expenses	(2,537		)		—
		Goodwill	(16,580		)		(7,129		)
		Core deposit intangibles	(22,013		)		(25,302		)
		Other	—				(3,510		)
		Total deferred tax liabilities	(83,994		)		(86,160		)
	Total net deferred tax asset		$	289,082			$	331,050
Change in Deferred Taxes	At December 31, 2014, the Corporation had gross federal loss carryforwards of $374.8 million that expire in 2028 through 2032, general business credits of $2.0 million that expire in 2028, and $83.4 million of federal alternative minimum tax credits with an indefinite life. In addition, future state income taxes are expected to be reduced by $2.3 million resulting from state non-operating losses at various levels in various states. This benefit is expected to be fully used during the expiration period of 2014 through 2027.
	The period change in deferred taxes recorded both directly to shareholders’ equity and as a part of the income tax expense is summarized as follows:
			Year Ended December 31,
	(In thousands)		2014				2013
	Deferred tax changes reflected in other comprehensive income		$	(2,698	)		$	(27,285	)
	Deferred tax changes reflected in Federal income tax expense		44,666				51,585
	Deferred tax changes reflected in acquired net assets		—				(348,239		)
		Net decrease/(increase) in DTA	$	41,968			$	(323,939	)
Summary of Income Tax Contingencies	A reconciliation of the change in the reserve for uncertain tax positions for 2014 and 2013 is as follows:
	(In thousands)	Federal and				Accrued				Gross Unrecognized Income Tax Benefits
		State Tax				Interest and
						Penalties
	Balance as of January 1, 2014	$	1,003			$	262			$	1,265
	Additions for tax provisions related to prior year	798				14				812
	Reduction for tax positions related to prior year due closed tax years	(31		)		(3		)		(34		)
	Reduction for tax positions related to prior tax years	(1,465		)		(254		)		(1,719		)
	Balance at December 31, 2014	$	305			$	19			$	324
	Components of Reserve:
	State income tax exposure	$	305			$	19			$	324
	Balance at December 31, 2014	$	305			$	19			$	324
	(In thousands)	Federal and				Accrued				Gross Unrecognized Income Tax Benefits
		State Tax				Interest and
						Penalties
	Balance as of January 1, 2013	$	953			$	854			$	1,807
	Additions for tax provisions related to prior year	77				72				149
	Reduction for tax positions related to prior tax years	(27		)		(664		)		(691		)
	Balance at December 31, 2013	$	1,003			$	262			$	1,265
	Components of Reserve:
	Potential adjustment to nondeductible interest expense	$	30			$	5			$	35
	State income tax exposure	973				257				1,230
	Balance at December 31, 2013	$	1,003			$	262			$	1,265

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Schedule of Net Benefit Costs	The combined components of net periodic pension and postretirement benefits and other amounts recognized in AOCI for the Corporation's pension and postretirement benefit plans as of December 31, 2014, 2013 and 2012, are as follows:
		Pension Benefits											Postretirement Benefits
	(In thousands)	2014				2013				2012			2014			2013			2012
	Net periodic cost consists of:
	Service cost	$	728			$	2,339			$	7,194		$	65		$	99		$	77
	Interest cost	14,337				12,814				11,862			655			563			697
	Expected return on plan assets	(16,035		)		(14,938		)		(12,136		)	—			—			—
	Amortization of prior service cost/(credit)	2,599				467				388			(468		)	(468		)	(468		)
	Amortization of actuarial (gains)/losses	2,930				4,693				10,371			236			268			288
	Settlement / curtailment income	—				(524		)		(142		)	—			—			—
	Net periodic cost (benefit)	4,559				4,851				17,537			488			462			594
	Other changes in plan assets and benefit obligations recognized in Other comprehensive income:
	Current year actuarial losses/(gains)	49,488				(47,257		)		1,281			64			(682		)	(57		)
	Amortization of actuarial gains/(losses)	(2,930		)		(4,169		)		(10,229		)	(236		)	(268		)	(288		)
	Amortization of prior service (cost)/credit	(2,599		)		(467		)		(388		)	468			468			468
	Total recognized in AOCI, before income taxes	43,959				(51,893		)		(9,336		)	296			(482		)	123
	Total recognized in net periodic cost and AOCI	$	48,518			$	(47,042	)		$	8,201		$	784		$	(20	)	$	717
Schedule of Net Funded Status	The following table sets forth a reconciliation of the changes in the projected benefit obligation for the Corporation’s pension and postretirement benefit plans as of December 31, 2014, and 2013, as well as the change in plan assets for the Corporation’s qualified pension plans:
		Pension Benefits								Postretirement Benefits
	(In thousands)	2014				2013				2014			2013
	Accumulated benefit obligation, end of year	$	354,402			$	307,739
	Change in projected benefit obligation:
	Projected benefit obligation, beginning of year	308,834				259,428				$	15,544		$	14,771
	Citizens acquisition	—				85,483				—			2,062
	Service cost	728				2,339				65			99
	Interest cost	14,337				12,814				655			563
	Plan amendments	—				3,927				(1,979		)	—
	Participant contributions	—				—				1,851			1,538
	Actuarial (gains)/losses and change in assumptions	50,115				(35,984		)		2,046			(682		)
	Benefits paid	(18,372		)		(19,172		)		(3,018		)	(2,808		)
	Projected benefit obligation, end of year	$	355,642			$	308,834			$	15,164		$	15,544
	Change in plan assets, at fair value:
	Fair value of plan assets, beginning of year	$	257,510			$	174,385			$	—		$	—
	Citizens acquisition	—				68,304				—			—
	Actual return on plan assets	16,663				30,298				—			—
	Participant contributions	—				—				1,851			1,538
	Employer contributions	1,554				3,695				1,167			1,270
	Benefits paid	(18,372		)		(19,172		)		(3,018		)	(2,808		)
	Fair value of plan assets, end of year	$	257,355			$	257,510			$	—		$	—
	Funded status (1)	(98,287		)		(51,324		)		(15,164		)	(15,544		)
	Amounts recognized in AOCI before income taxes:
	Prior service cost (credit)	$	2,587			$	5,121			$	(5,370	)	$	(3,858	)
	Net actuarial loss	99,715				53,061				5,138			3,329
	Amount recognized in AOCI	$	102,302			$	58,182			$	(232	)	$	(529	)
	(1) The Corporation recognizes the underfunded status of the plans in accrued taxes, expenses and other liabilities on the Consolidated Balance Sheet.
Schedule of Assumptions Used	The actuarial assumptions used to determine year end obligations for the Corporation’s pension and postretirement plans were as follows:
	Weighted-average assumptions for year end obligations	2014			2013			2012
	Discount rate
	Qualified pensions	4.19	%		4.99	%		4.21	%
	Nonqualified pensions	3.61	%		4.12	%		4.21	%
	Postretirement medical benefits, FirstMerit’s plan	3.5	%		4.01	%		3.18	%
	Postretirement medical benefits, Citizens’ plan	3.61	%		3.98	%		na
	Postretirement life insurance benefits	4.36	%		5.08	%		4.3	%
	Expected long-term rate of return	6.5	%		6.75	%		7	%
	Rate of compensation increase
	Qualified pensions	na			na			na
	Nonqualified pensions	3.75	%		3.75	%		3.75	%
	Assumed health care cost trend rate, pre-65 (1)
	Initial trend	7	%		7.5	%		8	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2019			2019			2019
	Assumed health care cost trend rate, post-65 (1)
	Initial trend	11	%		11.5	%		12	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2027			2027			2027
	Prescription Drugs
	Initial trend	7	%		7.5	%		8	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2019			2019			2019
	(1) The health care cost trend assumptions relate only to the postretirement benefit plans. Increasing or decreasing the assumed health care cost trend rates by one percentage point each future year would not have a material impact on total service and interest cost or the year end benefit obligation.
	The actuarial assumptions used as of the beginning of the year to determine the net periodic costs for the Corporation’s pension and postretirement plans were as follows:
	Weighted-average assumptions for benefit cost at beginning of year	2014			2013			2012
	Discount rate
	Qualified pension	4.99	%		4.21	%		5.04	%
	Nonqualified pensions	4.12	%		4.21	%		5.04	%
	Postretirement medical benefits	4.01	%		3.18	%		4.23	%
	Postretirement life insurance benefits	5.08	%		4.3	%		5.03	%
	Expected long-term rate of return	6.75	%		7	%		7.25	%
	Rate of compensation increase
	Qualified pension	na			na			5.22	%
	Nonqualified pensions	3.75	%		3.75	%		3.75	%
	Assumed health care cost trend rate, pre-65 (1)
	Initial trend	7.5	%		8	%		8.5	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2019			2019			2019
	Assumed health care cost trend rate, post-65 (1)
	Initial trend	11.5	%		12	%		12.5	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2027			2027			2027
	Prescription Drugs
	Initial trend	7.5	%		8	%		8.5	%
	Ultimate trend	5	%		5	%		5	%
	Year ultimate trend reached	2019			2019			2019
	(1) The health care cost trend assumptions relate only to the postretirement benefit plans. Increasing or decreasing the assumed health care cost trend rates by one percentage point each future year would not have a material impact on total service and interest cost or the year end benefit obligation
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost (credit) during the next fiscal year are as follows:
	(In thousands)	Pension				Postretirement				Total
	Prior service cost/(credit)	$	2,279			$	(639	)		$	1,640
	Actuarial net loss	4,224				325				4,549
Schedule of Expected Benefit Payments	The expected benefits were estimated using the same assumptions as those used to calculate the benefit obligations in the preceding tables and includes benefits attributable to estimated future employee service.
	(In thousands)	Pension				Postretirement
	2015	$	26,555			$	1,247
	2016	26,420				1,137
	2017	22,162				1,063
	2018	21,858				1,004
	2019	20,239				951
	2020 through 2024	93,104				4,331
Investment Allocation Strategy	As the plan’s funded ratio status improves, the allocation to liability-hedging assets will increase.
	Dynamic Investment Policy Schedule
	Return-Seeking (and Diversification) Allocation Strategy
	Funded Ratio	Minimum	Target	Maximum
	≤97%	36%	40%	44%
	98%	34%	38%	42%
	99%	31%	35%	39%
	100%	30%	33%	36%
	101%	28%	31%	34%
	102%	26%	29%	32%
	103%	23%	26%	29%
	104%	21%	24%	27%
	105%	18%	21%	24%
	106%	16%	18%	20%
	107%	12%	14%	16%
	≥108%	8%	10%	12%
Schedule of Allocation of Plan Assets	The weighted-average allocations for the FirstMerit Pension Plan as of December 31, 2014 and 2013, by asset category, are as follows:
			Percentage of
			Plan Assets on
			Measurement Date
			December 31,
	Asset Category		2014			2013
	Cash and domestic money market funds		1.49	%		1.92	%
	U.S. Treasury obligations		1.97	%		1.76	%
	U.S. Government agencies		1.12	%		0.95	%
	Corporate bonds		2.79	%		3.12	%
	Common stocks		13.54	%		11.24	%
	Equity mutual funds		18.85	%		27.62	%
	Fixed income mutual funds		50.11	%		36.56	%
	Foreign mutual funds		10.13	%		16.83	%
			100	%		100	%
Schedule of Defined Benefit Plans Disclosure	The following table sets forth by level, within the fair value hierarchy, the FirstMerit Pension Plan’s assets at fair value as of December 31, 2014:
	(In thousands)	Level 1				Level 2				Level 3			Total
	Domestic money market funds	$	3,836			$	—			$	—		$	3,836
	United States government securities	—				5,067				—			5,067
	United States government agency issues	—				2,897				—			2,897
	Corporate bonds	—				7,177				—			7,177
	Common stocks	34,835				—				—			34,835
	Equity mutual funds	48,518				—				—			48,518
	Fixed income mutual funds	128,951				—				—			128,951
	Foreign mutual funds	26,074				—				—			26,074
	Total assets at fair value	$	242,214			$	15,141			$	—		$	257,355

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	A summary of stock option activity under the Plans as of December 31, 2014, 2013, and 2012, and changes during the years then ended is as follows:
	Options	Shares (000’s)		Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term	Aggregate InstrinsicValue (000’s)
	Outstanding at January 1, 2012	2,077		$	25.15	1.85	—
	Exercised	—		—
	Forfeited	(71	)	25.85
	Expired	(186	)	25.97
	Outstanding at December 31, 2012	1,820		$	24.73	1.82	$	—
	Acquired	63		218.01
	Exercised	—		—
	Forfeited	(8	)	23.93
	Expired	(479	)	36.64
	Outstanding at December 31, 2013	1,396		$	28.84	1.14	$	87
	Exercised	—		—
	Forfeited	—		—
	Expired	(558	)	31.91
	Outstanding at December 31, 2014	838		$	26.64	0.62	$	—
	Exercisable at December 31, 2014	838		$	26.64	0.62	$	—
Schedule of Nonvested Share Activity	A summary of the status of the Corporation’s nonvested shares as of December 31, 2014, 2013, and 2012, and changes during the years then ended, is as follows:
				Weighted-Average
				Grant Date
	Nonvested (restricted) Stock Awards	Shares (000’s)		Fair Value
	Nonvested at January 1, 2012	1,026		$	18.26
	Granted	596		16.06
	Vested	(493	)	18.29
	Forfeited or expired	(50	)	18.94
	Nonvested at December 31, 2012	1,079		$	17
	Granted	823		16.47
	Vested	(508	)	17.9
	Forfeited or expired	(52	)	16.89
	Nonvested at December 31, 2013	1,342		$	16.34
	Granted	777		19.67
	Vested	(664	)	16.3
	Forfeited or expired	(42	)	18.16
	Nonvested at December 31, 2014	1,413		$	18.16

Parent_Company_Tables

Parent Company (Tables)	12 Months Ended
	Dec. 31, 2014
Parent Company [Abstract]
Schedule Of Condensed Financial Statements	Condensed financial information of FirstMerit Corporation (Parent Company only) is as follows:
	(In thousands)			As of December 31,
	Condensed Balance Sheet			2014				2013
		Assets:
			Cash and due from banks	$	142,950			$	125,032
			Investment securities	1,553				2,253
			Investment in subsidiaries, at equity in underlying value of their net assets	2,936,865				2,863,473
			Other assets	20,479				77,674
			Total Assets	$	3,101,847			$	3,068,432
		Liabilities and Shareholders’ Equity:
			Long-term debt	$	249,935			$	324,428
			Accrued and other liabilities	17,631				41,110
			Shareholders’ equity	2,834,281				2,702,894
			Total Liabilities and Shareholders’ Equity	$	3,101,847			$	3,068,432
	(In thousands)			Year Ended December 31,
	Condensed Statement of Income			2014				2013				2012
		Income:
			Cash dividends from subsidiaries	$	82,642			$	81,715			$	155,493
			Noninterest income	437				483				309
			Total income	83,079				82,198				155,802
		Interest and other expenses		30,613				29,684				10,799
		Income before income tax benefit and equity in undistributed income of subsidiaries		52,466				52,514				145,003
		Income tax benefit		(10,324		)		(9,341		)		(2,004		)
			Income before equity in undistributed net income of subsidiaries	62,790				61,855				147,007
		Equity in undistributed income of subsidiaries		175,161				121,829				(12,901		)
		Net income		$	237,951			$	183,684			$	134,106
	(In thousands)				Year Ended December 31,
	Condensed Statement of Cash Flows				2014				2013				2012
	Operating activities:
			Net income		$	237,951			$	183,684			$	134,106
			Adjustments to reconcile net income to net cash provided by operating activities
			Equity in undistributed income of subsidiaries		(175,161		)		(121,829		)		12,901
			Decrease (increase) in Federal income tax receivable		35,672				(30,399		)		(4,446		)
			(Increase) decrease in deferred Federal tax asset		(1,449		)		27,032				106
			Increase in interest payable		—				4,618				—
			Other		(552		)		924				738
			Net cash provided by operating activities		96,461				64,030				143,405
	Investing activities:
			Loans or advances to subsidiaries		—				(50		)		—
			Repayment of loans to or investment in subsidiaries		110,675				—				—
			Cash paid for acquisition, net of cash received		—				(315,069		)		—
			Sale of investments in subsidiaries		—				—				7,827
			Sale of investment securities		784				—				—
			Purchases of investment securities		(81		)		(215		)		(44		)
			Net cash provided (used) by investing activities		111,378				(315,334		)		7,783
	Financing activities:
			Proceeds from issuance of subordinated debt		—				249,927				—
			Proceeds from issuance of preferred stock		—				96,550				—
			Repayment of long-term debt		(74,451		)		—				—
			Cash dividends-common stock		(105,333		)		(96,222		)		(69,459		)
			Cash dividends-preferred stock		(5,876		)		(5,337		)		—
			Purchase of treasury shares		(4,261		)		(9,521		)		(2,389		)
			Net cash (used) provided by financing activities		(189,921		)		235,397				(71,848		)
	Increase (decrease) in cash and cash equivalents				17,918				(15,907		)		79,340
	Cash and cash equivalents at beginning of year				125,032				140,939				61,599
	Cash and cash equivalents at end of year				$	142,950			$	125,032			$	140,939

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Lines of business results and key performance measures	The following tables present a summary of financial results as of and for the years ended December 31, 2014, 2013, and 2012:
	(In thousands)															FirstMerit
	December 31, 2014	Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)	$	421,136		$	378,597		$	19,836			$	(44,001	)		$	775,568
	Provision for loan losses	2,898			39,618			1,895				7,868				52,279
	Noninterest income	91,483			106,356			55,800				27,885				281,524
	Noninterest expense	240,142			354,305			51,269				19,203				664,919
	Net income/(loss)	175,227			59,169			14,606				(11,051		)		237,951
	AVERAGES:
	Assets	9,265,088			5,632,881			271,975				9,248,267				24,418,211
	Loans	9,262,224			5,305,513			261,321				62,257				14,891,315
	Earnings assets	9,549,341			5,328,548			261,321				6,363,537				21,502,747
	Deposits	6,679,007			11,484,769			1,089,068				275,591				19,528,435
	Economic capital	743,071			353,098			58,106				1,635,864				2,790,139
	(In thousands)																FirstMerit
	December 31, 2013		Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)		$	408,006		$	349,433		$	17,192			$	(63,846	)		$	710,785
	Provision for loan losses		17,072			16,151			(692		)		1,153				33,684
	Noninterest income		83,933			114,679			48,289				23,442				270,343
	Noninterest expense		209,936			330,875			54,196				89,246				684,253
	Net income/(loss)		172,206			76,105			7,784				(72,411		)		183,684
	AVERAGES:
	Assets		8,397,357			4,746,277			259,601				8,086,540				21,489,775
	Loans		8,292,805			4,367,701			226,152				62,008				12,948,666
	Earnings assets		8,480,005			4,392,937			226,179				5,393,874				18,492,995
	Deposits		5,572,287			10,749,725			826,794				152,782				17,301,588
	Economic capital		602,561			256,362			72,244				1,477,698				2,408,865
	(In thousands)																FirstMerit
	December 31, 2012		Commercial			Retail			Wealth				Other				Consolidated
	OPERATIONS:
	Net interest income/(expense)		$	258,575		$	207,907		$	17,444			$	(12,096	)		$	471,830
	Provision for loan losses		32,319			10,008			(626		)		12,997				54,698
	Noninterest income		67,606			103,279			32,996				19,723				223,604
	Noninterest expense		159,525			221,297			39,296				30,819				450,937
	Net income/(loss)		87,318			51,922			7,650				(12,784		)		134,106
	AVERAGES:
	Assets		6,424,226			2,952,280			238,805				5,005,316				14,620,627
	Loans		6,391,189			2,674,997			225,018				65,876				9,357,080
	Earnings assets		6,493,713			2,707,632			225,044				3,646,302				13,072,691
	Deposits		3,284,722			7,416,982			709,786				142,308				11,553,798
	Economic capital		404,005			212,409			49,313				942,381				1,608,108

Fair_Value_Measurement_Tables

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis	The following tables present the balance of assets and liabilities measured at fair value on a recurring and nonrecurring basis at December 31, 2014 and 2013:
					Fair Value by Hierarchy
	(In thousands)	31-Dec-14			Level 1			Level 2			Level 3
	Recurring fair value measurement
	Available-for-sale securities:
	Marketable equity securities	$	2,974		$	2,974		$	—		$	—
	U.S. government agency debentures	2,482			—			2,482			—
	U.S. States and political subdivisions	227,342			—			227,342			—
	Residential mortgage-backed securities:
	U.S. government agencies	970,998			—			970,998			—
	Commercial mortgage-backed securities:
	U.S. government agencies	103,403			—			103,403			—
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,676,567			—			1,676,567			—
	Nonagency	7			—			1			6
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	222,334			—			222,334			—
	Corporate debt securities	51,337			—			—			51,337
	Asset-backed securities:
	Collateralized loan obligations, nonagency issued	287,844			—			—			287,844
	Total available-for-sale securities	3,545,288			2,974			3,203,127			339,187
	Residential loans held for sale	13,428			—			13,428			—
	Derivative assets:
	Interest rate swaps - fair value hedges	5,256			—			5,256			—
	Interest rate swaps - nondesignated	48,366			—			48,366			—
	Mortgage loan commitments	1,408			—			1,408			—
	Foreign exchange	167			—			167			—
	Total derivative assets	55,197			—			55,197			—
	Total fair value of assets (1)	$	3,613,913		$	2,974		$	3,271,752		$	339,187
	Derivative liabilities:
	Interest rate swaps - fair value hedges	6,683			—			6,683			—
	Interest rate swaps - nondesignated	48,366			—			48,366			—
	Forward sales contracts	272			—			272			—
	Foreign exchange	118			—			118			—
	Total derivative liabilities	55,439			—			55,439			—
	True-up liability	13,294			—			—			13,294
	Total fair value of liabilities (1)	$	68,733		$	—		$	55,439		$	13,294
	Nonrecurring fair value measurement
	Mortgage servicing rights (2)	$	21,228		$	—		$	—		$	21,228
	Impaired loans (3)	56,041			—			—			56,041
	Other property (4)	12,510			—			—			12,510
	Other real estate covered by loss share (5)	3,614			—			—			3,614
	Total fair value	$	93,393		$	—		$	—		$	93,393
	(1) There were no transfers between levels 1, 2, or 3 of the fair value hierarchy during the year ended December 31, 2014.
	(2) MSRs with a recorded investment of $22.0 million were reduced by a specific valuation allowance totaling $1.0 million to a reported carrying value of $21.1 million resulting in a recovery of previously recognized expense of $0.7 million included in loans sales and servicing income in the year ended December 31, 2014.
	(3) Collateral dependent impaired loans with a recorded investment of $60.3 million were reduced by specific valuation allowance allocations totaling $4.3 million to a reported net carrying value of $56.0 million.
	(4) Amounts do not include assets held at cost at December 31, 2014. During the year ended December 31, 2014, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $2.6 million included in noninterest expense.
	(5) Amounts do not include assets held at cost at December 31, 2014. During the year ended December 31, 2014, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.2 million included in noninterest expense.
					Fair Value by Hierarchy
	(In thousands)	31-Dec-13			Level 1			Level 2			Level 3
	Recurring fair value measurement
	Available-for-sale securities:
	Marketable equity securities	$	3,036		$	3,036		$	—		$	—
	Nonmarketable equity securities	3,281			—			10			3,271
	U.S. States and political subdivisions	262,367			—			262,367			—
	Residential mortgage-backed securities:
	U.S. government agencies	969,922			—			969,922			—
	Commercial mortgage-backed securities:
	U.S. government agencies	69,567			—			69,567			—
	Residential collateralized mortgage-backed securities:
	U.S. government agencies	1,518,393			—			1,518,393			—
	Nonagency	9			—			—			9
	Commercial collateralized mortgage-backed securities:
	U.S. government agencies	102,268			—			102,268			—
Corporate debt securities	50,644			—			—			50,644
Asset-backed securities:
Collateralized loan obligations, nonagency issued	293,687			—			—			293,687
Total available-for-sale securities	3,273,174			3,036			2,922,527			347,611
Residential loans held for sale	11,622			—			11,622			—
Derivative assets:
Interest rate swaps - nondesignated	46,577			—			46,577			—
Mortgage loan commitments	891			—			891			—
Forward sale contracts	384			—			384			—
Foreign exchange	50			—			50			—
Total derivative assets	47,902			—			47,902			—
Total fair value of assets (1)	$	3,332,698		$	3,036		$	2,982,051		$	347,611
Derivative liabilities:
Interest rate swaps - fair value hedges	11,574			—			11,574			—
Interest rate swaps - nondesignated	46,577			—			46,577			—
Foreign exchange	50			—			50			—
Total derivative liabilities	58,201			—			58,201			—
True-up liability	11,463			—			—			11,463
Total fair value of liabilities (1)	$	69,664		$	—		$	58,201		$	11,463
Nonrecurring fair value measurement
Mortgage servicing rights (2)	$	23,041		$	—		$	—		$	23,041
Impaired loans (3)	47,870			—			—			47,870
Other property (4)	10,018			—			—			10,018
Other real estate covered by loss share (5)	8,754			—			—			8,754
Total fair value	$	89,683		$	—		$	—		$	89,683
(1) There were no transfers between levels 1, 2, or 3 of the fair value hierarchy during the year ended December 31, 2013.
(2) MSRs with a recorded investment of $22.8 million were reduced by a specific valuation allowance totaling $0.3 million to a reported carrying value of $22.5 million resulting in the recovery of previously recognized expense of $2.3 million included in loan sales and servicing income in the year ended December 31, 2013.
(3) Collateral dependent impaired loans with a recorded investment of $52.6 million were reduced by specific valuation allowance allocations totaling $4.8 million to a reported net carrying value of $47.9 million.
(4) Amounts do not include assets held at cost at December 31, 2013. During the year ended December 31, 2013, the re-measurement of foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.4 million included in noninterest expense.
(5) Amounts do not include assets held at cost at December 31, 2013. During the year ended December 31, 2013, the re-measurement of covered foreclosed assets at fair value subsequent to initial recognition resulted in losses of $1.0 million included in noninterest expense.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The changes in Level 3 assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2014 and 2013 are summarized as follows:
		Year Ended
		December 31, 2014						December 31, 2013
	(In thousands)	Available-for-sale securities			True-up liability			Available-for-sale securities			True-up liability
	Balance at beginning of period	$	347,611		$	11,463		$	49,661		$	12,259
	Fair value of assets acquired	—			—			3,271			—
	(Gains) losses included in earnings (1)	—			1,831			—			(796		)
	Unrealized gains (losses) (2)	(6,030		)	—			(2,635		)	—
	Purchases	—			—			297,232			—
	Settlements	(2,394		)	—			82			—
	Balance at ending of period	$	339,187		$	13,294		$	347,611		$	11,463
	(1) Reported in noninterest expense
	(2) Reported in other comprehensive income (loss)
Schedule of Change in Fair Value Carrying Amount of Residential Mortgages	Interest income on loans held for sale is accrued on the principal outstanding primarily using the “simple-interest” method. None of these loans were 90 days or more past due, nor were any on nonaccrual as of December 31, 2014 and 2013. The aggregate fair value, contractual balance, and gain or loss on loans held for sale was as follows:
	(In thousands)		December 31, 2014			December 31, 2013
	Aggregate fair value carrying amount		$	14,389		$	11,622
	Aggregate unpaid principal / contractual balance		13,873			11,438
	Carrying amount over aggregate unpaid principal (1)		$	516		$	184
	(1) These changes are included in loan sales and servicing income in the Consolidated Statement of Income.
Fair Value, by Balance Sheet Grouping	Disclosures about Fair Value of Financial Instruments
	The carrying amount and estimated fair value of the Corporation’s financial instruments that are carried at either fair value or cost as of December 31, 2014, and 2013, are shown in the tables below.
		December 31, 2014
		Carrying			Fair Value
	(In thousands)	Amount			Total			Level 1			Level 2			Level 3
	Financial assets:
	Cash and due from banks	$	697,424		$	697,424		$	697,424		$	—		$	—
	Available-for-sale securities	3,545,288			3,545,288			2,974			3,203,127			339,187
	Held-to-maturity securities	2,903,609			2,875,920			—			2,875,920			—
	Other securities	148,654			148,654			—			148,654			—
	Loans held for sale	13,428			13,428			—			13,428			—
	Net originated loans	12,398,116			12,235,530			—			—			12,235,530
	Net acquired loans	2,471,723			2,564,842			—			—			2,564,842
	Net covered loans and loss share receivable	312,659			312,659			—			—			312,659
	Accrued interest receivable	63,657			63,657			—			63,657			—
	Derivatives	55,197			55,197			—			55,197			—
	Financial liabilities:
	Deposits	$	19,504,665		$	19,510,192		$	—		$	19,510,192		$	—
	Federal funds purchased and securities sold under agreements to repurchase	1,272,591			1,272,591			—			1,272,591			—
	Wholesale borrowings	428,071			430,676			—			430,676			—
	Long-term debt	505,192			516,476			—			516,476			—
	Accrued interest payable	9,820			9,820			—			9,820			—
	Derivatives	55,439			55,439			—			55,439			—
		December 31, 2013
		Carrying			Fair Value
	(In thousands)	Amount			Total			Level 1			Level 2			Level 3
	Financial assets:
	Cash and due from banks	$	917,822		$	917,822		$	917,822		$	—		$	—
	Available for sale securities	3,273,174			3,273,174			3,036			2,922,527			347,611
	Held to maturity securities	2,935,688			2,824,240			—			2,824,240			—
	Other securities	180,803			180,803			—			180,803			—
	Loans held for sale	11,622			11,622			—			11,622			—
	Net originated loans	10,116,903			10,017,722			—			—			10,017,722
	Net acquired loans	3,494,874			3,627,275			—			—			3,627,275
	Net covered loans and loss share receivable	547,943			547,943			—			—			547,943
	Accrued interest receivable	52,929			52,929			—			52,929			—
	Derivatives	47,902			47,902			—			47,902			—
	Financial liabilities:
	Deposits	$	19,533,601		$	19,532,368		$	—		$	19,532,368		$	—
	Federal funds purchased and securities sold under agreements to repurchase	851,535			851,535			—			851,535			—
	Wholesale borrowings	200,600			204,124			—			204,124			—
	Long-term debt	324,428			319,711			—			319,711			—
	Accrued interest payable	9,339			9,339			—			9,339			—
	Derivatives	58,201			58,201			—			58,201			—

Derivatives_and_Hedging_Activi1

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments Designated as Hedging Instruments	At December 31, 2014 and 2013, the notional values or contractual amounts and fair value of the Corporation’s derivatives designated in hedge relationships were as follows:
		Asset Derivatives													Liability Derivatives
		December 31, 2014						December 31, 2013							December 31, 2014					December 31, 2013
	(In thousands)	Notional/ Contract Amount			Fair			Notional/ Contract Amount			Fair				Notional/ Contract Amount			Fair		Notional/ Contract Amount		Fair
					Value (1)						Value (1)							Value (2)				Value (2)
	Interest rate swaps:
	Fair value hedges	$	250,000		$	5,256		$	—		$	—			$	93,313		$	6,683	$	126,637	$	11,574
	(1) Included in Other Assets on the Consolidated Balance Sheet
	(2) Included in Other Liabilities on the Consolidated Balance Sheet
	Fair Value Hedges. Prior to 2009, the Corporation entered into interest rate swaps with dealer
	counterparties to convert certain fixed rate loans to variable rate instruments over the terms of the loans (termed
	by the Corporation as the FRAP Program). These interest rate swaps are designated as fair value hedges and meet the criteria to qualify for the short cut method of accounting. Based on this shortcut method of accounting
	treatment, no ineffectiveness is assumed. The Corporation discontinued originating interest rate swaps under the
	FRAP Program in February 2008.
	During the fourth quarter of 2014, the Corporation entered into a $250.0 million interest rate swap simultaneously with its long-term debt issuance for interest rate risk management purposes. This interest rate swap effectively modifies the receipt of fixed-rate interest amounts in exchange for floating-rate interest payments over the life of the swap, without an exchange of the underlying principal amount. This interest rate swap was designated as a fair value hedge, and through application of the “short cut method of accounting”, there is an assumption that the hedge is effective in offsetting changes in the fair value of the long-term debt due to changes in the U.S. LIBOR swap rate (the designated benchmark interest rate).
Derivative Instruments not Designated as Hedging Instruments	As of December 31, 2014 and 2013, the notional values or contractual amounts and fair value of the Corporation’s derivatives not designated in hedge relationships were as follows:
		Asset Derivatives													Liability Derivatives
		December 31, 2014						December 31, 2013							December 31, 2014					December 31, 2013
	(In thousands)	Notional/ Contract Amount			Fair			Notional/ Contract Amount			Fair				Notional/ Contract Amount			Fair		Notional/ Contract Amount		Fair
					Value (1)						Value (1)							Value (2)				Value (2)
	Interest rate swaps	$	1,673,012		$	48,366		$	1,622,525		$	46,577			$	1,673,012		$	48,366	$	1,622,531	$	46,577
	Mortgage loan commitments	102,523			1,408			90,541			891				—			—		—		—
	Forward sales contracts	47,657			—			40,906			384				—			272		—		—
	Credit contracts	10,001			—			—			—				69,227			—		49,914		—
	Foreign exchange	22,406			167			6,478			50				6,580			118		6,893		50
	Equity swap	—			—			—			—				75,138			—		63,813		—
	Total	$	1,855,599		$	49,941		$	1,760,450		$	47,902			$	1,823,957		$	48,756	$	1,743,151	$	46,627
	(1) Included in Other Assets on the Consolidated Balance Sheet
	(2) Included in Other Liabilities on the Consolidated Balance Sheet
Derivative Instruments, Gain (Loss)	Gains and losses recognized in income on nondesignated hedging instruments for the years ended December 31, 2014, 2013 and 2012, are as follows:
	(In thousands)
	Derivatives not		Location of Gain/(Loss)	Amount of Gain / (Loss) Recognized
	designated as hedging		Recognized	in Income on Derivatives
	instruments		in Income on	Year Ended December 31,
			Derivative	2014			2013			2012
	Mortgage loan commitments		Other operating income	$	517		$	(3,509	)	$	(559	)
	Forward sales contracts		Other operating income	(656		)	446			1,737
	Foreign exchange contracts		Other operating income	(193		)	(116		)	189
	Other		Other operating expense	—			—			—
	Total			$	(332	)	$	(3,179	)	$	1,367
Offsetting disclosure for derivatives contracts	Derivative assets and liabilities are recorded at fair value on the balance sheet and do not take into account the effects of master netting agreements the Corporation has with its financial institution counterparties. These master netting agreements allow the Corporation to settle all derivative contracts held with a single financial institution counterparty on a net basis, and to offset net derivative positions with related collateral, where applicable. Collateral, usually in the form of investment securities, is posted by the counterparty with net liability position in accordance with contract thresholds. The following tables illustrate the potential effect of the Corporation’s derivative master netting arrangements, by type of financial instrument, on the Corporation’s statement of financial position as of December 31, 2014 and 2013. The swap agreements the Corporation has in place with its commercial customers are not subject to enforceable master netting arrangements, and, therefore, are excluded from these tables.
		As of December 31, 2014
		Gross amounts recognized			Gross amounts offset in the consolidated balance sheet			Net amounts presented in the consolidated balance sheet			Gross amounts not offset in the consolidated balance sheet						Net amount
	(In thousands)										Financial instruments (1)			Collateral (2)
	Derivative Assets
	Interest rate swaps - designated	$	5,256		$	—		$	5,256		$	—		$	—		$	5,256
	Interest rate swaps - nondesignated	352			—			352			(352		)	—			—
	Total derivative assets	$	5,608		$	—		$	5,608		$	(352	)	$	—		$	5,256
		Gross amounts of recognized liabilities			Gross amounts offset in the statement of financial position			Net amounts of liabilities presented in the statement of financial position			Gross amounts of financial instruments not offset in the statement of financial position						Net amount
											Netting adjustment per applicable master netting agreements			Fair value of financial collateral
	Derivative Liabilities
	Interest rate swaps - designated	$	6,683		$	—		$	6,683		$	—		$	(6,683	)	$	—
	Interest rate swaps - nondesignated	48,014			—			48,014			(352		)	(47,662		)	—
	Total derivative liabilities	$	54,697		$	—		$	54,697		$	(352	)	$	(54,345	)	$	—
		As of December 31, 2013
		Gross amounts recognized			Gross amounts offset in the consolidated balance sheet			Net amounts presented in the consolidated balance sheet			Gross amounts not offset in the consolidated balance sheet						Net amount
	(In thousands)										Financial instruments (1)			Collateral (2)
	Derivative Assets
	Interest rate swaps - nondesignated	$	4,791		$	—		$	4,791		$	(4,791	)	$	—		$	—
	Foreign exchange	4			—			4			(46		)	42			—
	Total derivative assets	$	4,795		$	—		$	4,795		$	(4,837	)	$	42		$	—
		Gross amounts of recognized liabilities			Gross amounts offset in the statement of financial position			Net amounts of liabilities presented in the statement of financial position			Gross amounts of financial instruments not offset in the statement of financial position						Net amount
											Netting adjustment per applicable master netting agreements			Fair value of financial collateral
	Derivative Liabilities
	Interest rate swaps - designated	$	11,574		$	—		$	11,574		$	—		$	(11,574	)	$	—
	Interest rate swaps - nondesignated	41,787			—			41,787			(4,791		)	(36,996		)	—
	Foreign exchange	46			—			46			(46		)	—			—
	Total derivative liabilities	$	53,407		$	—		$	53,407		$	(4,837	)	$	(48,570	)	$	—
	(1) For derivative assets, this includes any derivative liability fair values that could be offset in the event of counterparty default. For derivative liabilities, this includes any derivative asset fair values that could be offset in the event of counterparty default.
	(2) For derivate assets, this includes the fair value of collateral received by the Corporation from the counterparty. Securities received as collateral are not included in the Consolidated Balance Sheet unless the counterparty defaults. For derivative liabilities, this includes the fair value of securities pledged by the Corporation to the counterparty. These securities are included in the Consolidated Balance Sheet unless the Corporation defaults.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The Corporation is obligated under various noncancelable operating leases on branch offices. Minimum future rental payments under noncancelable operating leases at December 31, 2014 are as follows:
	(In thousands)
	Year Ended December 31,		Lease
			Commitments
	2015		$	13,598
	2016		11,167
	2017		9,841
	2018		8,426
	2019		6,459
	2020-2031		21,999
	Total minimum future rental payments		$	71,490
Schedule of commitments to extend credit	This amount represents the Corporation’s maximum exposure to loss if the customer were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan.
			At December 31,
	(In thousands)		2014			2013
	Loan Commitments
		Commercial	$	3,748,690		$	3,367,625
		Consumer	2,387,623			2,179,010
		Total loan commitments	$	6,136,313		$	5,546,635
Schedule of Guarantor Obligations	The Corporation is a guarantor in certain agreements with third parties. The following table shows the types of guarantees the Corporation had outstanding as of December 31, 2014, and 2013.
			At December 31,
	(In thousands)		2014			2013
	Financial guarantees
		Standby letters of credit	$	242,390		$	196,400
		Loans sold with recourse	45,071			45,082
		Total financial guarantees	$	287,461		$	241,482
Changes in Repurchase Reserve	Changes in the amount of the repurchase reserve for the years ended December 31, 2014, and 2013, are as follows:
		Year Ended December 31, 2014
	(In thousands)	Reserve on residential mortgage loans			Reserve on manufactured housing loans			Total repurchased reserve
	Balance at beginning of period	$	8,737		$	1,114		$	9,851
	Net realized losses	(4,528		)	—			(4,528		)
	Net increase (decrease) to reserve	3,041			10			3,051
	Balance at end of period	$	7,250		$	1,124		$	8,374
		Year Ended December 31, 2013
	(In thousands)	Reserve on residential mortgage loans			Reserve on manufactured housing loans			Total repurchased reserve
	Balance at beginning of period	$	1,500		$	1,167		$	2,667
	Assumed Obligation	6,000			—			6,000
	Net realized losses	(5,818		)	—			(5,818		)
	Net increase (decrease) to reserve	7,055			(53		)	7,002
	Balance at end of period	$	8,737		$	1,114		$	9,851

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Shareholders' Equity [Abstract]
Earnings per share
		Year Ended December 31,
	(In thousands, except per share amounts)	2014		2013		2012
	Basic EPS:
	Net income	$	237,951	$	183,684	$	134,106
	Less:
	Cash dividends on 5.875% non-cumulative perpetual series A, preferred stock	5,876		5,337		—
	Income allocated to participating securities	1,930		1,545		—
	Net income attributable to common shareholders	$	230,145	$	176,802	$	134,106
	Weighted average Common Stock outstanding used in basic EPS	165,296		149,607		109,518
	Basic net income per common share	$	1.39	$	1.18	$	1.22
	Diluted EPS:
	Income used in diluted earnings per share calculation	$	230,145	$	176,802	$	134,106
	Weighted average Common Stock outstanding used in basic EPS	165,296		149,607		109,518
	Add: Common Stock equivalents:
	Warrant and stock plans	758		814		—
	Weighted average Common and Common Stock equivalent shares outstanding	166,054		150,421		109,518
	Diluted net income per common share	$	1.39	$	1.18	$	1.22

Changes_and_Reclassifications_1

Changes and Reclassifications Out of Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Changes and Reclassifications Out of Other Comprehensive Income [Abstract]
Comprehensive Income (Loss)	The following table presents the changes in AOCI by components of comprehensive income for the years ended December 31, 2014 and 2013:
		Year Ended December 31, 2014
	(In thousands)	Pre-tax			Tax			After-tax
	Unrealized and realized securities gains and losses:
	Balance at the beginning of the period	$	(45,072	)	$	(15,776	)	$	(29,296	)
	Changes in unrealized securities’ holding gains/(losses)	38,864			13,602			25,262
	Changes in unrealized securities’ holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity	(2,157		)	(753		)	(1,404		)
	Net losses/(gains) realized on sale of securities reclassified to noninterest income	(166		)	(58		)	(108		)
	Balance at the end of the period	(8,531		)	(2,985		)	(5,546		)
	Pension plans and other postretirement benefits:
	Balance at the beginning and end of the period	(57,813		)	(20,233		)	(37,580		)
	Current year actual gains/(losses)	(49,552		)	(17,344		)	(32,208		)
	Amortization of actuarial losses/(gains)	3,166			1,108			2,058
	Amortization of prior service cost reclassified to other noninterest expense	2,131			747			1,384
	Balance at the end of the period	(102,068		)	(35,722		)	(66,346		)
	Total Accumulated Other Comprehensive Income	$	(110,599	)	$	(38,707	)	$	(71,892	)
		Year Ended December 31, 2013
	(In thousands)	Pre-tax			Tax			After-tax
	Unrealized and realized securities gains and losses:
	Balance at the beginning of the period	$	85,259		$	29,841		$	55,418
	Changes in unrealized securities’ holding gains/(losses)	(130,947		)	(45,833		)	(85,114		)
	Changes in unrealized securities’ holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity	(2,187		)	(765		)	(1,422		)
	Net losses/(gains) realized on sale of securities reclassified to noninterest income	2,803			981			1,822
	Balance at the end of the period	(45,072		)	(15,776		)	(29,296		)
	Pension plans and other postretirement benefits:
	Balance at the beginning and end of the period	(110,188		)	(38,565		)	(71,623		)
	Current year actual gains/(losses)	47,939			16,779			31,160
	Amortization of actuarial losses/(gains)	4,437			1,553			2,884
	Amortization of prior service cost reclassified to other noninterest expense	(1		)	—			(1		)
	Balance at the end of the period	(57,813		)	(20,233		)	(37,580		)
	Total Accumulated Other Comprehensive Income	$	(102,885	)	$	(36,009	)	$	(66,876	)
Reclassification out of Accumulated Other Comprehensive Income	The following table presents current period reclassifications out of AOCI by component of comprehensive income for the years ended December 31, 2014 and 2013:
	(In thousands)	Year Ended December 31, 2014			Statement of Income line item presentation
	Realized (gains) losses on sale of securities	$	(166	)	Investment securities losses (gains), net
	Tax expense (benefit) (35%)	(58		)	Income tax expense (benefit)
	Reclassified amount, net of tax	$	(108	)
	(In thousands)	Year Ended December 31, 2013			Statement of Income line item presentation
	Realized (gains) losses on sale of securities	$	2,803		Investment securities losses (gains), net
	Tax expense (benefit) (35%)	981			Income tax expense (benefit)
	Reclassified amount, net of tax	$	1,822

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2014
Regulatory Capital Requirements [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The capital terms used in this note to the consolidated financial statements are defined in the regulations as well as in the “Capital Resources” section of Management’s Discussion and Analysis of Financial Condition and Results of Operations.
	(Dollars in thousands)	Consolidated
		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2014	Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)	$	2,653,893		15.26	%	>	$	1,391,282		8	%	>	$	1,739,102		10	%
	Tier I Capital
	(to Risk Weighted Assets)	$	2,004,461		11.53	%	>	$	695,641		4	%	>	$	1,043,461		6	%
	Tier I Capital
	(to Average Assets)	$	2,004,461		8.43	%	>	$	951,430		4	%	>	$	1,189,287		5	%
	(Dollars in thousands)	Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2013	Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)	$	2,279,891		13.97	%	>	$	1,305,667		8	%	>	$	1,632,083		10	%
	Tier I Capital
	(to Risk Weighted Assets)	$	1,880,804		11.52	%	>	$	652,833		4	%	>	$	979,250		6	%
	Tier I Capital
	(to Average Assets)	$	1,880,804		8.14	%	>	$	923,887		4	%	>	$	1,154,858		5	%
	At December 31, 2014 and 2013, the most recent notification from the OCC categorized the Bank as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well-capitalized the Bank must maintain minimum total risk-based, Tier I risk-based, and Tier I leverage ratios as set forth in the table. In Management’s opinion, there are no conditions or events since the OCC’s notification that have changed the Bank’s categorization as “well-capitalized.”
			Bank Only
	(Dollars in thousands)		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2014		Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)		$	2,521,412		14.49	%	>	$	1,391,988		8	%	>	$	1,739,986		10	%
	Tier I Capital
	(to Risk Weighted Assets)		$	2,127,065		12.22	%	>	$	695,994		4	%	>	$	1,043,991		6	%
	Tier I Capital
	(to Average Assets)		$	2,127,065		8.94	%	>	$	951,455		4	%	>	$	1,189,319		5	%
	(Dollars in thousands)		Actual						Adequately Capitalized:						Well Capitalized:
	As of December 31, 2013		Amount			Ratio			Amount			Ratio			Amount			Ratio
	Total Capital
	(to Risk Weighted Assets)		$	2,122,124		13.02	%	>	$	1,303,579		8	%	>	$	1,629,473		10	%
	Tier I Capital
	(to Risk Weighted Assets)		$	1,978,140		12.14	%	>	$	651,789		4	%	>	$	977,684		6	%
	Tier I Capital
	(to Average Assets)		$	1,978,140		8.58	%	>	$	922,312		4	%	>	$	1,152,890		5	%

Borrowed_Funds_Tables

Borrowed Funds (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Schedule Of Federal Funds Purchased And Securities Sold Under Agreements To Repurchase And Wholesale Borrowings	The following table presents federal funds purchased and securities sold under agreements to repurchase as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	Federal funds purchased and securities sold under agreements to repurchase		$	1,272,591		$	851,535
	The following table presents wholesale borrowings and long-term debt as of December 31, 2014 and 2013.
			As of December 31,
	(In thousands)		2014			2013
	FHLB advances		$	427,857		$	200,323
	Subordinated debentures		505,192			249,928
	Fixed and variable junior subordinated deferral debentures		—			74,500
	Other		214			277
	Total borrowed funds		$	933,263		$	525,028
Schedule of Select Financial Data Wholesale Borrowings	Selected financial statement information pertaining to the Corporation’s borrowed funds is as follows:
		As of December 31,
	(Dollars in thousands)	2014			2013			2012
	Average balance during the year	$	715,383		$	474,473		$	175,989
	Weighted-average annual interest rate during the year	2.8		%	3.62		%	2.51		%
	Maximum month-end balance	$	973,453		$	527,155		$	178,489
Schedule Of Contractual Maturities Of Federal Funds Purchased And Securities Sold Under Agreements To Repurchase And Wholesale Borrowings	The following table illustrates the contractual maturities of the Corporation's borrowed funds at December 31, 2014:
			One Year			One to			Three to		Over Five
	(In thousands)		or Less			Three Years			Five Years		Years		Total
	FHLB advances		$	189,808		$	212,495		$	202	$	25,352	$	427,857
	Subordinated debentures		—			—			—		505,192		505,192
	Other		67			147			—		—		214
	Total borrowed funds		$	189,875		$	212,642		$	202	$	530,544	$	933,263

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Allowance of Loan Losses) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Accounting Policies [Abstract]
Minimum Non Performing Substandard Loans Outstanding for Allowance for Credit Losses	$0.30
Minimum Non Performing Substandard Doubtful Loans Outstanding for Allowance for Credit Losses	$0.10

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Recently Adopted Accounting Standards) (Details) (Accounting Standards Update 2014-01, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Accounting Standards Update 2014-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$3.10	$2.70

Business_Combinations_Details

Business Combinations (Details) (USD $)	12 Months Ended			0 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
Schedule of recognized identifiable assets at acquisition date [Line Items]
Non-cash transaction: Common Stock issued in merger with Citizens	$0	$925,211	$0
Non-cash transaction: Consideration from the warrant issued to the Treasury for Citizens TARP	0	3,000	0
Citizens Republic Bancorp
Schedule of recognized identifiable assets at acquisition date [Line Items]
Business Acquisition, Share Price				$16.68
Non-cash transaction: Common Stock issued in merger with Citizens				925,211
Sale to the Treasury of Newly issued Non-Voting Preferred Shares Part of TARP				355,371
Cash paid in lieu of stock to Citizens stockholders at acquisition				61
Non-cash transaction: Consideration from the warrant issued to the Treasury for Citizens TARP				3,000
Business Combination, Consideration Transferred				1,283,643
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents				544,380
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities				3,202,575
Acquired Receivables, Fair Value				4,617,004
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				138,536
Finite-Lived intangible assets acquired				84,774
Addition of Citizens' MSR's on Acquisition Date				681,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets				9,268,369
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Deposits				7,276,754
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt				908,824
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other				80,842
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities				8,266,420
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net				1,001,949
Goodwill, Acquired During Period				281,694
Core Deposits | Citizens Republic Bancorp
Schedule of recognized identifiable assets at acquisition date [Line Items]
Finite-Lived intangible assets acquired				70,800
Useful Life	15 years
Customer Relationships | Citizens Republic Bancorp
Schedule of recognized identifiable assets at acquisition date [Line Items]
Finite-Lived intangible assets acquired				$14,000
Useful Life	12 years

Business_Combinations_Acquired

Business Combinations (Acquired Impaired and Non-Impaired Loans at Acquisition Date) (Details) (Citizens Republic Bancorp, USD $)	Apr. 12, 2013
In Thousands, unless otherwise specified
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	$4,617,004
Acquired Impaired Loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	819,715
Acquired performing loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	3,797,289
Commercial Loan | Acquired Impaired Loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	485,703
Commercial Loan | Acquired Impaired Loans | Commercial and Industrial Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	93,735
Commercial Loan | Acquired Impaired Loans | Commercial Real Estate Other Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	378,569
Commercial Loan | Acquired Impaired Loans | Commercial Real Estate Construction Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	13,399
Commercial Loan | Acquired performing loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	2,036,400
Commercial Loan | Acquired performing loans | Commercial and Industrial Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	1,660,199
Commercial Loan | Acquired performing loans | Commercial Real Estate Other Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	359,066
Commercial Loan | Acquired performing loans | Commercial Real Estate Construction Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	17,135
Commercial Loan | Acquired Loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	2,522,103
Commercial Loan | Acquired Loans | Commercial and Industrial Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	1,753,934
Commercial Loan | Acquired Loans | Commercial Real Estate Other Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	737,635
Commercial Loan | Acquired Loans | Commercial Real Estate Construction Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	30,534
Consumer Loan | Acquired Impaired Loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	334,012
Consumer Loan | Acquired Impaired Loans | Residential Mortgage
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	232,291
Consumer Loan | Acquired Impaired Loans | Consumer Installment Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	54,108
Consumer Loan | Acquired Impaired Loans | Consumer Home Equity Lines Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	47,613
Consumer Loan | Acquired performing loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	1,760,889
Consumer Loan | Acquired performing loans | Residential Mortgage
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	278,404
Consumer Loan | Acquired performing loans | Consumer Installment Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	1,165,235
Consumer Loan | Acquired performing loans | Consumer Home Equity Lines Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	317,250
Consumer Loan | Acquired Loans
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	2,094,901
Consumer Loan | Acquired Loans | Residential Mortgage
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	510,695
Consumer Loan | Acquired Loans | Consumer Installment Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	1,219,343
Consumer Loan | Acquired Loans | Consumer Home Equity Lines Financing Receivable
Acquired Impaired and Non-Impaired Loans at Acquisition Date [Line Items]
Acquired Receivables, Fair Value	$364,863

Business_Combinations_Acquired1

Business Combinations (Acquired Impaired Loans Fair Value at Acquisition Date) (Details) (Citizens Republic Bancorp, USD $)	0 Months Ended
In Thousands, unless otherwise specified	Apr. 12, 2013
Fair Value Adjustment for Acquired Non-Impaired Loans [Line Items]
Fair value of acquired nonimpaired loans	$4,617,004
Acquired performing loans
Fair Value Adjustment for Acquired Non-Impaired Loans [Line Items]
Outstanding balance	4,017,304
Less: Fair value adjustment	220,015
Fair value of acquired nonimpaired loans	$3,797,289

Business_Combinations_Nonimpai

Business Combinations (Nonimpaired Cash Flows Reconciliation at Acquisition Date) (Details) (Acquired performing loans, Citizens Republic Bancorp, USD $)	Apr. 12, 2013
In Thousands, unless otherwise specified
Acquired performing loans | Citizens Republic Bancorp
Nonimpaired Loans Cash Flows Reconciliation at Acquisition Date [Line Items]
Business Combination, Acquired Receivables, Gross Contractual Amount	$4,955,180
Business Combination, Acquired Receivables, Estimated Uncollectible	680,664
Contractually required payments at acquisition date, net of uncollectibles	$4,274,516

Business_Combinations_Reconcil

Business Combinations (Reconciliation of Carrying Amounts of Acquired Loans) (Details) (Acquired Impaired Loans, USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
In Thousands, unless otherwise specified
Reconciliation of Carrying Amount of Acquired Loans [Line Items]
Certain Loans Acquired in Transfer, Accretable Yield	($119,450)	($136,646)	$0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	423,209	601,000	0
Citizens Republic Bancorp
Reconciliation of Carrying Amount of Acquired Loans [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance				1,231,172
Certain Loans Acquired in Transfer, Nonaccretable Difference				279,899
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition				951,273
Certain Loans Acquired in Transfer, Accretable Yield	0			-131,558
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$0			$819,715

Business_Combinations_Acquisit

Business Combinations (Acquisition Proforma Details) (Details) (Citizens Republic Bancorp, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Citizens Republic Bancorp
Business Acquisition, Pro-forma Information [Line Items]
Business Acquisition, Pro Forma Revenue	$1,096,960
Business Acquisition, Pro Forma Net Income (Loss)	$196,744

Business_Combinations_Narrativ

Business Combinations (Narrative) (Details) (USD $)	12 Months Ended		0 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Apr. 15, 2013	Jun. 30, 2013	Apr. 12, 2013	Feb. 04, 2013
					Branch
Business Combinations [Line Items]
Assets	$24,902,347,000	$23,912,028,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	0
Deferred Tax Assets, Net	289,082,000	331,050,000
Business Combination, Acquisition Related Costs	1,000,000	75,100,000
Citizens Republic Bancorp
Business Combinations [Line Items]
Assets					9,600,000,000
Number of Branches					219
Business Acquisition, Equity Interest Issued or Issuable, Share Conversion Ratio					1.37
Amount of Citizens TARP Preferred Stock					300,000,000
Accumulated but unpaid interest and dividends related to Citizens TARP Preferred Stock					55,400,000
Debt Instrument, Face Amount						250,000,000
Debt Instrument, Interest Rate, Stated Percentage						4.35%
Total gross proceeds from issuance of depositary shares						100,000,000
Interest rate of Non-Cumulative Perpetual Preferred Stock, Series A						5.88%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Noncurrent					313,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent					51,300,000
Deferred Tax Assets, Net					261,700,000
Net Operating Loss and Tax Credit Carryforwards included in Acquired Deferred Tax Asset					224,800,000
Business combination, deferred tax asset fair market value adjustment					87,600,000
Deferred tax changes reflected in acquired net assets	0	-348,239,000			349,300,000
Acquired Receivables, Fair Value					4,617,004,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities					3,202,575,000
Amount of securities sold subsequent to acquisition				2,200,000,000
Repurchase of securities subsequent to acquisition				1,500,000,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Federal Home Loan Bank Advances					719,300,000
Repayments of Federal Home Loan Bank Borrowings			652,500,000
Federal home loan bank advances retained	66,800,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Subordinated Debt					74,500,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Long Term Repurchase Agreements					115,000,000
FirstMerit | Citizens Republic Bancorp
Business Combinations [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	2,549,701.61				2,408,203
Citizens Republic Bancorp | Citizens Republic Bancorp
Business Combinations [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					1,757,812.50
Acquired performing loans | Citizens Republic Bancorp
Business Combinations [Line Items]
Acquired Receivables, Fair Value					3,797,289,000
Acquired Impaired Loans | Citizens Republic Bancorp
Business Combinations [Line Items]
Acquired Receivables, Fair Value					819,715,000
Acquired Impaired Loans | Citizens Republic Bancorp
Business Combinations [Line Items]
Acquired Receivables, Fair Value					$1,100,000,000
VIE 2
Business Combinations [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		3.10%
London Interbank Offered Rate (LIBOR) [Member] | Maximum | Junior Subordinated Debt | Citizens Republic Bancorp
Business Combinations [Line Items]
Debt Instrument, Basis Spread on Variable Rate		11.75%
London Interbank Offered Rate (LIBOR) [Member] | VIE 2
Business Combinations [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR

Investment_Securities_Narrativ

Investment Securities (Narrative) (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-Sale and Held-to-Maturity Securities [Line Items]
Available for sale securities, net unrealized losses	($44,900,000)	($167,400,000)
Unrealized Gain (Loss) on Investments	-102,400,000	-208,400,000
Number of Single Issuer Trust Preferred Securities With Stated Maturities	8
Investment Securities
Other investment securities pledged	2,800,000,000	3,200,000,000
Number of states with aggregate fair value of general obligation bonds greater than $10 million	11
Total number of states general obligation bonds are held	37
Maximum portfolio concentration in municipal securities per corporate investment policy	20.00%
Amount of municipal securities with a combined individual state to total municipal outstanding equal to or less than, per corporate policy	25.00%
Percent of trust preferred securities included in fair value of entire investment portfolio	1.00%
Available-for-sale	3,545,288,000	3,273,174,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	424,916,000	1,908,543,000
Available-for-sale Securities, Gross Unrealized Loss at End of Period	52,631,000	90,220,000
Collateralized Loan Obligations
Investment Securities
Available-for-sale	287,844,000	293,687,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	79,042,000	223,458,000
Available-for-sale Securities, Gross Unrealized Loss at End of Period	9,613,000	4,332,000
Corporate bonds
Investment Securities
Available-for-sale	51,337,000	50,644,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	10,315,000	10,952,000
12 States
Investment Securities
General obligation bonds, fair value	$10,000,000

Investment_Securities_Amortize

Investment Securities (Amortized Cost Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Securities available for sale
Available-for-sale Securities, Amortized Cost	$3,562,537	$3,329,117
Available-for-sale Securities, Gross Unrealized Gain at End of Period	35,382	34,277
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-52,631	-90,220
Available-for-sale	3,545,288	3,273,174
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	2,903,609	2,935,688
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	22,108	6,761
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-49,797	-118,209
Held-to-maturity Securities, Fair Value	2,875,920	2,824,240
U.S. Government agencies
Securities available for sale
Available-for-sale Securities, Amortized Cost	2,500
Available-for-sale Securities, Gross Unrealized Gain at End of Period	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-18
Available-for-sale	2,482
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	25,000	25,000
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	0	0
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-537	-1,348
Held-to-maturity Securities, Fair Value	24,463	23,652
U.S. States and political subdivisions
Securities available for sale
Available-for-sale Securities, Amortized Cost	221,052	258,787
Available-for-sale Securities, Gross Unrealized Gain at End of Period	6,756	7,376
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-466	-3,796
Available-for-sale	227,342	262,367
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	517,824	480,703
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	12,645	5,335
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-191	-10,459
Held-to-maturity Securities, Fair Value	530,278	475,579
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Amortized Cost	951,839	962,687
Available-for-sale Securities, Gross Unrealized Gain at End of Period	22,377	21,662
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-3,218	-14,427
Available-for-sale	970,998	969,922
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	580,727	569,960
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	7,495	1,108
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-3,045	-11,617
Held-to-maturity Securities, Fair Value	585,177	559,451
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Amortized Cost	104,176	72,048
Available-for-sale Securities, Gross Unrealized Gain at End of Period	598	7
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-1,371	-2,488
Available-for-sale	103,403	69,567
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	58,143	56,596
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	281	0
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-329	-1,190
Held-to-maturity Securities, Fair Value	58,095	55,406
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Amortized Cost	1,698,015	1,566,262
Available-for-sale Securities, Gross Unrealized Gain at End of Period	4,777	4,199
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-26,225	-52,068
Available-for-sale	1,676,567	1,518,393
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	1,368,534	1,464,732
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	718	0
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-38,875	-81,818
Held-to-maturity Securities, Fair Value	1,330,377	1,382,914
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Securities available for sale
Available-for-sale Securities, Amortized Cost	7	9
Available-for-sale Securities, Gross Unrealized Gain at End of Period	0	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	0	0
Available-for-sale	7	9
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	0
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Amortized Cost	222,876	104,152
Available-for-sale Securities, Gross Unrealized Gain at End of Period	863	273
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-1,405	-2,157
Available-for-sale	222,334	102,268
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	257,642	240,069
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	557	6
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-6,768	-11,052
Held-to-maturity Securities, Fair Value	251,431	229,023
Collateralized Loan Obligations
Securities available for sale
Available-for-sale Securities, Amortized Cost	297,446	297,259
Available-for-sale Securities, Gross Unrealized Gain at End of Period	11	760
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-9,613	-4,332
Available-for-sale	287,844	293,687
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	0
Corporate bonds
Securities available for sale
Available-for-sale Securities, Amortized Cost	61,652	61,596
Available-for-sale Securities, Gross Unrealized Gain at End of Period	0	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-10,315	-10,952
Available-for-sale	51,337	50,644
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	90,739	93,628
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	412	308
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	-52	-725
Held-to-maturity Securities, Fair Value	91,099	93,211
Total debt securities
Securities available for sale
Available-for-sale Securities, Amortized Cost	3,559,563	3,322,800
Available-for-sale Securities, Gross Unrealized Gain at End of Period	35,382	34,277
Available-for-sale Securities, Gross Unrealized Loss at End of Period	-52,631	-90,220
Available-for-sale	3,542,314	3,266,857
Marketable equity securities
Securities available for sale
Available-for-sale Securities, Amortized Cost	2,974
Available-for-sale Securities, Gross Unrealized Gain at End of Period	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	0
Available-for-sale	2,974	3,036
Marketable Securities and Investments Held at Cost [Domain]
Securities available for sale
Available-for-sale Securities, Amortized Cost		3,036
Available-for-sale Securities, Gross Unrealized Gain at End of Period		0
Available-for-sale Securities, Gross Unrealized Loss at End of Period		0
Available-for-sale		3,036
Non-marketable equity securities
Securities available for sale
Available-for-sale Securities, Amortized Cost		3,281
Available-for-sale Securities, Gross Unrealized Gain at End of Period		0
Available-for-sale Securities, Gross Unrealized Loss at End of Period		0
Available-for-sale		3,281
Total equity securities
Securities available for sale
Available-for-sale Securities, Amortized Cost	2,974	6,317
Available-for-sale Securities, Gross Unrealized Gain at End of Period	0	0
Available-for-sale Securities, Gross Unrealized Loss at End of Period	0	0
Available-for-sale	2,974	6,317
U.S. Treasury obligations
Securities available for sale
Available-for-sale Securities, Amortized Cost	0
Available-for-sale	0
Securities held to maturity
Held-to-maturity Securities, Amortized Cost	5,000	5,000
Held-to-maturity Securities, Unrecognized Holding Gain End of Period	0	4
Held-to-Maturity Securities, Unrecognized Holding Loss End of Period	0	0
Held-to-maturity Securities, Fair Value	$5,000	$5,004

Investment_Securities_Schedule

Investment Securities (Schedule of general obligation bonds) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	825	886
General obligation bonds, average issue size, fair value	$917	$831
General obligation bonds, amortized cost	737,673	737,568
General obligation bonds, fair value	756,315	735,940
MICHIGAN
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	169	166
General obligation bonds, average issue size, fair value	842	744
General obligation bonds, amortized cost	138,325	122,198
General obligation bonds, fair value	142,292	123,571
OHIO
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	137	152
General obligation bonds, average issue size, fair value	979	1,048
General obligation bonds, amortized cost	130,741	158,641
General obligation bonds, fair value	134,127	159,232
ILLINOIS
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	66	75
General obligation bonds, average issue size, fair value	1,897	1,314
General obligation bonds, amortized cost	121,560	96,863
General obligation bonds, fair value	125,169	98,521
WISCONSIN
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	77	86
General obligation bonds, average issue size, fair value	841	648
General obligation bonds, amortized cost	62,543	54,516
General obligation bonds, fair value	64,776	55,747
TEXAS
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	64	69
General obligation bonds, average issue size, fair value	801	771
General obligation bonds, amortized cost	50,307	54,295
General obligation bonds, fair value	51,293	53,204
PENNSYLVANIA
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	45	50
General obligation bonds, average issue size, fair value	1,000	898
General obligation bonds, amortized cost	44,443	47,835
General obligation bonds, fair value	45,006	44,883
MINNESOTA
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	42	45
General obligation bonds, average issue size, fair value	674	663
General obligation bonds, amortized cost	27,740	29,840
General obligation bonds, fair value	28,326	29,816
WASHINGTON
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	30	30
General obligation bonds, average issue size, fair value	952	930
General obligation bonds, amortized cost	27,987	28,393
General obligation bonds, fair value	28,558	27,906
NEW JERSEY
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	37	38
General obligation bonds, average issue size, fair value	746	722
General obligation bonds, amortized cost	26,755	27,101
General obligation bonds, fair value	27,612	27,440
MISSOURI
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	19	20
General obligation bonds, average issue size, fair value	1,011	969
General obligation bonds, amortized cost	18,764	19,253
General obligation bonds, fair value	19,207	19,382
NEW YORK
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	19	22
General obligation bonds, average issue size, fair value	628	585
General obligation bonds, amortized cost	11,659	13,064
General obligation bonds, fair value	11,929	12,878
CALIFORNIA
general obligation bonds [Line Items]
General Obligation Bonds number of issuers		18
General obligation bonds, average issue size, fair value		599
General obligation bonds, amortized cost		10,651
General obligation bonds, fair value		10,788
Other states
general obligation bonds [Line Items]
General Obligation Bonds number of issuers	120	115
General obligation bonds, average issue size, fair value	650	631
General obligation bonds, amortized cost	76,849	74,918
General obligation bonds, fair value	$78,020	$72,572

Investment_Securities_Other_In

Investment Securities (Other Investments Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other investments
FRB stock	$55,681	$55,294
FHLB stock	92,547	125,032
Other	426	477
Total other investments	$148,654	$180,803

Investment_Securities_Realized

Investment Securities (Realized Gain Loss Table) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Proceeds and gross unrealized gains and losses on sales of available-for-sale securities
Realized gains	$382	$3,786	$3,786
Realized losses	-216	-6,589	0
Net securities gains	$166	($2,803)	$3,786

Investment_Securities_Gross_Un

Investment Securities (Gross Unrealized Loss Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$424,916	$1,908,543
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-2,807	-67,758
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	53	218
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,485,458	199,691
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-49,824	-22,462
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	162	46
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,910,374	2,108,234
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-52,631	-90,220
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	125,775	2,373,148
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-277	-118,026
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	30	492
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,577,797	2,478
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-49,520	-183
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	108	6
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,703,572	2,375,626
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-49,797	-118,209
U.S. Government agencies
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,482
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-18
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	0
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,482
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-18
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	23,652
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	0	-1,348
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	0	1
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	24,463	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-537	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	1	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	24,463	23,652
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-537	-1,348
U.S. States and political subdivisions
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	5,637	38,039
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-11	-1,996
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	11	65
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	22,528	14,157
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-455	-1,800
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	36	25
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	28,165	52,196
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-466	-3,796
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	9,085	222,154
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-17	-10,276
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	9	353
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	18,371	2,478
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-174	-183
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	21	6
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	27,456	224,632
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-191	-10,459
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	50,126	434,761
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-182	-13,109
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	5	35
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	199,773	14,890
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-3,036	-1,318
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	14	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	249,899	449,651
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-3,218	-14,427
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	0	422,192
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	0	-11,617
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	0	22
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	185,361	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-3,045	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	10	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	185,361	422,192
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-3,045	-11,617
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	12,284	33,387
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-55	-1,491
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	2	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	45,485	16,944
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-1,316	-997
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	6	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	57,769	50,331
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-1,371	-2,488
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	9,950	48,831
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-4	-1,190
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	2	8
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	16,735	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-325	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	2	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	26,685	48,831
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-329	-1,190
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	243,970	1,135,151
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-906	-44,775
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	15	74
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	905,478	100,530
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-25,319	-7,293
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	64	7
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,149,448	1,235,681
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-26,225	-52,068
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	28,333	1,382,915
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-149	-81,818
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	3	66
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	1,161,297	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-38,726	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	58	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	1,189,630	1,382,915
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-38,875	-81,818
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End		0
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period		0
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period		0
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End		0
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period		0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		0
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period		0
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	31,375	43,747
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-229	-2,055
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	4	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	67,169	2,525
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-1,176	-102
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	7	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	98,544	46,272
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-1,405	-2,157
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	41,474	208,863
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-55	-11,052
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	3	19
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	171,570	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	-6,713	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	16	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	213,044	208,863
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-6,768	-11,052
Collateralized Loan Obligations
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	79,042	223,458
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-1,406	-4,332
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	15	33
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	193,687	0
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-8,207	0
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	27	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	272,729	223,458
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-9,613	-4,332
Corporate bonds
Securities available for sale
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Available-for-sale Securities, Continous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	0	0
Available for Sale Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	51,338	50,644
available for sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss at end of period	-10,315	-10,952
Available for Sale Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	8	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	51,338	50,644
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	-10,315	-10,952
Securities held to maturity
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	36,933	64,541
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss as of Period End	-52	-725
Held to Maturity Securities in Unrealized Loss Positions Less than Twelve Months Qualitative Disclosure Number of Positions	13	23
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss at End of Period	0	0
Held to Maturity Securities in Unrealized Loss Positions Twelve Months or Longer Qualitative Disclosure Number of Positions	0	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	36,933	64,541
Held-to-Maturity Securities, Continuous Unrealized Loss Position, Aggregate Loss at End of Period	($52)	($725)

Investment_Securities_Maturiti

Investment Securities (Maturities Table) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Securities Available for Sale
One year or less	$47,740
Over one year through five years	2,636,819
Over five years through ten years	777,170
Over ten years	80,585
Available-for-sale	3,545,288	3,273,174
Weighted Average Yield, one year or less	3.72%
Weighted Average Yield, over one year through five years	2.22%
Weighted Average Yield, over five years through ten years	2.92%
Weighted Average Yield, over ten years	1.94%
Available-for-sale Securities, Amortized Cost Basis	3,562,537	3,329,117
Weighted-Average Yield	2.38%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	4 years 3 months 1 day
Securities Held to Maturity
One year or less	86,024
Over one year through five years	2,126,878
Over five years through ten years	475,035
Over ten years	187,983
Weighted Average Yield, over one year through five years	1.93%
Weighted Average Yield, over five years through ten years	1.88%
Weighted Average Yield, over ten years	3.04%
Weighted Average Yield, Total	5.51%
Held-to-maturity		2,935,688
Held-to-maturity Securities, Fair Value	2,875,920	2,824,240
Held-to-maturity Securities, Amortized Cost	2,903,609	2,935,688
Held to Maturity Securities Debt Maturities Weighted Average Yield	2.30%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	4 years 9 months 4 days
U.S. Government agencies
Securities Available for Sale
One year or less	0
Over one year through five years	0
Over five years through ten years	2,482
Over ten years	0
Available-for-sale	2,482
Available-for-sale Securities, Amortized Cost Basis	2,500
Weighted-Average Yield	1.25%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	3 years 5 months 2 days
Securities Held to Maturity
One year or less	0
Over one year through five years	0
Over five years through ten years	24,463
Over ten years	0
Held-to-maturity Securities, Fair Value	24,463	23,652
Held-to-maturity Securities, Amortized Cost	25,000	25,000
Held to Maturity Securities Debt Maturities Weighted Average Yield	1.33%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	4 years 9 months 29 days
U.S. Treasury obligations
Securities Available for Sale
One year or less	0
Over one year through five years	0
Over five years through ten years	0
Over ten years	0
Available-for-sale	0
Available-for-sale Securities, Amortized Cost Basis	0
Weighted-Average Yield	0.00%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	0 years
Securities Held to Maturity
One year or less	5,000
Over one year through five years	0
Over five years through ten years	0
Over ten years	0
Held-to-maturity Securities, Fair Value	5,000	5,004
Held-to-maturity Securities, Amortized Cost	5,000	5,000
Held to Maturity Securities Debt Maturities Weighted Average Yield	0.26%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	0 years 0 months 28 days
U.S. States and political subdivisions
Securities Available for Sale
One year or less	12,365
Over one year through five years	70,589
Over five years through ten years	115,140
Over ten years	29,248
Available-for-sale	227,342	262,367
Available-for-sale Securities, Amortized Cost Basis	221,052	258,787
Weighted-Average Yield	5.23%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	6 years 0 months 0 days
Securities Held to Maturity
One year or less	64,719
Over one year through five years	78,522
Over five years through ten years	199,054
Over ten years	187,983
Held-to-maturity Securities, Fair Value	530,278	475,579
Held-to-maturity Securities, Amortized Cost	517,824	480,703
Held to Maturity Securities Debt Maturities Weighted Average Yield	4.68%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	9 years 4 months 26 days
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
One year or less	2,777
Over one year through five years	791,641
Over five years through ten years	176,580
Over ten years	0
Available-for-sale	970,998	969,922
Available-for-sale Securities, Amortized Cost Basis	951,839	962,687
Weighted-Average Yield	2.60%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	3 years 9 months 22 days
Securities Held to Maturity
One year or less	0
Over one year through five years	468,348
Over five years through ten years	116,829
Over ten years	0
Held-to-maturity Securities, Fair Value	585,177	559,451
Held-to-maturity Securities, Amortized Cost	580,727	569,960
Held to Maturity Securities Debt Maturities Weighted Average Yield	2.16%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	4 years 3 months 8 days
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
One year or less	16,850
Over one year through five years	44,030
Over five years through ten years	42,523
Over ten years	0
Available-for-sale	103,403	69,567
Available-for-sale Securities, Amortized Cost Basis	104,176	72,048
Weighted-Average Yield	2.28%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	4 years 1 month 27 days
Securities Held to Maturity
One year or less	16,305
Over one year through five years	22,119
Over five years through ten years	19,671
Over ten years	0
Held-to-maturity Securities, Fair Value	58,095	55,406
Held-to-maturity Securities, Amortized Cost	58,143	56,596
Held to Maturity Securities Debt Maturities Weighted Average Yield	2.12%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	3 years 6 months 5 days
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
One year or less	8,248
Over one year through five years	1,579,527
Over five years through ten years	88,792
Over ten years	0
Available-for-sale	1,676,567	1,518,393
Available-for-sale Securities, Amortized Cost Basis	1,698,015	1,566,262
Weighted-Average Yield	1.96%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	3 years 8 months 5 days
Securities Held to Maturity
One year or less	0
Over one year through five years	1,307,203
Over five years through ten years	23,174
Over ten years	0
Held-to-maturity Securities, Fair Value	1,330,377	1,382,914
Held-to-maturity Securities, Amortized Cost	1,368,534	1,464,732
Held to Maturity Securities Debt Maturities Weighted Average Yield	1.61%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	3 years 10 months 28 days
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Securities Available for Sale
One year or less	0
Over one year through five years	7
Over five years through ten years	0
Over ten years	0
Available-for-sale	7	9
Available-for-sale Securities, Amortized Cost Basis	7	9
Weighted-Average Yield	3.35%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	2 years 0 months 0 days
Securities Held to Maturity
One year or less	0
Over one year through five years	0
Over five years through ten years	0
Over ten years	0
Held-to-maturity	0
Held-to-maturity Securities, Amortized Cost	0
Held to Maturity Securities Debt Maturities Weighted Average Yield	0.00%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	0 years
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
One year or less	0
Over one year through five years	151,025
Over five years through ten years	71,309
Over ten years	0
Available-for-sale	222,334	102,268
Available-for-sale Securities, Amortized Cost Basis	222,876	104,152
Weighted-Average Yield	1.97%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	4 years 0 months 2 days
Securities Held to Maturity
One year or less	0
Over one year through five years	159,587
Over five years through ten years	91,844
Over ten years	0
Held-to-maturity Securities, Fair Value	251,431	229,023
Held-to-maturity Securities, Amortized Cost	257,642	240,069
Held to Maturity Securities Debt Maturities Weighted Average Yield	2.28%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	4 years 7 months 10 days
Collateralized Loan Obligations
Securities Available for Sale
One year or less	7,500
Over one year through five years	0
Over five years through ten years	280,344
Over ten years	0
Available-for-sale	287,844	293,687
Available-for-sale Securities, Amortized Cost Basis	297,446	297,259
Weighted-Average Yield	2.67%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	6 years 0 months 22 days
Securities Held to Maturity
One year or less	0
Over one year through five years	0
Over five years through ten years	0
Over ten years	0
Held-to-maturity Securities, Amortized Cost	0
Held to Maturity Securities Debt Maturities Weighted Average Yield	0.00%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	0 years
Corporate bonds
Securities Available for Sale
One year or less	0
Over one year through five years	0
Over five years through ten years	0
Over ten years	51,337
Available-for-sale	51,337	50,644
Available-for-sale Securities, Amortized Cost Basis	61,652	61,596
Weighted-Average Yield	0.96%
Available for Sale Securities, Debt Maturities, Weighted-Average Maturity	12 years 9 months 22 days
Securities Held to Maturity
One year or less	0
Over one year through five years	91,099
Over five years through ten years	0
Over ten years	0
Held-to-maturity Securities, Fair Value	91,099	93,211
Held-to-maturity Securities, Amortized Cost	90,739	93,628
Held to Maturity Securities Debt Maturities Weighted Average Yield	2.25%
Held to Maturity Securities Debt Maturities Weighted Average Maturity	3 years 0 months 10 days
Total debt securities
Securities Available for Sale
Available-for-sale	3,542,314	3,266,857
Available-for-sale Securities, Amortized Cost Basis	3,559,563	3,322,800
Fair Value, Inputs, Level 2 [Member]
Securities Available for Sale
Available-for-sale	3,203,127	2,922,527
Securities Held to Maturity
Held-to-maturity Securities, Fair Value		2,824,240
Fair Value, Inputs, Level 2 [Member] | U.S. States and political subdivisions
Securities Available for Sale
Available-for-sale		262,367
Fair Value, Inputs, Level 2 [Member] | Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale		969,922
Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale		69,567
Fair Value, Inputs, Level 2 [Member] | Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale		1,518,393
Fair Value, Inputs, Level 2 [Member] | Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Securities Available for Sale
Available-for-sale	1	0
Fair Value, Inputs, Level 2 [Member] | Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale		102,268
Fair Value, Inputs, Level 2 [Member] | Collateralized Loan Obligations
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 2 [Member] | Corporate bonds
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member]
Securities Available for Sale
Available-for-sale	339,187	347,611
Securities Held to Maturity
Held-to-maturity Securities, Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | U.S. States and political subdivisions
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Securities Available for Sale
Available-for-sale	6	9
Fair Value, Inputs, Level 3 [Member] | Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Securities Available for Sale
Available-for-sale	0	0
Fair Value, Inputs, Level 3 [Member] | Collateralized Loan Obligations
Securities Available for Sale
Available-for-sale		293,687
Securities Held to Maturity
Held-to-maturity	0
Fair Value, Inputs, Level 3 [Member] | Corporate bonds
Securities Available for Sale
Available-for-sale		$50,644

Loans_Total_Originated_Acquire

Loans (Total Originated, Acquired and Covered Loans Outstanding Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	$9,128,591	$8,750,109
Loans and Leases Receivable, Gross, Consumer, Mortgage	1,061,043	1,050,584
Loans and Leases Receivable, Gross, Consumer, Installment, Other	3,162,493	2,738,656
Loans and Leases Receivable, Gross, Consumer, Home Equity	1,417,330	1,311,932
FDIC Indemnification Asset	22,033	61,827
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	164,478	148,313
Loans and Leases Receivable, Gross, Consumer, Lease Financing	370,179	239,551
Loans and Leases Receivable, Gross	15,326,147	14,300,972
Allowance for loan losses	-143,649	-141,252
Net loans	15,182,498	14,159,720
Loans and Leases Receivable, Gross, Carrying Amount, Covered		547,943
Originated Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	7,830,085	6,648,279
Loans and Leases Receivable, Gross, Consumer, Mortgage	625,283	529,253
Loans and Leases Receivable, Gross, Consumer, Installment, Other	2,393,451	1,727,925
Loans and Leases Receivable, Gross, Consumer, Home Equity	1,110,336	920,066
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	164,478	148,313
Loans and Leases Receivable, Gross, Consumer, Lease Financing	370,179	239,551
Loans and Leases Receivable, Gross	12,493,812	10,213,387
Allowance for loan losses	-95,696	-96,484
Net loans		10,116,903
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	1,086,899	1,725,970
Loans and Leases Receivable, Gross, Consumer, Mortgage	394,484	470,652
Loans and Leases Receivable, Gross, Consumer, Installment, Other	764,168	1,004,569
Loans and Leases Receivable, Gross, Consumer, Home Equity	233,629	294,424
Loans and Leases Receivable, Gross	2,479,180	3,495,615
Allowance for loan losses	-7,457	-741
Net loans	2,471,723	3,494,874
Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Commercial	211,607	375,860
Loans and Leases Receivable, Gross, Consumer, Mortgage	41,276	50,679
Loans and Leases Receivable, Gross, Consumer, Installment, Other	4,874	6,162
Loans and Leases Receivable, Gross, Consumer, Home Equity	73,365	97,442
FDIC Indemnification Asset	22,033	61,827
Loans and Leases Receivable, Gross, Carrying Amount, Covered	353,155	591,970
Loans and Leases Receivable, Allowance, Covered	-40,496	-44,027
Loans and Leases Receivable, Net Reported Amount, Covered	$312,659	$547,943

Loans_Summary_of_Loans_to_Rela

Loans (Summary of Loans to Related Parties Table) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loans and Leases Receivable, Related Parties [Roll Forward]
Aggregate amount at beginning of year	$24,536	$16,578	$15,629
New loans	2,534	11,507	3,500
Repayments	-6,388	-4,374	-2,739
Changes in directors and their affiliations	0	825	188
Aggregate amount at end of year	$20,682	$24,536	$16,578

Loans_Changes_in_the_carrying_

Loans (Changes in the carrying amount and accretable yield for acquired impaired loans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
Acquired Impaired Loans
Changes in the carrying amount and accretable yield for acquired impaired loans [Line Items]
Certain Loans Acquired in Transfer, Accretable Yield	$119,450	$136,646	$0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	423,209	601,000	0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	-49,271	-27,144
Certain Loans Acquired in Transfer not Accounted for as Debt Securities Carrying Amount Accretion	49,271	27,144
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	45,824	46,361
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities F D I C Payments Received under Loss Sharing Agreement	-227,062	-245,859
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans	-13,749	-14,129
Acquired Impaired Loans | Citizens Republic Bancorp
Changes in the carrying amount and accretable yield for acquired impaired loans [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance				1,231,172
Certain Loans Acquired in Transfer, Accretable Yield	0			131,558
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	0			819,715
Impaired loans | Acquired Loans
Changes in the carrying amount and accretable yield for acquired impaired loans [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$590,900	$817,600

Loans_Changes_in_Loss_Share_Re

Loans (Changes in Loss Share Receivable Associated with Covered Loans Table) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Acquired Impaired Loans
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	$45,824	$46,361
Loss Share Receivable
Changes in Loss Share Receivable Associated with Covered Loans [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield		61,827	113,734
Changes in Loss Share Receivable [Roll Forward]
Amortization	-20,943	-24,307
Increase due to impairment on covered loans	2,920	10,790
FDIC reimbursement	-17,837	-27,234
Covered loans paid in full	-3,934	-11,156
Balance at end of period	$22,033	$61,827

Loans_Changes_in_the_carrying_1

Loans (Changes in the carrying amount and accretable yield for covered loans) (Details) (Covered impaired loan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Covered impaired loan
Changes in the carrying amount of accretable yield for covered loans [Line Items]
Certain Loans Acquired in Transfer, Accretable Yield	$37,511	$67,282	$113,288
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	232,452	403,692	762,386
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	-42,161	-64,528
Certain Loans Acquired in Transfer not Accounted for as Debt Securities Carrying Amount Accretion	42,161	64,528
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	16,841	34,965
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities F D I C Payments Received under Loss Sharing Agreement	-213,401	-423,222
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans	($4,451)	($16,443)

Loans_Past_Due_Financing_Recei

Loans (Past Due Financing Receivables Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Consumer Loans Guaranteed by Government	$2,400,000	$2,100,000
FDIC Indemnification Asset	22,033,000	61,827,000
Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	33,099,000	52,585,000
Days Past Due 60 to 89	10,116,000	10,926,000
Days Past Due more than 90	26,329,000	35,888,000
Total Past Due	69,544,000	99,399,000
Current	12,424,268,000	10,113,988,000
Total Loans	12,493,812,000	10,213,387,000	8,731,659,000
More than 90 days Past Due and Accruing	12,156,000	11,176,000
Nonaccrual Loans	34,617,000	42,203,000
Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	25,656,000	32,793,000
Days Past Due 60 to 89	9,432,000	13,578,000
Days Past Due more than 90	40,268,000	45,133,000
Total Past Due	75,356,000	91,504,000
Current	2,403,824,000	3,404,111,000
Total Loans	2,479,180,000	3,495,615,000
More than 90 days Past Due and Accruing	3,471,000	4,148,000
Nonaccrual Loans	8,056,000	4,007,000
Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	7,915,000	13,922,000
Days Past Due 60 to 89	2,478,000	9,881,000
Days Past Due more than 90	66,803,000	143,238,000
Total Past Due	77,196,000	167,041,000
Current	253,926,000	363,102,000
Total Loans	331,122,000	530,143,000
Commercial and Industrial Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,212,000	8,941,000
Days Past Due 60 to 89	1,162,000	994,000
Days Past Due more than 90	2,670,000	10,622,000
Total Past Due	6,044,000	20,557,000
Current	5,169,157,000	4,119,010,000
Total Loans	5,175,201,000	4,139,567,000	3,306,526,000
More than 90 days Past Due and Accruing	1,547,000	151,000
Nonaccrual Loans	6,114,000	11,323,000
Commercial and Industrial Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	92,000	1,295,000
Days Past Due 60 to 89	234,000	862,000
Days Past Due more than 90	4,791,000	3,744,000
Total Past Due	5,117,000	5,901,000
Current	444,137,000	788,178,000
Total Loans	449,254,000	794,079,000
More than 90 days Past Due and Accruing	0	40,000
Nonaccrual Loans	787,000	795,000
Commercial and Industrial Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	58,000	836,000
Days Past Due 60 to 89	0	1,489,000
Days Past Due more than 90	6,041,000	12,957,000
Total Past Due	6,099,000	15,282,000
Current	42,738,000	60,955,000
Total Loans	48,837,000	76,237,000
Commercial Real Estate Other Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,155,000	4,507,000
Days Past Due 60 to 89	1,460,000	2,400,000
Days Past Due more than 90	8,864,000	9,688,000
Total Past Due	12,479,000	16,595,000
Current	2,104,639,000	2,153,192,000
Total Loans	2,117,118,000	2,169,787,000
More than 90 days Past Due and Accruing	1,696,000	460,000
Nonaccrual Loans	11,033,000	14,229,000
Commercial Real Estate Other Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	3,479,000	5,603,000
Days Past Due 60 to 89	3,398,000	5,281,000
Days Past Due more than 90	23,509,000	26,366,000
Total Past Due	30,386,000	37,250,000
Current	600,288,000	881,395,000
Total Loans	630,674,000	918,645,000
More than 90 days Past Due and Accruing	44,000	403,000
Nonaccrual Loans	4,171,000	651,000
Commercial Real Estate Other Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	234,000	2,855,000
Days Past Due 60 to 89	1,517,000	3,443,000
Days Past Due more than 90	47,233,000	103,077,000
Total Past Due	48,984,000	109,375,000
Current	104,524,000	164,219,000
Total Loans	153,508,000	273,594,000
Commercial Construction Financing Receivable [Member] | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59		2,675,000
Days Past Due 60 to 89		0
Days Past Due more than 90		0
Total Past Due		2,675,000
Current		10,571,000
Total Loans		13,246,000
More than 90 days Past Due and Accruing		0
Nonaccrual Loans		0
Commercial Real Estate Construction Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	351,000
Days Past Due 60 to 89	0	21,000
Days Past Due more than 90	0	66,000
Total Past Due	0	438,000
Current	537,766,000	338,487,000
Total Loans	537,766,000	338,925,000
More than 90 days Past Due and Accruing	0	0
Nonaccrual Loans	0	122,000
Commercial Real Estate Construction Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0
Days Past Due 60 to 89	0
Days Past Due more than 90	685,000
Total Past Due	685,000
Current	6,286,000
Total Loans	6,971,000	13,246,000
More than 90 days Past Due and Accruing	0
Nonaccrual Loans	0
Commercial Real Estate Construction Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	2,191,000
Days Past Due 60 to 89	0	1,917,000
Days Past Due more than 90	6,064,000	20,388,000
Total Past Due	6,064,000	24,496,000
Current	3,198,000	1,533,000
Total Loans	9,262,000	26,029,000
Commercial Leases Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	0	902,000
Days Past Due 60 to 89	0	0
Days Past Due more than 90	0	0
Total Past Due	0	902,000
Current	370,179,000	238,649,000
Total Loans	370,179,000	239,551,000
More than 90 days Past Due and Accruing	0	0
Nonaccrual Loans	0	0
Commercial Leases Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Total Loans	0	0
Commercial Leases Financing Receivable | Covered Loans
Summary of loans by portfolio type
Total Loans	0	0
Consumer Installment Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	14,621,000	15,433,000
Days Past Due 60 to 89	3,647,000	4,050,000
Days Past Due more than 90	4,716,000	4,462,000
Total Past Due	22,984,000	23,945,000
Current	2,370,467,000	1,703,980,000
Total Loans	2,393,451,000	1,727,925,000
More than 90 days Past Due and Accruing	3,695,000	3,735,000
Nonaccrual Loans	3,268,000	3,681,000
Consumer Installment Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	6,204,000	14,528,000
Days Past Due 60 to 89	2,029,000	4,076,000
Days Past Due more than 90	1,861,000	3,354,000
Total Past Due	10,094,000	21,958,000
Current	754,074,000	982,611,000
Total Loans	764,168,000	1,004,569,000
More than 90 days Past Due and Accruing	615,000	2,263,000
Nonaccrual Loans	1,218,000	679,000
Consumer Installment Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	23,000	33,000
Days Past Due 60 to 89	0	0
Days Past Due more than 90	34,000	0
Total Past Due	57,000	33,000
Current	4,817,000	6,130,000
Total Loans	4,874,000	6,163,000
Consumer Home Equity Lines Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	1,357,000	1,864,000
Days Past Due 60 to 89	587,000	918,000
Days Past Due more than 90	1,206,000	965,000
Total Past Due	3,150,000	3,747,000
Current	1,107,186,000	916,319,000
Total Loans	1,110,336,000	920,066,000
More than 90 days Past Due and Accruing	569,000	418,000
Nonaccrual Loans	1,654,000	1,819,000
Consumer Home Equity Lines Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	2,819,000	4,774,000
Days Past Due 60 to 89	2,123,000	1,933,000
Days Past Due more than 90	2,333,000	3,606,000
Total Past Due	7,275,000	10,313,000
Current	226,354,000	284,111,000
Total Loans	233,629,000	294,424,000
More than 90 days Past Due and Accruing	1,519,000	1,039,000
Nonaccrual Loans	631,000	1,300,000
Consumer Home Equity Lines Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	1,395,000	544,000
Days Past Due 60 to 89	870,000	1,467,000
Days Past Due more than 90	3,859,000	1,651,000
Total Past Due	6,124,000	3,662,000
Current	67,241,000	93,780,000
Total Loans	73,365,000	97,442,000
Consumer Credit Card Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	668,000	729,000
Days Past Due 60 to 89	516,000	471,000
Days Past Due more than 90	860,000	735,000
Total Past Due	2,044,000	1,935,000
Current	162,434,000	146,378,000
Total Loans	164,478,000	148,313,000
More than 90 days Past Due and Accruing	407,000	404,000
Nonaccrual Loans	596,000	558,000
Consumer Residential Mortgages Financing Receivable | Originated Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	12,086,000	19,858,000
Days Past Due 60 to 89	2,744,000	2,072,000
Days Past Due more than 90	8,013,000	9,350,000
Total Past Due	22,843,000	31,280,000
Current	602,440,000	497,973,000
Total Loans	625,283,000	529,253,000
More than 90 days Past Due and Accruing	4,242,000	6,008,000
Nonaccrual Loans	11,952,000	10,471,000
Consumer Residential Mortgages Financing Receivable | Acquired Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	13,062,000	3,918,000
Days Past Due 60 to 89	1,648,000	1,426,000
Days Past Due more than 90	7,089,000	8,063,000
Total Past Due	21,799,000	13,407,000
Current	372,685,000	457,245,000
Total Loans	394,484,000	470,652,000
More than 90 days Past Due and Accruing	1,293,000	403,000
Nonaccrual Loans	1,249,000	582,000
Consumer Residential Mortgages Financing Receivable | Covered Loans
Summary of loans by portfolio type
Days Past Due 30 to 59	6,205,000	7,463,000
Days Past Due 60 to 89	91,000	1,565,000
Days Past Due more than 90	3,572,000	5,165,000
Total Past Due	9,868,000	14,193,000
Current	31,408,000	36,485,000
Total Loans	$41,276,000	$50,678,000

Loans_Financing_Receivables_Cr

Loans (Financing Receivables Credit Quality Indicators Table) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Originated Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	$12,493,812	$10,213,387	$8,731,659
Originated Loans | Commercial and Industrial Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	5,175,201	4,139,567	3,306,526
Originated Loans | Commercial and Industrial Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	52,676	34,909
Originated Loans | Commercial and Industrial Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	186,278	108,709
Originated Loans | Commercial and Industrial Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,340,100	802,624
Originated Loans | Commercial and Industrial Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	3,413,446	3,083,458
Originated Loans | Commercial and Industrial Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	139,083	71,857
Originated Loans | Commercial and Industrial Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	43,618	38,010
Originated Loans | Commercial and Industrial Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Originated Loans | Commercial Real Estate Other Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	2,117,118	2,169,787
Originated Loans | Commercial Real Estate Other Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	683	241
Originated Loans | Commercial Real Estate Other Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	3,454	3,730
Originated Loans | Commercial Real Estate Other Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	294,281	315,150
Originated Loans | Commercial Real Estate Other Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,745,470	1,759,383
Originated Loans | Commercial Real Estate Other Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	29,990	34,969
Originated Loans | Commercial Real Estate Other Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	43,240	56,314
Originated Loans | Commercial Real Estate Other Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Originated Loans | Commercial Real Estate Construction Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	537,766	338,925
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	678	0
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	46,074	25,632
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	490,757	306,795
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	257	267
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	6,231
Originated Loans | Commercial Real Estate Construction Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Originated Loans | Commercial Leases Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	370,179	239,551
Originated Loans | Commercial Leases Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	4,451	9,271
Originated Loans | Commercial Leases Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	14,959	2,900
Originated Loans | Commercial Leases Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	71,908	54,446
Originated Loans | Commercial Leases Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	277,277	167,022
Originated Loans | Commercial Leases Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,389	5,750
Originated Loans | Commercial Leases Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	195	162
Originated Loans | Commercial Leases Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Originated Loans | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	8,200,264	6,887,830
Originated Loans | Commercial | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	58,488	44,421
Originated Loans | Commercial | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	204,691	115,339
Originated Loans | Commercial | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,752,363	1,197,852
Originated Loans | Commercial | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	5,926,950	5,316,658
Originated Loans | Commercial | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	170,719	112,843
Originated Loans | Commercial | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	87,053	100,717
Originated Loans | Commercial | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	2,479,180	3,495,615
Acquired Loans | Commercial and Industrial Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	449,254	794,079
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,076	0
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	1,741
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	20,891	79,634
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	376,129	643,495
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	23,268	46,807
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	27,890	22,402
Acquired Loans | Commercial and Industrial Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Other Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	630,674	918,645
Acquired Loans | Commercial Real Estate Other Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Other Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	703
Acquired Loans | Commercial Real Estate Other Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	24,867	29,224
Acquired Loans | Commercial Real Estate Other Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	532,447	722,307
Acquired Loans | Commercial Real Estate Other Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	28,382	93,499
Acquired Loans | Commercial Real Estate Other Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	44,978	72,912
Acquired Loans | Commercial Real Estate Other Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	6,971	13,246
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	6,286	13,246
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	685	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Real Estate Construction Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial Leases Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Acquired Loans | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,086,899	1,725,970
Acquired Loans | Commercial | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,076	0
Acquired Loans | Commercial | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	2,444
Acquired Loans | Commercial | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	45,758	108,858
Acquired Loans | Commercial | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	914,862	1,379,048
Acquired Loans | Commercial | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	52,335	140,306
Acquired Loans | Commercial | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	72,868	95,314
Acquired Loans | Commercial | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	331,122	530,143
Covered Loans | Commercial and Industrial Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	48,837	76,237
Covered Loans | Commercial and Industrial Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial and Industrial Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,347	968
Covered Loans | Commercial and Industrial Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial and Industrial Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	36,406	41,115
Covered Loans | Commercial and Industrial Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	167	427
Covered Loans | Commercial and Industrial Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	10,917	31,621
Covered Loans | Commercial and Industrial Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	2,106
Covered Loans | Commercial Real Estate Other Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	153,508	273,594
Covered Loans | Commercial Real Estate Other Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Other Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Other Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Other Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	86,779	113,863
Covered Loans | Commercial Real Estate Other Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	3,401	6,219
Covered Loans | Commercial Real Estate Other Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	63,328	153,318
Covered Loans | Commercial Real Estate Other Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	194
Covered Loans | Commercial Real Estate Construction Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	9,262	26,029
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	823	601
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	8,248	23,208
Covered Loans | Commercial Real Estate Construction Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	191	2,220
Covered Loans | Commercial Leases Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial Leases Financing Receivable | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	211,607	375,860
Covered Loans | Commercial | Grade 1
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial | Grade 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	1,347	968
Covered Loans | Commercial | Grade 3
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	0	0
Covered Loans | Commercial | Grade 4
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	124,008	155,579
Covered Loans | Commercial | Grade 5
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	3,568	6,646
Covered Loans | Commercial | Grade 6
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	82,493	208,147
Covered Loans | Commercial | Grade 7
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Net	$191	$4,520

Loans_Details_Textual

Loans (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$5,400,000	$6,600,000
Loans and Leases Receivable, Gross, Carrying Amount, Covered		547,943,000
Time period for non-payment of loans that are placed on non-accrual status	90 days
Days past due for nonaccrual status credit card loans	120 days
Covered impaired loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Gross, Carrying Amount, Covered	451,200,000	756,100,000
Acquired Loans | Impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance, including contractual principal, interest, fees and penalties, of all purchased loans	$590,900,000	$817,600,000

Allowance_for_Loan_Losses_Sche

Allowance for Loan Losses (Schedule of Credit Losses Related to Originated Financing Receivables, Current and Non-Current) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses, Write-downs	($14,700)	($6,800)
Provision for Loan, Lease, and Other Losses	-52,279	-33,684	-54,698
Originated Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	95,696	96,484	98,942	107,699
Financing Receivable, Allowance for Credit Losses, Write-downs	44,923	40,173	65,905
Financing Receivable, Allowance for Credit Losses, Recovery	20,964	24,681	23,172
Provision for Loan, Lease, and Other Losses	23,171	13,034	33,976
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	5,950	6,146	5,004
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	89,746	90,338	93,938
Financing Receivable, Individually Evaluated for Impairment	93,448	87,764	96,371
Financing Receivable, Collectively Evaluated for Impairment	12,400,364	10,125,623	8,635,288
Financing Receivable, Net	12,493,812	10,213,387	8,731,659
Originated Loans | Commercial and Industrial Financing Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	37,375	42,981	36,209	32,363
Financing Receivable, Allowance for Credit Losses, Write-downs	9,617	5,840	22,639
Financing Receivable, Allowance for Credit Losses, Recovery	3,872	7,981	4,266
Provision for Loan, Lease, and Other Losses	139	4,631	22,219
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	72	3,235	577
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	37,303	39,746	35,632
Financing Receivable, Individually Evaluated for Impairment	11,759	8,053	6,187
Financing Receivable, Collectively Evaluated for Impairment	5,163,442	4,131,514	3,300,339
Financing Receivable, Net	5,175,201	4,139,567	3,306,526
Originated Loans | Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	10,492	12,265	20,126	31,857
Financing Receivable, Allowance for Credit Losses, Write-downs	3,512	1,281	5,312
Financing Receivable, Allowance for Credit Losses, Recovery	515	524	911
Provision for Loan, Lease, and Other Losses	1,224	-7,104	-7,330
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		229	913
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	7,578	12,036	19,213
Financing Receivable, Individually Evaluated for Impairment	23,300	20,616	24,007
Financing Receivable, Collectively Evaluated for Impairment	2,093,818	2,149,171	2,200,409
Financing Receivable, Net	2,117,118	2,169,787	2,224,416
Originated Loans | Commercial Construction Financing Receivable Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	2,202	2,810	3,821	5,173
Financing Receivable, Allowance for Credit Losses, Write-downs	0	516	697
Financing Receivable, Allowance for Credit Losses, Recovery	39	507	449
Provision for Loan, Lease, and Other Losses	-647	-1,002	-1,104
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		0	105
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,202	2,810	3,716
Financing Receivable, Individually Evaluated for Impairment	0	906	3,405
Financing Receivable, Collectively Evaluated for Impairment	537,766	338,019	332,142
Financing Receivable, Net	537,766	338,925	335,547
Originated Loans | Finance Leases Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	674	1,081	639	341
Financing Receivable, Allowance for Credit Losses, Write-downs	0	1,237	144
Financing Receivable, Allowance for Credit Losses, Recovery	379	100	38
Provision for Loan, Lease, and Other Losses	-786	1,579	404
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	0	0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	674	1,081	639
Financing Receivable, Individually Evaluated for Impairment	0	0	0
Financing Receivable, Collectively Evaluated for Impairment	370,179	239,551	139,236
Financing Receivable, Net	370,179	239,551	139,236
Originated Loans | Installment Financing Receivable Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	12,918	11,935	11,154	17,981
Financing Receivable, Allowance for Credit Losses, Write-downs	20,328	16,683	18,029
Financing Receivable, Allowance for Credit Losses, Recovery	11,185	10,519	11,694
Provision for Loan, Lease, and Other Losses	10,126	6,945	-492
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		1,014	1,526
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	11,740	10,921	9,628
Financing Receivable, Individually Evaluated for Impairment	24,905	27,285	30,870
Financing Receivable, Collectively Evaluated for Impairment	2,368,546	1,700,640	1,297,388
Financing Receivable, Net	2,393,451	1,727,925	1,328,258
Originated Loans | Home Equity Receivable Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	19,324	12,900	13,724	6,766
Financing Receivable, Allowance for Credit Losses, Write-downs	4,831	7,172	8,949
Financing Receivable, Allowance for Credit Losses, Recovery	2,940	2,979	3,441
Provision for Loan, Lease, and Other Losses	8,315	3,369	12,466
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		223	34
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	19,117	12,677	13,690
Financing Receivable, Individually Evaluated for Impairment	7,379	6,726	6,281
Financing Receivable, Collectively Evaluated for Impairment	1,102,957	913,340	799,797
Financing Receivable, Net	1,110,336	920,066	806,078
Originated Loans | Credit Card Receivables Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	7,966	7,740	7,384	7,369
Financing Receivable, Allowance for Credit Losses, Write-downs	4,604	5,541	6,171
Financing Receivable, Allowance for Credit Losses, Recovery	1,716	1,841	2,138
Provision for Loan, Lease, and Other Losses	3,114	4,056	4,048
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		312	127
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	7,670	7,428	7,257
Financing Receivable, Individually Evaluated for Impairment	854	1,112	1,612
Financing Receivable, Collectively Evaluated for Impairment	163,624	147,201	144,775
Financing Receivable, Net	164,478	148,313	146,387
Originated Loans | Residential Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	4,745	4,772	5,885	5,849
Financing Receivable, Allowance for Credit Losses, Write-downs	2,031	1,903	3,964
Financing Receivable, Allowance for Credit Losses, Recovery	318	230	235
Provision for Loan, Lease, and Other Losses	1,686	560	3,765
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,283	1,133	1,722
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	3,462	3,639	4,163
Financing Receivable, Individually Evaluated for Impairment	25,251	23,066	24,009
Financing Receivable, Collectively Evaluated for Impairment	600,032	506,187	421,202
Financing Receivable, Net	$625,283	$529,253	$445,211

Allowance_for_Loan_Losses_Sche1

Allowance for Loan Losses (Schedule of Credit Losses Related to Acquired Financing Receivables) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for loan losses	$52,279	$33,684	$54,698
Acquired Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	7,457	741	0
Provision for loan losses	$6,716	$741

Allowance_for_Loan_Losses_Sche2

Allowance for Loan Losses (Schedule of Credit Losses Related to Covered Financing Receivables, Current) (Details) (Covered Loans, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Covered Loans
Schedule of Allowance for Loan Losses Related to Covered Financing Receivables, Current [Line Items]
Loans and Leases Receivable, Allowance, Covered	$40,496	$44,027	$43,255	$36,417
Provision for Loan Losses Before Benefit Attributable to FDIC Loss Share Agreements	10,568	23,892	35,450
Benefit Attributable to FDIC Loss Share Agreements	2,920	-10,790	-14,728
Provision for Loan Lease and Other Losses Covered	7,648	13,102	20,722
Increase in Indemnification Asset	2,920	10,790	14,728
Allowance for Loan and Lease Losses, Write-offs	$14,099	($23,120)	($28,612)

Allowance_for_Loan_Losses_Impa

Allowance for Loan Losses (Impaired Financing Receivables) (Details) (Originated Loans, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Impaired [Line Items]
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	$5,950	$6,146	$5,004
Impaired Financing Receivable, Recorded Investment	93,448	87,764
Impaired Financing Receivable, Unpaid Principal Balance	110,055	104,244
Impaired Financing Receivable, Related Allowance	5,950	6,146
Impaired Financing Receivable, Average Recorded Investment	95,108	93,702
Commercial and Industrial Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	11,451	2,503
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	18,207	6,679
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	14,193	7,256
Impaired Financing Receivable, with Related Allowance, Recorded Investment	308	5,551
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	344	7,428
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	72	3,235	577
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	326	5,009
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	16,874	17,871
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	22,696	23,709
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	18,027	18,639
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,426	2,744
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,440	2,870
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,914	229
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	4,497	2,836
Commercial Real Estate Construction Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0	906
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0	1,179
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	0	1,035
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	0
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0	0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0	0
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	0	0
Consumer Installment Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	4,460	2,813
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	4,584	3,978
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	4,272	3,338
Impaired Financing Receivable, with Related Allowance, Recorded Investment	20,445	24,472
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	21,024	24,558
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,178	1,014
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	19,513	24,985
Consumer Home Equity Lines Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,723	1,018
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,754	1,347
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,792	1,079
Impaired Financing Receivable, with Related Allowance, Recorded Investment	5,656	5,707
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	5,875	5,707
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	207	223
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,944	5,874
Consumer Credit Card Financing Receivable
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	16	49
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	16	49
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	32	91
Impaired Financing Receivable, with Related Allowance, Recorded Investment	838	1,064
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	838	1,064
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	296	312
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	966	1,238
Residential Portfolio Segment
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	12,204	10,250
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	15,119	12,778
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	12,425	10,258
Impaired Financing Receivable, with Related Allowance, Recorded Investment	13,047	12,816
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	13,158	12,898
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,283	1,133	1,722
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	13,121	12,064
Total impaired loans with no related allowance
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	46,728	35,410
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	62,376	49,719
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	50,741	41,696
Total impaired loans with a related allowance
Financing Receivable, Impaired [Line Items]
Impaired Financing Receivable, with Related Allowance, Recorded Investment	46,720	52,354
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	47,679	54,525
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	5,950	6,146
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	$44,367	$52,006

Allowance_for_Loan_Losses_Trou

Allowance for Loan Losses (Troubled Debt Restructurings on Financing Receivables) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2,494	2,624
Financing Receivable, Modifications, Recorded Investment	$130,458	$133,187
Financing Receiables, Modifications, Unpaid Principal Balance	173,976	184,293
Commercial and Industrial Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	51	40
Financing Receivable, Modifications, Recorded Investment	7,318	5,559
Financing Receiables, Modifications, Unpaid Principal Balance	15,495	9,996
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	94	77
Financing Receivable, Modifications, Recorded Investment	45,648	57,657
Financing Receiables, Modifications, Unpaid Principal Balance	67,466	79,307
Commercial Real Estate Construction Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	40	40
Financing Receivable, Modifications, Recorded Investment	339	5,049
Financing Receiables, Modifications, Unpaid Principal Balance	9,552	25,726
Commercial Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	185	157
Financing Receivable, Modifications, Recorded Investment	53,305	68,265
Financing Receiables, Modifications, Unpaid Principal Balance	92,513	115,029
Consumer Installment Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	1,245	1,565
Financing Receivable, Modifications, Recorded Investment	25,880	27,790
Financing Receiables, Modifications, Unpaid Principal Balance	26,662	29,078
Home Equity Line of Credit
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	483	286
Financing Receivable, Modifications, Recorded Investment	23,201	12,371
Financing Receiables, Modifications, Unpaid Principal Balance	23,513	12,745
Consumer Credit Card Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	238	307
Financing Receivable, Modifications, Recorded Investment	854	1,113
Financing Receiables, Modifications, Unpaid Principal Balance	854	1,113
Residential Mortgage
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	343	309
Financing Receivable, Modifications, Recorded Investment	27,218	23,648
Financing Receiables, Modifications, Unpaid Principal Balance	30,434	26,328
Consumer Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2,309	2,467
Financing Receivable, Modifications, Recorded Investment	77,153	64,922
Financing Receiables, Modifications, Unpaid Principal Balance	81,463	69,264
Originated Loans Commercial | Commercial and Industrial Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	41	35
Financing Receivable, Modifications, Recorded Investment	7,123	4,449
Financing Receiables, Modifications, Unpaid Principal Balance	13,887	7,660
Originated Loans Commercial | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	67	52
Financing Receivable, Modifications, Recorded Investment	17,607	15,932
Financing Receiables, Modifications, Unpaid Principal Balance	22,645	20,569
Originated Loans Commercial | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	31	30
Financing Receivable, Modifications, Recorded Investment	0	905
Financing Receiables, Modifications, Unpaid Principal Balance	0	1,179
Originated Loans Commercial | Commercial Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	139	117
Financing Receivable, Modifications, Recorded Investment	24,730	21,286
Financing Receiables, Modifications, Unpaid Principal Balance	36,532	29,408
Originated Consumer Loans | Consumer Installment Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	1,205	1,553
Financing Receivable, Modifications, Recorded Investment	24,905	27,285
Financing Receiables, Modifications, Unpaid Principal Balance	25,608	28,536
Originated Consumer Loans | Home Equity Line of Credit
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	270	231
Financing Receivable, Modifications, Recorded Investment	7,379	6,725
Financing Receiables, Modifications, Unpaid Principal Balance	7,629	7,054
Originated Consumer Loans | Consumer Credit Card Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	238	307
Financing Receivable, Modifications, Recorded Investment	854	1,113
Financing Receiables, Modifications, Unpaid Principal Balance	854	1,113
Originated Consumer Loans | Residential Mortgage
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	315	301
Financing Receivable, Modifications, Recorded Investment	25,251	23,067
Financing Receiables, Modifications, Unpaid Principal Balance	28,277	25,676
Originated Consumer Loans | Consumer Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2,028	2,392
Financing Receivable, Modifications, Recorded Investment	58,389	58,190
Financing Receiables, Modifications, Unpaid Principal Balance	62,368	62,379
Originated Loans
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2,167	2,509
Financing Receivable, Modifications, Recorded Investment	83,119	79,476
Financing Receiables, Modifications, Unpaid Principal Balance	98,900	91,787
Acquired Loans
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	216	29
Financing Receivable, Modifications, Recorded Investment	12,100	2,917
Financing Receiables, Modifications, Unpaid Principal Balance	12,474	3,049
Acquired Loans | Commercial and Industrial Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2	1
Financing Receivable, Modifications, Recorded Investment	18	6
Financing Receiables, Modifications, Unpaid Principal Balance	19	5
Acquired Loans | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	3	1
Financing Receivable, Modifications, Recorded Investment	2,542	1,730
Financing Receiables, Modifications, Unpaid Principal Balance	2,595	1,730
Acquired Loans | Commercial
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end		2
Financing Receivable, Modifications, Recorded Investment		1,736
Financing Receiables, Modifications, Unpaid Principal Balance		1,735
Acquired Loans | Commercial Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	5
Financing Receivable, Modifications, Recorded Investment	2,560	1,736
Financing Receiables, Modifications, Unpaid Principal Balance	2,614
Acquired Loans | installment
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	40	12
Financing Receivable, Modifications, Recorded Investment	975	505
Financing Receiables, Modifications, Unpaid Principal Balance	1,054	542
Acquired Loans | Home Equity Line of Credit
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	145	8
Financing Receivable, Modifications, Recorded Investment	6,932	245
Financing Receiables, Modifications, Unpaid Principal Balance	6,983	270
Acquired Loans | Residential Mortgage
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	26	7
Financing Receivable, Modifications, Recorded Investment	1,633	431
Financing Receiables, Modifications, Unpaid Principal Balance	1,823	502
Acquired Loans | Consumer Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	211	27
Financing Receivable, Modifications, Recorded Investment	9,540	1,181
Financing Receiables, Modifications, Unpaid Principal Balance	9,860	1,314
Covered Loans Commercial | Commercial and Industrial Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	8	4
Financing Receivable, Modifications, Recorded Investment	177	1,104
Financing Receiables, Modifications, Unpaid Principal Balance	1,589	2,331
Covered Loans Commercial | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	24	24
Financing Receivable, Modifications, Recorded Investment	25,499	39,995
Financing Receiables, Modifications, Unpaid Principal Balance	42,226	57,008
Covered Loans Commercial | Commercial Real Estate Construction Financing Receivable
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	9	10
Financing Receivable, Modifications, Recorded Investment	339	4,144
Financing Receiables, Modifications, Unpaid Principal Balance	9,552	24,547
Covered Loans Commercial | Commercial Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	41	38
Financing Receivable, Modifications, Recorded Investment	26,015	45,243
Financing Receiables, Modifications, Unpaid Principal Balance	53,367	83,886
Covered Consumer Loans
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,224	5,551
Covered Consumer Loans | Home Equity Line of Credit
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	68	47
Financing Receivable, Modifications, Recorded Investment	8,890	5,401
Financing Receiables, Modifications, Unpaid Principal Balance	8,901	5,421
Covered Consumer Loans | Residential Mortgage
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	2
Financing Receivable, Modifications, Recorded Investment	334	150
Financing Receiables, Modifications, Unpaid Principal Balance	334
Covered TDR Loans
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	111	86
Financing Receivable, Modifications, Recorded Investment	35,239	50,794
Financing Receiables, Modifications, Unpaid Principal Balance	62,602	89,457
Covered TDR Loans | Residential Mortgage
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end		1
Financing Receivable, Modifications, Recorded Investment		150
Financing Receiables, Modifications, Unpaid Principal Balance		150
Covered TDR Loans | Consumer Loan
Financing Receivable, Modifications [Line Items]
financing receivables, modifications, number of contracts at period end	70	48
Financing Receivable, Modifications, Recorded Investment	9,224	5,551
Financing Receiables, Modifications, Unpaid Principal Balance	$9,235	$5,571

Allowance_for_Loan_Losses_Accr

Allowance for Loan Losses (Accruing and Non-Accruing Troubled Debt Restructurings) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	$130,458	$133,187
Originated Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	12,424,268	10,113,988
Financing Receivable, Recorded Investment, Past Due	69,544	99,399
Financing Receivable, Modifications, Recorded Investment	83,119	79,476
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	5,950	6,146	5,004
Impaired Financing Receivable, Related Allowance	5,950	6,146
Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	2,403,824	3,404,111
Financing Receivable, Recorded Investment, Past Due	75,356	91,504
Financing Receivable, Modifications, Recorded Investment	12,100	2,917
Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,224	5,551
Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	35,239	50,794
Commercial and Industrial Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,318	5,559
Commercial and Industrial Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,123	4,449
Commercial and Industrial Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	18	6
Commercial and Industrial Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	177	1,104
Commercial Real Estate
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	45,648	57,657
Commercial Real Estate | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	17,607	15,932
Commercial Real Estate | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,542	1,730
Commercial Real Estate | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,499	39,995
Commercial Real Estate Construction Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	339	5,049
Commercial Real Estate Construction Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	0	905
Commercial Real Estate Construction Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	339	4,144
Commercial Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	53,305	68,265
Commercial Loan | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	24,730	21,286
Commercial Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	2,560	1,736
Commercial Loan | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	26,015	45,243
Consumer Installment
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,880	27,790
Consumer Installment | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	24,905	27,285
Consumer Installment | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	975	505
Consumer Home Equity Lines Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	23,201	12,371
Consumer Home Equity Lines Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	7,379	6,725
Consumer Home Equity Lines Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	6,932	245
Consumer Home Equity Lines Financing Receivable | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	8,890	5,401
Consumer Credit Card Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	854	1,113
Consumer Credit Card Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	854	1,113
Residential Mortgage
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	27,218	23,648
Residential Mortgage | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	25,251	23,067
Residential Mortgage | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	1,633	431
Residential Mortgage | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	334	150
Residential Mortgage | Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment		150
Consumer Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	77,153	64,922
Consumer Loan | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	58,389	58,190
Consumer Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,540	1,181
Consumer Loan | Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Modifications, Recorded Investment	9,224	5,551
Accruing TDRs
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	84,600	69,077
Financing Receivable, Recorded Investment, Past Due	26,792	45,170
Financing Receivable, Modifications, Recorded Investment	111,392	114,247
Accruing TDRs | Originated Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	62,333	54,705
Financing Receivable, Recorded Investment, Past Due	5,545	6,086
Financing Receivable, Modifications, Recorded Investment	67,878	60,791
Accruing TDRs | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	7,910	2,526
Financing Receivable, Recorded Investment, Past Due	694	136
Financing Receivable, Modifications, Recorded Investment	8,604	2,662
Accruing TDRs | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	8,895	5,527
Financing Receivable, Recorded Investment, Past Due	0	24
Financing Receivable, Modifications, Recorded Investment	8,895	5,551
Accruing TDRs | Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	14,357	11,846
Financing Receivable, Recorded Investment, Past Due	20,553	38,948
Financing Receivable, Modifications, Recorded Investment	34,910	50,794
Accruing TDRs | Commercial and Industrial Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	6,755	1,800
Financing Receivable, Recorded Investment, Past Due	177	1,621
Financing Receivable, Modifications, Recorded Investment	6,932	3,421
Accruing TDRs | Commercial and Industrial Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	6,740	1,438
Financing Receivable, Recorded Investment, Past Due	0	879
Financing Receivable, Modifications, Recorded Investment	6,740	2,317
Accruing TDRs | Commercial and Industrial Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	15	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	15	0
Accruing TDRs | Commercial and Industrial Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	362
Financing Receivable, Recorded Investment, Past Due	177	742
Financing Receivable, Modifications, Recorded Investment	177	1,104
Accruing TDRs | Commercial Real Estate
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	18,008	17,431
Financing Receivable, Recorded Investment, Past Due	21,328	35,118
Financing Receivable, Modifications, Recorded Investment	39,336	52,549
Accruing TDRs | Commercial Real Estate | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	12,885	10,442
Financing Receivable, Recorded Investment, Past Due	952	382
Financing Receivable, Modifications, Recorded Investment	13,837	10,824
Accruing TDRs | Commercial Real Estate | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	1,730
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	1,730
Accruing TDRs | Commercial Real Estate | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	5,123	5,259
Financing Receivable, Recorded Investment, Past Due	20,376	34,736
Financing Receivable, Modifications, Recorded Investment	25,499	39,995
Accruing TDRs | Commercial Real Estate Construction Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	339	1,546
Financing Receivable, Recorded Investment, Past Due	0	3,446
Financing Receivable, Modifications, Recorded Investment	339	4,992
Accruing TDRs | Commercial Real Estate Construction Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	848
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	848
Accruing TDRs | Commercial Real Estate Construction Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	339	698
Financing Receivable, Recorded Investment, Past Due	0	3,446
Financing Receivable, Modifications, Recorded Investment	339	4,144
Accruing TDRs | Commercial Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	25,102	20,777
Financing Receivable, Recorded Investment, Past Due	21,505	40,185
Financing Receivable, Modifications, Recorded Investment	46,607	60,962
Accruing TDRs | Commercial Loan | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	19,625	12,728
Financing Receivable, Recorded Investment, Past Due	952	1,261
Financing Receivable, Modifications, Recorded Investment	20,577	13,989
Accruing TDRs | Commercial Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	15	1,730
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	15	1,730
Accruing TDRs | Commercial Loan | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	5,462	6,319
Financing Receivable, Recorded Investment, Past Due	20,553	38,924
Financing Receivable, Modifications, Recorded Investment	26,015	45,243
Accruing TDRs | Consumer Installment
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	23,095	23,711
Financing Receivable, Recorded Investment, Past Due	813	1,374
Financing Receivable, Modifications, Recorded Investment	23,908	25,085
Accruing TDRs | Consumer Installment | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	22,254	23,342
Financing Receivable, Recorded Investment, Past Due	726	1,238
Financing Receivable, Modifications, Recorded Investment	22,980	24,580
Accruing TDRs | Consumer Installment | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	841	369
Financing Receivable, Recorded Investment, Past Due	87	136
Financing Receivable, Modifications, Recorded Investment	928	505
Accruing TDRs | Consumer Home Equity Lines Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	20,986	10,872
Financing Receivable, Recorded Investment, Past Due	876	218
Financing Receivable, Modifications, Recorded Investment	21,862	11,090
Accruing TDRs | Consumer Home Equity Lines Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	6,239	5,313
Financing Receivable, Recorded Investment, Past Due	269	194
Financing Receivable, Modifications, Recorded Investment	6,508	5,507
Accruing TDRs | Consumer Home Equity Lines Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	6,186	182
Financing Receivable, Recorded Investment, Past Due	607	0
Financing Receivable, Modifications, Recorded Investment	6,793	182
Accruing TDRs | Consumer Home Equity Lines Financing Receivable | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	8,561	5,377
Financing Receivable, Recorded Investment, Past Due	0	24
Financing Receivable, Modifications, Recorded Investment	8,561	5,401
Accruing TDRs | Consumer Credit Card Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	775	1,046
Financing Receivable, Recorded Investment, Past Due	60	66
Financing Receivable, Modifications, Recorded Investment	835	1,112
Accruing TDRs | Consumer Credit Card Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	775	1,046
Financing Receivable, Recorded Investment, Past Due	60	66
Financing Receivable, Modifications, Recorded Investment	835	1,112
Accruing TDRs | Residential Mortgage
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	14,642	12,671
Financing Receivable, Recorded Investment, Past Due	3,538	3,327
Financing Receivable, Modifications, Recorded Investment	18,180	15,998
Accruing TDRs | Residential Mortgage | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	13,440	12,276
Financing Receivable, Recorded Investment, Past Due	3,538	3,327
Financing Receivable, Modifications, Recorded Investment	16,978	15,603
Accruing TDRs | Residential Mortgage | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	868	245
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	868	245
Accruing TDRs | Residential Mortgage | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	334	150
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	334	150
Accruing TDRs | Consumer Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	59,498	48,300
Financing Receivable, Recorded Investment, Past Due	5,287	4,985
Financing Receivable, Modifications, Recorded Investment	64,785	53,285
Accruing TDRs | Consumer Loan | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	42,708	41,977
Financing Receivable, Recorded Investment, Past Due	4,593	4,825
Financing Receivable, Modifications, Recorded Investment	47,301	46,802
Accruing TDRs | Consumer Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	7,895	796
Financing Receivable, Recorded Investment, Past Due	694	136
Financing Receivable, Modifications, Recorded Investment	8,589	932
Nonaccruing TDRs
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	9,892	9,535
Financing Receivable, Recorded Investment, Past Due	9,174	9,405
Financing Receivable, Modifications, Recorded Investment	19,066	18,940
Nonaccruing TDRs | Originated Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	7,949	9,434
Financing Receivable, Recorded Investment, Past Due	7,292	9,251
Financing Receivable, Modifications, Recorded Investment	15,241	18,685
Nonaccruing TDRs | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,614	101
Financing Receivable, Recorded Investment, Past Due	1,882	154
Financing Receivable, Modifications, Recorded Investment	3,496	255
Nonaccruing TDRs | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	329	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	329	0
Nonaccruing TDRs | Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	329	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	329	0
Nonaccruing TDRs | Commercial and Industrial Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	3	183
Financing Receivable, Recorded Investment, Past Due	383	1,955
Financing Receivable, Modifications, Recorded Investment	386	2,138
Nonaccruing TDRs | Commercial and Industrial Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	177
Financing Receivable, Recorded Investment, Past Due	383	1,955
Financing Receivable, Modifications, Recorded Investment	383	2,132
Nonaccruing TDRs | Commercial and Industrial Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	3	6
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	3	6
Nonaccruing TDRs | Commercial and Industrial Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	0
Nonaccruing TDRs | Commercial Real Estate
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,372	1,208
Financing Receivable, Recorded Investment, Past Due	4,940	3,900
Financing Receivable, Modifications, Recorded Investment	6,312	5,108
Nonaccruing TDRs | Commercial Real Estate | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	394	1,208
Financing Receivable, Recorded Investment, Past Due	3,376	3,900
Financing Receivable, Modifications, Recorded Investment	3,770	5,108
Nonaccruing TDRs | Commercial Real Estate | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	978	0
Financing Receivable, Recorded Investment, Past Due	1,564	0
Financing Receivable, Modifications, Recorded Investment	2,542	0
Nonaccruing TDRs | Commercial Real Estate | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	0
Nonaccruing TDRs | Commercial Real Estate Construction Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	57
Financing Receivable, Modifications, Recorded Investment	0	57
Nonaccruing TDRs | Commercial Real Estate Construction Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	57
Financing Receivable, Modifications, Recorded Investment	0	57
Nonaccruing TDRs | Commercial Real Estate Construction Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	0
Nonaccruing TDRs | Commercial Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,375	1,391
Financing Receivable, Recorded Investment, Past Due	5,323	5,912
Financing Receivable, Modifications, Recorded Investment	6,698	7,303
Nonaccruing TDRs | Commercial Loan | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	394	1,385
Financing Receivable, Recorded Investment, Past Due	3,759	5,912
Financing Receivable, Modifications, Recorded Investment	4,153	7,297
Nonaccruing TDRs | Commercial Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	981	6
Financing Receivable, Recorded Investment, Past Due	1,564	0
Financing Receivable, Modifications, Recorded Investment	2,545	6
Nonaccruing TDRs | Commercial Loan | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	0
Nonaccruing TDRs | Consumer Installment
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,687	2,483
Financing Receivable, Recorded Investment, Past Due	285	222
Financing Receivable, Modifications, Recorded Investment	1,972	2,705
Nonaccruing TDRs | Consumer Installment | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,663	2,483
Financing Receivable, Recorded Investment, Past Due	262	222
Financing Receivable, Modifications, Recorded Investment	1,925	2,705
Nonaccruing TDRs | Consumer Installment | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	24	0
Financing Receivable, Recorded Investment, Past Due	23	0
Financing Receivable, Modifications, Recorded Investment	47	0
Nonaccruing TDRs | Consumer Home Equity Lines Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	1,339	1,269
Financing Receivable, Recorded Investment, Past Due	0	12
Financing Receivable, Modifications, Recorded Investment	1,339	1,281
Nonaccruing TDRs | Consumer Home Equity Lines Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	871	1,206
Financing Receivable, Recorded Investment, Past Due	0	12
Financing Receivable, Modifications, Recorded Investment	871	1,218
Nonaccruing TDRs | Consumer Home Equity Lines Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	139	63
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	139	63
Nonaccruing TDRs | Consumer Home Equity Lines Financing Receivable | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	329	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	329	0
Nonaccruing TDRs | Consumer Credit Card Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	15	0
Financing Receivable, Recorded Investment, Past Due	4	1
Financing Receivable, Modifications, Recorded Investment	19	1
Nonaccruing TDRs | Consumer Credit Card Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	15	0
Financing Receivable, Recorded Investment, Past Due	4	1
Financing Receivable, Modifications, Recorded Investment	19	1
Nonaccruing TDRs | Residential Mortgage
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	5,476	4,392
Financing Receivable, Recorded Investment, Past Due	3,562	3,258
Financing Receivable, Modifications, Recorded Investment	9,038	7,650
Nonaccruing TDRs | Residential Mortgage | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	5,006	4,360
Financing Receivable, Recorded Investment, Past Due	3,267	3,104
Financing Receivable, Modifications, Recorded Investment	8,273	7,464
Nonaccruing TDRs | Residential Mortgage | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	470	32
Financing Receivable, Recorded Investment, Past Due	295	154
Financing Receivable, Modifications, Recorded Investment	765	186
Nonaccruing TDRs | Residential Mortgage | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Financing Receivable, Modifications, Recorded Investment	0	0
Nonaccruing TDRs | Consumer Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	8,517	8,144
Financing Receivable, Recorded Investment, Past Due	3,851	3,493
Financing Receivable, Modifications, Recorded Investment	12,368	11,637
Nonaccruing TDRs | Consumer Loan | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	7,555	8,049
Financing Receivable, Recorded Investment, Past Due	3,533	3,339
Financing Receivable, Modifications, Recorded Investment	11,088	11,388
Nonaccruing TDRs | Consumer Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Financing Receivable, Recorded Investment, Current	633	95
Financing Receivable, Recorded Investment, Past Due	318	154
Financing Receivable, Modifications, Recorded Investment	951	249
Total Tdr Allowance
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	6,645	7,201
Total Tdr Allowance | Originated Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,195	3,379
Total Tdr Allowance | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	228	0
Total Tdr Allowance | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	48	0
Total Tdr Allowance | Covered TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,222	3,822
Total Tdr Allowance | Commercial and Industrial Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	90	665
Total Tdr Allowance | Commercial and Industrial Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	72	665
Total Tdr Allowance | Commercial and Industrial Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	18	0
Total Tdr Allowance | Commercial and Industrial Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	0	0
Total Tdr Allowance | Commercial Real Estate
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,172	3,054
Total Tdr Allowance | Commercial Real Estate | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	159	32
Total Tdr Allowance | Commercial Real Estate | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	134	0
Total Tdr Allowance | Commercial Real Estate | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	2,879	3,022
Total Tdr Allowance | Commercial Real Estate Construction Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	295	800
Total Tdr Allowance | Commercial Real Estate Construction Financing Receivable | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	0	0
Total Tdr Allowance | Commercial Real Estate Construction Financing Receivable | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	295	800
Total Tdr Allowance | Commercial Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,557	4,519
Total Tdr Allowance | Commercial Loan | Originated Loans Commercial
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	231	697
Total Tdr Allowance | Commercial Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	152	0
Total Tdr Allowance | Commercial Loan | Covered Commercial TDR Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,174	3,822
Total Tdr Allowance | Consumer Installment
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	1,243	1,014
Total Tdr Allowance | Consumer Installment | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance		1,014
Total Tdr Allowance | Consumer Installment | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	65	0
Total Tdr Allowance | Consumer Home Equity Lines Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	243	223
Total Tdr Allowance | Consumer Home Equity Lines Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance		223
Total Tdr Allowance | Consumer Home Equity Lines Financing Receivable | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	9	0
Total Tdr Allowance | Consumer Home Equity Lines Financing Receivable | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	27	0
Total Tdr Allowance | Consumer Credit Card Financing Receivable
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	296	312
Total Tdr Allowance | Consumer Credit Card Financing Receivable | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance		312
Total Tdr Allowance | Residential Mortgage
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	1,306	1,133
Total Tdr Allowance | Residential Mortgage | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance		1,133
Total Tdr Allowance | Residential Mortgage | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	2	0
Total Tdr Allowance | Residential Mortgage | Covered Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	21	0
Total Tdr Allowance | Consumer Loan
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	3,088	2,682
Total Tdr Allowance | Consumer Loan | Originated Consumer Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	2,964	2,682
Total Tdr Allowance | Consumer Loan | Acquired Loans
Accruing and Nonaccruing Troubled Debt Restructurings [Line Items]
Impaired Financing Receivable, Related Allowance	$76	$0

Allowance_for_Loan_Losses_Sche3

Allowance for Loan Losses (Schedule of Debtor Troubled Debt Restructuring, Current Period) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	$6,338,000	$5,640,000
financing receivable, modifications, subsequent default, number of contracts at period end	51	64
Commercial and Industrial Financing Receivable
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	5,357,000	1,773,000
financing receivable, modifications, subsequent default, number of contracts at period end	4	4
Commercial and Industrial Financing Receivable | Originated Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	4,930,116	1,773,000
financing receivable, modifications, subsequent default, number of contracts at period end	3	4
Commercial and Industrial Financing Receivable | Covered Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	427,000	0
financing receivable, modifications, subsequent default, number of contracts at period end	1	0
Commercial Real Estate
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	363,000	3,101,000
financing receivable, modifications, subsequent default, number of contracts at period end	1	7
Commercial Real Estate | Originated Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	362,812	3,101,000
financing receivable, modifications, subsequent default, number of contracts at period end	1	6
Commercial Real Estate | Covered Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	0	0
financing receivable, modifications, subsequent default, number of contracts at period end	0	1
Commercial Real Estate Construction Financing Receivable
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	0	276,000
financing receivable, modifications, subsequent default, number of contracts at period end	0	2
Commercial Real Estate Construction Financing Receivable | Originated Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	0	231,000
financing receivable, modifications, subsequent default, number of contracts at period end	0	1
Commercial Real Estate Construction Financing Receivable | Covered Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	0	45,000
financing receivable, modifications, subsequent default, number of contracts at period end	0	1
Commercial Loan
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	5,720,000	5,150,000
financing receivable, modifications, subsequent default, number of contracts at period end	5	13
Commercial Loan | Originated Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	5,293,000	5,105,000
financing receivable, modifications, subsequent default, number of contracts at period end	4	11
Commercial Loan | Covered Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	427,000	45,000
financing receivable, modifications, subsequent default, number of contracts at period end	1	2
Consumer Installment
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	205,000	170,000
financing receivable, modifications, subsequent default, number of contracts at period end	13	17
Consumer Installment | Originated Consumer Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	40,358	170,000
financing receivable, modifications, subsequent default, number of contracts at period end	11	17
Consumer Installment | Acquired Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	165,000
financing receivable, modifications, subsequent default, number of contracts at period end	2
Home Equity Line of Credit
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	90,000	0
financing receivable, modifications, subsequent default, number of contracts at period end	2	0
Home Equity Line of Credit | Originated Consumer Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	29,000	0
financing receivable, modifications, subsequent default, number of contracts at period end	1	0
Home Equity Line of Credit | Acquired Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	61,000
financing receivable, modifications, subsequent default, number of contracts at period end	1
Consumer Credit Card Financing Receivable
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	140,000	245,000
financing receivable, modifications, subsequent default, number of contracts at period end	28	33
Consumer Credit Card Financing Receivable | Originated Consumer Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	140,000	245,000
financing receivable, modifications, subsequent default, number of contracts at period end	28	33
Residential Mortgage
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	183,000	75,000
financing receivable, modifications, subsequent default, number of contracts at period end	3	1
Residential Mortgage | Originated Consumer Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	183,000	75,000
financing receivable, modifications, subsequent default, number of contracts at period end	3	1
Residential Mortgage | Acquired Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	0
financing receivable, modifications, subsequent default, number of contracts at period end	0
Consumer Loan
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	618,000	490,000
financing receivable, modifications, subsequent default, number of contracts at period end	46	51
Consumer Loan | Originated Consumer Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	392,000	490,000
financing receivable, modifications, subsequent default, number of contracts at period end	43	51
Consumer Loan | Acquired Loans
Troubled Debt Restructuring, Debtor, Current Period [Line Items]
financing receivables, modifications, subsequent default, recorded investment at period end	$226,000
financing receivable, modifications, subsequent default, number of contracts at period end	3

Allowance_for_Loan_Losses_Narr

Allowance for Loan Losses (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Minimum Non Performing Substandard Loans Outstanding for Allowance for Credit Losses	$300,000
Minimum Non Performing Substandard Doubtful Loans Outstanding for Allowance for Credit Losses	100,000
Financing Receivable, Allowance for Credit Losses, Write-downs	14,700,000	6,800,000
Impaired Financing Receivable, Interest Income, Cash Basis Method	900,000	1,300,000
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	2,800,000	5,500,000	3,200,000
Loan Commitments	6,136,313,000	5,546,635,000
Total impaired loans with no related allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Loan Commitments	200,000
Acquired Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Allowance for Credit Losses	7,457,000	741,000	0
Covered Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for Loan Losses Before Benefit Attributable to FDIC Loss Share Agreements	10,568,000	23,892,000	35,450,000
Benefit Attributable to FDIC Loss Share Agreements	-2,920,000	10,790,000	14,728,000
Provision for Loan Lease and Other Losses Covered	$7,648,000	$13,102,000	$20,722,000

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets (Details Textual) (USD $)	12 Months Ended			0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$741,740	$741,740
Amortization of intangible assets	11,735	8,392	1,866
Citizens Republic Bancorp
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived intangible assets acquired				84,774
Goodwill, Acquired During Period				281,694
Citizens Republic Bancorp | Core Deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived intangible assets acquired				70,800
Useful Life	15 years
Citizens Republic Bancorp | Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived intangible assets acquired				$14,000
Useful Life	12 years

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets (Schedule of Goodwill) (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Apr. 12, 2013	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		$96,561	$101,873
Goodwill		741,740	741,740
Finite-Lived Intangible Assets, Accumulated Amortization		25,541	19,118
Finite-Lived Intangible Assets, Net		71,020	82,755
Commercial
Goodwill [Line Items]
Goodwill		527,406	527,406
Retail
Goodwill [Line Items]
Goodwill		193,961	193,961
Wealth
Goodwill [Line Items]
Goodwill		20,373	20,373
Citizens Republic Bancorp
Goodwill [Line Items]
Goodwill, Acquired During Period	281,694
Core Deposits
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		82,323	87,533
Finite-Lived Intangible Assets, Accumulated Amortization		19,996	16,065
Finite-Lived Intangible Assets, Net		62,327	71,468
Noncompete Agreements
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross			102
Finite-Lived Intangible Assets, Accumulated Amortization			102
Finite-Lived Intangible Assets, Net			0
Lease Agreements
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		238	238
Finite-Lived Intangible Assets, Accumulated Amortization		176	140
Finite-Lived Intangible Assets, Net		62	98
Customer Relationships
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross			14,000
Finite-Lived Intangible Assets, Accumulated Amortization			2,811
Finite-Lived Intangible Assets, Net			11,189
Customer Relationships | Citizens Republic Bancorp
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross		14,000
Finite-Lived Intangible Assets, Accumulated Amortization		5,369
Finite-Lived Intangible Assets, Net		$8,631

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets (Accumulated Amortization of Intangible Asset Schedule) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Apr. 12, 2013
In Thousands, unless otherwise specified
Accumulated amortization of intangible assets
Gross Carrying Amount	$96,561	$101,873
Accumulated Amortization	-25,541	-19,118
Net Carrying Amount	71,020	82,755
Core Deposits
Accumulated amortization of intangible assets
Gross Carrying Amount	82,323	87,533
Accumulated Amortization	-19,996	-16,065
Net Carrying Amount	62,327	71,468
Noncompete Agreements
Accumulated amortization of intangible assets
Gross Carrying Amount		102
Accumulated Amortization		-102
Net Carrying Amount		0
Lease Agreements
Accumulated amortization of intangible assets
Gross Carrying Amount	238	238
Accumulated Amortization	-176	-140
Net Carrying Amount	62	98
Customer Relationships
Accumulated amortization of intangible assets
Gross Carrying Amount		14,000
Accumulated Amortization		-2,811
Net Carrying Amount		11,189
Citizens Republic Bancorp
Accumulated amortization of intangible assets
Finite-Lived intangible assets acquired			84,774
Citizens Republic Bancorp | Core Deposits
Accumulated amortization of intangible assets
Finite-Lived intangible assets acquired			70,800
Citizens Republic Bancorp | Customer Relationships
Accumulated amortization of intangible assets
Gross Carrying Amount	14,000
Accumulated Amortization	-5,369
Net Carrying Amount	8,631
Finite-Lived intangible assets acquired			$14,000

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets (Schedule of Expected Amortization Expense) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
31-Dec-15	$10,391
31-Dec-16	9,209
31-Dec-17	8,161
31-Dec-18	7,273
31-Dec-19	6,500
Total estimated future amortization	$41,534

Mortgage_Servicing_Rights_and_2

Mortgage Servicing Rights and Mortgage Servicing Activity (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding of Loans Held-in-portfolio	$356,500,000	$562,300,000
Mortgage Servicing rights Valuation Allowance	-955,000	282,000	2,564,000	3,539,000
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale, Gain (Loss) on Sale	7,200,000	12,100,000
Qualitative and Quantitative Information, Transferor's Continuing Involvement, Principal Amount Outstanding, Continued Recognition, Amount	314,400,000	514,600,000
Minimum percentage adverse change in prepayment speed	10.00%
Maximum percentage adverse change in prepayment speed	25.00%
Percentage of variation in prepayment speed	10.00%
Residential Mortgage
Servicing Assets at Fair Value [Line Items]
Servicing Asset	2,600,000,000	2,700,000,000
Contractually Specified Servicing Fees, Amount	$6,600,000	$6,400,000	$5,800,000

Mortgage_Servicing_Rights_and_3

Mortgage Servicing Rights and Mortgage Servicing Activity (Changes in the Carrying Amount of Mortgage Servicing Rights) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
Mortage Servicing Rights Amortized Value [Roll Forward]
Mortgage Servicing Rights Beginning of Period	$22,760	$21,316	$21,179
Mortgage Servicing Rights Additions	3,049	4,952	5,876
Amortization of Mortgage Servicing Rights (MSRs)	-3,798	-4,573	-5,739
Mortgage Servicing Rights, End of Period	22,011	22,760	21,316
Mortage Servicing Rights Valuation Rollforward [Roll Forward]
Mortgage Servicing rights Valuation Allowance Beginning of Period	-282	-2,564	-3,539
Mortgage Servicing Rights (MSR) Impairment (Recovery)	-673	2,282	975
Mortgage Servicing rights Valuation Allowance, End of Period	955	-282	-2,564
MSRs, net carrying balance	21,056	22,478	18,752
Fair value at end of period	21,228	23,041
Citizens Republic Bancorp
Mortage Servicing Rights Amortized Value [Roll Forward]
Addition of Citizens' MSR's on Acquisition Date				681,100
Mortgage Servicing Rights [Member] | Citizens Republic Bancorp
Mortage Servicing Rights Amortized Value [Roll Forward]
Addition of Citizens' MSR's on Acquisition Date	$0		$0	$1,065

Mortgage_Servicing_Rights_and_4

Mortgage Servicing Rights and Mortgage Servicing Activity (Changes In Key Economic Assumptions) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Transfers and Servicing [Abstract]
Prepayment speed assumption (annual CPR)	11.79%
Decrease in fair value from 10% adverse change	$767
Decrease in fair value from 25% adverse change	1,837
Discount rate assumption	9.89%
Decrease in fair value from 100 basis point adverse change	660
Decrease in fair value from 200 basis point adverse change	$1,277
Expected weighted-average life (in months)	96 years 10 months 24 days

Mortgage_Servicing_Rights_and_5

Mortgage Servicing Rights and Mortgage Servicing Activity (Estimated Amortization Expense for Mortgage Servicing Rights) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Transfers and Servicing [Abstract]
2015	$3,562
2016	3,128
2017	2,610
2018	2,189
2019	1,836
more than 5 years	7,731
Total estimated future amortization	$21,056

Restrictions_on_Cash_and_Divid1

Restrictions on Cash and Dividends (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restrictions on Cash and Dividends [Abstract]
Average Balance On Deposit To Satisfy Reserve Requirements	$5.90	$41.80
Cash And Due Deposited With The Federal Reserve Bank	$0.10

Premises_and_Equipment_Schedul

Premises and Equipment (Schedule of Premises and Equipment) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Premises and Equipment [Line Items]
Premises and Equipment, gross	674,380	$639,537
Less accumulated depreciation and amortization	342,083	312,483
Premises and Equipment, net	332,297	327,054
Land
Premises and Equipment [Line Items]
Premises and Equipment, gross	60,397	64,810
Buildings
Premises and Equipment [Line Items]
Premises and Equipment, gross	308,144	310,345
Equipment
Premises and Equipment [Line Items]
Premises and Equipment, gross	176,906	156,521
Leasehold improvements
Premises and Equipment [Line Items]
Premises and Equipment, gross	25,151	23,872
Software
Premises and Equipment [Line Items]
Premises and Equipment, gross	103,782	$83,989
Minimum | Buildings
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	10 years
Minimum | Equipment
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Minimum | Leasehold improvements
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	1 year
Minimum | Software
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	3 years
Maximum | Buildings
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	35 years
Maximum | Equipment
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	15 years
Maximum | Leasehold improvements
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	20 years
Maximum | Software
Premises and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives	7 years

Premises_and_Equipment_Narrati

Premises and Equipment (Narrative) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Depreciation, Amortization and Accretion, Net	$37,594	$32,153	$23,060

Certificates_and_Other_Time_De2

Certificates and Other Time Deposits (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Certificates and Other Deposits [Abstract]
Value of Certificates Disclosed, Equal or Greater Than	$100,000
Time Deposits, $100,000 or More	716,500,000	882,400,000	489,900,000
Interest Expense, Time Deposits, $100,000 or More	$3,800,000	$4,500,000	$3,800,000

Certificates_and_Other_Time_De3

Certificates and Other Time Deposits (Maturities of Certificates and Other Time Deposits) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Time Deposits [Abstract]
2015	$1,627,788
2016	341,135
2017	101,325
2018	109,896
2019	105,632
2020 and after	3,727
Total certificates and other time deposits	$2,289,503

Federal_Funds_Purchased_and_Se2

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Schedule of Federal Funds Purchased and Securities Sold Under Agreements to Repurchase and Wholesale Borrowings) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Federal funds purchased and securities sold under agreements to repurchase	$1,272,591	$851,535

Federal_Funds_Purchased_and_Se3

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Abstract]
Securities Sold under Agreements to Repurchase, Fair Value of Collateral	$888.40	$1,000

Federal_Funds_Purchased_and_Se4

Federal Funds Purchased and Securities Sold Under Agreements to Repurchase (Schedule of Select Financial Data Federal Funds Purchased and Securities Sold Under Agreements to Repurchase) (Details) (Federal Funds Purchased and Securities Sold under Agreements to Repurchase, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013
Federal Funds Purchased and Securities Sold under Agreements to Repurchase
Average balance during the year	$1,084,532	$949,068	$949,756
Weighted-average annual interest rate during the year	0.09%	0.13%		0.12%
Maximum month-end balance	$1,289,460	$1,123,795	$1,104,525

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax [Line Items]
Federal NOL carryforwards	$131,195,000	$190,350,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	2,300,000
Total income tax expense	101,943,000	79,507,000	55,693,000
Income Tax (Benefits), Probability Threshold For Recognition, Minimum Percentage	50.00%
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions	9
Unrecognized Tax Benefits, Effective Tax Rate If Fully Recognized	29.90%
Alternative minimum tax credit carryforward	83,428,000	41,882,000
Expiration of Statues of Limitation
Income Tax [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	-50,000
2013 Tax Filings
Income Tax [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	-200,000
Net-worth Taxes
Income Tax [Line Items]
Total income tax expense	8,200,000	9,900,000	7,800,000
Federal
Income Tax [Line Items]
Federal NOL carryforwards	374,800,000
General Business Tax Credit Carryforward
Income Tax [Line Items]
General business tax credit carryforward	$1,982,000	$5,715,000

Income_Taxes_Schedule_of_Compo

Income Taxes (Schedule of Components of Income Tax Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal	$52,514	$24,426	$48,359
State	4,763	3,496	2,655
Deferred expense (benefit)	44,666	51,585	4,679
Total income tax expense	$101,943	$79,507	$55,693

Income_Taxes_Schedule_of_Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in rate due to:
Interest on tax-exempt securities and tax-free loans, net	-2.77%	-3.16%	-3.23%
Merger expenses at acquisition	0.00%	0.54%	0.00%
Reduction in excess tax reserves	0.00%	0.11%	0.00%
Bank owned life insurance	-2.10%	-2.53%	-3.10%
State income tax (net)	0.91%	0.87%	0.94%
Tax credits	-0.96%	-1.06%	-1.14%
ESOP Dividends	-0.13%	-0.14%	-0.21%
Nondeductible meals and entertainment	0.22%	0.27%	0.25%
Other	-0.18%	0.31%	0.83%
Effective tax rates	29.99%	30.21%	29.34%

Income_Taxes_Schedule_of_Defer

Income Taxes (Schedule of Deferred Income Tax Assets and Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Tax Assets, Gross [Abstract]
Allowance for credit losses	$35,760	$37,857
Employee benefits	51,584	33,676
Real Estate Mortgage Investment Credit	4,831	5,645
Acquired liabilities	6,296	14,768
Acquired loans	51,701	62,993
Available for sale securities	3,862	16,819
Loan fees and expenses	0	2,777
Federal NOL carryforwards	131,195	190,350
Alternative minimum tax credit carryforward	83,428	41,882
State income tax (net of federal benefit)	1,970	4,728
Other	467	0
Deferred Tax Assets, Gross	373,076	417,210
Deferred tax liabilities:
Leased assets and depreciation	-24,699	-25,818
FHLB stock	-18,165	-24,401
Loan fees and expenses	2,537	0
Goodwill	-16,580	7,129
Core deposit intangibles	-22,013	25,302
Other	0	-3,510
Deferred Tax Liabilities, Net	-83,994	-86,160
Total net deferred tax asset	$289,082	$331,050

Income_Taxes_Change_in_Deferre

Income Taxes (Change in Deferred Income Taxes) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 12, 2013
Period Change in Deferred Taxes [Line Items]
Deferred tax changes reflected in other comprehensive income	($2,698)	($27,285)	$4,136
Deferred tax changes reflected in Federal income tax expense	44,666	51,585
Net decrease/(increase) in DTA	41,968	-323,939
Citizens Republic Bancorp
Period Change in Deferred Taxes [Line Items]
Deferred tax changes reflected in acquired net assets	$0	($348,239)		$349,300

Income_Taxes_Summary_of_Income

Income Taxes (Summary of Income Tax Contingencies) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$1,265	$1,807
Additions for tax provisions related to prior year	812	149
Reduction for tax positions related to prior year due closed tax years	-34
Reduction for tax positions related to prior tax years	-1,719	-691
Potential adjustment to nondeductible interest expense		35
State income tax exposure	324	1,230
Balance at end of period	324	1,265
Federal and State Tax
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	1,003	953
Additions for tax provisions related to prior year	798	77
Reduction for tax positions related to prior year due closed tax years	-31
Reduction for tax positions related to prior tax years	-1,465	-27
Potential adjustment to nondeductible interest expense		30
State income tax exposure	305	973
Balance at end of period	305	1,003
Accrued Interest and Penalties
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	262	854
Additions for tax provisions related to prior year	14	72
Reduction for tax positions related to prior year due closed tax years	-3
Reduction for tax positions related to prior tax years	-254	-664
Potential adjustment to nondeductible interest expense		5
State income tax exposure	19	257
Balance at end of period	$19	$262

Benefit_Plans_Narratives_Detai

Benefit Plans (Narratives) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 02, 2011
Defined Benefit Plan Disclosure [Line Items]
Pension Plan Transition Contribution	$700,000	$1,100,000
Postretirement Medical Plans, Description of Change, Limit Employer Medical Contributions, Percent	200.00%
Postretirement Medical Plans, Description of Change, Age Limit for Subsidized Retiree Coverage	65
Deferred Compensation Arrangements, Participating Executive Election to Defer, Percent	1.00%
Defined Benefit Plan, Contributions by Employer, Amount Matched Every One Dollar				0.5
Defined Benefit Plan, Contributions by Employer, Matching Policy Per Dollar				1
Defined Benefit Plan, Contributions by Employer, Maximum Limit of Employee Salary, Percent				1.00%
Savings Plan, 401k
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions			1,100,000
FirstMerit | Savings Plan, 401k
Defined Benefit Plan Disclosure [Line Items]
Employer Contributions	$7,700,000	$4,400,000	$600,000

Benefit_Plans_Schedule_of_Net_

Benefit Plans (Schedule of Net Benefit Costs) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Net change from defined benefit pension plans, Pre-Tax	$44,255	($52,375)	($9,213)
Net change from defined benefit pension plans, After-tax	-28,766	34,043	5,989
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	728	2,339	7,194
Interest cost	14,337	12,814	11,862
Expected return on assets	-16,035	-14,938	-12,136
Prior service cost	-2,599	-467	-388
Defined Benefit Plan, Amortization of Gains (Losses), prior to settlement/curtailment income	2,930	4,693	10,371
Curtailment gain	0	-524	-142
Defined Benefit Plan, Net Periodic Benefit Cost	4,559	4,851	17,537
Defined Benefit Plan, Actuarial Gain (Loss)	49,488	-47,257	1,281
Cumulative net loss	-2,930	-4,169	-10,229
Net change from defined benefit pension plans, Pre-Tax	43,959	-51,893	-9,336
Net change from defined benefit pension plans, After-tax	-48,518	47,042	-8,201
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	65	99	77
Interest cost	655	563	697
Expected return on assets	0	0	0
Prior service cost	468	468	468
Defined Benefit Plan, Amortization of Gains (Losses), prior to settlement/curtailment income	236	268	288
Curtailment gain	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	488	462	594
Defined Benefit Plan, Actuarial Gain (Loss)	64	-682	-57
Cumulative net loss	-236	-268	-288
Net change from defined benefit pension plans, Pre-Tax	296	-482	123
Net change from defined benefit pension plans, After-tax	($784)	$20	($717)

Schedule_of_Net_Funded_Status_

(Schedule of Net Funded Status) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Accumulated Benefit Obligation	$354,402	$307,739
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, ending balance	257,355
Pension Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation, Beginning Balance	308,834	259,428
Service cost	728	2,339	7,194
Interest cost	14,337	12,814	11,862
Plan amendments	0	3,927
Participant contributions	0	0
actuarial gains/losses and changes in assumptions	50,115	-35,984
Benefits paid	-18,372	19,172
Projected Benefit Obligation, Ending Balance	355,642	308,834	259,428
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning balance	257,510	174,385
Citizens acquisition	0	68,304
Actual return on plan assets	16,663	30,298
Participant contributions	0	0
Employer Contributions	1,554	3,695
Benefits paid	-18,372	19,172
Fair value of plan assets, ending balance	257,355	257,510	174,385
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded Status	98,287	51,324
Amounts recognized in AOCI before income taxes:
Prior service cost (credit)	-2,587	-5,121
Net actuarial loss	99,715	53,061
Amount recognized in AOCI	102,302	58,182
Pension Benefits | Citizens Republic Bancorp
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation, Ending Balance	0	85,483
Postretirement Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation, Beginning Balance	15,544	14,771
Service cost	65	99	77
Interest cost	655	563	697
Plan amendments	-1,979	0
Participant contributions	1,851	1,538
actuarial gains/losses and changes in assumptions	2,046	-682
Benefits paid	-3,018	2,808
Projected Benefit Obligation, Ending Balance	15,164	15,544	14,771
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning balance	0	0
Citizens acquisition	0	0
Actual return on plan assets	0	0
Participant contributions	1,851	1,538
Employer Contributions	1,167	1,270
Benefits paid	-3,018	2,808
Fair value of plan assets, ending balance	0	0	0
Defined Benefit Plan, Funded Status of Plan [Abstract]
Funded Status	15,164	15,544
Amounts recognized in AOCI before income taxes:
Prior service cost (credit)	-5,370	3,858
Net actuarial loss	5,138	3,329
Amount recognized in AOCI	232	-529
Postretirement Benefits | Citizens Republic Bancorp
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected Benefit Obligation, Ending Balance	$0	$2,062

Schedule_of_Assumptions_Used_D

(Schedule of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013
End of year | Supplemental Executive Retirement Nonqualified Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	3.61%	4.12%	4.21%
Nonqualified pensions	3.75%	3.75%		3.75%
End of year | Medical Trend Rates, Non-Medicare Risk, Under Age 65, Percent
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	7.00%	7.50%	8.00%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2019	2019	2019
End of year | Medical Trend Rates, Non-Medicare Risk, After Age 65, Percent
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	11.00%	11.50%	12.00%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2027	2027	2027
End of year | Prescription Drugs
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	7.00%	7.50%	8.00%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2019	2019	2019
Beginning of year | Supplemental Executive Retirement Nonqualified Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	4.12%	4.21%	5.04%
Nonqualified pensions	3.75%	3.75%	3.75%
Beginning of year | Medical Trend Rates, Non-Medicare Risk, Under Age 65, Percent
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	7.50%	8.00%	8.50%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2019	2019	2019
Beginning of year | Medical Trend Rates, Non-Medicare Risk, After Age 65, Percent
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	11.50%	12.00%	12.50%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2027	2027	2027
Beginning of year | Prescription Drugs
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Initial trend	7.50%	8.00%	8.50%
Ultimate trend	5.00%	5.00%	5.00%
Year ultimate trend reached	2019	2019	2019
Pension Benefits | End of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	4.19%	4.99%	4.21%
Expected long-term rate of return	6.50%	6.75%	7.00%
Pension Benefits | Beginning of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	4.99%	4.21%	5.04%
Rate of Compensation Increase			5.22%
Postretirement Benefits | End of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	3.50%	4.01%	3.18%
Postretirement Benefits | End of year | Citizens Republic Bancorp
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	3.61%	3.98%
Postretirement Benefits | Beginning of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	4.01%	3.18%	4.23%
Defined Benefit Postretirement Life Insurance | End of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	4.36%	5.08%	4.30%
Defined Benefit Postretirement Life Insurance | Beginning of year
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount Rate	5.08%	4.30%	5.03%
Expected long-term rate of return	6.75%	7.00%	7.25%

Schedule_of_Amounts_in_Accumul

(Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Prior service cost	($1,640)
Cumulative net loss	4,549
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service cost	-2,279
Cumulative net loss	4,224
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Prior service cost	-639
Cumulative net loss	$325

Benefit_Plans_Estimated_Future

Benefit Plans (Estimated Future Benefit Payments) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2015	$26,555
2016	26,420
2017	22,162
2018	21,858
2019	20,239
2020 through 2024	93,104
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2015	1,247
2016	1,137
2017	1,063
2018	1,004
2019	951
2020 through 2024	$4,331

Benefit_Plans_Investment_Alloc

Benefit Plans (Investment Allocation Strategy) (Details) (Return Seeking Investments)	12 Months Ended
	Dec. 31, 2014
b $97%
Minimum	36.00%
Target	40.00%
Maximum	44.00%
0.98
Minimum	34.00%
Target	38.00%
Maximum	42.00%
0.99
Minimum	31.00%
Target	35.00%
Maximum	39.00%
1
Minimum	30.00%
Target	33.00%
Maximum	36.00%
1.01
Minimum	28.00%
Target	31.00%
Maximum	34.00%
1.02
Minimum	26.00%
Target	29.00%
Maximum	32.00%
1.03
Minimum	23.00%
Target	26.00%
Maximum	29.00%
1.04
Minimum	21.00%
Target	24.00%
Maximum	27.00%
1.05
Minimum	18.00%
Target	21.00%
Maximum	24.00%
1.06
Minimum	16.00%
Target	18.00%
Maximum	20.00%
1.07
Minimum	12.00%
Target	14.00%
Maximum	16.00%
Greater than 110%
Minimum	8.00%
Target	10.00%
Maximum	12.00%

Schedule_of_Allocation_of_Plan

(Schedule of Allocation of Plan Assets) (Details)	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	100.00%	100.00%
Cash and domestic money market funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	1.49%	1.92%
U.S. Treasury obligations
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	1.97%	1.76%
U.S. Government agencies
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	1.12%	0.95%
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	2.79%	3.12%
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	13.54%	11.24%
Equity mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	18.85%	27.62%
Fixed income mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	50.11%	36.56%
Foreign mutual funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets on Measurement Date	10.13%	16.83%

Schedule_of_Fair_Value_of_Plan

(Schedule of Fair Value of Plan Assets by Measurement) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$257,355
Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	242,214
Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	15,141
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Cash and domestic money market funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	3,836
Cash and domestic money market funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	3,836
Cash and domestic money market funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Cash and domestic money market funds | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
U.S. Treasury obligations
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,067
U.S. Treasury obligations | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
U.S. Treasury obligations | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5,067
U.S. Treasury obligations | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
U.S. Government agencies
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2,897
U.S. Government agencies | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
U.S. Government agencies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2,897
U.S. Government agencies | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	7,177
Corporate bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	7,177
Corporate bonds | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Common stock
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	34,835
Common stock | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	34,835
Common stock | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Common stock | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Equity mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	48,518
Equity mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	48,518
Equity mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Equity mutual funds | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Fixed income mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	128,951
Fixed income mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	128,951
Fixed income mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Fixed income mutual funds | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Foreign mutual funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,074
Foreign mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,074
Foreign mutual funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Foreign mutual funds | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$0

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Authorized	5,769,655
Share-based Compensation Expense	$13,900,000	$10,900,000	$9,300,000
Share-based Compensation Expense, Tax Benefit	4,900,000	3,800,000	3,300,000
Share-based Compensation, Share-based Payment Award, Participant Period of Service	15 years
Share-based Compensation, Share-Based Award, Participant Age, Minimum	55
Award Vesting Period	3 years
Award Requisite Service Period	10 years
Treasury Stock, Shares, Acquired	262,140	217,674	198,407
Total Compensation Cost Not yet Recognized	14,600,000
Total Compensation Cost Not yet Recognized, Period for Recognition	1 year 7 months 24 days
Restricted Stock Vested in Period, Total Fair Value	10,800,000	9,100,000	9,000,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total Compensation Cost Not yet Recognized	$0

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Option Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	1 year 1 month 20 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Balance Outstanding (shares) Beginning Balance	1,396	1,820	2,077
Outstanding, Weighted-Average Exercise Price (dollars per share) Beginning	$28.84	$24.73	$25.15
Exercised (shares)	0	0	0
Exercised, Weighted-Average Exercise Price (dollars per share)	$0	$0	$0
Forfeited (shares)	0	-8	-71
Forfeited, Weighted-Average Exercise Price (dollars per share)	$0	$23.93	$25.85
Expired (shares)	-558	-479	-186
Expired, Weighted-Average Exercise Price (dollars per share)	$31.91	$36.64	$25.97
Balance Outstanding (shares) Ending Balance	838	1,396	1,820	2,077
Outstanding, Weighted-Average Exercise Price (dollars per share) Ending	$26.64	$28.84	$24.73	$25.15
Outstanding, Weighted-Average Remaining Contractual Term (years)	1 year 1 month 20 days	1 year 1 month 20 days	1 year 9 months 26 days	1 year 10 months 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value	$0	$87	$0	$0
Acquired (shares)		63
Weighted average exercise price acquired stock		$218.01
Exercisable (shares)	838
Exercisable, Weighted-Average Exercise Price (dollars per share)	$26.64

ShareBased_Compensation_Restri

Share-Based Compensation (Restricted Stock Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested Balance Outstanding (shares) Beginning Balance	1,342	1,079	1,026
Nonvested, Outstanding, Weighted-Average Grant Date Fair Value (dollars per share) Beginning	$16.34	$17	$18.26
Granted (shares)	777	823	596
Granted, Weighted-Average Grant Date Fair Value (dollars per share)	$19.67	$16.47	$16.06
Vested (shares)	-664	-508	-493
Vested, Weighted-Average Grant Date Fair Value (dollars per share)	$16.30	$17.90	$18.29
Forfeited or expired (shares)	-42	-52	-50
Forfeited or expired, Weighted-Average Grant Date Fair Value (dollars per share)	$18.16	$16.89	$18.94
Nonvested Balance Outstanding (shares) Ending Balance	1,413	1,342	1,079
Nonvested, Outstanding, Weighted-Average Grant Date Fair Value (dollars per share) Ending	$18.16	$16.34	$17

Parent_Company_Schedule_of_Con

Parent Company (Schedule of Condensed Financial Statements-Balance Sheet) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets:
Cash and due from banks	$480,998	$571,171
Loans to subsidiaries	20,682	24,536	16,578	15,629
Other assets	1,216,748	1,216,416
Assets	24,902,347	23,912,028
Long-term debt	505,192	324,428
Liabilities and Shareholders' Equity:
Shareholders' equity	2,834,281	2,702,894	1,645,202	1,565,953
Total liabilities and shareholders' equity	24,902,347	23,912,028
Parent
Assets:
Cash and due from banks	142,950	125,032
Investment securities	1,553	2,253
Investment in subsidiaries, at equity in underlying value of their net assets	2,936,865	2,863,473
Other assets	20,479	77,674
Assets	3,101,847	3,068,432
Long-term debt	249,935	324,428
Liabilities and Shareholders' Equity:
Accrued and other liabilities	17,631	41,110
Shareholders' equity	2,834,281	2,702,894
Total liabilities and shareholders' equity	$3,101,847	$3,068,432

Parent_Company_Schedule_of_Con1

Parent Company (Schedule of Condensed Financial Statements-Income Statement ) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Income before income tax expense	$339,894	$263,191	$189,799
Income tax benefit	-101,943	-79,507	-55,693
Net income	237,951	183,684	134,106
Parent
Condensed Financial Statements, Captions [Line Items]
Cash dividends from subsidiaries	82,642	81,715	155,493
Other income	437	483	309
Total Income	83,079	82,198	155,802
Interest and other expenses	30,613	29,684	10,799
Income before income tax expense	52,466	52,514	145,003
Income tax benefit	10,324	9,341	2,004
Income before undistributed income of subsidiaries	62,790	61,855	147,007
Equity in undistributed income of subsidiaries	175,161	121,829	-12,901
Net income	$237,951	$183,684	$134,106

Parent_Company_Schedule_of_Con2

Parent Company (Schedule of Condensed Financial Statements-Cash Flows) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net income	$237,951	$183,684	$134,106
Adjustments to reconcile net income to net cash provided by operating activities
NET CASH PROVIDED BY OPERATING ACTIVITIES	284,637	309,366	180,466
Investing activities:
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	-1,189,920	641,219	-727,469
Financing activities:
Cash dividends - common	-105,333	-96,222	-69,459
Cash dividends - preferred	-5,876	-5,337	0
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES	684,885	-290,777	427,698
Increase (decrease) in cash and cash equivalents	-220,398	659,808	-119,305
Cash and cash equivalents at beginning of year	917,822	258,014	377,319
Cash and cash equivalents at end of year	697,424	917,822	258,014
Parent
Operating activities:
Net income	237,951	183,684	134,106
Adjustments to reconcile net income to net cash provided by operating activities
Equity in undistributed income of subsidiaries	-175,161	-121,829	12,901
Increase (Decrease) in Income Taxes Receivable	35,672	-30,399	-4,446
(Decrease) increase in Federal income tax payable	-1,449	27,032	106
Increase (Decrease) in Interest Payable, Net	0	4,618	0
Other	-552	924	738
NET CASH PROVIDED BY OPERATING ACTIVITIES	96,461	64,030	143,405
Investing activities:
Loans to subsidiaries	0	-50	0
Repayment of loans to subsidiaries	110,675	0	0
Payments for investments in and advances to subsidiaries	0	-315,069	0
Sale of Investments and Advances to Subsidiaries	0	0	7,827
Proceeds from Sale of Available-for-sale Securities, Equity	784	0	0
Purchases of investment securities	-81	-215	-44
NET CASH PROVIDED (USED) BY INVESTING ACTIVITIES	111,378	-315,334	7,783
Proceeds from Issuance of Subordinated Long-term Debt	0	249,927	0
Financing activities:
Proceeds from Issuance of Subordinated Long-term Debt	0	249,927	0
Proceeds from Issuance of Convertible Preferred Stock	0	96,550	0
Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities	-74,451	0	0
Cash dividends - common	-105,333	-96,222	-69,459
Cash dividends - preferred	-5,876	-5,337	0
Purchase of treasury shares	-4,261	-9,521	-2,389
NET CASH PROVIDED (USED) BY FINANCING ACTIVITIES	-189,921	235,397	-71,848
Increase (decrease) in cash and cash equivalents	17,918	-15,907	79,340
Cash and cash equivalents at beginning of year	125,032		61,599
Cash and cash equivalents at end of year	$142,950	$125,032

Segment_Information_Details

Segment Information (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
OPERATIONS:
Net interest income	$775,568	$710,785	$471,830
Provision for Loan, Lease, and Other Losses	-52,279	-33,684	-54,698
Other income	281,524	270,343	223,604
Other expenses	664,919	684,253	450,937
Net income	237,951	183,684	134,106
SegmentReportingInformationAverageAssets1	24,418,211	21,489,775	14,620,627
AVERAGES :
Loans	14,891,315	12,948,666	9,357,080
Earnings assets	21,502,747	18,492,995	13,072,691
Deposits	19,528,435	17,301,588	11,553,798
Economic Capital	2,790,139	2,408,865	1,608,108
Nonreportable segments and reconciling items
OPERATIONS:
Net interest income	-44,001	-63,846	-12,096
Provision for Loan, Lease, and Other Losses	-7,868	-1,153	-12,997
Other income	27,885	23,442	19,723
Other expenses	19,203	89,246	30,819
Net income	-11,051	-72,411	-12,784
SegmentReportingInformationAverageAssets1	9,248,267	8,086,540	5,005,316
AVERAGES :
Loans	62,257	62,008	65,876
Earnings assets	6,363,537	5,393,874	3,646,302
Deposits	275,591	152,782	142,308
Economic Capital	1,635,864	1,477,698	942,381
Commercial Loan
OPERATIONS:
Net interest income	421,136	408,006	258,575
Provision for Loan, Lease, and Other Losses	-2,898	-17,072	-32,319
Other income	91,483	83,933	67,606
Other expenses	240,142	209,936	159,525
Net income	175,227	172,206	87,318
SegmentReportingInformationAverageAssets1	9,265,088	8,397,357	6,424,226
AVERAGES :
Loans	9,262,224	8,292,805	6,391,189
Earnings assets	9,549,341	8,480,005	6,493,713
Deposits	6,679,007	5,572,287	3,284,722
Economic Capital	743,071	602,561	404,005
Retail
OPERATIONS:
Net interest income	378,597	349,433	207,907
Provision for Loan, Lease, and Other Losses	-39,618	-16,151	-10,008
Other income	106,356	114,679	103,279
Other expenses	354,305	330,875	221,297
Net income	59,169	76,105	51,922
SegmentReportingInformationAverageAssets1	5,632,881	4,746,277	2,952,280
AVERAGES :
Loans	5,305,513	4,367,701	2,674,997
Earnings assets	5,328,548	4,392,937	2,707,632
Deposits	11,484,769	10,749,725	7,416,982
Economic Capital	353,098	256,362	212,409
Wealth
OPERATIONS:
Net interest income	19,836	17,192	17,444
Provision for Loan, Lease, and Other Losses	-1,895	692	626
Other income	55,800	48,289	32,996
Other expenses	51,269	54,196	39,296
Net income	14,606	7,784	7,650
SegmentReportingInformationAverageAssets1	271,975	259,601	238,805
AVERAGES :
Loans	261,321	226,152	225,018
Earnings assets	261,321	226,179	225,044
Deposits	1,089,068	826,794	709,786
Economic Capital	$58,106	$72,244	$49,313

Fair_Value_Measurement_Narrati

Fair Value Measurement (Narrative) (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage Servicing Rights	$22,011,000	$22,760,000	$21,316,000	$21,179,000
Mortgage Servicing rights Valuation Allowance	-955,000	282,000	2,564,000	3,539,000
MSRs, net carrying balance	21,056,000	22,478,000	18,752,000
Mortgage Servicing Rights (MSR) Impairment (Recovery)	673,000	-2,282,000	-975,000
Impaired Collateral Dependant Loans, Recorded Investment	60,300,000	52,600,000
Determination Of Specific Allowance For Loan Losses	4,300,000	4,800,000
Collateral Dependant Impaired and Non Accrual Loans Carrying Amount	56,000,000	47,900,000
Impairment of Other Real Estate Owned	2,600,000	1,400,000
Impairment of Covered Other Real Esate Owned	1,200,000	1,000,000
Percent of available for sale securities classified as level 2	90.00%
Percentage of Level 3 investments in available for sale investment portfolio	10.00%
True up liability, discount period	10 years
True-up Liabitlity Discount Rate	3.36%	3.69%
True-up Liability Effect of Change in Discount Rate Increase By One Percent	700,000	-1,300,000
Number of loans that were 90 days or more past due, or were any on nonaccrual status	0
Time period for non-payment of loans that are placed on non-accrual status	90 days
Midwest
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percent of FDIC Intrinsic Loss Estimate	20.00%
Intrinsic Loss Estimate of the FDIC	152,000,000
Percent of Asset Premium Paid	25.00%
Asset Premium Paid	21,000,000
Percent of cumulative shared loss payments under loss sharing agreements	25.00%
Estimated fair value of true up liability	8,500,000	7,100,000
George Washington
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Percent of cumulative shared loss payments under loss sharing agreements	25.00%
Estimated fair value of true up liability	4,800,000	4,300,000
Percent of excess threshold paid by the Bank under loss sharing agreements	50.00%
Percent Theshold of Loss Sharing Agreements Paid by Bank	20.00%
Stated Threshold of Loss Sharing Agreements Paid by Bank	34,400,000
Percent of Asset Discount Under Loss Sharing Percent of Asset Discount Under Loss Sharing Agreements	25.00%
Stated amount of Asset Discount Under Loss Sharing Agreements	$12,000,000

Fair_Value_Measurement_Recurri

Fair Value Measurement (Recurring and Nonrecurring Table) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Recurring Fair Value Measurements
Available-for-sale	$3,545,288,000	$3,273,174,000
Residential loans held for sale	13,428,000	11,622,000
Derivative Asset, Fair Value, Gross Asset	55,197,000	47,902,000
Total Assets, Fair Value Disclosure, Recurring	3,613,913,000	3,332,698,000
Derivative Liability, Fair Value, Gross Liability	55,439,000	58,201,000
True Up Liability	13,294,000	11,463,000
Total liabilities at fair value on a recurring basis	68,733,000	69,664,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	21,228,000	23,041,000
Impaired and Non Accrual Loans Fair Value Disclosure	56,041,000	47,870,000
Other Real Estate, Non Covered	12,510,000	10,018,000
Other Real Estate Covered by Loss Share	3,614,000	8,754,000
Nonrecurring Fair Value	93,393,000	89,683,000
Mortgage Servicing Rights	22,011,000	22,760,000	21,316,000	21,179,000
Mortgage Servicing rights Valuation Allowance	955,000	-282,000	-2,564,000	-3,539,000
MSRs, net carrying balance	21,056,000	22,478,000	18,752,000
Mortgage Servicing Rights (MSR) Impairment (Recovery)	673,000	-2,282,000	-975,000
Impaired Collateral Dependant Loans, Recorded Investment	60,300,000	52,600,000
Determination Of Specific Allowance For Loan Losses	-4,300,000	-4,800,000
Collateral Dependant Impaired and Non Accrual Loans Carrying Amount	56,000,000	47,900,000
Impairment of Other Real Estate Owned	2,600,000	1,400,000
Impairment of Covered Other Real Esate Owned	1,200,000	1,000,000
Level 1
Recurring Fair Value Measurements
Available-for-sale	2,974,000	3,036,000
Residential loans held for sale	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Total Assets, Fair Value Disclosure, Recurring	2,974,000	3,036,000
Derivative Liability, Fair Value, Gross Liability	0	0
True Up Liability	0	0
Total liabilities at fair value on a recurring basis	0	0
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	0	0
Impaired and Non Accrual Loans Fair Value Disclosure	0	0
Other Real Estate, Non Covered	0	0
Other Real Estate Covered by Loss Share	0	0
Nonrecurring Fair Value	0	0
Level 2
Recurring Fair Value Measurements
Available-for-sale	3,203,127,000	2,922,527,000
Residential loans held for sale		11,622,000
Derivative Asset, Fair Value, Gross Asset	55,197,000	47,902,000
Total Assets, Fair Value Disclosure, Recurring	3,271,752,000	2,982,051,000
Derivative Liability, Fair Value, Gross Liability	55,439,000	58,201,000
True Up Liability	0	0
Total liabilities at fair value on a recurring basis	55,439,000	58,201,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	0	0
Impaired and Non Accrual Loans Fair Value Disclosure	0	0
Other Real Estate, Non Covered	0	0
Other Real Estate Covered by Loss Share	0	0
Nonrecurring Fair Value	0	0
Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	339,187,000	347,611,000
Residential loans held for sale	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Total Assets, Fair Value Disclosure, Recurring	339,187,000	347,611,000
Derivative Liability, Fair Value, Gross Liability	0	0
True Up Liability	13,294,000	11,463,000
Total liabilities at fair value on a recurring basis	13,294,000	11,463,000
Nonrecurring Fair Value Measurements [Abstract]
Fair Value of Mortgage Servicing Rights	21,228,000	23,041,000	18,833,000
Impaired and Non Accrual Loans Fair Value Disclosure	56,041,000	47,870,000
Other Real Estate, Non Covered	12,510,000	10,018,000
Other Real Estate Covered by Loss Share	3,614,000	8,754,000
Nonrecurring Fair Value	93,393,000	89,683,000
Marketable equity securities
Recurring Fair Value Measurements
Available-for-sale	2,974,000	3,036,000
Marketable equity securities | Level 1
Recurring Fair Value Measurements
Available-for-sale		3,036,000
Marketable equity securities | Level 2
Recurring Fair Value Measurements
Available-for-sale	0	0
Marketable equity securities | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Non-marketable Equity Securities
Recurring Fair Value Measurements
Available-for-sale		3,281,000
Non-marketable Equity Securities | Level 1
Recurring Fair Value Measurements
Available-for-sale		0
Non-marketable Equity Securities | Level 2
Recurring Fair Value Measurements
Available-for-sale		10,000
Non-marketable Equity Securities | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale		3,271,000
U.S. Government agencies
Recurring Fair Value Measurements
Available-for-sale	2,482,000
U.S. States and political subdivisions
Recurring Fair Value Measurements
Available-for-sale	227,342,000	262,367,000
U.S. States and political subdivisions | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
U.S. States and political subdivisions | Level 2
Recurring Fair Value Measurements
Available-for-sale		262,367,000
U.S. States and political subdivisions | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	970,998,000	969,922,000
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale		969,922,000
Residential Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	103,403,000	69,567,000
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale		69,567,000
Commercial Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	1,676,567,000	1,518,393,000
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale		1,518,393,000
Residential Collateralized Mortgage-Backed Securities Issued by US Government Sponsored Enterprises | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency
Recurring Fair Value Measurements
Available-for-sale	7,000	9,000
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Level 2
Recurring Fair Value Measurements
Available-for-sale	1,000	0
Residential Collateralized Mortgage-Backed Securities Issued by Non-US Government Agency | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	6,000	9,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises
Recurring Fair Value Measurements
Available-for-sale	222,334,000	102,268,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Level 2
Recurring Fair Value Measurements
Available-for-sale		102,268,000
Commercial Collateralized Mortgage Backed Securities Issued by US Government Sponsored Enterprises | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale	0	0
Corporate bonds
Recurring Fair Value Measurements
Available-for-sale	51,337,000	50,644,000
Corporate bonds | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Corporate bonds | Level 2
Recurring Fair Value Measurements
Available-for-sale	0	0
Corporate bonds | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale		50,644,000
Collateralized Loan Obligations
Recurring Fair Value Measurements
Available-for-sale	287,844,000	293,687,000
Collateralized Loan Obligations | Level 1
Recurring Fair Value Measurements
Available-for-sale	0	0
Collateralized Loan Obligations | Level 2
Recurring Fair Value Measurements
Available-for-sale	0	0
Collateralized Loan Obligations | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Available-for-sale		293,687,000
Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	49,941,000	47,902,000
Derivative Liability, Fair Value, Gross Liability	48,756,000	46,627,000
Interest Rate Swap | Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	5,256,000	0
Derivative Liability, Fair Value, Gross Liability	6,683,000	11,574,000
Interest Rate Swap | Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability, Fair Value, Gross Liability	0	0
Interest Rate Swap | Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	5,256,000
Derivative Liability, Fair Value, Gross Liability	6,683,000	11,574,000
Interest Rate Swap | Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0
Derivative Liability, Fair Value, Gross Liability	0	0
Interest Rate Swap | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	48,366,000	46,577,000
Derivative Liability, Fair Value, Gross Liability	48,366,000	46,577,000
Interest Rate Swap | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Interest Rate Swap | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	48,366,000	46,577,000
Derivative Liability, Fair Value, Gross Liability	48,366,000	46,577,000
Interest Rate Swap | Not Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Mortgage Loan Commitments | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	1,408,000	891,000
Derivative Liability, Fair Value, Gross Liability	0	0
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	1,408,000	891,000
Mortgage Loan Commitments | Not Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Forward Contracts | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset		384,000
Derivative Liability, Fair Value, Gross Liability	272,000	0
Forward Contracts | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability	0
Forward Contracts | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	384,000
Derivative Liability, Fair Value, Gross Liability	272,000
Forward Contracts | Not Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset		0
Derivative Liability, Fair Value, Gross Liability	0
Foreign Exchange | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	167,000	50,000
Derivative Liability, Fair Value, Gross Liability	118,000	50,000
Foreign Exchange | Not Designated as Hedging Instrument | Level 1
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Foreign Exchange | Not Designated as Hedging Instrument | Level 2
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	167,000	50,000
Derivative Liability, Fair Value, Gross Liability	118,000	50,000
Foreign Exchange | Not Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Other Contract | Not Designated as Hedging Instrument
Recurring Fair Value Measurements
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability		0
Other Contract | Not Designated as Hedging Instrument | Fair Value, Inputs, Level 3 [Member]
Recurring Fair Value Measurements
Derivative Liability, Fair Value, Gross Liability	$0

Fair_Value_Measurement_Fair_Va

Fair Value Measurement (Fair Value, Assets Measured on a Recurring Basis, Unobservable Inputs) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Available-for-sale	$3,545,288	$3,273,174
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Available-for-sale securities, Beginning balance	347,611	49,661
True-up liability, Beginning balance	11,463	12,259
Available-for-sale securities, Total unrealized gains/losses	0	0
True-up liability, Total unrealized gains/losses	1,831	-796
fair value measurement asssets acquired	0	3,271
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	-6,030	-2,635
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0
Available-for-sale securities, Purchases	0	297,232
True-up liability, Purchases	0	0
Available-for-sale securities, Settlements	-2,394	82
True-up liability, Settlements	0	0
Available-for-sale securities, Ending balance	339,187	347,611
True-up liability, Ending balance	$13,294	$11,463

Fair_Value_Measurement_Changes

Fair Value Measurement (Changes in Fair Value Carrying Amount of Residential Mortgages) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale	$13,428	$11,622
Aggregate Fair Value
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale	14,389	11,622
Contractual Balance
Fair Value of Assets Loans Receivable Aggregate Unpaid Principal [Line Items]
Loans held for sale	13,873	11,438
Fair Value, Option, Loans Held as Assets, Aggregate Difference	$516	$184

Fair_Value_Measurement_Fair_Va1

Fair Value Measurement (Fair Value, by Balance Sheet Grouping) (Details) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$697,424	$917,822	$258,014	$377,319
Cash and Cash Equivalents, Fair Value Disclosure	697,424	917,822
Available-for-sale	3,545,288	3,273,174
Held-to-maturity		2,935,688
Held-to-maturity Securities, Fair Value	2,875,920	2,824,240
Other Investments and Securities, at Cost	148,654	180,803
Other Investments	148,654	180,803
Loans Receivable Held-for-sale, Net	13,428	11,622
Loans held for sale	13,428	11,622
Originated loans and leases receivable, carrying value	12,398,116	10,116,903
Originated Loans and Leases Receivable Fair Value	12,235,530	10,017,722
Loans and Leases Receivable, Net Amount	15,182,498	14,159,720
Covered Loans and Leases Receivable Fair Value Disclosure	312,659	547,943
Interest Receivable	63,657	52,929
Accrued Interest Receivable Fair Value Disclosure	63,657	52,929
Derivative Asset	55,197	47,902
Derivative Asset, Fair Value, Gross Asset	55,197	47,902
Deposits	19,504,665	19,533,601
Deposits, Fair Value Disclosure	19,510,192	19,532,368
Total borrowed funds	1,272,591	851,535
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	1,272,591	851,535
Wholesale borrowings	428,071	200,600
Other Borrowings, Fair Value	430,676	204,124
Long-term debt	505,192	324,428
Long-term Debt, Fair Value	516,476	319,711
Interest Payable	9,820	9,339
Accrued Liabilities, Fair Value Disclosure	9,820	9,339
Derivative Liability	55,439	58,201
Derivative Liability, Fair Value, Gross Liability	55,439	58,201
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure		917,822
Available-for-sale	2,974	3,036
Held-to-maturity Securities, Fair Value	0	0
Other Investments	0	0
Loans held for sale	0	0
Originated Loans and Leases Receivable Fair Value	0	0
Covered Loans and Leases Receivable Fair Value Disclosure	0	0
Accrued Interest Receivable Fair Value Disclosure	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Deposits, Fair Value Disclosure	0	0
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0	0
Other Borrowings, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Accrued Liabilities, Fair Value Disclosure	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Available-for-sale	3,203,127	2,922,527
Held-to-maturity Securities, Fair Value		2,824,240
Other Investments		180,803
Loans held for sale		11,622
Originated Loans and Leases Receivable Fair Value	0	0
Covered Loans and Leases Receivable Fair Value Disclosure	0	0
Accrued Interest Receivable Fair Value Disclosure	63,657	52,929
Derivative Asset, Fair Value, Gross Asset	55,197	47,902
Deposits, Fair Value Disclosure	19,510,192	19,532,368
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure		851,535
Other Borrowings, Fair Value	430,676	204,124
Long-term Debt, Fair Value	516,476	319,711
Accrued Liabilities, Fair Value Disclosure	9,820	9,339
Derivative Liability, Fair Value, Gross Liability	55,439	58,201
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Available-for-sale	339,187	347,611
Held-to-maturity Securities, Fair Value	0	0
Other Investments	0	0
Loans held for sale	0	0
Originated Loans and Leases Receivable Fair Value	12,235,530	10,017,722
Covered Loans and Leases Receivable Fair Value Disclosure	312,659	547,943
Accrued Interest Receivable Fair Value Disclosure	0	0
Derivative Asset, Fair Value, Gross Asset	0	0
Deposits, Fair Value Disclosure	0	0
Federal Funds Purchased and Securities Loaned or Sold under Agreements to Repurchase, Fair Value Disclosure	0	0
Other Borrowings, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Accrued Liabilities, Fair Value Disclosure	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Originated Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and Leases Receivable, Net Amount		10,116,903
Acquired Loans
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Originated Loans and Leases Receivable Fair Value	2,564,842	3,627,275
Loans and Leases Receivable, Net Amount	2,471,723	3,494,874
Acquired Loans | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Originated Loans and Leases Receivable Fair Value	0	0
Acquired Loans | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Originated Loans and Leases Receivable Fair Value	0	0
Acquired Loans | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Originated Loans and Leases Receivable Fair Value	$2,564,842	$3,627,275

Derivatives_and_Hedging_Activi2

Derivatives and Hedging Activities (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Term of written loan commitments, days	60 days
Default Assumptions Percentage	100.00%
Government Agency Issued Bonds or MBS
Derivative [Line Items]
Collateral Already Posted, Aggregate Fair Value	53,500,000	$70,500,000
Collateral posted against derivative liabilities	53,500,000	70,500,000
Designated as Hedging Instrument | Interest Rate Swap
Derivative [Line Items]
Derivative Asset, Notional Amount	250,000,000	$0

Derivatives_and_Hedging_Activi3

Derivatives and Hedging Activities (Derivative Instruments Designated as Hedging Instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives designated in hedge relationships
Derivative Asset, Fair Value	$55,197	$47,902
Derivative Liability, Fair Value	55,439	58,201
Interest Rate Swap | Designated as Hedging Instrument
Derivatives designated in hedge relationships
Derivative Asset, Notional/Contract Amount	250,000	0
Derivative Asset, Fair Value	5,256	0
Derivative Liability, Notional/Contract Amount	93,313	126,637
Derivative Liability, Fair Value	$6,683	$11,574

Derivatives_and_Hedging_Activi4

Derivatives and Hedging Activities (Derivative Instruments not Designated as Hedging Instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives not designated in hedge relationships
Derivative Asset, Fair Value	$55,197	$47,902
Derivative Liability, Fair Value	55,439	58,201
Not Designated as Hedging Instrument
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,855,599	1,760,450
Derivative Asset, Fair Value	49,941	47,902
Derivative Liability, Notional/Contract Amount	1,823,957	1,743,151
Derivative Liability, Fair Value	48,756	46,627
Not Designated as Hedging Instrument | Interest Rate Swap
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	1,673,012	1,622,525
Derivative Asset, Fair Value	48,366	46,577
Derivative Liability, Notional/Contract Amount	1,673,012	1,622,531
Derivative Liability, Fair Value	48,366	46,577
Not Designated as Hedging Instrument | Mortgage Loan Commitments
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	102,523	90,541
Derivative Asset, Fair Value	1,408	891
Derivative Liability, Notional/Contract Amount	0	0
Derivative Liability, Fair Value	0	0
Not Designated as Hedging Instrument | Forward Contracts
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	47,657	40,906
Derivative Asset, Fair Value		384
Derivative Liability, Notional/Contract Amount	0	0
Derivative Liability, Fair Value	272	0
Not Designated as Hedging Instrument | Foreign Exchange
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	22,406	6,478
Derivative Asset, Fair Value	167	50
Derivative Liability, Notional/Contract Amount	6,580	6,893
Derivative Liability, Fair Value	118	50
Not Designated as Hedging Instrument | Credit contracts
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	10,001	0
Derivative Asset, Fair Value	0	0
Derivative Liability, Notional/Contract Amount	69,227	49,914
Derivative Liability, Fair Value	0	0
Not Designated as Hedging Instrument | Other Contract
Derivatives not designated in hedge relationships
Derivative Asset, Notional/Contract Amount	0	0
Derivative Asset, Fair Value	0	0
Derivative Liability, Notional/Contract Amount	75,138	63,813
Derivative Liability, Fair Value		$0

Derivatives_and_Hedging_Activi5

Derivatives and Hedging Activities (Derivative Instruments, Gain (Loss)) (Details) (Not Designated as Hedging Instrument, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	($332)	($3,179)	$1,367
Mortgage Loan Commitments | Other income
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	517	-3,509	-559
Forward Contracts | Other income
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	-656	446	1,737
Credit contracts | Other income
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	-193	-116	189
Other [Member] | Other Expenses
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	$0	$0	$0

Derivatives_and_Hedging_Activi6

Derivatives and Hedging Activities (Offsetting Disclosure for Derivative Contracts) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	$5,608	$4,795
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0
offsetting disclosure, net amount, derivative asset, falir value	5,608	4,795
offseting disclosure, netting adjustment, derivative liability, fair value	-352	-4,837
offsetting disclosure, collateral value, derivative asset	0	42
offsetting disclosure, net amount total, derivative asset, fair value	5,256	0
offsetting disclosure, derivative liability, fair value, gross	54,697	53,407
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0
offsetting disclosure, net amount, derivative liability, falir value	54,697	53,407
offseting disclosure, netting adjustment, derivative asset, fair value	-352	-4,837
offsetting disclosure, collateral value, derivative liability	-54,345	-48,570
offsetting disclosure, net amount total, derivative liability, fair value	0	0
Designated as Hedging Instrument | Interest Rate Swap
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative liability, fair value, gross	6,683	11,574
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0
offsetting disclosure, net amount, derivative liability, falir value	6,683	11,574
offseting disclosure, netting adjustment, derivative asset, fair value	0	0
offsetting disclosure, collateral value, derivative liability	-6,683	-11,574
offsetting disclosure, net amount total, derivative liability, fair value	0	0
Not Designated as Hedging Instrument | Interest Rate Swap
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross	352	4,791
offsetting disclosure, offset amount, derivative liability, fair value, gross	0	0
offsetting disclosure, net amount, derivative asset, falir value	352	4,791
offseting disclosure, netting adjustment, derivative liability, fair value	-352	-4,791
offsetting disclosure, collateral value, derivative asset	0	0
offsetting disclosure, net amount total, derivative asset, fair value	0	0
offsetting disclosure, derivative liability, fair value, gross	48,014	41,787
offsetting disclosure, offset amount, derivative asset, fair value, gross	0	0
offsetting disclosure, net amount, derivative liability, falir value	48,014	41,787
offseting disclosure, netting adjustment, derivative asset, fair value	-352	-4,791
offsetting disclosure, collateral value, derivative liability	-47,662	-36,996
offsetting disclosure, net amount total, derivative liability, fair value	0	0
Not Designated as Hedging Instrument | Foreign Exchange Contract [Member]
Offsetting Disclosure for Derivative Contracts [Line Items]
offsetting disclosure, derivative asset, fair value, gross		4
offsetting disclosure, offset amount, derivative liability, fair value, gross		0
offsetting disclosure, net amount, derivative asset, falir value		4
offseting disclosure, netting adjustment, derivative liability, fair value		-46
offsetting disclosure, collateral value, derivative asset		42
offsetting disclosure, net amount total, derivative asset, fair value		0
offsetting disclosure, derivative liability, fair value, gross		46
offsetting disclosure, offset amount, derivative asset, fair value, gross		0
offsetting disclosure, net amount, derivative liability, falir value		46
offseting disclosure, netting adjustment, derivative asset, fair value		-46
offsetting disclosure, collateral value, derivative liability		0
offsetting disclosure, net amount total, derivative liability, fair value		$0

Commitments_and_Contingencies_1

Commitments and Contingencies (Narratives) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Apr. 12, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Outstanding, Intrinsic Value	$800,000	$1,400,000		$3,400,000
Allowance for unfunded lending commitments	5,800,000	7,900,000
Short-term guarantees	176,400,000
Repurchase Reserve	8,374,000	9,851,000		2,667,000
Assumed Obligation			6,000,000
Residential Mortgage
Loss Contingencies [Line Items]
Financing Receivable, Loans Sold to Third Party Investors	38,100,000	34,600,000
Repurchase Reserve	7,250,000	8,737,000		1,500,000
Assumed Obligation			6,000,000
Manufactured Housing
Loss Contingencies [Line Items]
Financing Receivable, Loans Sold to Third Party Investors	3,700,000	6,400,000
Repurchase Reserve	1,124,000	1,114,000		1,167,000
Assumed Obligation			$0

Commitments_and_Contingencies_2

Commitments and Contingencies (Schedule of Future Minimum Rental Payments for Operating Leases) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating Leases, Future Minimum Payments Due [Abstract]
2015	$13,598
2016	11,167
2017	9,841
2018	8,426
2019	6,459
2020-2031	21,999
Operating Leases, Future Minimum Payments Due	$71,490

Commitments_and_Contingencies_3

Commitments and Contingencies (Schedule of Commitments to Extend Credit) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$6,136,313	$5,546,635
Commercial Loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	3,748,690	3,367,625
Consumer Loan
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Loan Commitments	$2,387,623	$2,179,010

Commitments_and_Contingencies_4

Commitments and Contingencies (Schedule of Guarantor Obligations) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$287,461	$241,482
Standby Letters of Credit
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	242,390	196,400
Loans Sold with Recourse
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$45,071	$45,082

Commitments_and_Contingencies_5

Commitments and Contingencies (Changes in Repurchase Reserve) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Apr. 12, 2013
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$9,851	$2,667
Assumed Obligation			6,000
Net realized losses	-4,528	-5,818
Net increase (decrease) to reserve	3,051	7,002
Balance at end of period	8,374	9,851
Residential Mortgage
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	8,737	1,500
Assumed Obligation			6,000
Net realized losses	-4,528	-5,818
Net increase (decrease) to reserve	3,041	7,055
Balance at end of period	7,250	8,737
Manufactured Housing
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,114	1,167
Assumed Obligation			0
Net realized losses	0	0
Net increase (decrease) to reserve	10	-53
Balance at end of period	$1,124	$1,114

Shareholders_Equity_Narrative_

Shareholders' Equity (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 04, 2013	Apr. 12, 2013
In Millions, except Share data, unless otherwise specified
Business Acquisition [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	0
Preferred Stock, Shares Authorized	7,000,000
Non-cumulative Perpetual Preferred Stock, Series A, Shares Authorized	115,000
Non-cumulative Perpetual Preferred Stock, Shares Outstanding	100,000
Outstanding, Intrinsic Value	$0.80	$1.40	$3.40
Citizens Republic Bancorp
Business Acquisition [Line Items]
Interest rate of Non-Cumulative Perpetual Preferred Stock, Series A				5.88%
FirstMerit | Citizens Republic Bancorp
Business Acquisition [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	2,549,701.60				2,408,203
Citizens Republic Bancorp | Citizens Republic Bancorp
Business Acquisition [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights					1,757,812.50
Class of Warrant or Right, Exercise Price of Warrants or Rights	$17.65

Shareholders_Equity_Earnings_P

Shareholders' Equity (Earnings Per Share Reconciliation) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Plan	166,054	150,421	109,518
Net income	$237,951	$183,684	$134,106
Preferred Stock dividends	5,876	5,337	0
Less: Net income allocated to participating securities	1,930	1,545	0
Net income attributable to common shareholders	230,145	176,802	134,106
Weighted average number of common shares outstanding - basic	165,296	149,607	109,518
Basic earnings per common share	$1.39	$1.18	$1.22
Diluted earnings per common share	$1.39	$1.18	$1.22
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Plan	758	814	0
Net income attributable to common shareholders	$230,145	$176,802	$134,106

Changes_and_Reclassifications_2

Changes and Reclassifications Out of Other Comprehensive Income (Changes in AOCI by Components of Comprehensive Income) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the Period, Pre-tax	($102,885)
Balance at the beginning of the period, Tax	-36,009
Balance at the beginning of the period, After-tax	-66,876
Changes in unrealized securities' holding gains/(losses), Pre-Tax	38,864	-130,947	-6,668
Changes in unrealized securities' holding gains/(losses), Tax	13,602	-45,833	-2,334
Changes in unrealized securities' holding gains/(losses), After-tax	25,262	-85,114	-4,334
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, Pre-tax	-2,157	-2,187	13,059
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, Tax	-753	-765	4,571
Changes in unrealized securities' holding gains/(losses) that result from securities being transferred into available-for-sale from held-to-maturity, After-tax	-1,404	-1,422	8,488
Net losses/(gains) realized on sale of securities reclassified to noninterest income, Pre-Tax	-166	2,803	-3,786
Net losses/(gains) realized on sale of securities reclassified to noninterest income, Tax	-58	981	-1,325
Net losses/(gains) realized on sale of securities reclassified to noninterest income, After-tax	-108	1,822	-2,461
Balance at the beginning and end of the period, Pre-tax	-102,068	-57,813	-110,188
Accumulated other comprehensive income reclassifications, benefit plan, tax	-35,722	-20,233	-38,565
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	-66,346	-37,580	-71,623
Net gains/(losses) arising during the period, Pre-Tax	-49,552	47,939	-1,224
Net gains/(losses) arising during the period, Tax	-17,344	16,779	-429
Net gains/(losses) arising during the period, After-tax	-32,208	31,160	-795
Amortization of actuarial gain, Pre-Tax	3,166	4,437	10,517
Amortization of actuarial gain, Tax	1,108	1,553	3,681
Amortization of actuarial gain, After-tax	2,058	2,884	6,836
Amortization of prior service cost reclassified to other noninterest expense, Pre-Tax	-2,131	1	80
Amortization of prior service cost reclassified to other noninterest expense, Tax	-747	0	28
Amortization of prior service cost reclassified to other noninterest expense, After-tax	-1,384	1	52
Balance at the end of the Period, Pre-tax	-110,599	-102,885
Balance at the end of the period, Tax	-38,707	-36,009
Balance at the end of the period, After-tax	-71,892	-66,876
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the end of the Period, Pre-tax	-8,531	-45,072	85,259
Balance at the end of the period, Tax	-2,985	-15,776	29,841
Balance at the end of the period, After-tax	($5,546)	($29,296)	$55,418

Changes_and_Reclassifications_3

Changes and Reclassifications Out of Other Comprehensive Income (Current Period Reclassifications out of AOCI) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Changes and Reclassifications Out of Comprehensive Income [Abstract]
Realized (gains) losses on sale of securities	$166	($2,803)	$3,786
Tax expense (benefit) (35%)	58	-981	1,325
Reclassified amount, net of tax	$108	($1,822)	$2,461

Regulatory_Matters_Narrative_D

Regulatory Matters (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Regulatory Matters [Abstract]
Minimum net worth requirement of HUD	$1

Regulatory_Matters_Schedule_of

Regulatory Matters (Schedule of Compliance with Regulatory Capital Requirements Under Banking Regulations) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Consolidated
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital	$2,653,893	$2,279,891
Total Capital to Risk Weighted Assets (Ratio)	15.26%	13.97%
Capital Required for Capital Adequacy	1,391,282	1,305,667
Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	8.00%	8.00%
Capital Required to be Well Capitalized	1,739,102	1,632,083
Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	11.53%	11.52%
Tier One Risk Based Capital Required for Capital Adequacy	695,641	652,833
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	4.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	1,043,461	979,250
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	6.00%	6.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital	2,004,461	1,880,804
Tier One Leverage Capital to Average Assets (Ratio)	8.43%	8.14%
Tier One Leverage Capital Required for Capital Adequacy	951,430	923,887
Tier One Leverage Capital Required for Capital Adequacy to Average Assets (Ratio)	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	1,189,287	1,154,858
Tier One Leverage Capital Required to be Well Capitalized to Average Assets (Ratio)	5.00%	5.00%
Bank Only
Total Capital (to Risk Weighted Assets) [Abstract]
Total Capital	2,521,412	2,122,124
Total Capital to Risk Weighted Assets (Ratio)	14.49%	13.02%
Capital Required for Capital Adequacy	1,391,988	1,303,579
Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	8.00%	8.00%
Capital Required to be Well Capitalized	1,739,986	1,629,473
Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets) [Abstract]
Tier One Risk Based Capital to Risk Weighted Assets (Ratio)	12.22%	12.14%
Tier One Risk Based Capital Required for Capital Adequacy	695,994	651,789
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets (Ratio)	4.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	1,043,991	977,684
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets (Ratio)	6.00%	6.00%
Tier I Capital (to Average Assets) [Abstract]
Tier One Leverage Capital	2,127,065	1,978,140
Tier One Leverage Capital to Average Assets (Ratio)	8.94%	8.58%
Tier One Leverage Capital Required for Capital Adequacy	951,455	922,312
Tier One Leverage Capital Required for Capital Adequacy to Average Assets (Ratio)	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	$1,189,319	$1,152,890
Tier One Leverage Capital Required to be Well Capitalized to Average Assets (Ratio)	5.00%	5.00%

Borrowed_Funds_Narrative_Detai

Borrowed Funds (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Nov. 25, 2014	Apr. 12, 2013	Feb. 04, 2013
Debt Instrument [Line Items]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	2,400,000,000	$5,100,000,000
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate, Range from		1.11%
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate, Range to		4.12%
Subordinate debentures | Subordinated Notes Due 2026
Debt Instrument [Line Items]
Debt Instrument, Face Amount			250,000,000
Debt Instrument, Interest Rate, Stated Percentage			4.27%
Citizens Republic Bancorp
Debt Instrument [Line Items]
Debt Instrument, Face Amount					250,000,000
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Subordinated Debt				74,500,000
Citizens Republic Bancorp | Subordinate debentures | Subordinated Notes Due 2023
Debt Instrument [Line Items]
Debt Instrument, Face Amount					250,000,000
Debt Instrument, Interest Rate, Stated Percentage					4.35%
Citizens Republic Bancorp | Maximum | Junior Subordinated Debt | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	11.75%
VIE 2
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.10%
VIE 2 | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Variable Interest Entity-Aggregate Liquidation Amount Outstanding	25,800,000
Debt Instrument, Description of Variable Rate Basis	LIBOR
VIE 1
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Variable Interest Entity-Aggregate Liquidation Amount Outstanding	48,700,000

Borrowed_Funds_Wholesale_Borro

Borrowed Funds (Wholesale Borrowings and Long-term Debt) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Total borrowed funds	$1,272,591	$851,535
FHLB advances
Debt Instrument [Line Items]
Federal Home Loan Bank Advances	427,857	200,323
Wholesale Borrowings
Debt Instrument [Line Items]
Federal Home Loan Bank Advances	214	277
Subordinated debentures	505,192	249,928
Other	0	74,500
Total borrowed funds	$933,263	$525,028

Borrowed_Funds_Selected_Inform

Borrowed Funds (Selected Information Pertaining to the Corporation's Borrowed Funds) (Details) (Wholesale Borrowings [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Wholesale Borrowings [Member]
Debt Instrument [Line Items]
Average balance during the year	$715,383	$474,473	$175,989
Weighted-average annual interest rate during the year	2.80%	3.62%	2.51%
Maximum month-end balance	$973,453	$527,155	$178,489

Borrowed_Funds_Wholesale_Borro1

Borrowed Funds (Wholesale Borrowings Schedule of Maturities) (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
One year or less	$189,875
One to three years	212,642
Three to five years	202
Over five years	530,544
Total	933,263
FHLB advances
Debt Instrument [Line Items]
One year or less	189,808
One to three years	212,495
Three to five years	202
Over five years	25,352
Total	427,857
Subordinate debentures
Debt Instrument [Line Items]
One year or less	0
One to three years	0
Three to five years	0
Over five years	505,192
Total	505,192
Wholesale Borrowings
Debt Instrument [Line Items]
One year or less	67
One to three years	147
Three to five years	0
Over five years	0
Total	$214

Uncategorized_Items

Uncategorized Items
[us-gaap_CashAndCashEquivalentsAtCarryingValue]	140,939,000