TCF Financial 10-Q 9 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 04, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	CHEMICAL FINANCIAL CORP
Entity Central Index Key	19,612
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Amendment Flag	false
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		70,546,621

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Cash and cash equivalents:
Cash and cash due from banks	$ 286,351	$ 194,136
Interest-bearing deposits with the Federal Reserve Bank and other banks and federal funds sold	270,216	44,653
Total cash and cash equivalents	556,567	238,789
Investment securities:
Available-for-sale, at fair value	1,303,381	553,731
Held-to-maturity (fair value of $575,144 at September 30, 2016 and $512,705 at December 31, 2015)	563,721	509,971
Total investment securities	1,867,102	1,063,702
Loans held-for-sale, at fair value	276,061	10,327
Loans	12,715,789	7,271,147
Allowance for loan losses	(73,775)	(73,328)
Net loans	12,642,014	7,197,819
Premises and equipment (net of accumulated depreciation of $124,986 at September 30, 2016 and $120,382 at December 31, 2015)	144,165	106,317
Loan servicing rights	51,393	11,122
Goodwill	1,137,166	287,393
Other intangible assets	35,700	26,982
Interest receivable and other assets	673,469	246,346
Total assets	17,383,637	9,188,797
Deposits:
Noninterest-bearing	3,264,934	1,934,583
Interest-bearing	10,007,928	5,522,184
Total deposits	13,272,862	7,456,767
Interest payable and other liabilities	143,708	76,466
Securities sold under agreements to repurchase with customers	326,789	297,199
Short-term borrowings	400,000	100,000
Long-term borrowings	676,612	242,391
Total liabilities	14,819,971	8,172,823
Shareholders’ equity
Preferred stock, no par value: Authorized – 2,000,000 shares at 9/30/2016 and 12/31/2015, none issued	0	0
Common stock, $1.00 par value per share, Authorized - 100,000,000 shares at 9/30/2016 and 60,000,000 at 12/31/2015, Issued and outstanding — 70,497,027 shares at 9/30/2016 and 38,167,861 shares at 12/31/2015	70,497	38,168
Additional paid-in capital	2,207,345	725,280
Retained earnings	310,966	281,558
Accumulated other comprehensive loss	(25,142)	(29,032)
Total shareholders’ equity	2,563,666	1,015,974
Total liabilities and shareholders’ equity	$ 17,383,637	$ 9,188,797

Consolidated Statements of Fin3

Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Held-to-maturity, fair value	$ 575,144	$ 512,705
Accumulated depreciation of premises and equipment	$ 124,986	$ 120,382
Preferred stock, no par value (in dollars per share)
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	100,000,000	60,000,000
Common stock, shares issued (in shares)	70,497,027	38,167,861
Common stock, shares outstanding (in shares)	70,497,027	38,167,861

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest Income
Interest and fees on loans	$ 97,103	$ 73,809	$ 249,082	$ 196,519
Interest on investment securities:
Taxable	2,575	2,233	6,302	6,742
Tax-exempt	3,072	2,399	8,377	6,490
Total interest on securities	5,647	4,632	14,679	13,232
Dividends on nonmarketable equity securities	358	266	1,391	1,015
Interest on deposits with the Federal Reserve Bank, other banks and Federal funds sold	454	144	811	394
Total interest income	103,562	78,851	265,963	211,160
Interest Expense
Interest on deposits	5,836	4,304	14,155	11,286
Interest on short-term borrowings	459	144	785	343
Interest on long-term borrowings	458	786	2,389	999
Total interest expense	6,753	5,234	17,329	12,628
Net Interest Income	96,809	73,617	248,634	198,532
Provision for loan losses	4,103	1,500	8,603	4,500
Net interest income after provision for loan losses	92,706	72,117	240,031	194,032
Noninterest Income
Service charges and fees on deposit accounts	7,665	6,722	19,722	19,083
Wealth management revenue	5,584	4,725	16,567	15,401
Other charges and fees for customer services	7,410	6,818	20,265	19,324
Mortgage banking revenue	4,439	1,436	7,439	4,527
Net gain on sale of investment securities	16	5	53	612
Other	2,656	509	4,040	1,217
Total noninterest income	27,770	20,215	68,086	60,164
Operating Expenses
Salaries, wages and employee benefits	40,565	33,985	107,582	94,949
Occupancy	5,462	4,781	15,881	13,593
Equipment and software	6,420	4,589	15,699	13,467
Merger and acquisition-related transaction expenses	37,470	900	43,118	5,719
Other	16,227	14,010	41,836	38,342
Total operating expenses	106,144	58,265	224,116	166,070
Income before income taxes	14,332	34,067	84,001	88,126
Income tax expense	3,600	9,600	24,300	26,800
Net Income	$ 10,732	$ 24,467	$ 59,701	$ 61,326
Net Income Per Common Share:
Basic (in dollars per share)	$ 0.22	$ 0.64	$ 1.43	$ 1.73
Diluted (in dollars per share)	0.21	0.64	1.40	1.72
Cash Dividends Declared Per Common Share (in dollars per share)	$ 0.27	$ 0.26	$ 0.79	$ 0.74

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income		$ 10,732	$ 24,467	$ 59,701	$ 61,326
Other comprehensive income (loss):
Unrealized holding (losses) gains on securities available-for-sale arising during the period		(1,238)	1,869	5,082	2,377
Reclassification adjustment for gains on realized income		(16)	(5)	(53)	(612)
Tax effect		439	(653)	(1,760)	(618)
Net unrealized (losses) gains on securities available-for-sale, net of tax		(815)	1,211	3,269	1,147
Pension plan remeasurement	[1]	(786)	0	(786)	0
Adjustment for pension and other postretirement benefits		2,895	1,087	1,742	3,261
Tax effect		(738)	(380)	(335)	(1,141)
Net adjustment for pension and other postretirement benefits		1,371	707	621	2,120
Other comprehensive income, net of tax		556	1,918	3,890	3,267
Total comprehensive income, net of tax		$ 11,288	$ 26,385	$ 63,591	$ 64,593
[1]	Refer to Footnote 12, Pension and Other Postretirement Benefit Plans, for further information.

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2014	$ 797,133	$ 32,774	$ 565,166	$ 231,646	$ (32,453)
Changes in Stockholders' Equity
Comprehensive income	64,593			61,326	3,267
Cash dividends declared and paid, $0.79 and $0.74 per share at September 30, 2016 and September 30, 2015, respectively	(26,981)			(26,981)
Issuance of common stock in business acquisitions	159,904	5,183	154,721
Stock issued - stock options	1,234	98	1,136
Shares issued – directors’ stock plans	316	11	305
Shares issued – restricted stock units	(343)	54	(397)
Share-based compensation	2,507	11	2,496
Ending Balance at Sep. 30, 2015	998,363	38,131	723,427	265,991	(29,186)
Beginning Balance at Jun. 30, 2015					(31,104)
Changes in Stockholders' Equity
Comprehensive income	26,385
Ending Balance at Sep. 30, 2015	998,363	38,131	723,427	265,991	(29,186)
Beginning Balance at Dec. 31, 2015	1,015,974	38,168	725,280	281,558	(29,032)
Changes in Stockholders' Equity
Comprehensive income	63,591			59,701	3,890
Cash dividends declared and paid, $0.79 and $0.74 per share at September 30, 2016 and September 30, 2015, respectively	(30,293)			(30,293)
Issuance of common stock in business acquisitions	1,504,811	32,074	1,472,737
Stock issued - stock options	998	100	898
Shares issued – directors’ stock plans	2,597	95	2,502
Shares issued – restricted stock units	(466)	60	(526)
Share-based compensation	6,454		6,454
Ending Balance at Sep. 30, 2016	2,563,666	70,497	2,207,345	310,966	(25,142)
Beginning Balance at Jun. 30, 2016					(25,698)
Changes in Stockholders' Equity
Comprehensive income	11,288
Ending Balance at Sep. 30, 2016	$ 2,563,666	$ 70,497	$ 2,207,345	$ 310,966	$ (25,142)

Consolidated Statements of Cha7

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Dividend declared (in dollars per share)	$ 0.27	$ 0.26	$ 0.79	$ 0.74

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash Flows From Operating Activities
Net income	$ 59,701	$ 61,326
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	8,603	4,500
Gains on sales of loans	(8,957)	(4,900)
Proceeds from sales of loans	287,295	176,029
Loans originated for sale	(299,156)	(171,245)
Net gains from sales/writedowns of other real estate and repossessed assets	(3,150)	(2,428)
Depreciation of premises and equipment	8,925	8,182
Amortization of intangible assets	6,736	9,405
Net gains on sale of investment securities	(53)	(612)
Valuation change in loan servicing rights	1,558	(200)
Additions to loan servicing rights	(2,422)	(1,118)
Share-based compensation expense	5,211	4,254
Share-based compensation expense	6,454	2,507
Deferred income tax expense (benefit)	7,052	(2,900)
Net (increase) decrease in interest receivable and other assets	(37,836)	(19,075)
Net decrease in interest payable and other liabilities	(35,081)	(8,438)
Net cash provided by operating activities	4,880	55,287
Investment securities – available-for-sale:
Proceeds from sales	7,820	37,897
Proceeds from maturities, calls and principal reductions	157,125	140,260
Purchases	(104,657)	0
Investment securities – held-to-maturity:
Proceeds from maturities, calls and principal reductions	71,226	72,071
Purchases	(124,492)	(254,695)
Net increase in loans	(575,963)	(434,767)
Proceeds from sales of other real estate and repossessed assets	10,989	13,277
Purchases of premises and equipment, net of disposals	(10,196)	(5,074)
Cash acquired, net of cash paid, in business combinations	325,714	16,551
Net cash used in investing activities	(242,434)	(414,480)
Cash Flows From Financing Activities
Net increase in interest- and noninterest-bearing demand deposits and savings accounts	734,330	594,058
Net decrease in time deposits	(213,105)	(126,902)
Net increase (decrease) in securities sold under agreements to repurchase with customers and other short-term borrowings	9,886	(98,451)
Proceeds from issuance of long-term borrowings	275,000	125,000
Repayment of long-term borrowings	(223,018)	0
Cash dividends paid	(30,293)	(26,981)
Proceeds from directors’ stock plans and exercise of stock options, net of shares withheld	3,595	1,550
Cash paid for payroll taxes upon conversion of share-based awards	(1,063)	(564)
Net cash provided by financing activities	555,332	467,710
Net increase (decrease) in cash and cash equivalents	317,778	108,517
Cash and cash equivalents at beginning of period	238,789	183,020
Cash and cash equivalents at end of period	556,567	291,537
Supplemental Disclosure of Cash Flow Information:
Interest paid	13,810	11,655
Loans transferred to other real estate and repossessed assets	6,029	7,411
Closed branch offices transferred to other assets	2,136	455
Income taxes paid	22,200	33,450
Fair value of tangible assets acquired (non-cash)	6,374,784	1,284,552
Goodwill, loans servicing rights and other identifiable intangible assets acquired	905,160	116,478
Liabilities assumed	6,100,847	1,257,917
Common stock issued	$ 1,504,811	$ 159,904

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Nature of Operations Chemical Financial Corporation ("Corporation" or "Chemical") operates in a single operating segment — commercial banking. The Corporation is a financial holding company, headquartered in Midland, Michigan, that operates through two commercial banks, Chemical Bank and Talmer Bank and Trust. Talmer Bank and Trust was added to operations in the August 31, 2016 merger with Talmer Bancorp, Inc. ("Talmer"), and is expected to be consolidated with and into Chemical Bank during the fourth quarter of 2016. Chemical Bank operates within the State of Michigan as a state-chartered commercial bank. Talmer Bank and Trust is a Michigan state-chartered bank. Chemical Bank and Talmer Bank and Trust operate through an internal organizational structure of seven regional banking units and offer a full range of traditional banking and fiduciary products and services to the residents and business customers in the bank’s geographical market areas. The products and services offered by the regional banking units, through branch banking offices, are generally consistent throughout the Corporation, as is the pricing of those products and services. The marketing of products and services throughout the Corporation’s regional banking units is generally uniform, as many of the markets served by the regional banking units overlap. The distribution of products and services is uniform throughout the Corporation’s regional banking units and is achieved primarily through retail branch banking offices, automated teller machines and electronically accessed banking products. The Corporation’s primary sources of revenue are interest from its loan products and investment securities, service charges and fees from customer deposit accounts, wealth management revenue and mortgage banking revenue. Basis of Presentation The accompanying unaudited consolidated financial statements of the Corporation and its subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the interim consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Corporation’s consolidated financial statements and footnotes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015. In the opinion of management, the accompanying unaudited interim consolidated financial statements contain all adjustments believed necessary to present fairly the financial condition and results of operations of the Corporation for the periods presented. Operating results for the nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . Use of Estimates Management makes estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying footnotes. Estimates that are particularly susceptible to significant change include the determination of the allowance for loan losses, expected cash flows from acquired loans, fair value amounts related to business combinations, pension expense, income taxes, goodwill impairment and those assets that require fair value measurement. Actual results could differ from these estimates. Business Combinations Pursuant to the guidance of Accounting Standards Codification ("ASC") Topic 805, Business Combinations ("ASC 805"), the Corporation recognizes assets acquired, including identified intangible assets, and the liabilities assumed in acquisitions at their fair values as of the acquisition date, with the acquisition-related transaction and restructuring costs expensed in the period incurred. On August 31, 2016, the Corporation acquired all the outstanding stock of Talmer for total consideration of $1.61 billion , which included stock consideration of $1.50 billion and cash consideration of $107.6 million . The Corporation recorded $850.3 million of goodwill in conjunction with the merger, which represented the purchase price over the fair value of identifiable net assets acquired. Additionally, the Corporation recorded $12.4 million of core deposit intangible assets in conjunction with the acquisition related to total deposits acquired of $5.29 billion . ASC 805 affords a measurement period beyond the acquisition date that allows the Corporation the opportunity to finalize the acquisition accounting in the event that new information is identified that existed as of the acquisition date but was not known by the Corporation at that time. The Corporation anticipates that measurement period adjustments may arise from adjustments to the fair values of assets and liabilities recognized at the acquisition date for its August 31, 2016 merger with Talmer, as additional information is obtained, such as appraisals of collateral securing loans and other borrower information. In the event that a measurement period adjustment is identified, the Corporation will recognize the adjustment as part of its acquisition accounting, which may result in an adjustment to goodwill being recorded in the period the adjustment was identified. See Note 2 for further information regarding the Corporation's mergers and acquisitions. Originated Loans Originated loans include all of the Corporation's portfolio loans, excluding loans acquired in business combinations, as further discussed below. Originated loans are stated at their principal amount outstanding, net of unearned income, charge-offs and unamortized deferred fees and costs. Loan interest income is recognized on the accrual basis. Deferred loan fees and costs are amortized over the loan term based on the level-yield method. Net loan commitment fees are deferred and amortized into fee income on a straight-line basis over the commitment period. The past due status of a loan is based on the loan’s contractual terms. A loan is placed in nonaccrual status (accrual of interest is discontinued) when principal or interest is past due 90 days or more (except for a loan that is secured by residential real estate, which is transferred to nonaccrual status at 120 days past due), unless the loan is both well-secured and in the process of collection, or earlier when, in the opinion of management, there is sufficient reason to doubt the collectibility of principal or interest. Interest previously accrued, but not collected, is reversed and charged against interest income at the time the loan is placed in nonaccrual status. Subsequent receipts of interest while a loan is in nonaccrual status are recorded as a reduction of principal. Loans are returned to accrual status when principal and interest payments are brought current, payments have been received consistently for a period of time (generally six months ) and collectibility is no longer in doubt. Loans Acquired in a Business Combination Loans acquired in a business combination ("acquired loans") consist of loans acquired on August 31, 2016 in the merger with Talmer, on May 31, 2015 in the acquisition of Lake Michigan Financial Corporation ("Lake Michigan"), on April 1, 2015 in the acquisition of Monarch Community Bancorp, Inc. ("Monarch"), on October 31, 2014 in the acquisition of Northwestern Bancorp, Inc. ("Northwestern"), and on April 30, 2010 in the acquisition of O.A.K. Financial Corporation ("OAK"). Acquired loans were recorded at fair value at the date of acquisition, without a carryover of the associated allowance for loan losses related to these loans. The Corporation accounts for acquired loans, which are recorded at fair value at acquisition, in accordance with ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality ("ASC 310-30"). ASC 310-30 allows investors to aggregate loans acquired into loan pools that have common risk characteristics and thereby use a composite interest rate and expectation of cash flows expected to be collected for the loan pools. Under the provisions of ASC 310-30, the Corporation aggregated acquired loans into 5 pools in the merger with Talmer, 2 pools in the acquisition of Lake Michigan, 2 pools in the acquisition of Monarch, 4 pools in the acquisition of Northwestern and 14 pools in the acquisition of OAK based upon common risk characteristics, including types of loans, commercial type loans with similar risk grades and whether loans were performing or nonperforming. A pool is considered a single unit of accounting for the purposes of applying the guidance prescribed in ASC 310-30. A loan will be removed from a pool of acquired loans only if the loan is sold, foreclosed, paid off or written off, and will be removed from the pool at the carrying value. If an individual loan is removed from a pool of loans, the difference between its relative carrying amount and the cash, fair value of the collateral, or other assets received would not affect the effective yield used to recognize the accretable difference on the remaining pool. The estimate of expected credit losses was determined based on due diligence performed by executive and senior officers of the Corporation, with assistance from third-party consultants. The Corporation estimated the cash flows expected to be collected over the life of the pools of loans at acquisition and estimates expected cash flows quarterly thereafter, based on a set of assumptions including expectations as to default rates, prepayment rates and loss severities. The Corporation must make numerous assumptions, interpretations and judgments using internal and third-party credit quality information to determine whether it is probable that the Corporation will be able to collect all contractually required payments. This is a point in time assessment and inherently subjective due to the nature of the available information and judgment involved. The calculation of the fair value of the acquired loan pools entails estimating the amount and timing of cash flows attributable to both principal and interest expected to be collected on such loan pools and then discounting those cash flows at market interest rates. The excess of a loan pool's expected cash flows at the acquisition date over its estimated fair value is referred to as the "accretable yield," which is recognized into interest income over the estimated remaining life of the loan pool on a level-yield basis. The difference between a loan pool's contractually required principal and interest payments at the acquisition date and the cash flows expected to be collected at the acquisition date is referred to as the "nonaccretable difference," which includes an estimate of future credit losses expected to be incurred over the estimated life of the loan pool and interest payments that are not expected to be collected. Decreases to the expected cash flows in each loan pool in subsequent periods will require the Corporation to record a provision for loan losses. Improvements in expected cash flows in each loan pool in subsequent periods will result in reversing a portion of the nonaccretable difference, which is then classified as part of the accretable yield and subsequently recognized into interest income over the estimated remaining life of the loan pool. Loans Modified Under Troubled Debt Restructurings Loans modified under troubled debt restructurings ("TDRs") involve granting a concession to a borrower who is experiencing financial difficulty. Concessions generally include modifications to original loan terms, including changes to a loan’s payment schedule or interest rate, which generally would not otherwise be considered. The Corporation’s TDRs include performing and nonperforming TDRs, which consist of originated loans that continue to accrue interest at the loan's original interest rate as the Corporation expects to collect the remaining principal and interest on the loan, and nonaccrual TDRs, which include originated loans that are in a nonaccrual status and are no longer accruing interest, as the Corporation does not expect to collect the full amount of principal and interest owed from the borrower on these loans. At the time of modification (except for loans on nonaccrual status), a TDR is reported as a nonperforming TDR until a six -month payment history of principal and interest payments, in accordance with the terms of the loan modification, is sustained, at which time the Corporation moves the loan to a performing status ("performing TDR"). If the Corporation does not expect to collect all principal and interest on the loan, the modified loan is classified as a nonaccrual TDR. All TDRs are accounted for as impaired loans and are included in the Corporation’s analysis of the allowance for loan losses. A TDR that has been renewed by a borrower who is no longer experiencing financial difficulty and which yields a market rate of interest at the time of a renewal is no longer reported as a TDR. Loans in the Corporation’s commercial loan portfolio (comprised of commercial, commercial real estate, real estate construction and land development loans) that meet the definition of a TDR generally consist of loans where the Corporation has allowed borrowers to defer scheduled principal payments and make interest-only payments for a specified period of time at the stated interest rate of the original loan agreement or reduced payments due to a moderate extension of the loan’s contractual term. If the Corporation does not expect to collect all principal and interest on the loan, the modified loan is classified as a nonaccrual TDR. If the Corporation does not expect to incur a loss on the loan based on its assessment of the borrowers’ expected cash flows, as the pre- and post-modification effective yields are approximately the same, the loan is classified as a nonperforming TDR until a six-month payment history is sustained, at which time the loan is classified as a performing TDR. Since no loss is expected to be incurred on nonperforming TDRs, no additional provision for loan losses has been recognized for these loans and they continue to accrue interest at their contractual interest rate. Nonperforming TDRs are transferred to nonaccrual status if they become 90 days past due as to principal or interest payments or if it is probable that any remaining principal and interest payments due on the loan will not be collected in accordance with the modified terms of the loan. Loans in the Corporation’s consumer loan portfolio (comprised of residential mortgage, consumer installment and home equity loans) that meet the definition of a performing or nonperforming TDR generally consist of residential mortgage loans that include a concession that reduces a borrower’s monthly payments by decreasing the interest rate charged on the loan for a specified period of time (generally 24 months ) under a formal modification agreement. The Corporation recognizes an additional provision for loan losses related to impairment on these loans on an individual basis based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. These loans continue to accrue interest at their effective interest rate, which consists of contractual interest under the terms of the modification agreement in addition to an adjustment for the accretion of computed impairment. These loans are moved to nonaccrual status if they become 90 days past due as to principal or interest payments, or sooner if conditions warrant. Impaired Loans A loan is defined to be impaired when it is probable that payment of principal and interest will not be paid in accordance with the original contractual terms of the loan agreement. Impaired loans include nonaccrual loans (including nonaccrual TDRs), performing and nonperforming TDRs and acquired loans that were not performing in accordance with original contractual terms. Impaired loans are accounted for at the lower of the present value of expected cash flows discounted at the loan's original effective interest rate or the estimated fair value of the collateral, if the loan is collateral dependent. When the present value of expected cash flows or the fair value of collateral of an impaired loan in the originated loan portfolio is less than the amount of unpaid principal outstanding on the loan, the principal balance of the loan is reduced to its carrying value through either an allocation of the allowance for loan losses or a partial charge-off of the loan balance. Nonperforming Loans Nonperforming loans are comprised of loans for which the accrual of interest has been discontinued (nonaccrual loans, including nonaccrual TDRs), accruing originated loans contractually past due 90 days or more as to interest or principal payments and nonperforming TDRs. Acquired loans that were classified as nonperforming loans prior to being acquired and acquired loans that are not performing in accordance with contractual terms subsequent to acquisition are not classified as nonperforming loans subsequent to acquisition because the loans are recorded in pools at net realizable value based on the principal and interest the Corporation expects to collect on such loans. Allowance for Loan Losses The allowance for loan losses ("allowance") is presented as a reserve against loans. The allowance represents management’s assessment of probable loan losses inherent in the Corporation’s loan portfolio. Management’s evaluation of the adequacy of the allowance is based on a continuing review of the loan portfolio, actual loan loss experience, the underlying value of the collateral, risk characteristics of the loan portfolio, the level and composition of nonperforming loans, the financial condition of the borrowers, the balance of the loan portfolio, loan growth, economic conditions, employment levels in the Corporation’s local markets, and special factors affecting specific business sectors. The Corporation maintains formal policies and procedures to monitor and control credit risk. Management evaluates the allowance on a quarterly basis in an effort to ensure the level is appropriate to absorb probable losses inherent in the loan portfolio. The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be incurred in the remainder of the originated loan portfolio, but that have not been specifically identified. The Corporation utilizes its own loss experience to estimate inherent losses on originated loans. Internal risk ratings are assigned to each loan in the commercial loan portfolio (commercial, commercial real estate, real estate construction and land development loans) at the time of origination and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review quarterly on all loans greater than $0.25 million that have deteriorated below certain levels of credit risk, and may allocate a specific portion of the allowance to such loans based upon this review. A portion of the allowance is allocated to the remaining loans by applying projected loss ratios, based on numerous factors. Projected loss ratios incorporate factors such as charge-off experience, trends with respect to adversely risk-rated loans in the commercial loan portfolio, trends with respect to past due and nonaccrual loans, changes in economic conditions and trends, changes in the value of underlying collateral and other credit risk factors. This evaluation involves a high degree of uncertainty. In determining the allowance and the related provision for loan losses, the Corporation considers four principal elements: (i) valuation allowances based upon probable losses identified during the review of impaired loans in the commercial loan portfolio, (ii) reserves established for adversely-rated loans in the commercial loan portfolio and nonaccrual residential mortgage, consumer installment and home equity loans based on loan loss experience of other adversely-rated loans, (iii) reserves, by loan classes, on all other loans based principally on a five -year historical loan loss experience, with equal weighting placed on all of the years, loan loss trends and giving consideration to estimated loss emergence periods, and (iv) a reserve for qualitative factors that take into consideration risks inherent in the originated loan portfolio that differ from historical loan loss experience. Although the Corporation allocates portions of the allowance to specific loans and loan types, the entire allowance attributable to originated loans is available for any loan losses that occur in the originated portfolio. Loans that are deemed not collectible are charged off and reduce the allowance. The provision for loan losses and recoveries on loans previously charged off increase the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off. Acquired loans are aggregated into pools based upon common risk characteristics. An allowance may be recorded related to an acquired loan pool if it experiences a decrease in expected cash flows, as compared to those projected at the acquisition date. On a quarterly basis, the expected future cash flow of each pool is estimated based on various factors, including changes in property values of collateral dependent loans, default rates, loss severities and prepayment speeds. Decreases in estimates of expected cash flows within a pool generally result in a charge to the provision for loan losses and a corresponding increase in the allowance allocated to acquired loans for the particular pool. Increases in estimates of expected cash flows within a pool generally result in a reduction in the allowance allocated to acquired loans for the particular pool, if applicable, and then an adjustment to the accretable yield for the pool, which will increase amounts recognized in interest income in subsequent periods. Various regulatory agencies, as an integral part of their examination process, periodically review the allowance. Such agencies may require additions to the allowance, based on their judgment, reflecting information available to them at the time of their examinations. Fair Value Measurements Fair value for assets and liabilities measured at fair value on a recurring or nonrecurring basis refers to the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants in the market in which the reporting entity transacts such sales or transfers based on the assumptions market participants would use when pricing an asset or liability. Assumptions are developed based on prioritizing information within a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data, such as the reporting entity’s own data. The Corporation may choose to measure eligible items at fair value at specified election dates. Unrealized gains and losses on items for which the fair value measurement option has been elected are reported in earnings at each subsequent reporting date. At September 30, 2016 and December 31, 2015 , the Corporation had elected the fair value option on all of its residential mortgage loans held-for-sale. In addition, the Corporation elected to account for loan servicing rights acquired in the merger with Talmer effective August 31, 2016 under the fair value method. The Corporation has not elected the fair value option for any other financial assets or liabilities. Share-Based Compensation The Corporation has outstanding share-based compensation, including stock options, stock awards, restricted stock awards, restricted stock performance units and restricted stock service-based units to certain executive and senior management employees. The Corporation accounts for share-based compensation expense using the modified-prospective transition method. Under that method, compensation expense is recognized for stock options based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance. The Corporation accounts for stock awards based on the closing stock price of the Corporation's common stock on the date the award is granted. The fair values of stock options, stock awards and restricted stock awards are recognized as compensation expense on a straight-line basis over the requisite service period. The Corporation accounts for restricted stock performance units based on the closing stock price of the Corporation's common stock on the date of grant, discounted by the present value of estimated future dividends to be declared over the requisite performance or service period. The fair value of restricted stock performance units is recognized as compensation expense over the expected requisite performance period, or requisite service period for awards with multiple performance and service conditions. The Corporation accounts for restricted stock service-based units based on the closing stock price of the Corporation's common stock on the date of grant, as these awards accrue dividend equivalents equal to the amount of any cash dividends that would have been payable to a shareholder owning the number of shares of the Corporation's common stock represented by the restricted stock service-based units. The fair value of the restricted stock service-based units is recognized as compensation expense over the requisite service period. Cash flows realized from the tax benefits of exercised stock option awards that result from actual tax deductions that are in excess of the recorded tax benefits related to the compensation expense recognized for those options (excess tax benefits) are classified as financing activities on the consolidated statements of cash flows. Bank-Owned Life Insurance The Corporation has life insurance policies on certain key officers of Chemical Bank and Talmer Bank and Trust. The majority of the bank-owned life insurance policies of the Corporation were obtained through its acquisition of Lake Michigan and the merger with Talmer. Bank-owned life insurance is recorded at the cash surrender value, net of surrender charges, and is included within other assets on the consolidated statements of financial position and changes in the cash surrender values are recorded as other noninterest income on the consolidated statements of income. Earnings Per Share Beginning in the third quarter of 2016, the Corporation applies the two-class method of computing earnings per share as the Corporation acquired unvested restricted stock awards in the merger with Talmer which qualify as participating securities. Under this calculation, all outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends are considered participating securities and earnings per share is determined according to dividends declared and participating rights in undistributed earnings. Basic earnings per common share is net income divided by the weighted average number of common shares outstanding during the period. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights and then are divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per common share include the dilutive effect of additional potential common shares issuable under common stock equivalents. Income and Other Taxes The Corporation is subject to the income and other tax laws of the United States, the State of Michigan and any other states where nexus has been created. These laws are complex and are subject to different interpretations by the taxpayer and the various taxing authorities. In determining the provision for income and other taxes, management must make judgments and estimates about the application of these inherently complex laws, related regulations and case law. In the process of preparing the Corporation’s tax returns, management attempts to make reasonable interpretations of enacted tax laws. These interpretations are subject to challenge by the tax authorities upon audit or to reinterpretation based on management’s ongoing assessment of facts and evolving case law. On a quarterly basis, management assesses the reasonableness of its effective federal tax rate based upon its estimate of taxable income and the applicable taxes expected for the full year. Deferred tax assets and liabilities are reassessed on a quarterly basis, including the need for a valuation allowance for deferred tax assets. Uncertain income tax positions are evaluated to determine whether it is more-likely-than-not that a tax position will be sustained upon examination based on the technical merits of the tax position. If a tax position is more-likely-than-not to be sustained, a tax benefit is recognized for the amount that is greater than 50% likely to be realized. Reserves for contingent income tax liabilities attributable to unrecognized tax benefits associated with uncertain tax positions are reviewed quarterly for adequacy based upon developments in tax law and the status of audits or examinations. The Corporation had no contingent income tax liabilities recorded at September 30, 2016 or December 31, 2015 . Investments in Qualified Affordable Housing Projects, Federal Historic Projects and New Market Tax Credits The Corporation invests in qualified affordable housing projects, federal historic projects, and new market projects for the purpose of community reinvestment and obtaining tax credits. Return on the Corporation's investment in these projects comes in the form of the tax credits and tax losses that pass through to the Corporation. The carrying value of the investments are reflected in other assets on the consolidated statements of financial position. The Corporation utilizes the proportional amortization method to account for investments in qualified affordable housing projects and the equity method to account for investments in other tax credit projects. Under the proportional amortization method, the Corporation amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits. The Corporat ion re cognized additional income tax expense attributable to the amortization of investments in qualified affordable housing projects of $0.4 million and $1.6 million during the three and nine months ended September 30, 2016 , respectively, and $0.6 million and $0.8 million during the three and nine months ended September 30, 2015 , respectively. The Corporation's remaining investment in qualified affordable housing projects accounted for under the proportional amortization method totaled $30.3 million at September 30, 2016 and $21.7 million at December 31, 2015 . Under the equity method, the Corporation's share of the earnings or losses are included in other operating expenses on the consolidated statements of income. The Corporation's remaining investment in new market projects accounted for under the equity method totaled $10.2 million and $1.7 million at September 30, 2016 and December 31, 2015 , respectively. The Corporation's unfunded equity contributions relating to investments in qualified affordable housing projects, federal historic tax projects and new market projects is recorded in other liabilities on the consolidated statements of financial position. The Corporation's remaining unfunded equity contributions totaled $16.8 million and $8.0 million at September 30, 2016 and December 31, 2015 . Management analyzes these investments for potential impairment when events or changes in circumstances indicate that it is more-likely-than-not that the carrying amount of the investment will not be realized. An impairment loss is measured as the amount by which the carrying amount of an investment exceeds its fair value. There were no impairment losses recognized as of September 30, 2016 or December 31, 2015 . The Corporation consolidates variable interest entities ("VIEs") in which it is the primary beneficiary. In general, a VIE is an entity that either (i) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (ii) has a group of equity owners that are unable to make significant decisions about its activities or (iii) has a group of equity owners that do not have the obligation to absorb losses or the right to receive returns as gene

Mergers and Acquisitions

Mergers and Acquisitions	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Mergers and Acquisitions	Mergers and Acquisitions Merger with Talmer On August 31, 2016, the Corporation completed a merger with Talmer for total consideration of $1.61 billion . As a result of the merger, the Corporation issued 32.1 million shares of its common stock based on an exchange ratio where each Talmer shareholder received 0.4725 shares of the Corporation's common stock, and paid $1.61 in cash, for each share of Talmer common stock. In conjunction with the merger, the Corporation entered into and drew on a $125.0 million credit facility, which is described in more detail in Note 7. The proceeds from the credit facility were used to pay off the Corporation's $25.0 million line-of-credit and a $37.5 million line-of-credit of Talmer, with the remaining proceeds used to partially fund the cash portion of the merger consideration. The Corporation incurred $37.5 million and $43.1 million of merger and acquisition-related transaction expenses during the three and nine months ended September 30, 2016, primarily related to the merger with Talmer. As a result of the merger, Talmer Bank and Trust became a wholly-owned subsidiary of the Corporation. Subsequent to the merger with Talmer, in the fourth quarter of 2016, the Corporation sold the single branch locations in Chicago, Illinois and Las Vegas, Nevada. Please refer to Note 1 for further details related to these transactions. Talmer Bank and Trust is a full service community bank offering a full suite of commercial banking, retail banking, mortgage banking, wealth management and trust services to small and medium-sized businesses and individuals. As of September 30, 2016, Talmer Bank and Trust had 81 full service banking offices located primarily within southeast Michigan and northeast Ohio, as well as in west Michigan, northeast Michigan, and northern Indiana. Talmer Bank and Trust is expected to be consolidated with and into Chemical Bank during the fourth quarter of 2016. The Company determined that the merger with Talmer constitutes a business combination as defined by ASC 805. Accordingly, the assets acquired and liabilities assumed were recorded at their fair values on the date of acquisition. Fair values were determined in accordance with the guidance provided in ASC Topic 820, Fair Value Measurements. In many cases the determination of the fair values required management to make estimates about discount rates, future expected cash flows, market conditions and other future events that are highly subjective in nature and subject to change. The following allocation is based on the information that was available to make preliminary estimates of the fair value and may change as additional information becomes available and additional analyses are completed. While the Corporation believes that information provided a reasonable basis for estimating the fair values, it expects that it could obtain additional information and evidence during the measurement period that may result in changes to the estimated fair value amounts. This measurement period ends on the earlier of one year after the merger date or the date we receive the information about the facts and circumstances that existed at the merger date. Subsequent adjustments are, and if necessary, will be reflected in future filings. These refinements include: (1) changes in the estimated fair value of loans acquired: (2) changes in the estimated fair value of intangible assets acquired: (3) changes in deferred tax assets related to fair value estimates and a change in the expected realization of items considered to be net operating loss carry forwards and (4) a change in the goodwill caused by the net effect of these adjustments. (Dollars in thousands) Consideration paid: Stock $ 1,504,811 Cash 107,638 Total consideration 1,612,449 Fair value of identifiable assets acquired: Cash and cash equivalents 433,352 Investment securities: Available-for-sale 808,894 Held-to-maturity 1,657 Loans held-for-sale 244,916 Loans 4,882,864 Premises and equipment 38,793 Loan servicing rights 42,462 Other intangible assets 12,399 Interest receivable and other assets 397,660 Total identifiable assets acquired 6,862,997 Fair value of liabilities assumed: Noninterest-bearing deposits 1,236,902 Interest-bearing deposits 4,057,968 Interest payable and other liabilities 99,176 Securities sold under agreements to repurchase with customers 19,704 Short-term borrowings 387,500 Long-term borrowings 299,597 Total liabilities assumed 6,100,847 Fair value of net identifiable assets acquired 762,150 Goodwill resulting from acquisition $ 850,299 Information regarding loans accounted for under ASC 310-30 at the merger date is as follows: (Dollars in thousands) Accounted for under ASC 310-30: Contractual cash flows $ 5,968,950 Contractual cash flows not expected to be collected (nonaccretable difference) 223,959 Expected cash flows 5,744,991 Interest component of expected cash flows (accretable yield) 862,127 Fair value at acquisition $ 4,882,864 The following unaudited pro forma financial information presents the consolidated results of operation of the Corporation and Talmer as if the merger had occurred as of January 1, 2015 with pro forma adjustments to give effect to any change in interest income due to the accretion of the discount (premium) associated with the fair value adjustments to acquired loans, any change in interest expense due to estimated premium amortization/discount accretion associated with the fair value adjustments to acquired time deposits and borrowings and other debt and the amortization of the core deposit intangible that would have resulted had the deposits been acquired as of January 1, 2015. Dollars in thousands For the three months ended, September 30, 2016 September 30, 2015 Net interest and other income $ 176,102 $ 163,933 Net Income 9,320 38,849 Earnings per share: Basic $ 0.13 $ 0.55 Diluted 0.13 0.55 Dollars in thousands For the nine months ended, September 30, 2016 September 30, 2015 Net interest and other income $ 504,831 $ 460,791 Net Income 84,808 93,764 Earnings per share: Basic $ 1.20 $ 1.39 Diluted 1.19 1.37 Acquisition of Lake Michigan Financial Corporation On May 31, 2015, the Corporation acquired all the outstanding stock of Lake Michigan for total consideration of $187.4 million , which included stock consideration of $132.9 million and cash consideration of $54.5 million . As a result of the acquisition, the Corporation issued approximately 4.3 million shares of its common stock, based on an exchange ratio of 1.326 shares of its common stock, and paid $16.64 in cash, for each share of Lake Michigan common stock outstanding. Lake Michigan, a bank holding company which owned The Bank of Holland and The Bank of Northern Michigan, provided traditional banking services and products with five banking offices in Holland, Grand Haven, Grand Rapids, Petoskey and Traverse City, Michigan. The Bank of Holland and The Bank of Northern Michigan were consolidated with and into Chemical Bank on November 13, 2015. At the acquisition date, Lake Michigan added total assets of $1.24 billion , including total loans of $985.5 million , and total deposits of $924.7 million to the Corporation's consolidated statement of financial position. The Corporation recorded $ 100.9 million of goodwill, which was primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and Lake Michigan. In addition, the Corporation recorded $8.6 million of core deposit and other intangible assets in conjunction with the acquisition. During the first quarter 2016, the Corporation obtained additional information regarding the valuation of deferred tax assets, which resulted in a decrease to goodwill recognized in the transaction of $0.5 million . In accordance with ASU 2015-16, no amounts were recorded in the consolidated statements of income during 2016 for these adjustments that would have been recorded in a previous reporting period had these adjustments been recognized as of the acquisition date. Upon acquisition, the Lake Michigan loan portfolio had contractually required principal and interest payments receivable of $1.01 billion and $190.2 million , respectively, expected principal and interest cash flows of $986.1 million and $189.6 million , respectively, and a fair value of $985.5 million . The difference between the contractually required payments receivable and the expected cash flows represents the nonaccretable difference, which totaled $22.6 million at the acquisition date, with $22.0 million attributable to expected credit losses. The difference between the expected cash flows and fair value represents the accretable yield, which totaled $190.2 million at the date of acquisition. The outstanding contractual principal balance and the carrying amount of the Lake Michigan acquired loan portfolio were $697.4 million and $675.0 million , respectively, at September 30, 2016 , compared to $ 864.0 million and $842.0 million , respectively, at December 31, 2015 . There was no related allowance for loan losses at those dates. Acquisition of Monarch Community Bancorp, Inc. On April 1, 2015, the Corporation acquired all of the outstanding stock of Monarch in an all-stock transaction valued at $27.2 million . As a result of the acquisition, the Corporation issued 860,575 shares of its common stock based on an exchange ratio of 0.0982 shares of its common stock for each share of Monarch common stock outstanding. Monarch, a bank holding company, owned Monarch Community Bank, which operated five full service branch offices in Coldwater, Marshall, Hillsdale and Union City, Michigan. Monarch Community Bank was consolidated with and into Chemical Bank on May 8, 2015. As of the April 1, 2015 acquisition date, Monarch added total assets of $182.8 million , including total loans of $121.8 million , and total deposits of $144.3 million to the Corporation's consolidated statement of financial position. In connection with the acquisition of Monarch, the Corporation recorded $5.3 million of goodwill, which was primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and Monarch. In addition, the Corporation recorded $1.9 million of core deposit intangible assets in conjunction with the acquisition. Upon acquisition, the Monarch loan portfolio had contractually required principal and interest payments receivable of $128.9 million and $37.8 million , respectively, expected principal and interest cash flows of $122.6 million and $37.1 million , respectively, and a fair value of $121.8 million . The difference between the contractually required payments receivable and the expected cash flows represents the nonaccretable difference, which totaled $7.1 million at the acquisition date, with $6.3 million attributable to expected credit losses. The difference between the expected cash flows and fair value represents the accretable yield, which totaled $37.9 million at the date of acquisition. The outstanding contractual principal balance and the carrying amount of the Monarch acquired loan portfolio were $97.1 million and $91.0 million , respectively, at September 30, 2016 , compared to $115.0 million and $108.0 million , respectively, at December 31, 2015 . There was no related allowance for loan losses at those dates. Acquisition of Northwestern Bancorp, Inc. On October 31, 2014, the Corporation acquired all of the outstanding stock of Northwestern Bancorp, Inc. (Northwestern) for total cash consideration of $121.0 million . Northwestern, a bank holding company which owned Northwestern Bank, provided traditional banking services and products through 25 banking offices serving communities in the northwestern lower peninsula of Michigan. At the acquisition date, Northwestern added total assets of $815.0 million , including total loans of $475.0 million , and total deposits of $794.0 million to the Corporation. Northwestern Bank was consolidated with and into Chemical Bank as of the acquisition date. In connection with the acquisition of Northwestern, the Corporation recorded $60.3 million of goodwill, which was primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and Northwestern. In addition, the Corporation recorded $12.9 million of core deposit intangible assets in conjunction with the acquisition. Upon acquisition, the Northwestern loan portfolio had contractually required principal and interest payments receivable of $507.0 million and $112.0 million , respectively, expected principal and interest cash flows of $481.0 million and $104.0 million , respectively, and a fair value of $475.0 million . The difference between the contractually required payments receivable and the expected cash flows represents the nonaccretable difference, which totaled $34.0 million at the acquisition date, with $26.0 million attributable to expected credit losses. The difference between the expected cash flows and fair value represents the accretable yield, which totaled $110.0 million at the acquisition date. The outstanding contractual principal balance and the carrying amount of the Northwestern acquired loan portfolio were $296.7 million and $266.7 million , respectively, at September 30, 2016 , compared to $361.0 million and $330.0 million , respectively, at December 31, 2015 . Acquisition of 21 Branches On December 7, 2012, Chemical Bank acquired 21 branches from Independent Bank, a subsidiary of Independent Bank Corporation, located in the Northeast and Battle Creek regions of Michigan, including $404.0 million in deposits and $44.0 million in loans (branch acquisition transaction). The purchase price of the branch offices, including equipment, was $8.1 million and the Corporation paid a premium on deposits of $11.5 million , or approximately 2.85% of total deposits. The loans were purchased at a discount of 1.75% . In connection with the branch acquisition transaction, the Corporation recorded goodwill of $6.8 million and other intangible assets attributable to customer core deposits of $5.6 million . Acquisition of O.A.K. Financial Corporation On April 30, 2010, the Corporation acquired OAK in an all-stock transaction for total consideration of $83.7 million . OAK provided traditional banking services and products through 14 banking offices serving communities in Ottawa, Allegan and Kent counties in west Michigan. At the acquisition date, OAK added total assets of $820 million , including total loans of $627.0 million , and total deposits of $693.0 million , including brokered deposits of $193.0 million . Upon acquisition, the OAK loan portfolio had contractually required principal payments receivable of $683.0 million and a fair value of $627.0 million . The outstanding contractual principal balance and the carrying amount of the OAK acquired loan portfolio were $165.3 million and $150.4 million , respectively, at September 30, 2016 , compared to $204.0 million and $183.0 million , respectively, at December 31, 2015 . Accretable Yield Activity for the accretable yield, which includes contractually due interest for acquired loans that have been renewed or extended since the date of acquisition and continue to be accounted for in loan pools in accordance with ASC 310-30, follows: (Dollars in thousands) Talmer Lake Michigan Monarch North-western OAK Total Three Months Ended September 30, 2016 Balance at beginning of period $ — $ 125,343 $ 30,859 $ 73,746 $ 26,592 $ 256,540 Addition attributable to acquisitions 862,127 — — — — 862,127 Additions (reductions) (1) — 6,565 114 526 19 7,224 Accretion recognized in interest income (17,415 ) (7,968 ) (1,322 ) (3,890 ) (3,423 ) (34,018 ) Balance at end of period $ 844,712 $ 123,940 $ 29,651 $ 70,382 $ 23,188 $ 1,091,873 Three Months Ended September 30, 2015 Balance at beginning of period $ — $ 188,310 $ 35,805 $ 91,758 $ 32,175 $ 348,048 Additions attributable to acquisitions — — — — — — Additions (reductions) (1) — (747 ) (351 ) (1,337 ) 1,202 (1,233 ) Accretion recognized in interest income — (10,704 ) (2,085 ) (4,376 ) (2,825 ) (19,990 ) Balance at end of period $ — $ 176,859 $ 33,369 $ 86,045 $ 30,552 $ 326,825 (1) Represents additions of estimated contractual interest expected to be collected from acquired loans being renewed or extended, less reductions in contractual interest resulting from the early payoff of acquired loans. (Dollars in thousands) Talmer Lake Michigan Monarch North-western OAK Total Nine Months Ended September 30, 2016 Balance at beginning of period $ — $ 152,999 $ 34,558 $ 82,623 $ 28,077 $ 298,257 Addition attributable to acquisitions 862,127 — — — — 862,127 Additions (reductions) (1) — (3,800 ) (749 ) (5,322 ) (182 ) (10,053 ) Accretion recognized in interest income (17,415 ) (25,259 ) (4,158 ) (11,919 ) (9,707 ) (68,458 ) Reclassification from nonaccretable difference — — — 5,000 5,000 10,000 Balance at end of period $ 844,712 $ 123,940 $ 29,651 $ 70,382 $ 23,188 $ 1,091,873 Nine Months Ended September 30, 2015 Balance at beginning of period $ — $ — $ — $ 104,675 $ 33,286 $ 137,961 Additions attributable to acquisitions — 190,246 37,914 — — 228,160 Additions (reductions) (1) — 803 (1,492 ) (4,196 ) 6,417 1,532 Accretion recognized in interest income — (14,190 ) (3,053 ) (14,434 ) (9,151 ) (40,828 ) Balance at end of period $ — $ 176,859 $ 33,369 $ 86,045 $ 30,552 $ 326,825 (1) Represents additions of estimated contractual interest expected to be collected from acquired loans being renewed or extended, less reductions in contractual interest resulting from the early payoff of acquired loans. As part of its ongoing assessment of the acquired loan portfolios, management has determined that the overall credit quality of the Northwestern and OAK acquired loan portfolios has improved, which has resulted in an improvement in expected cash flows of certain loan pools in these acquired loan portfolios. Accordingly, management reclassified $5.0 million during the nine months ended September 30, 2016 from the nonaccretable difference to the accretable yield for each of these acquired loan portfolios, which will increase amounts recognized into interest income over the estimated remaining lives of the loan pools within these portfolios.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The following is a summary of the amortized cost and fair value of investment securities available-for-sale and investment securities held-to-maturity at September 30, 2016 and December 31, 2015 : Investment Securities Available-for-Sale (Dollars in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value September 30, 2016 U.S. Treasury securities $ 5,784 $ 17 $ — $ 5,801 Government sponsored agencies 223,917 535 414 224,038 State and political subdivisions 306,196 384 1,043 305,537 Residential mortgage-backed securities 301,194 2,206 2 303,398 Collateralized mortgage obligations 343,502 629 392 343,739 Corporate bonds 96,283 37 235 96,085 Preferred stock and trust preferred securities 24,381 515 113 24,783 Total $ 1,301,257 $ 4,323 $ 2,199 $ 1,303,381 December 31, 2015 U.S. Treasury securities $ 5,773 $ — $ 8 $ 5,765 Government sponsored agencies 195,711 78 800 194,989 State and political subdivisions 14,731 395 6 15,120 Residential mortgage-backed securities 189,452 538 2,222 187,768 Collateralized mortgage obligations 133,256 111 1,137 132,230 Corporate bonds 14,825 2 200 14,627 Preferred stock and trust preferred securities 2,888 344 — 3,232 Total $ 556,636 $ 1,468 $ 4,373 $ 553,731 Investment Securities Held-to-Maturity (Dollars in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value September 30, 2016 State and political subdivisions $ 563,221 $ 13,110 $ 1,487 $ 574,844 Trust preferred securities 500 — 200 300 Total $ 563,721 $ 13,110 $ 1,687 $ 575,144 December 31, 2015 State and political subdivisions $ 509,471 $ 7,446 $ 4,512 $ 512,405 Trust preferred securities 500 — 200 300 Total $ 509,971 $ 7,446 $ 4,712 $ 512,705 The majority of the Corporation’s residential mortgage-backed securities and collateralized mortgage obligations are backed by a U.S. government agency (Government National Mortgage Association) or a government sponsored enterprise (Federal Home Loan Mortgage Corporation or Federal National Mortgage Association). Proceeds from sales of securities and the associated gains and losses recorded in earnings are listed below: For the three months ended September 30, For the nine months ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Proceeds $ 2,820 $ 8,000 $ 7,820 $ 37,897 Gross gains 17 5 54 613 Gross losses (1 ) — (1 ) (1 ) The following is a summary of the amortized cost and fair value of investment securities at September 30, 2016 , by maturity, for both available-for-sale and held-to-maturity investment securities. The maturities of residential mortgage-backed securities and collateralized mortgage obligations are based on scheduled principal payments. The maturities of all other debt securities are based on final contractual maturity. September 30, 2016 (Dollars in thousands) Amortized Cost Fair Value Investment Securities Available-for-Sale: Due in one year or less $ 303,733 $ 304,279 Due after one year through five years 563,948 565,258 Due after five years through ten years 266,242 266,463 Due after ten years 165,946 165,576 Preferred stock 1,388 1,805 Total $ 1,301,257 $ 1,303,381 Investment Securities Held-to-Maturity: Due in one year or less $ 60,391 $ 60,508 Due after one year through five years 276,065 279,172 Due after five years through ten years 138,202 143,257 Due after ten years 89,063 92,207 Total $ 563,721 $ 575,144 Securities with a carrying value of $838.0 million and $530.8 million were pledged at September 30, 2016 and December 31, 2015 , respectively, to secure borrowings and deposits. At September 30, 2016 and December 31, 2015 , there were no holdings of securities of any one issuer, other than the U.S. government and it's agencies, in an amount greater than 10% of shareholders' equity. The following schedule summarizes information for both available-for-sale and held-to-maturity investment securities with gross unrealized losses at September 30, 2016 and December 31, 2015 , aggregated by category and length of time that individual securities have been in a continuous unrealized loss position. As of September 30, 2016 , the Corporation’s securities portfolio consisted of 2,473 securities, 598 of which were in an unrealized loss position. Less Than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses September 30, 2016 Government sponsored agencies $ 20,532 $ 29 $ 17,546 $ 385 $ 38,078 $ 414 State and political subdivisions 391,355 2,342 29,379 188 420,734 2,530 Residential mortgage-backed securities 10,607 2 8 — 10,615 2 Collateralized mortgage obligations 112,890 230 20,812 162 133,702 392 Corporate bonds 71,912 156 4,921 79 76,833 235 Preferred stock and trust preferred securities 12,131 113 300 200 12,431 313 Total $ 619,427 $ 2,872 $ 72,966 $ 1,014 $ 692,393 $ 3,886 December 31, 2015 U.S. Treasury securities $ 5,765 $ 8 $ — $ — $ 5,765 $ 8 Government sponsored agencies 114,640 292 21,681 508 136,321 800 State and political subdivisions 195,285 2,891 68,361 1,627 263,646 4,518 Residential mortgage-backed securities 169,226 2,146 3,435 76 172,661 2,222 Collateralized mortgage obligations 60,459 408 39,382 729 99,841 1,137 Corporate bonds 9,532 200 — — 9,532 200 Trust preferred securities — — 300 200 300 200 Total $ 554,907 $ 5,945 $ 133,159 $ 3,140 $ 688,066 $ 9,085 An assessment is performed quarterly by the Corporation to determine whether unrealized losses in its investment securities portfolio are temporary or other-than-temporary by carefully considering all reasonably available information. The Corporation reviews factors such as financial statements, credit ratings, news releases and other pertinent information of the underlying issuer or company to make its determination. Management did not believe any individual unrealized loss on any investment security, as of September 30, 2016 , represented an other-than-temporary impairment (OTTI). Management believed that the unrealized losses on investment securities at September 30, 2016 were temporary in nature and due primarily to changes in interest rates and reduced market liquidity and not as a result of credit-related issues. At September 30, 2016 , the Corporation did not have the intent to sell any of its impaired investment securities and believed that it was more-likely-than-not that the Corporation will not have to sell any such investment securities before a full recovery of amortized cost. Accordingly, at September 30, 2016 , the Corporation believed the impairments in its investment securities portfolio were temporary in nature. However, there is no assurance that OTTI may not occur in the future.

Loans

Loans	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Loans	Loans Loan portfolio segments are defined as the level at which an entity develops and documents a systematic methodology to determine its allowance. The Corporation has two loan portfolio segments (commercial loans and consumer loans) that it uses in determining the allowance. Both quantitative and qualitative factors are used by management at the loan portfolio segment level in determining the adequacy of the allowance for the Corporation. Classes of loans are a disaggregation of an entity’s loan portfolio segments. Classes of loans are defined as a group of loans which share similar initial measurement attributes, risk characteristics, and methods for monitoring and assessing credit risk. The Corporation has six classes of loans, which are set forth below. Commercial — Loans and lines of credit to varying types of businesses, including municipalities, school districts and nonprofit organizations, for the purpose of supporting working capital, operational needs and term financing of equipment. Repayment of such loans is generally provided through operating cash flows of the business. Commercial loans are predominately secured by equipment, inventory, accounts receivable, personal guarantees of the owner and other sources of repayment, although the Corporation may also secure commercial loans with real estate. Commercial real estate — Loans secured by real estate occupied by the borrower for ongoing operations, non-owner occupied real estate leased to one or more tenants and vacant land that has been acquired for investment or future land development. Real estate construction and land development — Real estate construction loans represent secured loans for the construction of business properties. Real estate construction loans often convert to a commercial real estate loan at the completion of the construction period. Land development loans represent secured development loans made to borrowers for the purpose of infrastructure improvements to vacant land to create finished marketable residential and commercial lots/land. Most land development loans are originated with the intention that the loans will be paid through the sale of developed lots/land by the developers within twelve months of the completion date. Land development loans are primarily comprised of loans to develop residential properties. Residential mortgage — Loans secured by one - to four -family residential properties, generally with fixed interest rates for periods of fifteen years or less. The loan-to-value ratio at the time of origination is generally 80% or less. Residential mortgage loans with a loan-to-value ratio of more than 80% generally require private mortgage insurance. Consumer installment — Loans to consumers primarily for the purpose of acquiring automobiles, recreational vehicles and personal watercraft and comprised primarily of indirect loans purchased from dealers. These loans consist of relatively small amounts that are spread across many individual borrowers. Home equity — Loans and lines of credit whereby consumers utilize equity in their personal residence, generally through a second mortgage, as collateral to secure the loan. Commercial, commercial real estate, and real estate construction and land development loans are referred to as the Corporation’s commercial loan portfolio, while residential mortgage, consumer installment and home equity loans are referred to as the Corporation’s consumer loan portfolio. A summary of loans follows: (Dollars in thousands) September 30, December 31, Commercial loan portfolio: Commercial $ 3,159,936 $ 1,905,879 Commercial real estate 3,773,017 2,112,162 Real estate construction and land development 500,494 232,076 Subtotal 7,433,447 4,250,117 Consumer loan portfolio: Residential mortgage 3,046,959 1,429,636 Consumer installment 1,335,707 877,457 Home equity 899,676 713,937 Subtotal 5,282,342 3,021,030 Total loans $ 12,715,789 $ 7,271,147 Credit Quality Monitoring The Corporation maintains loan policies and credit underwriting standards as part of the process of managing credit risk. These standards include making loans generally only within the Corporation’s market areas. The Corporation’s lending markets generally consist of communities throughout Michigan and additional communities located within northeast Ohio and northern Indiana. The Corporation has no foreign loans. The Corporation, through Chemical Bank and Talmer Bank and Trust, has a commercial loan portfolio approval process involving underwriting and individual and group loan approval authorities to consider credit quality and loss exposure at loan origination. The loans in the Corporation’s commercial loan portfolio are risk rated at origination based on the grading system set forth below. The approval authority of relationship managers is established based on experience levels, with credit decisions greater than $1.0 million requiring group loan authority approval, except for six executive and senior officers who have varying loan limits exceeding $1.5 million and up to $3.5 million . With respect to the group loan authorities, Chemical Bank has a loan committee, consisting of certain executive and senior officers, that meets weekly to consider loans ranging in amounts from $1.0 million to $10.0 million , depending on risk rating and credit action required. A directors’ loan committee of Chemical Bank, consisting of eight independent members of the board of directors of Chemical Bank, the chief executive officer of Chemical Bank and the senior credit officer of Chemical Bank, meets bi-weekly to consider loans in amounts over $10.0 million , and certain loans under $10.0 million depending on a loan’s risk rating and credit action required. Loans over $15.0 million require the approval of the board of directors of Chemical Bank. The majority of the Corporation’s consumer loan portfolio is comprised of secured loans that are relatively small. The Corporation’s consumer loan portfolio has a centralized approval process which utilizes standardized underwriting criteria. The ongoing measurement of credit quality of the consumer loan portfolio is largely done on an exception basis. If payments are made on schedule, as agreed, then no further monitoring is performed. However, if delinquency occurs, the delinquent loans are turned over to the Corporation’s collection department for resolution, resulting in repossession or foreclosure if payments are not brought current. Credit quality for the entire consumer loan portfolio is measured by the periodic delinquency rate, nonaccrual amounts and actual losses incurred. Loans in the commercial loan portfolio tend to be larger and more complex than those in the consumer loan portfolio, and therefore, are subject to more intensive monitoring. All loans in the commercial loan portfolio have an assigned relationship manager, and most borrowers provide periodic financial and operating information that allows the relationship managers to stay abreast of credit quality during the life of the loans. The risk ratings of loans in the commercial loan portfolio are reassessed at least annually, with loans below an acceptable risk rating reassessed more frequently and reviewed by various loan committees within the Corporation at least quarterly. The Corporation maintains a centralized independent loan review function that monitors the approval process and ongoing asset quality of the loan portfolio, including the accuracy of loan grades. The Corporation also maintains an independent appraisal review function that participates in the review of all appraisals obtained by the Corporation for loans in the commercial loan portfolio. Credit Quality Indicators Commercial Loan Portfolio The Corporation uses a nine grade risk rating system to monitor the ongoing credit quality of its commercial loan portfolio. These loan grades rank the credit quality of a borrower by measuring liquidity, debt capacity, coverage and payment behavior as shown in the borrower’s financial statements. The loan grades also measure the quality of the borrower’s management and the repayment support offered by any guarantors. A summary of the Corporation’s loan grades (or characteristics of the loans within each grade) follows: Risk Grades 1-5 (Acceptable Credit Quality) — All loans in risk grades 1 through 5 are considered to be acceptable credit risks by the Corporation and are grouped for purposes of allowance for loan loss considerations and financial reporting. The five grades essentially represent a ranking of loans that are all viewed to be of acceptable credit quality, taking into consideration the various factors mentioned above, but with varying degrees of financial strength, debt coverage, management and factors that could impact credit quality. Business credits within risk grades 1 through 5 range from Risk Grade 1: Prime Quality (factors include: excellent business credit; excellent debt capacity and coverage; outstanding management; strong guarantors; superior liquidity and net worth; favorable loan-to-value ratios; debt secured by cash or equivalents, or backed by the full faith and credit of the U.S. Government) to Risk Grade 5: Acceptable Quality With Care (factors include: acceptable business credit, but with added risk due to specific industry or internal situations). Risk Grade 6 (Watch) — A business credit that is not acceptable within the Corporation’s loan origination criteria; cash flow may not be adequate or is continually inconsistent to service current debt; financial condition has deteriorated as company trends/management have become inconsistent; the company is slow in furnishing quality financial information; working capital needs of the company are reliant on short-term borrowings; personal guarantees are weak and/or with little or no liquidity; the net worth of the company has deteriorated after recent or continued losses; the loan requires constant monitoring and attention from the Corporation; payment delinquencies becoming more serious; if left uncorrected, these potential weaknesses may, at some future date, result in deterioration of repayment prospects. Risk Grade 7 (Substandard — Accrual) — A business credit that is inadequately protected by the current financial net worth and paying capacity of the obligor or of the collateral pledged, if any; management has deteriorated or has become non-existent; quality financial information is not available; a high level of maintenance is required by the Corporation; cash flow can no longer support debt requirements; loan payments are continually and/or severely delinquent; negative net worth; personal guaranty has become insignificant; a credit that has a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. The Corporation still expects a full recovery of all contractual principal and interest payments; however, a possibility exists that the Corporation will sustain some loss if deficiencies are not corrected. Risk Grade 8 (Substandard — Nonaccrual ) — A business credit accounted for on a nonaccrual basis that has all the weaknesses inherent in a loan classified as risk grade 7 with the added characteristic that the weaknesses are so pronounced that, on the basis of current financial information, conditions and values, collection in full is highly questionable; a partial loss is possible and interest is no longer being accrued. This loan meets the definition of an impaired loan. The risk of loss requires analysis to determine whether a valuation allowance needs to be established. Risk Grade 9 (Substandard — Doubtful) — A business credit that has all the weaknesses inherent in a loan classified as risk grade 8 and interest is no longer being accrued, but additional deficiencies make it highly probable that liquidation will not satisfy the majority of the obligation; the primary source of repayment is nonexistent and there is doubt as to the value of the secondary source of repayment; the possibility of loss is likely, but current pending factors could strengthen the credit. This loan meets the definition of an impaired loan. A loan charge-off is recorded when management deems an amount uncollectible; however, the Corporation will establish a valuation allowance for probable losses, if required. The Corporation considers all loans graded 1 through 5 as acceptable credit risks and structures and manages such relationships accordingly. Periodic financial and operating data combined with regular loan officer interactions are deemed adequate to monitor borrower performance. Loans graded 6 and 7 are considered higher-risk credits than loans graded 1 through 5 and the frequency of loan officer contact and receipt of financial data is increased to stay abreast of borrower performance. Loans graded 8 and 9 are considered problematic and require special care. Further, loans graded 6 through 9 are managed and monitored regularly through a number of processes, procedures and committees, including oversight by a loan administration committee comprised of executive and senior management of the Corporation, and include highly structured reporting of financial and operating data, intensive loan officer intervention and strategies to exit, as well as potential management by the Corporation’s special assets group. The following schedule presents the recorded investment of loans in the commercial loan portfolio by risk rating categories at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Commercial Commercial Real Estate Real Estate Construction and Land Development Total September 30, 2016 Originated Portfolio: Risk Grades 1-5 $ 1,624,836 $ 1,528,013 $ 291,841 $ 3,444,690 Risk Grade 6 49,934 40,710 288 90,932 Risk Grade 7 35,719 15,132 515 51,366 Risk Grade 8 12,612 19,913 80 32,605 Risk Grade 9 1,130 1 — 1,131 Subtotal 1,724,231 1,603,769 292,724 3,620,724 Acquired Portfolio: Risk Grades 1-5 1,331,689 1,988,676 203,159 3,523,524 Risk Grade 6 49,679 94,829 742 145,250 Risk Grade 7 37,813 52,317 886 91,016 Risk Grade 8 16,524 33,426 2,983 52,933 Subtotal 1,435,705 2,169,248 207,770 3,812,723 Total $ 3,159,936 $ 3,773,017 $ 500,494 $ 7,433,447 December 31, 2015 Originated Portfolio: Risk Grades 1-5 $ 1,418,301 $ 1,341,202 $ 183,323 $ 2,942,826 Risk Grade 6 34,727 31,036 180 65,943 Risk Grade 7 39,933 26,658 1,123 67,714 Risk Grade 8 26,459 25,163 521 52,143 Risk Grade 9 2,095 — — 2,095 Subtotal 1,521,515 1,424,059 185,147 3,130,721 Acquired Portfolio: Risk Grades 1-5 340,782 629,430 41,683 1,011,895 Risk Grade 6 28,321 23,926 2,556 54,803 Risk Grade 7 11,607 29,975 1,537 43,119 Risk Grade 8 3,654 4,772 1,153 9,579 Subtotal 384,364 688,103 46,929 1,119,396 Total $ 1,905,879 $ 2,112,162 $ 232,076 $ 4,250,117 Consumer Loan Portfolio The Corporation evaluates the credit quality of loans in the consumer loan portfolio based on the performing or nonperforming status of the loan. Loans in the consumer loan portfolio that are performing in accordance with original contractual terms and are less than 90 days past due and accruing interest are considered to be in a performing status, while those that are in nonaccrual status, contractually past due 90 days or more as to interest or principal payments or classified as a nonperforming TDR are considered to be in a nonperforming status. Nonaccrual TDRs in the consumer loan portfolio are included with nonaccrual loans, while other TDRs in the consumer loan portfolio are considered to be in a nonperforming status until they meet the Corporation’s definition of a performing TDR, at which time they are considered to be in a performing status. Acquired loans that are not performing in accordance with contractual terms are not reported because these loans are recorded in pools at their net realizable value based on the principal and interest the Corporation expects to collect on these loans. The following schedule presents the recorded investment of loans in the consumer loan portfolio based on loans in a performing status and loans in a nonperforming status at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Residential Mortgage Consumer Installment Home Equity Total Consumer September 30, 2016 Originated Loans: Performing $ 1,363,819 $ 1,171,759 $ 589,374 $ 3,124,952 Nonperforming 7,185 378 2,692 10,255 Subtotal 1,371,004 1,172,137 592,066 3,135,207 Acquired Loans 1,675,955 163,570 307,610 2,147,135 Total $ 3,046,959 $ 1,335,707 $ 899,676 $ 5,282,342 December 31, 2015 Originated Loans: Performing $ 1,207,945 $ 868,975 $ 587,566 $ 2,664,486 Nonperforming 9,030 451 3,246 12,727 Subtotal 1,216,975 869,426 590,812 2,677,213 Acquired Loans 212,661 8,031 123,125 343,817 Total $ 1,429,636 $ 877,457 $ 713,937 $ 3,021,030 Nonperforming Loans A summary of nonperforming loans follows: (Dollars in thousands) September 30, December 31, Nonaccrual loans: Commercial $ 13,742 $ 28,554 Commercial real estate 19,914 25,163 Real estate construction and land development 80 521 Residential mortgage 5,119 5,557 Consumer installment 378 451 Home equity 2,064 1,979 Total nonaccrual loans 41,297 62,225 Accruing loans contractually past due 90 days or more as to interest or principal payments: Commercial 221 364 Commercial real estate 739 254 Real estate construction and land development 1,439 — Residential mortgage 375 402 Home equity 628 1,267 Total accruing loans contractually past due 90 days or more as to interest or principal payments 3,402 2,287 Nonperforming TDRs: Commercial loan portfolio 15,261 16,297 Consumer loan portfolio 1,691 3,071 Total nonperforming TDRs 16,952 19,368 Total nonperforming loans (1) $ 61,651 $ 83,880 (1) Acquired loans that are not performing in accordance with contractual terms are not reported as nonperforming loans because these loans are recorded in pools at their net realizable value based on the principal and interest the Corporation expects to collect on these loans. The Corporation’s nonaccrual loans at September 30, 2016 and December 31, 2015 included $29.5 million and $35.9 million , respectively, of nonaccrual TDRs. The Corporation had $8.1 million of residential mortgage loans that were in the process of foreclosure at September 30, 2016 , compared to $2.9 million at December 31, 2015 . Impaired Loans The following schedule presents impaired loans by classes of loans at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Recorded Investment Unpaid Principal Balance Related Valuation Allowance September 30, 2016 Impaired loans with a valuation allowance: Commercial $ 4,906 $ 4,911 $ 2,729 Commercial real estate 2,741 2,741 516 Residential mortgage 19,864 19,864 154 Subtotal 27,511 27,516 3,399 Impaired loans with no related valuation allowance: Commercial 53,542 78,494 — Commercial real estate 69,713 118,751 — Real estate construction and land development 3,362 8,894 — Residential mortgage 34,310 54,414 — Consumer installment 1,004 1,538 — Home equity 7,573 10,245 — Subtotal 169,504 272,336 — Total impaired loans: Commercial 58,448 83,405 2,729 Commercial real estate 72,454 121,492 516 Real estate construction and land development 3,362 8,894 — Residential mortgage 54,174 74,278 154 Consumer installment 1,004 1,538 — Home equity 7,573 10,245 — Total $ 197,015 $ 299,852 $ 3,399 December 31, 2015 Impaired loans with a valuation allowance: Commercial $ 18,898 $ 19,426 $ 5,700 Commercial real estate 4,448 4,688 497 Residential mortgage 21,037 21,037 192 Subtotal 44,383 45,151 6,389 Impaired loans with no related valuation allowance: Commercial 31,039 37,703 — Commercial real estate 53,518 69,130 — Real estate construction and land development 2,136 3,108 — Residential mortgage 7,638 8,644 — Consumer installment 498 512 — Home equity 2,986 3,270 — Subtotal 97,815 122,367 — Total impaired loans: Commercial 49,937 57,129 5,700 Commercial real estate 57,966 73,818 497 Real estate construction and land development 2,136 3,108 — Residential mortgage 28,675 29,681 192 Consumer installment 498 512 — Home equity 2,986 3,270 — Total $ 142,198 $ 167,518 $ 6,389 The difference between an impaired loan’s recorded investment and the unpaid principal balance for originated loans represents a partial charge-off resulting from a confirmed loss due to the value of the collateral securing the loan being below the loan balance and management’s assessment that full collection of the loan balance is not likely, and for acquired loans that meet the definition of an impaired loan represents fair value adjustments recognized at the acquisition date attributable to expected credit losses and the discounting of expected cash flows at market interest rates. The difference between the recorded investment and the unpaid principal balance of $102.8 million and $25.3 million at September 30, 2016 and December 31, 2015 , respectively, includes confirmed losses (partial charge-offs) of $17.4 million and $17.1 million , respectively, and fair value discount adjustments of $85.4 million and $8.2 million , respectively. Impaired loans included $89.9 million and $12.8 million at September 30, 2016 and December 31, 2015 , respectively, of acquired loans that were not performing in accordance with original contractual terms. Acquired loans that are not performing in accordance with contractual terms are not reported as nonperforming loans because these loans are recorded in pools at their net realizable value based on the principal and interest the Corporation expects to collect on these loans. Impaired loans also included $48.8 million and $47.8 million at September 30, 2016 and December 31, 2015 , respectively, of performing TDRs. The following schedule presents information related to impaired loans for the three and nine months ended September 30, 2016 and 2015 , respectively: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Average Recorded Investment Interest Income Recognized While on Impaired Status Average Recorded Investment Interest Income Recognized While on Impaired Status Commercial $ 43,812 $ 1,073 $ 42,478 $ 1,750 Commercial real estate 58,658 1,219 56,779 2,068 Real estate construction and land development 2,400 64 2,243 115 Residential mortgage 35,986 818 30,499 1,540 Consumer installment 601 17 439 19 Home equity 4,466 95 3,504 123 Total $ 145,923 $ 3,286 $ 135,942 $ 5,615 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Average Recorded Investment Interest Income Recognized While on Impaired Status Average Recorded Investment Interest Income Recognized While on Impaired Status Commercial $ 42,847 $ 310 $ 39,387 $ 862 Commercial real estate 59,150 470 59,927 1,453 Real estate construction and land development 2,210 26 2,338 89 Residential mortgage 30,467 387 29,084 1,098 Consumer installment 497 — 474 1 Home equity 3,026 20 2,635 42 Total $ 138,197 $ 1,213 $ 133,845 $ 3,545 The following schedule presents the aging status of the recorded investment in loans by classes of loans at September 30, 2016 and December 31, 2015 : (Dollars in thousands) 31-60 Days Past Due 61-89 Days Past Due Accruing Loans Past Due 90 Days or More Non-accrual Loans Total Past Due Current Total Loans September 30, 2016 Originated Portfolio: Commercial $ 6,313 $ 2,675 $ 221 $ 13,742 $ 22,951 $ 1,701,280 $ 1,724,231 Commercial real estate 11,913 726 739 19,914 33,292 1,570,477 1,603,769 Real estate construction and land development 3,003 — 1,439 80 4,522 288,202 292,724 Residential mortgage 2,627 — 375 5,119 8,121 1,362,883 1,371,004 Consumer installment 2,425 448 — 378 3,251 1,168,886 1,172,137 Home equity 3,097 940 628 2,064 6,729 585,337 592,066 Total $ 29,378 $ 4,789 $ 3,402 $ 41,297 $ 78,866 $ 6,677,065 $ 6,755,931 Acquired Portfolio: Commercial $ 3,116 $ 1,146 $ 11,984 $ — $ 16,246 $ 1,419,459 $ 1,435,705 Commercial real estate 4,315 2,844 25,444 — 32,603 2,136,645 2,169,248 Real estate construction and land development 208 153 2,902 — 3,263 204,507 207,770 Residential mortgage 1,452 2,895 10,719 — 15,066 1,660,889 1,675,955 Consumer installment 1,367 200 203 — 1,770 161,800 163,570 Home equity 1,082 1,143 1,461 — 3,686 303,924 307,610 Total $ 11,540 $ 8,381 $ 52,713 $ — $ 72,634 $ 5,887,224 $ 5,959,858 December 31, 2015 Originated Portfolio: Commercial $ 3,685 $ 1,230 $ 364 $ 28,554 $ 33,833 $ 1,487,682 $ 1,521,515 Commercial real estate 4,168 1,603 254 25,163 31,188 1,392,871 1,424,059 Real estate construction and land development — — — 521 521 184,626 185,147 Residential mortgage 1,737 — 402 5,557 7,696 1,209,279 1,216,975 Consumer installment 3,145 644 — 451 4,240 865,186 869,426 Home equity 1,767 788 1,267 1,979 5,801 585,011 590,812 Total $ 14,502 $ 4,265 $ 2,287 $ 62,225 $ 83,279 $ 5,724,655 $ 5,807,934 Acquired Portfolio: Commercial $ 490 $ 532 $ 3,735 $ — $ 4,757 $ 379,607 $ 384,364 Commercial real estate 3,557 691 4,771 — 9,019 679,084 688,103 Real estate construction and land development — — 1,154 — 1,154 45,775 46,929 Residential mortgage 1,370 — 2,081 — 3,451 209,210 212,661 Consumer installment 55 — 47 — 102 7,929 8,031 Home equity 847 78 1,007 — 1,932 121,193 123,125 Total $ 6,319 $ 1,301 $ 12,795 $ — $ 20,415 $ 1,442,798 $ 1,463,213 Loans Modified Under Troubled Debt Restructurings (TDRs) The following schedule presents the Corporation’s TDRs at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Performing TDRs Non-Performing TDRs Nonaccrual TDRs Total September 30, 2016 Commercial loan portfolio $ 30,662 $ 15,261 $ 26,340 $ 72,263 Consumer loan portfolio 18,173 1,691 3,165 23,029 Total $ 48,835 $ 16,952 $ 29,505 $ 95,292 December 31, 2015 Commercial loan portfolio $ 29,844 $ 16,297 $ 32,682 $ 78,823 Consumer loan portfolio 17,966 3,071 3,251 24,288 Total $ 47,810 $ 19,368 $ 35,933 $ 103,111 The following schedule provides information on the Corporation's TDRs that were modified during the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial loan portfolio: Commercial 4 $ 4,160 $ 4,160 32 $ 12,141 $ 12,141 Commercial real estate — — — 6 2,441 2,441 Subtotal – commercial loan portfolio 4 4,160 4,160 38 14,582 14,582 Consumer loan portfolio 2 89 89 23 783 783 Total 6 $ 4,249 $ 4,249 61 $ 15,365 $ 15,365 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial loan portfolio: Commercial 3 $ 882 $ 882 21 $ 5,146 $ 5,146 Commercial real estate 3 2,044 2,044 12 5,105 5,105 Real estate construction and land development — — — 1 305 305 Subtotal – commercial loan portfolio 6 2,926 2,926 34 10,556 10,556 Consumer loan portfolio 15 481 481 54 2,450 2,448 Total 21 $ 3,407 $ 3,407 88 $ 13,006 $ 13,004 The pre-modification and post-modification recorded investment represents amounts as of the date of loan modification. The difference between the pre-modification and post-modification recorded investment of residential mortgage TDRs represents impairment recognized by the Corporation through the provision for loan losses computed based on a loan's post-modification present value of expected future cash flows discounted at the loan's original effective interest rate. The following schedule includes TDRs for which there was a payment default during the three and nine months ended September 30, 2016 and 2015 , whereby the borrower was past due with respect to principal and/or interest for 90 days or more, and the loan became a TDR during the twelve-month period prior to the default: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Number of Loans Principal Balance at End of Period Number of Loans Principal Balance at End of Period Commercial loan portfolio: Commercial real estate — $ — 2 $ 1,721 Subtotal – commercial loan portfolio — — 2 1,721 Consumer loan portfolio 1 — 3 — Total 1 $ — 5 $ 1,721 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Number of Loans Principal Balance at End of Period Number of Loans Principal Balance at End of Period Commercial loan portfolio: Commercial real estate 1 $ 74 5 $ 1,016 Subtotal – commercial loan portfolio 1 74 5 1,016 Consumer loan portfolio 1 13 2 46 Total 2 $ 87 7 $ 1,062 Allowance for Loan Losses The following schedule presents, by loan portfolio segment, the changes in the allowance for the three and nine months ended September 30, 2016 and 2015 , respectively, and details regarding the balance in the allowance and the recorded investment in loans at September 30, 2016 by impairment evaluation method. (Dollars in thousands) Commercial Loan Portfolio Consumer Loan Portfolio Unallocated Total Changes in allowance for loan losses for the three months ended September 30, 2016: Beginning balance $ 44,228 $ 27,278 $ — $ 71,506 Provision for loan losses 3,537 566 — 4,103 Charge-offs (824 ) (2,037 ) — (2,861 ) Recoveries 489 538 — 1,027 Ending balance $ 47,430 $ 26,345 $ — $ 73,775 Changes in allowance for loan losses for the nine months ended September 30, 2016: Beginning balance $ 47,234 $ 26,094 $ — $ 73,328 Provision for loan losses 5,437 3,166 — 8,603 Charge-offs (7,262 ) (4,677 ) — (11,939 ) Recoveries 2,021 1,762 — 3,783 Ending balance $ 47,430 $ 26,345 $ — $ 73,775 Changes in allowance for loan losses for the three months ended September 30, 2015: Beginning balance $ 45,527 $ 23,321 $ 6,093 $ 74,941 Provision for loan losses 2,637 (351 ) (786 ) 1,500 Charge-offs (539 ) (1,656 ) — (2,195 ) Recoveries 769 611 — 1,380 Ending balance $ 48,394 $ 21,925 $ 5,307 $ 75,626 Changes in allowance for loan losses for the nine months ended September 30, 2015: Beginning balance $ 44,156 $ 28,803 $ 2,724 $ 75,683 Provision for loan losses 5,604 (3,687 ) 2,583 4,500 Charge-offs (2,958 ) (5,104 ) — (8,062 ) Recoveries 1,592 1,913 — 3,505 Ending balance $ 48,394 $ 21,925 $ 5,307 $ 75,626 Allowance for loan losses balance at September 30, 2016 attributable to: Loans individually evaluated for impairment $ 3,245 $ 154 $ — $ 3,399 Loans collectively evaluated for impairment 44,185 26,191 — 70,376 Loans acquired with deteriorated credit quality — — — — Total $ 47,430 $ 26,345 $ — $ 73,775 Recorded investment (loan balance) at September 30, 2016: Loans individually evaluated for impairment $ 79,659 $ 19,864 $ — $ 99,523 Loans collectively evaluated for impairment 3,541,065 3,115,343 — 6,656,408 Loans acquired with deteriorated credit quality 3,812,723 2,147,135 — 5,959,858 Total $ 7,433,447 $ 5,282,342 $ — $ 12,715,789 The following schedule presents, by loan portfolio segment, details regarding the balance in the allowance and the recorded investment in loans at December 31, 2015 by impairment evaluation method. (Dollars in thousands) Commercial Loan Portfolio Consumer Loan Portfolio Total Allowance for loan losses balance at December 31, 2015 attributable to: Loans individually evaluated for impairment $ 6,197 $ 192 $ 6,389 Loans collectively evaluated for impairment 41,037 25,902 66,939 Loans acquired with deteriorated credit quality — — — Total $ 47,234 $ 26,094 $ 73,328 Recorded investment (loan balance) at December 31, 2015: Loans individually evaluated for impairment $ 100,379 $ 21,037 $ 121,416 Loans collectively evaluated for impairment 3,030,342 2,656,176 5,686,518 Loans acquired with deteriorated credit quality 1,119,396 343,817 1,463,213 Total $ 4,250,117 $ 3,021,030 $ 7,271,147

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets The Corporation has the following types of intangible assets: goodwill, core deposit intangible assets, non-compete intangible assets and loan servicing rights (LSRs). Goodwill, core deposit intangible assets, and non-compete intangible assets arose as a result of business combinations or other acquisitions. LSRs arose as a result of selling residential mortgage and commercial real estate loans in the secondary market while retaining the right to service these loans and receive servicing income over the life of the loan and from acquisitions of other banks that had LSRs. Loans serviced for others are not reported as assets in the Consolidated Statements of Financial Position. Amortization is recorded on the core deposit intangible assets, non-compete intangible assets and LSRs where there has not been an accounting election to account under the fair value method. Goodwill recorded is primarily attributable to the synergies and economies of scale expected from combining the operations of the Corporation and other acquisitions. The Corporation recorded goodwill in the amount of $850.3 million related to the merger with Talmer completed on August 31, 2016. The Corporation recorded additional goodwill in the first quarter of 2016 of $0.5 million related to the 2015 acquisition of Lake Michigan resulting from adjustments to the original acquisition date valuation of acquired assets and liabilities. Goodwill is not amortized but is evaluated at least annually for impairment. The Corporation’s most recent annual goodwill impairment review performed in the fourth quarter of 2015 did not indicate that an impairment of goodwill existed. The Corporation also determined that no triggering events have occurred that indicated impairment from the most recent valuation date through September 30, 2016 and that the Corporation's goodwill was not impaired at September 30, 2016 . The following table shows the net carrying value of the Corporation’s intangible assets: (Dollars in thousands) September 30, December 31, Goodwill $ 1,137,166 $ 287,393 Loan servicing rights 51,393 11,122 Other intangible assets: Core deposit intangible assets $ 35,618 $ 26,654 Non-compete intangible assets 82 328 Total other intangible assets $ 35,700 $ 26,982 The following table sets forth the carrying amount and accumulated amortization of core deposit intangible assets that are amortizable and arose from business combinations or other acquisitions: (Dollars in thousands) September 30, December 31, Gross original amount $ 52,454 $ 40,055 Accumulated amortization 16,836 13,401 Net carrying amount $ 35,618 $ 26,654 Amortization expense recognized on core deposit intangible assets was $1.2 million and $1.2 million for the three months ended September 30, 2016 and 2015, respectively, and $3.4 million and $2.9 million for the nine months ended September 30, 2016 and 2015, respectively. The estimated future amortization expense on core deposit intangible assets for periods ending after September 30, 2016 is as follows: 2016 — $1.4 million ; 2017 — $5.2 million ; 2018 — $5.0 million ; 2019 — $4.8 million ; 2020 — $4.2 million ; 2021 and thereafter — $15.0 million . The non-compete intangible assets will be fully amortized during 2016. The Corporation elected to account for LSRs acquired related to the merger with Talmer effective August 31, 2016 under the fair value method. Loan servicing rights are established and recorded at the estimated fair value by calculating the present value of estimated future net servicing cash flows, taking into consideration actual and expected mortgage loan prepayment rates, discount rates, servicing costs, and other economic factors, which are determined based on current market conditions. The following table represents the activity for LSRs accounted for under the fair value method and the related fair value changes: (Dollars in thousands) Three and nine months ended September 30, 2016 Commercial Real Estate Mortgage Total Fair value, beginning of period $ — $ — $ — Acquired in Talmer Bancorp, Inc. merger 365 42,097 42,462 Additions from loans sold with servicing retained — 810 810 Changes in fair value due to: Reductions from pay-offs, pay downs and run-off (2 ) (685 ) (687 ) Changes in estimates of fair value (1) — (657 ) (657 ) Fair value, end of period $ 363 $ 41,565 $ 41,928 Principal balance of loans serviced for others that have servicing capitalized $ 79,405 $ 5,523,423 $ 5,602,828 (1) Represents estimated LSR value change resulting primarily from market-driven changes in interest rates. The Corporation continues to account for all other LSRs using the amortization method. The following shows the net carrying value and fair value of LSRs and the total loans that the Corporation is servicing for others accounted for under the amortization method: (Dollars in thousands) September 30, December 31, Net carrying value of LSRs $ 9,465 $ 11,122 Fair value of LSRs $ 12,434 $ 15,542 Valuation allowance $ 214 $ — Loans serviced for others that have servicing rights capitalized $ 1,981,157 $ 2,082,899 LSRs accounted for under the amortization method are stratified into servicing assets originated by the Corporation and those acquired in acquisitions of other institutions and further stratified into relatively homogeneous pools based on products with similar characteristics. There was a valuation allowance of $0.2 million as of September 30, 2016 related to impairment within certain pools attributable to the Corporation's servicing portfolios that were acquired in the Northwestern and Monarch transactions. There was no impairment valuation allowance recorded on the Corporation's LSRs at December 31, 2015. The following table shows the activity for capitalized LSRs accounted for under the amortization method: (Dollars in thousands) Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Balance at beginning of period $ 9,677 $ 12,307 $ 11,122 $ 12,217 Acquired in Monarch acquisition — — — 1,284 Additions 695 303 1,612 1,118 Amortization (1,105 ) (1,070 ) (3,055 ) (3,279 ) Change in valuation allowance 198 — (214 ) 200 Balance at end of period $ 9,465 $ 11,540 $ 9,465 $ 11,540 The Company realized total loan servicing fee income of $2.1 million and $1.4 million for the three months ended September 30, 2016 and 2015 , respectively, and $4.7 million and $4.1 million for the nine months ended September 30, 2016 and 2015 , respectively. Expected and actual loan prepayment speeds are the most significant factors driving the fair value of loan servicing rights. The following table presents assumptions utilized in determining the fair value of loan servicing rights as of September 30, 2016 and December 31, 2015 . Commercial Real Estate Mortgage As of September 30, 2016 Prepayment speed 0.00 - 22.47% 0.00 - 38.28% Weighted average (“WA”) discount rate 16.46 % 10.09 % Cost to service/per year $467-$500 $65-$90 Ancillary income/per year N/A $ 28 WA float range 0.53 % 0.68 % As of December 31, 2015 Prepayment speed N/A 6.96 - 17.65% WA discount rate N/A 10.04 % Cost to service/per year N/A $70-$85 Ancillary income/per year N/A $ 20 WA float range N/A 1.72 %

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The following table summarizes the changes within each component of accumulated other comprehensive income (loss), net of related tax benefit/expense for the three and nine months ended September 30, 2016, and 2015: (Dollars in thousands) Unrealized gains Defined Benefit Pension Plans Total For the three months ended September 30, 2016 Beginning balance $ 2,196 $ (27,894 ) $ (25,698 ) Other comprehensive income (loss) before reclassifications (805 ) (511 ) (1,316 ) Amounts reclassified from accumulated other comprehensive income (10 ) 1,882 1,872 Net current period other comprehensive income (loss) (815 ) 1,371 556 Ending balance $ 1,381 $ (26,523 ) $ (25,142 ) For the three months ended September 30, 2015 Beginning balance $ (274 ) $ (30,830 ) $ (31,104 ) Other comprehensive income before reclassifications 1,214 — 1,214 Amounts reclassified from accumulated other comprehensive income (3 ) 707 704 Net current period other comprehensive income 1,211 707 1,918 Ending balance $ 937 $ (30,123 ) $ (29,186 ) For the nine months ended September 30, 2016 Beginning balance $ (1,888 ) $ (27,144 ) $ (29,032 ) Other comprehensive income (loss) before reclassifications 3,304 (511 ) 2,793 Amounts reclassified from accumulated other comprehensive income (35 ) 1,132 1,097 Net current period other comprehensive income (loss) 3,269 621 3,890 Ending balance $ 1,381 $ (26,523 ) $ (25,142 ) For the nine months ended September 30, 2015 Beginning balance $ (210 ) $ (32,243 ) $ (32,453 ) Other comprehensive income before reclassifications 1,545 — 1,545 Amounts reclassified from accumulated other comprehensive income (398 ) 2,120 1,722 Net current period other comprehensive income 1,147 2,120 3,267 Ending balance $ 937 $ (30,123 ) $ (29,186 ) The following table summarizes the amounts reclassified out of each component of accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2016 and 2015: (Dollars in thousands) Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Income Statement Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Gains and losses on available-for-sale securities $ 16 $ 5 $ 53 $ 612 Gain on sale of investment securities (noninterest income) (6 ) (2 ) (18 ) (214 ) Income tax (expense)/benefit $ 10 $ 3 $ 35 $ 398 Net Income Amortization of defined benefit pension plan items $ (2,895 ) $ (1,087 ) $ (1,742 ) $ (3,261 ) Salaries, wages and employee benefits (operating expenses) 1,013 380 610 1,141 Income tax (expense)/benefit $ (1,882 ) $ (707 ) $ (1,132 ) $ (2,120 ) Net Income

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Borrowings	Borrowings A summary of the Corporation's short- and long-term borrowings follows: September 30, December 31, (Dollars in thousands) Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Short-term borrowings: FHLB advances: 0.45% - 0.81% fixed-rate notes $ 400,000 0.52 % $ 100,000 0.34 % Long-term borrowings: FHLB advances: 0.59% - 7.44% fixed-rate notes due 2016 to 2027 (2) $ 494,013 1.45 181,394 1.41 Securities sold under agreements to repurchase: 1.48% - 4.30% fixed-rate notes due 2016 to 2017 (3) 42,394 3.61 17,453 0.27 Line-of-credit: floating-rate based on one-month LIBOR plus 1.75% 124,698 2.27 25,000 2.27 Subordinated debt obligations: floating-rate based on three-month LIBOR plus 1.45% - 2.85% due 2034 to 2035 (4) 11,260 3.09 — — Subordinated debt obligations: floating-rate based on three-month LIBOR plus 3.25% due in 2032 (5) 4,247 4.09 — — Subordinated debt obligations — — 18,544 3.99 Total long-term borrowings $ 676,612 1.78 $ 242,391 1.59 (1) Weighted average rate presented is the contractual rate which excludes premiums and discounts related to purchase accounting. (2) The September 30, 2016 balances include advances payable of $492.8 million and purchase accounting premiums of $1.2 million . The December 31, 2015 balance includes advances payable of $181.0 million and purchase accounting premiums of $0.4 million . (3) The September 30, 2016 balance includes advances payable of $42.0 million and purchase accounting premiums of $0.4 million . The December 31, 2015 balance includes advance payable of $17.0 million and purchase accounting premiums of $0.5 million . (4) The September 30, 2016 balance includes advances payable of $15.0 million and purchase accounting discounts of $3.7 million . (5) The September 30, 2016 balance includes advances payable of $5.0 million and purchase accounting discounts of $0.8 million . The Corporation's FHLB advances, including both short-term and long-term, require monthly interest payments and are collateralized by eligible loans totaling $5.10 billion as of September 30, 2016 . Securities sold under agreements to repurchase are with an unaffiliated financial institution and are secured by available for-sale-securities. The Corporation's securities sold under agreements to repurchase do not qualify as sales for accounting purposes. The remaining contract maturity, excluding purchase accounting adjustments, of long-term securities under agreement to repurchase, is as follows: September 30, 2016 Remaining Contractual Maturities of the Agreements (Dollars in thousands) Overnight and continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities sold under agreements to repurchase $ — $ 13,000 $ 10,000 $ 19,000 $ 42,000 Total borrowings $ — $ 13,000 $ 10,000 $ 19,000 $ 42,000 Amounts related to securities sold under agreements to repurchase not included in offsetting disclosure in Footnote 14 $ 42,000 In conjunction with the merger with Talmer, the Corporation entered into a credit agreement of $145.0 million consisting of a $125.0 million term line-of credit and a $20.0 million revolving line-of-credit. The Corporation drew $125.0 million on the term line-of-credit to pay off the Corporation's prior $25.0 million line-of-credit and a $37.5 million line-of-credit acquired in the merger with Talmer, with the remaining proceeds used to partially fund the cash portion of the merger consideration. As a result of the Lake Michigan transaction on May 31, 2015, the Corporation acquired subordinated debt obligations in the amount of $18.6 million . The Corporation fully repaid these debt obligations during the first quarter of 2016. As a result of the merger with Talmer on August 31, 2016, the Corporation acquired $687.1 million in short and long-term debt obligations, of which $142.2 million was paid off prior to September 30, 2016.

Regulatory Capital

Regulatory Capital	9 Months Ended
	Sep. 30, 2016
Banking and Thrift [Abstract]
Regulatory Capital	Regulatory Capital Federal and state banking regulations place certain restrictions on the transfer of assets, in the form of dividends, loans, or advances, from Chemical Bank and Talmer Bank and Trust to the Corporation. As of September 30, 2016 , substantially all of the assets of the banks were restricted from transfer to the Corporation in the form of loans or advances. Dividends from the banks are the principal source of funds for the Corporation. In addition to the statutory limits, the Corporation considers the overall financial and capital position of the banks prior to making any cash dividend decisions. The Corporation and the banks are subject to various regulatory capital requirements administered by federal banking agencies. Under these capital requirements, the banks must meet specific capital guidelines that involve quantitative measures of assets and certain off-balance sheet items as calculated under regulatory accounting practices. In addition, capital amounts and classifications are subject to qualitative judgments by regulators. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on the Corporation’s consolidated financial statements. Management believes as of September 30, 2016, the Corporation and the banks met all capital adequacy requirements to which they are subject. Quantitative measures established by regulation to ensure capital adequacy require minimum ratios of Tier 1 capital to average assets (Leverage Ratio) and common equity Tier 1, Tier 1 and Total capital to risk-weighted assets. These capital guidelines assign risk weights to on- and off-balance sheet items in arriving at total risk-weighted assets. Minimum capital levels are based upon the perceived risk of various asset categories and certain off-balance sheet instruments. Risk-weighted assets of the Corporation totaled $13.43 billion and $7.14 billion at September 30, 2016 and December 31, 2015 , respectively. Effective January 1, 2015, the Company adopted the new Basel III regulatory capital framework as approved by federal banking agencies, which are subject to a multi-year phase-in period. The adoption of this new framework modified the calculation of the various capital ratios, added a new ratio, common equity tier 1, and revised the adequately and well capitalized thresholds. In addition, Basel III establishes a new capital conservation buffer of 2.5% of risk-weighted assets, which is phased-in over a four-year period beginning January 1, 2016. The capital conservation buffer for 2016 is .625%. The Corporation has elected to opt-out of including capital in accumulated other comprehensive income in common equity tier 1 capital. At September 30, 2016 and December 31, 2015 , the banks' capital ratios exceeded the quantitative capital ratios required for an institution to be considered “well-capitalized.” Significant factors that may affect capital adequacy include, but are not limited to, a disproportionate growth in assets versus capital and a change in mix or credit quality of assets. There are no conditions or events since that notification that management believes have changed the institutions' category. The summary below compares the actual capital amounts and ratios with the quantitative measures established by regulation to ensure capital adequacy: Actual Minimum Required for Capital Adequacy Purposes Minimum Required for Capital Adequacy Purposes Plus Capital Conservation Buffer Required to be Well Capitalized Under Prompt Corrective Action Regulations (Dollars in thousands) Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio September 30, 2016 Total Capital to Risk-Weighted Assets Corporation $ 1,491,389 11.1 % $ 1,074,506 8.0 % $ 1,155,093 8.6 % N/A N/A Chemical Bank 825,504 10.8 614,281 8.0 660,352 8.6 $ 767,851 10.0 % Talmer Bank and Trust 719,213 12.7 453,090 8.0 487,071 8.6 566,362 10.0 Tier 1 Capital to Risk-Weighted Assets Corporation 1,413,464 10.5 805,879 6.0 886,467 6.6 N/A N/A Chemical Bank 752,957 9.8 460,711 6.0 506,782 6.6 614,281 8.0 Talmer Bank and Trust 713,835 12.6 339,817 6.0 373,799 6.6 453,090 8.0 Common Equity Tier 1 Capital to Risk-Weighted Assets Corporation 1,413,464 10.5 604,409 4.5 684,997 5.1 N/A N/A Chemical Bank 752,957 9.8 345,533 4.5 391,604 5.1 499,103 6.5 Talmer Bank and Trust 713,835 12.6 254,863 4.5 288,845 5.1 368,135 6.5 Leverage Ratio Corporation 1,413,464 12.8 442,317 4.0 442,317 4.0 N/A N/A Chemical Bank 752,957 8.1 373,897 4.0 373,897 4.0 467,371 5.0 Talmer Bank and Trust 713,835 10.9 262,318 4.0 262,318 4.0 327,898 5.0 December 31, 2015 Total Capital to Risk-Weighted Assets Corporation $ 841,257 11.8 % $ 571,509 8.0 % N/A N/A N/A N/A Chemical Bank 830,294 11.7 570,073 8.0 N/A N/A $ 712,591 10.0 % Tier 1 Capital to Risk-Weighted Assets Corporation 767,929 10.7 428,631 6.0 N/A N/A N/A N/A Chemical Bank 756,966 10.6 427,555 6.0 N/A N/A 570,073 8.0 Common Equity Tier 1 Capital to Risk-Weighted Asset Corporation 753,815 10.6 321,474 4.5 N/A N/A N/A N/A Chemical Bank 756,966 10.6 320,666 4.5 N/A N/A 463,184 6.5 Leverage Ratio Corporation 767,929 8.6 356,396 4.0 N/A N/A N/A N/A Chemical Bank 756,966 8.5 355,911 4.0 N/A N/A 444,888 5.0

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value, as defined by GAAP, is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability. The price in the principal (or most advantageous) market used to measure the fair value of the asset or liability is not adjusted for transaction costs. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date to allow for market activities that are usual and customary for transactions involving such assets and liabilities; it is not a forced transaction. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact and (iv) willing to transact. The Corporation utilizes fair value measurements to record fair value adjustments to certain assets and to determine fair value disclosures. Investment securities — available-for-sale, loans held-for-sale, certain loan servicing rights and derivatives are recorded at fair value on a recurring basis. Additionally, the Corporation may be required to record other assets, such as impaired loans, goodwill, other intangible assets, other real estate and repossessed assets, at fair value on a nonrecurring basis. These nonrecurring fair value adjustments typically involve the application of lower of cost or market accounting or write-downs of individual assets. The Corporation determines the fair value of its financial instruments based on a three-level hierarchy established by GAAP. The classification and disclosure of assets and liabilities within the hierarchy is based on whether the inputs to the valuation methodology used for measurement are observable or unobservable. Observable inputs reflect market-derived or market-based information obtained from independent sources, while unobservable inputs reflect management’s estimates about market data. The three levels of inputs that may be used to measure fair value within the GAAP hierarchy are as follows: Level 1 Valuation is based upon quoted prices for identical instruments traded in active markets. Level 1 valuations for the Corporation include U.S. Treasury securities that are traded by dealers or brokers in active over-the-counter markets. Valuations are obtained from a third-party pricing service for these investment securities. Level 2 Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. Level 2 valuations for the Corporation include government sponsored agency securities, including securities issued by the Federal Home Loan Bank, Federal Home Loan Mortgage Corporation, Federal National Mortgage Association, Federal Farm Credit Bank, Student Loan Marketing Corporation and the Small Business Administration, securities issued by certain state and political subdivisions, residential mortgage-backed securities, collateralized mortgage obligations, corporate bonds, preferred stock and available-for-sale trust preferred securities. Valuations are obtained from a third-party pricing service for these investment securities. Additionally included in Level 2 valuations are loans held for sale and derivative assets and liabilities. Level 3 Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in pricing the asset or liability. Valuation techniques include use of option pricing models, discounted cash flow models, yield curves and similar techniques. The determination of fair value requires management judgment or estimation and generally is corroborated by external data, which includes third-party pricing services. Level 3 valuations for the Corporation include securities issued by certain state and political subdivisions, held-to-maturity trust preferred investment securities, impaired loans, goodwill, core deposit intangible assets, non-compete intangible assets, LSRs and other real estate and repossessed assets. A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below. These valuation methodologies were applied to all of the Corporation’s financial assets and financial liabilities carried at fair value and all financial instruments disclosed at fair value. In general, fair value is based upon quoted market prices, where available. If quoted market prices are not available, fair value is based upon third-party pricing services when available. Fair value may also be based on internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be required to record financial instruments at fair value. Any such valuation adjustments are applied consistently over time. The Corporation’s valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While management believes the Corporation’s valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Furthermore, the fair value amounts may change significantly after the date of the statement of financial position from the amounts reported in the consolidated financial statements and related notes. Assets and Liabilities Recorded at Fair Value on a Recurring Basis Investment securities: Investment securities classified as available-for-sale are recorded at fair value on a recurring basis. Fair value measurement is based upon quoted prices, if available. If quoted prices are not available, fair values are generally measured using independent pricing models or other model-based valuation techniques that include market inputs, such as benchmark yields, reported trades, broker dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data and industry and economic events. Loans held-for-sale: The Corporation elected the fair value option for all residential mortgage loans held-for-sale originated on or after July 1, 2012. Accordingly, loans held-for-sale are recorded at fair value on a recurring basis. The fair values of loans held-for-sale are based on the market price for similar loans sold in the secondary market, and therefore, are classified as Level 2 valuations. Loan servicing rights: LSRs acquired related to the merger with Talmer effective August 31, 2016 are accounted for under the fair value measurement method based on accounting election. A third party valuation model is used to determine the fair value at the end of each reporting period utilizing a discounted cash flow analysis using interest rates and prepayment speed assumptions currently quoted for comparable instruments and a discount rate determined by management. Because of the nature of the valuation inputs, the Corporation classifies loan servicing rights as Level 3. Refer to Note 5, “Intangible Assets”, for the assumptions included in the valuation of loan servicing rights. Derivatives: The Corporation enters into interest rate lock commitments with prospective borrowers to be sold into the secondary market and forward commitments for the future delivery of mortgage loans to third party investors, which are carried at fair value on a recurring basis. The fair value of these commitments is based on the fair value of related mortgage loans determined using observable market data. Interest rate lock commitments are adjusted for expectations of exercise and funding. This adjustment is not considered to be a material input. The Corporation classifies interest rate lock commitments and forward contracts related to mortgage loans to be delivered for sale as recurring Level 2. Derivative instruments held or issued for customer-initiated activities are traded in over-the counter markets where quoted market prices are not readily available. Fair value for over-the-counter derivative instruments is measured on a recurring basis using third party models that use primarily market observable inputs, such as yield curves and option volatilities. The fair value for these derivatives may include a credit valuation adjustment that is determined by applying a credit spread for the counterparty or the Corporation, as appropriate, to the total expected exposure of the derivative after considering collateral and other master netting arrangements. These adjustments, which are considered Level 3 inputs, are based on estimates of current credit spreads to evaluate the likelihood of default. The Corporation assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions at both September 30, 2016 and December 31, 2015 and it was determined that the credit valuation adjustments were not significant to the overall valuation of its derivatives. As a result, the Corporation classifies its customer-initiated derivatives valuations in Level 2 of the fair value hierarchy. Disclosure of Recurring Basis Fair Value Measurements For assets and liabilities measured at fair value on a recurring basis, quantitative disclosures about the fair value measurements for each major category of assets were as follows: (Dollars in thousands) Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2016 Investment securities – available-for-sale: U.S. Treasury securities $ 5,801 $ — $ — $ 5,801 Government sponsored agencies — 224,038 — 224,038 State and political subdivisions — 305,537 — 305,537 Residential mortgage-backed securities — 303,398 — 303,398 Collateralized mortgage obligations — 343,739 — 343,739 Corporate bonds — 96,085 — 96,085 Preferred stock and trust preferred securities — 24,783 — 24,783 Total investment securities – available-for-sale 5,801 1,297,580 — 1,303,381 Loans held-for-sale — 276,061 — 276,061 Loan servicing rights — — 41,928 41,928 Derivative assets: Customer-initiated derivatives — 12,250 — 12,250 Forward contracts related to mortgage loans to be delivered for sale — 89 — 89 Interest rate lock commitments — 2,674 — 2,674 Power Equity CD — 2,183 — 2,183 Total derivatives — 17,196 — 17,196 Total assets at fair value $ 5,801 $ 1,590,837 $ 41,928 $ 1,638,566 Derivative liabilities: Customer-initiated derivatives — 12,787 — 12,787 Forward contracts related to mortgage loans to be delivered for sale — 944 — 944 Interest rate lock commitments — 56 — 56 Power Equity CD — 2,183 — 2,183 Total derivatives — 15,970 — 15,970 Total liabilities at fair value $ — $ 15,970 $ — $ 15,970 December 31, 2015 Investment securities – available-for-sale: U.S. Treasury securities $ 5,765 $ — $ — $ 5,765 Government sponsored agencies — 194,989 — 194,989 State and political subdivisions — 15,120 — 15,120 Residential mortgage-backed securities — 187,768 — 187,768 Collateralized mortgage obligations — 132,230 — 132,230 Corporate bonds — 14,627 — 14,627 Preferred stock and trust preferred securities — 3,232 — 3,232 Total investment securities – available-for-sale 5,765 547,966 — 553,731 Loans held-for-sale — 10,327 — 10,327 Derivative assets: Forward contracts related to mortgage loans to be delivered for sale — 144 — 144 Interest rate lock commitments — 42 — 42 Power Equity CD — 1,832 — 1,832 Total derivatives — 2,018 — 2,018 Total assets at fair value $ 5,765 $ 560,311 $ — $ 566,076 Derivative liabilities: Forward contracts related to mortgage loans to be delivered for sale — 57 — 57 Interest rate lock commitments — 90 — 90 Power Equity CD — 1,832 — 1,832 Total derivatives — 1,979 — 1,979 Total liabilities at fair value $ — $ 1,979 $ — $ 1,979 There were no transfers between levels within the fair value hierarchy during the nine months ended September 30, 2016. The following table summarizes the changes in Level 3 assets measured at fair value on a recurring basis. (Dollars in thousands) Three and nine months ended September 30, 2016 Loan servicing rights Balance, beginning of period $ — Additions due to acquisition 42,462 Gains (losses): Recorded in earnings (realized): Recorded in “Mortgage banking revenue” (1,344 ) New originations 810 Balance, end of period $ 41,928 The Corporation has elected the fair value option for loans held-for-sale. These loans are intended for sale and the Corporation believes that the fair value is the best indicator of the resolution of these loans. Interest income is recorded based on the contractual terms of the loans in accordance with the Corporation's policy on loans held for investment in “Interest and fees on loans” in the Consolidated Statements of Income. There were no loans held for sale that were on nonaccrual status or 90 days past due and on accrual status as of September 30, 2016 and December 31, 2015. The aggregate fair value, contractual balance (including accrued interest), and gain or loss for loans held-for-sale carried at fair value was as follows: (Dollars in thousands) September 30, 2016 December 31, 2015 Aggregate fair value $ 276,061 $ 10,327 Contractual balance 274,406 10,366 Unrealized gain (loss) 1,655 (39 ) The total amount of gains (losses) from loans held for sale included in the Consolidated Statements of Income were as follows: For the three months ended For the nine months ended (Dollars in thousands) 2016 2015 2016 2015 Interest income (1) $ 811 $ 23 $ 849 $ 56 Change in fair value (2) 43 76 199 (15 ) Total included in earnings $ 854 $ 99 $ 1,048 $ 41 (1) Included in "Interest and fees on loans" in the Consolidated Statements of Income. (2) Included in "Mortgage banking revenue" in the Consolidated Statements of Income. Assets and Liabilities Recorded at Fair Value on a Nonrecurring Basis Loans: The Corporation does not record loans held for investment at fair value on a recurring basis. However, from time to time, a loan is considered impaired and an allocation of the allowance (valuation allowance) may be established or a portion of the loan is charged off. Loans for which it is probable that payment of interest and principal will not be made in accordance with the contractual terms of the loan agreement are considered impaired. The fair value of impaired loans is estimated using one of several methods, including the loan’s observable market price, the fair value of the collateral or the present value of the expected future cash flows discounted at the loan’s effective interest rate. Those impaired loans not requiring a valuation allowance represent loans for which the fair value of the expected repayments or collateral exceed the remaining carrying amount of such loans. Impaired loans where a valuation allowance is established or a portion of the loan is charged off based on the fair value of collateral are subject to nonrecurring fair value measurement and require classification in the fair value hierarchy. The Corporation records impaired loans as Level 3 valuations as there is generally no observable market price or independent appraised value, or management determines the fair value of the collateral is further impaired below the appraised value. When management determines the fair value of the collateral is further impaired below appraised value, discount factors ranging between 70% and 80% of the appraised value are used depending on the nature of the collateral and the age of the most recent appraisal. Goodwill: Goodwill is subject to impairment testing on an annual basis. The assessment of goodwill for impairment requires a significant degree of judgment. In the event the assessment indicates that it is more-likely-than-not that the fair value is less than the carrying value, the asset is considered impaired and recorded at fair value. Goodwill that is impaired and subject to nonrecurring fair value measurements is a Level 3 valuation. At September 30, 2016 and December 31, 2015 , no goodwill was impaired. Other intangible assets: Other intangible assets consist of core deposit intangible assets and non-compete intangible assets. These items are recorded at fair value when initially recorded. Subsequently, core deposit intangible assets and non-compete intangible assets are amortized primarily on an accelerated basis over periods ranging from ten to fifteen years and are subject to impairment testing whenever events or changes in circumstances indicate that the carrying amount exceeds the fair value of the asset. If core deposit intangible asset or non-compete intangible asset impairment is identified, the Corporation classifies impaired core deposit intangible assets and impaired non-compete intangible assets subject to nonrecurring fair value measurements as Level 3 valuations. At September 30, 2016 and December 31, 2015 , there was no impairment identified for core deposit intangible assets or non-compete intangible assets. Loan servicing rights: LSRs originated by the Corporation and those acquired in acquisitions of other institutions prior to the merger with Talmer are accounted for under the amortization method. The fair value of these LSRs is initially estimated using a model that calculates the net present value of estimated future cash flows using various assumptions, including prepayment speeds, the discount rate and servicing costs. If the valuation model reflects a value less than the carrying value, LSRs are adjusted to fair value, as determined by the model, through a valuation allowance. The Corporation classifies the LSRs subject to nonrecurring fair value measurements as Level 3 valuations. At September 30, 2016 , the Corporation recognized a valuation allowance of $0.2 million related to impairment within certain pools attributable to the Corporation's servicing portfolios that were acquired in the Northwestern and Monarch transactions. As a result, the LSRs related to these servicing portfolios were considered to be recorded at fair value on a nonrecurring basis as of September 30, 2016 . At December 31, 2015 , there was no impairment identified for LSRs. Other real estate owned and repossessed assets : The carrying amounts for other real estate and repossessed assets are reported in the Consolidated Statements of Financial Position under “Interest receivable and other assets.” Other real estate and repossessed assets include real estate and other types of assets repossessed by the Corporation. Other real estate and repossessed assets are recorded at the lower of cost or fair value upon the transfer of a loan to other real estate and repossessed assets and, subsequently, continue to be measured and carried at the lower of cost or fair value. Fair value is based upon independent market prices, appraised values of the property or management’s estimation of the value of the property. The Corporation records other real estate and repossessed assets as Level 3 valuations as management generally determines that the fair value of the property is impaired below the appraised value. When management determines the fair value of the property is further impaired below appraised value, discount factors ranging between 67% and 90% of the appraised value are used depending on the nature of the property and the age of the most recent appraisal. Disclosure of Nonrecurring Basis Fair Value Measurements For assets measured at fair value on a nonrecurring basis, quantitative disclosures about fair value measurements for each major category of assets were as follows: (Dollars in thousands) Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2016 Impaired originated loans $ — $ — $ 25,344 $ 25,344 Other real estate/repossessed assets — — 380 380 Loan servicing rights — — 5,688 5,688 Total $ — $ — $ 31,412 $ 31,412 December 31, 2015 Impaired originated loans $ — $ — $ 42,065 $ 42,065 Other real estate/repossessed assets — — 3,068 3,068 Total $ — $ — $ 45,133 $ 45,133 There were no liabilities recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 . The following table presents additional information about the significant unobservable inputs used in the fair value measurement of financial assets measured on a nonrecurring basis that were categorized within the Level 3 of the fair value hierarchy: (Dollars in thousands) Fair Value at September 30, 2016 Valuation Technique Significant Unobservable Inputs Range Impaired originated loans $ 25,344 Appraisal of collateral Discount for type of collateral and age of appraisal 20%-30% Other real estate/repossessed assets 380 Appraisal of property Discount for type of property and age of appraisal 10%-33% Loan servicing rights 5,688 Discounted cash flow Constant prepayment rate 13%-22% Discount rate 10%-11% Disclosures about Fair Value of Financial Instruments GAAP requires disclosures about the estimated fair value of the Corporation's financial instruments, including those financial assets and liabilities that are not measured and reported at fair value on a recurring or nonrecurring basis. However, the method of estimating fair value for certain financial instruments, such as loans, that are not required to be measured on a recurring or nonrecurring basis, as prescribed by ASC 820, Fair Value Measurements and Disclosures, does not incorporate the exit-price concept of fair value. The Corporation utilized the fair value hierarchy in computing the fair values of its financial instruments. In cases where quoted market prices were not available, the Corporation employed present value methods using unobservable inputs requiring management's judgment to estimate the fair values of its financial instruments, which are considered Level 3 valuations. These Level 3 valuations are affected by the assumptions made and, accordingly, do not necessarily indicate amounts that could be realized in a current market exchange. It is also the Corporation's general practice and intent to hold the majority of its financial instruments until maturity and, therefore, the Corporation does not expect to realize the estimated amounts disclosed. The methodologies for estimating the fair value of financial assets and financial liabilities on a recurring or nonrecurring basis are discussed above. At September 30, 2016 and December 31, 2015 , the estimated fair values of cash and cash equivalents, interest receivable and interest payable approximated their carrying values at those dates. The methodologies for other financial assets and financial liabilities follow. Investment securities — held-to-maturity : Fair value measurements for investment securities — held to maturity is based upon quoted prices, if available. If quoted prices are not available, fair values are measured using independent pricing models or other model-based valuation techniques that include market inputs such as benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data and industry and economic events. Fair value measurements using Level 2 valuations of investment securities — held-to-maturity include the majority of the Corporation's investment securities issued by state and political subdivisions. Level 3 valuations include certain securities issued by state and political subdivisions and trust preferred investment securities. Nonmarketable equity securities: Fair value measurements of nonmarketable equity securities, which consist of Federal Home Loan Bank (FHLB) and Federal Reserve Bank (FRB) stock, are based on their redeemable value, which is cost. The market for these securities is restricted to the issuer of the stock and subject to impairment evaluation. It is not practicable to determine the fair value of these securities within the fair value hierarchy due to the restrictions placed on their transferability. Loans: The fair value of variable interest rate loans that reprice regularly with changes in market interest rates are based on carrying values. The fair values for fixed interest rate loans are estimated using discounted cash flow analyses, using the Corporation’s interest rates currently being offered for loans with similar terms to borrowers of similar credit quality. The resulting fair value amounts are adjusted to estimate the impact of changes in the credit quality of borrowers after the loans were originated. The fair value measurements for loans are Level 3 valuations. Deposits: The fair values of deposit accounts without defined maturities, such as interest- and noninterest-bearing checking, savings and money market accounts, are equal to the amounts payable on demand. The fair values for variable-interest rate time deposits with defined maturities approximate their carrying amounts. Fair value measurements for fixed-interest rate time deposits with defined maturities are based on the discounted value of contractual cash flows, using the Corporation’s interest rates currently being offered for deposits of similar maturities, and are therefore classified as Level 2 valuations. However, if the estimated fair value is less than the carrying value, the carrying value is reported as the fair value. Short-term borrowings: Short-term borrowings consist of securities sold under agreements to repurchase with customers, short-term FHLB advances and federal funds purchased. Fair value measurements for short-term borrowings are based on the present value of future estimated cash flows using current interest rates offered to the Corporation for debt with similar terms and are Level 2 valuations. Lon g -term borrowings: Long-term borrowings consist of long-term FHLB advances, securities sold under agreements to repurchase with an unaffiliated financial institution, a non-revolving line-of-credit and subordinated debt obligations. Fair value measurements for long-term borrowings are based on the present value of future estimated cash flows using current interest rates offered to the Corporation for debt with similar terms and are therefore classified as Level 2 valuations. Financial guarantees : The Corporation’s unused commitments to extend credit, standby letters of credit and loan commitments have no carrying amount and have been estimated to have no realizable fair value. Historically, a majority of the unused commitments to extend credit have not been drawn upon and, generally, the Corporation does not receive fees in connection with these commitments other than standby letter of credit fees, which are not significant. A summary of carrying amounts and estimated fair values of the Corporation’s financial instruments not recorded at fair value in their entirety on a recurring basis on the Consolidated Statements of Financial Position was as follows: Level in Fair Value Measurement Hierarchy September 30, 2016 December 31, 2015 (Dollars in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Cash and cash equivalents Level 1 $ 556,567 $ 556,567 $ 238,789 $ 238,789 Investment securities: Held-to-maturity Level 2 563,221 574,844 509,471 512,405 Held-to-maturity Level 3 500 300 500 300 Nonmarketable equity securities NA 77,396 77,396 36,907 36,907 Net loans (1) Level 3 12,642,014 12,650,332 7,197,819 7,201,994 Interest receivable Level 2 43,131 43,131 21,953 21,953 Liabilities: Deposits without defined maturities Level 2 $ 9,924,502 $ 9,924,502 $ 5,809,355 $ 5,809,355 Time deposits Level 2 3,348,360 3,348,942 1,647,412 1,647,412 Interest payable Level 2 5,097 5,097 1,578 1,578 Short-term borrowings Level 2 726,789 726,789 397,199 397,199 Long-term borrowings Level 2 676,612 676,750 242,391 242,391 (1) Included $25.3 million and $42.1 million of impaired loans recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 , respectively.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share The two-class method is used in the calculation of basic and diluted earnings per share. Under the two-class method, earnings available to common shareholders for the period are allocated between common shareholders and participating securities according to dividends declared (or accumulated) and participating rights in undistributed earnings. Average shares of common stock for diluted net income per common share include shares to be issued upon the exercise of stock options granted under the Corporation’s share-based compensation plans, restricted stock units that may be converted to stock, restricted stock awards and stock to be issued under the deferred stock compensation plan for non-employee directors. The factors used in the earnings per share computation follow: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2016 2015 2016 2015 Net income $ 10,732 $ 24,467 $ 59,701 $ 61,326 Net income allocated to participating securities 36 — 78 — Net income allocated to common shareholders (1) $ 10,696 $ 24,467 $ 59,623 $ 61,326 Weighted average common shares - issued 49,107 38,123 41,881 35,384 Average unvested restricted share awards (163 ) — (55 ) — Weighted average common shares outstanding - basic 48,944 38,123 41,826 35,384 Effect of dilutive securities Weighted average common stock equivalents 687 270 493 246 Weighted average common shares outstanding - diluted 49,631 38,393 42,319 35,630 EPS available to common shareholders Basic earnings per common share $ 0.22 $ 0.64 $ 1.43 $ 1.73 Diluted earnings per common share $ 0.21 $ 0.64 $ 1.40 $ 1.72 (1) Net income allocated to common shareholders for basic and diluted earnings per share may differ under the two-class method as a result of adding common share equivalents for options and warrants to dilutive shares outstanding, which alters the ratio used to allocate net income to common shareholders and participating securities for the purposes of calculating diluted earnings per share. The average number of exercisable employee stock options outstanding that were “out-of-the-money,” whereby the option exercise price per share exceeded the market price per share and, therefore, were not included in the computation of diluted earnings per common share because they would have been anti-dilutive totaled zero and 17,333 for the three months ended September 30, 2016 and 2015 , respectively, and zero and 73,028 for the nine months ended September 30, 2016 and 2015 , respectively.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation The Corporation maintains share-based compensation plans under which it periodically grants share-based awards for a fixed number of shares to certain officers of the Corporation. The fair value of share-based awards is recognized as compensation expense over the requisite service or performance period. During the three-month periods ended September 30, 2016 and 2015 , share-based compensation expense related to share-based awards totaled $4.7 million and $1.2 million , respectively. During the nine months ended September 30, 2016 and 2015 , share-based compensation expense related to share-based awards totaled $6.5 million and $2.7 million , respectively. During the nine-month period ended September 30, 2016 , the Corporation granted options to purchase 441,167 shares of common stock, 133,620 restricted stock units and 940 shares of common stock to certain officers of the Corporation. In addition, the Corporation assumed options to purchase 1,466,408 shares of common stock and 484,892 restricted stock awards in connection with the Talmer merger. On April 20, 2015, the shareholders of the Corporation approved the Stock Incentive Plan of 2015, which provides for 1,300,000 shares of the Corporation's common stock to be made available for future equity-based awards and canceled the amount of shares available for future grant under prior share-based compensation plans. At September 30, 2016 , there were 669,081 shares of common stock available for future grants under the Stock Incentive Plan of 2015. Stock Options The Corporation issues stock options to certain officers from time to time. The exercise price on stock options equals the current market price of the Corporation's common stock on the date of grant and stock options expire ten years from the date of grant. Stock options granted after 2012 vest ratably over a five -year period. Stock options granted prior to 2013 generally vest ratably over a three -year period. Stock options granted prior to 2016 fully vested upon the merger with Talmer. Stock options assumed by the Corporation in the merger with Talmer were fully vested upon assumption. A summary of activity for the Corporation’s stock options as of and for the nine months ended September 30, 2016 is presented below: Non-Vested Stock Options Outstanding Stock Options Outstanding Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Grant Date Fair Value Per Share Number of Options Weighted- Average Exercise Price Per Share Outstanding at December 31, 2015 479,755 $ 28.75 $ 8.49 1,054,739 $ 25.38 Acquired — — — 1,466,408 15.08 Granted 441,167 32.81 — 441,167 32.81 Exercised — — — (220,026 ) 24.08 Vested (454,360 ) 28.74 8.49 — — Forfeited/expired (47,286 ) 30.69 7.42 (47,286 ) 30.69 Outstanding at September 30, 2016 419,276 $ 32.81 $ 6.15 2,695,002 $ 21.01 Exercisable/vested at September 30, 2016 2,275,726 $ 18.84 The weighted-average remaining contractual terms were 6.2 years for all outstanding stock options and 5.7 years for exercisable stock options at September 30, 2016 . The intrinsic value of all outstanding in-the-money stock options and exercisable in-the-money stock options was $62.3 million and $57.6 million , respectively, at September 30, 2016 . The aggregate intrinsic values of outstanding and exercisable options at September 30, 2016 were calculated based on the closing market price of the Corporation’s common stock on September 30, 2016 of $44.13 per share less the exercise price. Options with intrinsic values less than zero, or “out-of-the-money” options, are not included in the aggregate intrinsic value reported. At September 30, 2016 , unrecognized compensation expense related to stock options totaled $2.3 million and is expected to be recognized over a remaining weighted average period of 4.4 years . Stock options granted prior to 2016 contain change-of-control provisions that triggered full vesting upon the merger with Talmer. As a result, unrecognized compensation expense related to these stock options was recognized by the Corporation during the three months ended September 30, 2016. The fair value of the stock options granted during the nine months ended September 30, 2016 was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions. Expected dividend yield 3.30 % Risk-free interest rate 1.39 % Expected stock price volatility 27.9 % Expected life of options – in years 6.5 Weighted average fair value of options granted $ 6.15 Restricted Stock Units The Corporation grants restricted stock performance units and restricted stock service-based units (collectively referred to as restricted stock units) to certain officers from time to time. The restricted stock performance units vest based on the Corporation achieving certain performance target levels and the grantee completing the requisite service period. The restricted stock performance units are eligible to vest from 0.5 x to 1.5 x the number of units originally granted depending on which, if any, of the performance target levels are met. However, if the minimum performance target levels are not achieved, no shares will become vested or be issued for that respective year’s restricted stock performance units. The restricted stock service-based units vest upon satisfaction of a service condition. Upon achievement of the performance target level and/or satisfaction of a service condition, as applicable, the restricted stock units are converted into shares of the Corporation’s common stock on a one-to-one basis. Compensation expense related to restricted stock units is recognized over the expected requisite performance or service period, as applicable. A summary of the activity for restricted stock units as of and for the nine months ended September 30, 2016 is presented below: Number of Units Weighted-average grant date fair value per unit Outstanding at December 31, 2015 207,989 $ 26.41 Granted 133,620 34.75 Converted into shares of common stock (67,207 ) 24.54 Forfeited/expired (5,656 ) 29.30 Outstanding at September 30, 2016 268,746 $ 30.97 At September 30, 2016 , unrecognized compensation expense related to restricted stock units totaled $5.6 million and is expected to be recognized over a remaining weighted average period of 2.6 years . Certain restricted stock units granted prior to 2016 fully vested upon completion of the merger with Talmer in accordance with the terms of the restricted stock units. In addition, while certain holders of restricted stock units agreed, in consideration for the award of additional restricted stock units that the holder and the Corporation agreed was a material benefit to which the holder was not otherwise entitled, with the Corporation to amend the terms of their restricted stock units such that vesting did not occur upon completion of the merger and remained subject to existing performance-based or time-based vesting schedules. As a result, unrecognized compensation expense related to the elected restricted stock units was recognized by the Corporation during the three months ended September 30, 2016. Restricted Stock Awards The Corporation assumed restricted stock awards that vest upon completion of future service requirements in the merger with Talmer. The fair value of these awards is equal to the market price of the Corporation's common stock at the date the awards were assumed with the portion of the fair value related to post-combination service. The Corporation recognizes stock-based compensation expense over the vesting period, using the straight-lined method, based upon the number of shares of restricted stock ultimately expected to vest. If an individual awarded restricted stock awards terminates employment prior to the end of the vesting period, the unvested portion of the stock is forfeited, with certain exceptions. The following table provides information regarding nonvested restricted stock awards: Nonvested restricted stock awards Number of Awards Weighted-average acquisition-date Nonvested at January 1, 2016 — $ — Acquired 484,892 46.23 Vested — — Forfeited (508 ) 46.23 Nonvested at September 30, 2016 484,384 $ 46.23 At September 30, 2016, unrecognized compensation expense related to nonvested restricted stock awards totaled $ 14.8 million and is expected to be recognized over a remaining weighted average period of 1.5 years.

Pension and Other Postretiremen

Pension and Other Postretirement Benefit Plans	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefit Plans	Pension and Other Postretirement Benefit Plans The Corporation's retirement plans include a qualified pension plan, a nonqualified pension plan, a nonqualified postretirement benefit plan, a 401(k) savings plan, and a multi-employer defined benefit plan. Qualified and Nonqualified Pension Plans and Nonqualified Postretirement Benefit Plans The components of net periodic benefit cost for the Corporation’s qualified and nonqualified pension plans and nonqualified postretirement benefit plan are as follows: Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Defined Benefit Pension Plans Service cost $ 279 $ 273 $ 834 $ 818 Interest cost 1,357 1,331 4,072 3,995 Contractual termination cost 32 — 32 — Expected return on plan assets (2,141 ) (2,161 ) (6,422 ) (6,483 ) Amortization of prior service credit — (2 ) — (4 ) Amortization of unrecognized net loss 585 1,057 1,729 3,169 Net periodic benefit cost $ 112 $ 498 $ 245 $ 1,495 Postretirement Benefit Plan Service cost $ 2 $ 4 $ 7 $ 12 Interest cost 33 33 99 100 Amortization of prior service cost 29 32 88 97 Amortization of unrecognized net gain (24 ) — (75 ) (1 ) Net periodic benefit cost $ 40 $ 69 $ 119 $ 208 The Corporation’s pension plan does not have a contribution requirement in 2016 . The Corporation did no t make a contribution to the pension plan during 2015 . The discount rate used to compute the Corporation's pension plan expense for 2016 is 4.55% . The discount rate used to compare the Corporation's nonqualified pension plan for 2016 was 4.51% . Effective September 1, 2016, the discount rate was adjusted to 2.87% based on the remeasurement of the Plan required due to the merger with Talmer. The remeasurement resulted in the Corporation recognizing an additional $786 thousand of pension liability. 401(k) Savings Plan 401(k) Savings Plan expense for the Corporation’s match of participants’ base compensation contributions and a 4% of eligible pay contribution to certain employees who are not grandfathered under the pension plan was $1.7 million and $1.4 million for the three months ended September 30, 2016 and 2015 , respectively, and $4.4 million and $3.8 million for the nine months ended September 30, 2016 and 2015 , respectively. Multi-Employer Defined Benefit Plan In conjunction with the April 1, 2015 acquisition of Monarch, the Corporation acquired a participation in the Pentegra Defined Benefit Plan for Financial Institutions (Pentegra DB Plan), a qualified defined benefit pension plan. Employee benefits for Monarch employees under the Plan were frozen effective April 1, 2004. The Pentegra DB Plan operates as a multi-employer plan for accounting purposes and as a multiple-employer plan under the Employee Retirement Income Security Act of 1974 and the Internal Revenue Code (IRC). The Pentegra DB Plan is a single plan under IRC Section 413(c) and, as a result, all of the plan's assets stand behind all of the plan's liabilities. Accordingly, contributions made by a participating employer may be used to provide benefits to participants of other participating employers. No contributions were made by the Corporation to the Pentegra DB Plan for the three and nine months ended September 30, 2016 and 2015.

Financial Guarantees

Financial Guarantees	9 Months Ended
	Sep. 30, 2016
Guarantees [Abstract]
Financial Guarantees	Financial Guarantees In the normal course of business, the Corporation offers a variety of financial instruments containing credit risk that are not required to be reflected in the Consolidated Statements of Financial Position. These financial instruments include outstanding commitments to extend credit, approved but undisbursed loans (undisbursed loan commitments), credit lines, commercial letters of credit and standby letters of credit. The Corporation has risk management policies to identify, monitor and limit exposure to credit risk. To mitigate credit risk for these financial guarantees, the Corporation generally determines the need for specific covenant, guarantee and collateral requirements on a case-by-case basis, depending on the nature of the financial instrument and the customer’s creditworthiness. At September 30, 2016 and December 31, 2015 , the Corporation had $117.3 million and $38.8 million , respectively, of outstanding financial and performance standby letters of credit. The majority of these standby letters of credit are collateralized. The Corporation determined that there were no potential losses from standby letters of credit at September 30, 2016 and December 31, 2015 . Commitments to extend credit are agreements to lend to a customer provided there is no violation of any condition established in the commitment. Commitments generally have fixed expiration dates or other termination clauses and may not require payment of a fee. Since many commitments expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Corporation evaluates each customer's creditworthiness on an individual basis. The amount of collateral obtained, if deemed necessary by the Corporation upon extension of credit, is based on management's credit evaluation of the counterparty. The collateral held varies, but may include securities, real estate, accounts receivable, inventory, plant or equipment. Unfunded commitments under commercial lines of credit, revolving credit lines and overdraft protection agreements are included in commitments to extend credit. These lines of credit are generally uncollateralized, usually do not contain a specified maturity date and may be drawn upon only to the total extend to which the Corporation is committed. At September 30, 2016 and December 31, 2015 , the Corporation had $3.25 billion and $1.59 billion , respectively, of commitments to extend credit. The Corporation had undisbursed loan commitments of $480.0 million and $293.6 million at September 30, 2016 and December 31, 2015 , respectively. Undisbursed loan commitments are not included in loans on the Consolidated Statements of Financial Position. The majority of undisbursed loan commitments will be funded and convert to a portfolio loan within a one year period. The allowance for credit losses on lending-related commitments included $950 thousand and $0 at September 30, 2016 and December 31, 2015 , respectively, for probable credit losses inherent in the Corporation's unused commitments and was recorded in "Interest payable and other liabilities" in the Consolidated Statements of Financial Position. The Corporation has originated and sold certain loans, and additionally acquired the potential liability for those historical originated and sold loans by Talmer, for which the buyer has limited recourse to us in the event the loans do not perform as specified in the agreements. These loans had an outstanding balance of $22.6 million and $1.5 million at September 30, 2016 and December 31, 2015 , respectively. The maximum potential amount of undiscounted future payments that the Corporation could be required to make in the event of nonperformance by the borrower totaled $21.6 million and $1.5 million at September 30, 2016 and December 31, 2015 , respectively. In the event of nonperformance, the Corporation has rights to the underlying collateral securing the loans. As of September 30, 2016 and December 31, 2015 , respectively, the Corporation had recorded a liability of $200 thousand and $100 thousand , respectively, in connection with the recourse agreements, recorded in "Interest payable and other liabilities" in the Consolidated Statements of Financial Position. In connection with the Corporation's mortgage banking loan sales, and the historical sales of Talmer, the Corporation makes certain representations and warranties that the loans meet certain criteria, such as collateral type and underwriting standards. The Corporation may be required to repurchase individual loans and/or indemnify the purchaser against losses if the loan fails to meet established criteria. At September 30, 2016 and December 31, 2015 , respectively, the liability recorded in connection with these representations and warranties totaled $6.9 million and $4.0 million , respectively.

Derivative Instruments and Bala

Derivative Instruments and Balance Sheet Offsetting	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Balance Sheet Offsetting	Derivative Instruments and Balance Sheet Offsetting In the normal course of business, the Corporation enters into various transactions involving derivative instruments to manage exposure to fluctuations in interest rates and to meet the financing needs of customers (customer-initiated derivatives). These financial instruments involve, to varying degrees, elements of market and credit risk. Market and credit risk are included in the determination of fair value. Commitments to fund mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of mortgage loans to third party investors are considered derivatives. It is the Corporation’s practice to enter into forward commitments for the future delivery of mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of changes in interest rates resulting from its commitments to fund the loans. The Corporation enters into interest rate derivatives to provide a service to certain qualifying customers to help facilitate their respective risk management strategies, customer-initiated derivatives, and, therefore, are not used for interest rate risk management purposes. The Corporation generally takes offsetting positions with dealer counterparts to mitigate the inherent risk. Income primarily results from the spread between the customer derivative and the offsetting dealer positions. The Corporation additionally has written and purchased option derivatives consisting of instruments to facilitate an equity-linked time deposit product (the “Power Equity CD”). The Power Equity CD is a time deposit that provides the purchaser a guaranteed return of principal at maturity plus a potential equity return (a written option), while the Corporation receives a known stream of funds based on the equity return (a purchased option). The written and purchased options are mirror derivative instruments which are carried at fair value on the Consolidated Statements of Financial Position. The following table presents the notional amount and fair value of the Corporation’s derivative instruments held or issued in connection with customer-initiated and mortgage banking activities. September 30, 2016 December 31, 2015 Fair Value Fair Value (Dollars in thousands) Notional Amount (1) Gross Derivative Assets (2) Gross Derivative Liabilities (2) Notional Amount (1) Gross Derivative Assets (2) Gross Derivative Liabilities (2) Customer-initiated and mortgage banking derivatives: Customer-initiated derivatives $ 559,458 $ 12,250 $ 12,787 $ — $ — $ — Forward contracts related to mortgage loans to be delivered for sale 197,874 89 944 33,787 144 57 Interest rate lock commitments 157,743 2,674 56 23,421 42 90 Power Equity CD 36,372 2,183 2,183 33,703 1,832 1,832 Total gross derivatives $ 951,447 $ 17,196 $ 15,970 $ 90,911 $ 2,018 $ 1,979 (1) Notional or contract amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the Consolidated Statements of Financial Position. (2) Derivative assets are included within “Other assets” and derivative liabilities are included within “Other liabilities” on the Consolidated Statements of Financial Position. Included in the fair value of the derivative assets are credit valuation adjustments for counterparty credit risk totaling $745 thousand at September 30, 2016 and $0 at December 31, 2015 . In the normal course of business, the Corporation may decide to settle a forward contract rather than fulfill the contract. Cash received or paid in this settlement manner is included in “Mortgage banking revenue” in the Consolidated Statements of Income and is considered a cost of executing a forward contract. The following table presents the net gains (losses) related to derivative instruments reflecting the changes in fair value. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) Location of Gain (Loss) 2016 2015 2016 2015 Forward contracts related to mortgage loans to be delivered for sale Mortgage banking revenue $ (156 ) $ (384 ) $ (798 ) $ (24 ) Interest rate lock commitments Mortgage banking revenue (179 ) 308 307 39 Power Equity CD Other noninterest income — — — — Customer-initiated derivatives Other noninterest income (60 ) — (60 ) — Total gain (loss) recognized in income $ (395 ) $ (76 ) $ (551 ) $ 15 Methods and assumptions used by the Corporation in estimating the fair value of its forward contracts, interest rate lock commitments and customer-initiated derivatives are discussed in Note 9: Fair Value Measurements. Balance Sheet Offsetting Certain financial instruments, including customer-initiated derivatives, may be eligible for offset in the Consolidated Statements of Financial Position and/or subject to master netting arrangements or similar agreements. The Corporation is party to master netting arrangements with its financial institution counterparties; however, the Corporation does not offset assets and liabilities under these arrangements for financial statement presentation purposes based on an accounting policy election. The tables below present information about the Corporation’s financial instruments that are eligible for offset. There were no financial instruments eligible for offset as of December 31, 2015. Gross amounts not offset in the (Dollars in thousands) Gross Gross amounts Net amounts Financial Collateral Net September 30, 2016 Offsetting derivative assets Derivative assets $ 12,247 $ — $ 12,247 $ — $ — $ 12,247 Offsetting derivative liabilities Derivative liabilities 12,785 — 12,785 — 12,530 255

Other Real Estate Owned and Rep

Other Real Estate Owned and Repossessed Assets	9 Months Ended
	Sep. 30, 2016
Other Real Estate [Abstract]
Other Real Estate Owned and Repossessed Assets	Other Real Estate Owned and Repossessed Assets Changes in other real estate owned and repossessed assets were as follows: (Dollars in thousands) Other real estate Repossessed Balance at January 1, 2016 $ 9,716 $ 219 Additions due to acquisitions 13,227 313 Other additions (1) 3,945 2,084 Net payments received (171 ) (764 ) Disposals (6,232 ) (1,231 ) Write-downs (376 ) — Balance at September 30, 2016 $ 20,109 $ 621 Balance at January 1, 2015 $ 13,953 $ 252 Additions due to acquisitions 440 — Other additions (1) 5,651 1,761 Net payments made/(received) 8 (13 ) Disposals (8,179 ) (1,739 ) Write-downs (927 ) — Balance at September 30, 2015 $ 10,946 $ 261 (1) Includes loans transferred to other real estate owned and other repossessed assets. At September 30, 2016 the Corporation had $893 thousand of other real estate owned and repossessed assets as a result of obtaining physical possession in accordance with ASU No. 2014-04, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans Upon Foreclosure. In addition, there were $8.1 million of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process, as of September 30, 2016 . Income and expenses related to other real estate owned and repossessed assets, recorded as a component of “Other expense” in the Consolidated Statements of Income, were as follows: (Dollars in thousands) Other real estate owned Repossessed assets For the three months ended September 30, 2016 Net gain (loss) on sale $ 788 $ (5 ) Write-downs (145 ) — Net operating expenses (176 ) (8 ) Total $ 467 $ (13 ) For the nine months ended September 30, 2016 Net gain (loss) on sale $ 2,830 $ 696 Write-downs (376 ) — Net operating expenses (588 ) (11 ) Total $ 1,866 $ 685 For the three months ended September 30, 2015 Net gain (loss) on sale $ 1,214 $ — Write-downs (363 ) — Net operating expenses (360 ) (2 ) Total $ 491 $ (2 ) For the nine months ended September 30, 2015 Net gain (loss) on sale $ 3,376 $ (21 ) Write-downs (927 ) — Net operating expenses (1,238 ) (10 ) Total $ 1,211 $ (31 )

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Corporation records its federal income tax expense using its estimate of the effective income tax rate expected for the full year and applies that rate on a year-to-date basis. The fluctuations in the Corporation's effective federal income tax rate reflect changes each period in the proportion of interest income exempt from federal taxation, nondeductible transaction costs and other nondeductible expenses relative to pretax income and tax credits. The differences between the provision for federal income taxes computed at the federal statutory income tax rate and the amounts recorded in the consolidated financial statements were as follows: Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Tax at statutory rate $ 5,016 $ 11,923 $ 29,400 $ 30,844 Changes resulting from: Tax-exempt interest income (1,321 ) (1,033 ) (3,599 ) (2,809 ) State taxes, net of federal benefit (803 ) — (803 ) — Change in valuation allowance (29 ) — (29 ) — Bank-owned life insurance adjustments (169 ) — (524 ) — Director plan change in control (525 ) — (525 ) — Income tax credits, net (413 ) (992 ) (2,428 ) (1,851 ) Nondeductible transaction expenses 2,100 — 2,100 525 Other, net (256 ) (298 ) 708 91 Provision for federal income taxes $ 3,600 $ 9,600 $ 24,300 $ 26,800 Effective federal income tax rate 25.1 % 28.2 % 28.9 % 30.4 % The significant components of the deferred tax assets and liabilities at September 30, 2016 and December 31, 2015 were as follows: (Dollars in thousands) September 30, December 31, Deferred tax assets: Allowance for loan losses $ 44,233 $ 24,863 Acquisition-related fair value adjustments 65,596 29,280 Accrued stock-based compensation 18,353 3,240 Loss and tax credit carry forwards 55,921 6,850 Acquisition built in loss carry forwards 31,316 — Depreciation 3,900 4,333 Nonaccrual interest 8,064 4,994 Accrued expense 18,400 13,296 Other 17,861 5,951 Total deferred tax assets 263,644 92,807 Deferred tax liabilities: Loan servicing rights 18,021 3,893 Core deposit intangible assets 9,938 7,379 Goodwill 6,350 5,808 Other 7,829 4,742 Total deferred tax liabilities 42,138 21,822 Net deferred tax asset before valuation allowance 221,506 70,985 Valuation allowance (2,502 ) (795 ) Net deferred tax asset $ 219,004 $ 70,190 On August 31, 2016, the Corporation merged with Talmer and recorded $155.9 million in net deferred tax assets. Upon merging, Talmer incurred an ownership change within the meaning of Section 382 of the Internal Revenue Code (IRC), limiting the Corporation’s ability to benefit from the use of Talmer’s pre-ownership change loss and tax credit carry forwards. At August 31, 2016, Talmer had $91.8 million in gross federal net operating loss carry forwards, $88.7 million in gross realized built-in loss carry forwards, $1.0 million in tax credit carry forwards that expire from 2026 through 2035, and $16.7 million in federal alternative minimum tax credits with an indefinite life. Talmer’s acquisitions prior to its merger with the Corporation on August 31, 2016 resulted in ownership changes within the meaning of IRC Section 382. As such, the Corporation’s ability to benefit from the use of Talmer’s previously acquired entities’ pre-ownership change net operating loss and tax credit carry forwards, as well as the deductibility of certain built-in losses if realized during a five-year recognition period (one year with respect to bad debt deductions), is limited, putting at risk the utilization of associated deferred tax assets before they expire. At August 31, 2016, a valuation allowance of $1.8 million was established against the deferred tax assets associated with Talmer’s previously acquired entities’ pre-change net operating losses and tax credit carry forwards, realized built-in loss carry forwards and management's estimate of the amount and timing of built-in losses more likely than not to be realized over the remaining Section 382 recognition periods. The valuation allowance against the Corporation’s deferred tax assets at September 30, 2016 totaled $2.5 million and included $1.7 million due to IRC Section 382 limitations on the utilization of pre-ownership change loss and tax credits carry forwards associated with Talmer’s previously acquired entities and $0.8 million due to management’s estimate of capital loss carry forwards more likely than not to expire unutilized. Actual outcomes could vary from the Corporation's current estimates, resulting in future increases or decreases in the valuation allowance and corresponding future tax expense or benefit. Management concluded that no valuation allowance was necessary on the remainder of the Corporation's net deferred tax assets at September 30, 2016 and December 31, 2015. This determination was based on the Corporation's history of pre-tax and financial taxable income over the prior three years, as well as management's expectations for sustainable profitability in the future. Management monitors deferred tax assets quarterly for changes affecting realizability and the valuation allowance could be adjusted in future periods.

Significant Accounting Polici25

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Chemical Financial Corporation ("Corporation" or "Chemical") operates in a single operating segment — commercial banking. The Corporation is a financial holding company, headquartered in Midland, Michigan, that operates through two commercial banks, Chemical Bank and Talmer Bank and Trust. Talmer Bank and Trust was added to operations in the August 31, 2016 merger with Talmer Bancorp, Inc. ("Talmer"), and is expected to be consolidated with and into Chemical Bank during the fourth quarter of 2016. Chemical Bank operates within the State of Michigan as a state-chartered commercial bank. Talmer Bank and Trust is a Michigan state-chartered bank. Chemical Bank and Talmer Bank and Trust operate through an internal organizational structure of seven regional banking units and offer a full range of traditional banking and fiduciary products and services to the residents and business customers in the bank’s geographical market areas. The products and services offered by the regional banking units, through branch banking offices, are generally consistent throughout the Corporation, as is the pricing of those products and services. The marketing of products and services throughout the Corporation’s regional banking units is generally uniform, as many of the markets served by the regional banking units overlap. The distribution of products and services is uniform throughout the Corporation’s regional banking units and is achieved primarily through retail branch banking offices, automated teller machines and electronically accessed banking products. The Corporation’s primary sources of revenue are interest from its loan products and investment securities, service charges and fees from customer deposit accounts, wealth management revenue and mortgage banking revenue.
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated financial statements of the Corporation and its subsidiaries have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, the interim consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Corporation’s consolidated financial statements and footnotes thereto included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2015. In the opinion of management, the accompanying unaudited interim consolidated financial statements contain all adjustments believed necessary to present fairly the financial condition and results of operations of the Corporation for the periods presented. Operating results for the nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 .
Use of Estimates	Use of Estimates Management makes estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying footnotes. Estimates that are particularly susceptible to significant change include the determination of the allowance for loan losses, expected cash flows from acquired loans, fair value amounts related to business combinations, pension expense, income taxes, goodwill impairment and those assets that require fair value measurement. Actual results could differ from these estimates.
Business Combinations	Business Combinations Pursuant to the guidance of Accounting Standards Codification ("ASC") Topic 805, Business Combinations ("ASC 805"), the Corporation recognizes assets acquired, including identified intangible assets, and the liabilities assumed in acquisitions at their fair values as of the acquisition date, with the acquisition-related transaction and restructuring costs expensed in the period incurred. On August 31, 2016, the Corporation acquired all the outstanding stock of Talmer for total consideration of $1.61 billion , which included stock consideration of $1.50 billion and cash consideration of $107.6 million . The Corporation recorded $850.3 million of goodwill in conjunction with the merger, which represented the purchase price over the fair value of identifiable net assets acquired. Additionally, the Corporation recorded $12.4 million of core deposit intangible assets in conjunction with the acquisition related to total deposits acquired of $5.29 billion . ASC 805 affords a measurement period beyond the acquisition date that allows the Corporation the opportunity to finalize the acquisition accounting in the event that new information is identified that existed as of the acquisition date but was not known by the Corporation at that time. The Corporation anticipates that measurement period adjustments may arise from adjustments to the fair values of assets and liabilities recognized at the acquisition date for its August 31, 2016 merger with Talmer, as additional information is obtained, such as appraisals of collateral securing loans and other borrower information. In the event that a measurement period adjustment is identified, the Corporation will recognize the adjustment as part of its acquisition accounting, which may result in an adjustment to goodwill being recorded in the period the adjustment was identified.
Originated Loans	Originated Loans Originated loans include all of the Corporation's portfolio loans, excluding loans acquired in business combinations, as further discussed below. Originated loans are stated at their principal amount outstanding, net of unearned income, charge-offs and unamortized deferred fees and costs. Loan interest income is recognized on the accrual basis. Deferred loan fees and costs are amortized over the loan term based on the level-yield method. Net loan commitment fees are deferred and amortized into fee income on a straight-line basis over the commitment period. The past due status of a loan is based on the loan’s contractual terms. A loan is placed in nonaccrual status (accrual of interest is discontinued) when principal or interest is past due 90 days or more (except for a loan that is secured by residential real estate, which is transferred to nonaccrual status at 120 days past due), unless the loan is both well-secured and in the process of collection, or earlier when, in the opinion of management, there is sufficient reason to doubt the collectibility of principal or interest. Interest previously accrued, but not collected, is reversed and charged against interest income at the time the loan is placed in nonaccrual status. Subsequent receipts of interest while a loan is in nonaccrual status are recorded as a reduction of principal. Loans are returned to accrual status when principal and interest payments are brought current, payments have been received consistently for a period of time (generally six months ) and collectibility is no longer in doubt.
Loans Acquired in a Business Combination	Loans Acquired in a Business Combination Loans acquired in a business combination ("acquired loans") consist of loans acquired on August 31, 2016 in the merger with Talmer, on May 31, 2015 in the acquisition of Lake Michigan Financial Corporation ("Lake Michigan"), on April 1, 2015 in the acquisition of Monarch Community Bancorp, Inc. ("Monarch"), on October 31, 2014 in the acquisition of Northwestern Bancorp, Inc. ("Northwestern"), and on April 30, 2010 in the acquisition of O.A.K. Financial Corporation ("OAK"). Acquired loans were recorded at fair value at the date of acquisition, without a carryover of the associated allowance for loan losses related to these loans. The Corporation accounts for acquired loans, which are recorded at fair value at acquisition, in accordance with ASC Topic 310-30, Loans and Debt Securities Acquired with Deteriorated Credit Quality ("ASC 310-30"). ASC 310-30 allows investors to aggregate loans acquired into loan pools that have common risk characteristics and thereby use a composite interest rate and expectation of cash flows expected to be collected for the loan pools. Under the provisions of ASC 310-30, the Corporation aggregated acquired loans into 5 pools in the merger with Talmer, 2 pools in the acquisition of Lake Michigan, 2 pools in the acquisition of Monarch, 4 pools in the acquisition of Northwestern and 14 pools in the acquisition of OAK based upon common risk characteristics, including types of loans, commercial type loans with similar risk grades and whether loans were performing or nonperforming. A pool is considered a single unit of accounting for the purposes of applying the guidance prescribed in ASC 310-30. A loan will be removed from a pool of acquired loans only if the loan is sold, foreclosed, paid off or written off, and will be removed from the pool at the carrying value. If an individual loan is removed from a pool of loans, the difference between its relative carrying amount and the cash, fair value of the collateral, or other assets received would not affect the effective yield used to recognize the accretable difference on the remaining pool. The estimate of expected credit losses was determined based on due diligence performed by executive and senior officers of the Corporation, with assistance from third-party consultants. The Corporation estimated the cash flows expected to be collected over the life of the pools of loans at acquisition and estimates expected cash flows quarterly thereafter, based on a set of assumptions including expectations as to default rates, prepayment rates and loss severities. The Corporation must make numerous assumptions, interpretations and judgments using internal and third-party credit quality information to determine whether it is probable that the Corporation will be able to collect all contractually required payments. This is a point in time assessment and inherently subjective due to the nature of the available information and judgment involved. The calculation of the fair value of the acquired loan pools entails estimating the amount and timing of cash flows attributable to both principal and interest expected to be collected on such loan pools and then discounting those cash flows at market interest rates. The excess of a loan pool's expected cash flows at the acquisition date over its estimated fair value is referred to as the "accretable yield," which is recognized into interest income over the estimated remaining life of the loan pool on a level-yield basis. The difference between a loan pool's contractually required principal and interest payments at the acquisition date and the cash flows expected to be collected at the acquisition date is referred to as the "nonaccretable difference," which includes an estimate of future credit losses expected to be incurred over the estimated life of the loan pool and interest payments that are not expected to be collected. Decreases to the expected cash flows in each loan pool in subsequent periods will require the Corporation to record a provision for loan losses. Improvements in expected cash flows in each loan pool in subsequent periods will result in reversing a portion of the nonaccretable difference, which is then classified as part of the accretable yield and subsequently recognized into interest income over the estimated remaining life of the loan pool.
Loans Modified Under Troubled Debt Restructurings	Loans Modified Under Troubled Debt Restructurings Loans modified under troubled debt restructurings ("TDRs") involve granting a concession to a borrower who is experiencing financial difficulty. Concessions generally include modifications to original loan terms, including changes to a loan’s payment schedule or interest rate, which generally would not otherwise be considered. The Corporation’s TDRs include performing and nonperforming TDRs, which consist of originated loans that continue to accrue interest at the loan's original interest rate as the Corporation expects to collect the remaining principal and interest on the loan, and nonaccrual TDRs, which include originated loans that are in a nonaccrual status and are no longer accruing interest, as the Corporation does not expect to collect the full amount of principal and interest owed from the borrower on these loans. At the time of modification (except for loans on nonaccrual status), a TDR is reported as a nonperforming TDR until a six -month payment history of principal and interest payments, in accordance with the terms of the loan modification, is sustained, at which time the Corporation moves the loan to a performing status ("performing TDR"). If the Corporation does not expect to collect all principal and interest on the loan, the modified loan is classified as a nonaccrual TDR. All TDRs are accounted for as impaired loans and are included in the Corporation’s analysis of the allowance for loan losses. A TDR that has been renewed by a borrower who is no longer experiencing financial difficulty and which yields a market rate of interest at the time of a renewal is no longer reported as a TDR. Loans in the Corporation’s commercial loan portfolio (comprised of commercial, commercial real estate, real estate construction and land development loans) that meet the definition of a TDR generally consist of loans where the Corporation has allowed borrowers to defer scheduled principal payments and make interest-only payments for a specified period of time at the stated interest rate of the original loan agreement or reduced payments due to a moderate extension of the loan’s contractual term. If the Corporation does not expect to collect all principal and interest on the loan, the modified loan is classified as a nonaccrual TDR. If the Corporation does not expect to incur a loss on the loan based on its assessment of the borrowers’ expected cash flows, as the pre- and post-modification effective yields are approximately the same, the loan is classified as a nonperforming TDR until a six-month payment history is sustained, at which time the loan is classified as a performing TDR. Since no loss is expected to be incurred on nonperforming TDRs, no additional provision for loan losses has been recognized for these loans and they continue to accrue interest at their contractual interest rate. Nonperforming TDRs are transferred to nonaccrual status if they become 90 days past due as to principal or interest payments or if it is probable that any remaining principal and interest payments due on the loan will not be collected in accordance with the modified terms of the loan. Loans in the Corporation’s consumer loan portfolio (comprised of residential mortgage, consumer installment and home equity loans) that meet the definition of a performing or nonperforming TDR generally consist of residential mortgage loans that include a concession that reduces a borrower’s monthly payments by decreasing the interest rate charged on the loan for a specified period of time (generally 24 months ) under a formal modification agreement. The Corporation recognizes an additional provision for loan losses related to impairment on these loans on an individual basis based on the present value of expected future cash flows discounted at the loan’s original effective interest rate. These loans continue to accrue interest at their effective interest rate, which consists of contractual interest under the terms of the modification agreement in addition to an adjustment for the accretion of computed impairment. These loans are moved to nonaccrual status if they become 90 days past due as to principal or interest payments, or sooner if conditions warrant.
Impaired Loans	Impaired Loans A loan is defined to be impaired when it is probable that payment of principal and interest will not be paid in accordance with the original contractual terms of the loan agreement. Impaired loans include nonaccrual loans (including nonaccrual TDRs), performing and nonperforming TDRs and acquired loans that were not performing in accordance with original contractual terms. Impaired loans are accounted for at the lower of the present value of expected cash flows discounted at the loan's original effective interest rate or the estimated fair value of the collateral, if the loan is collateral dependent. When the present value of expected cash flows or the fair value of collateral of an impaired loan in the originated loan portfolio is less than the amount of unpaid principal outstanding on the loan, the principal balance of the loan is reduced to its carrying value through either an allocation of the allowance for loan losses or a partial charge-off of the loan balance.
Nonperforming Loans	Nonperforming Loans Nonperforming loans are comprised of loans for which the accrual of interest has been discontinued (nonaccrual loans, including nonaccrual TDRs), accruing originated loans contractually past due 90 days or more as to interest or principal payments and nonperforming TDRs. Acquired loans that were classified as nonperforming loans prior to being acquired and acquired loans that are not performing in accordance with contractual terms subsequent to acquisition are not classified as nonperforming loans subsequent to acquisition because the loans are recorded in pools at net realizable value based on the principal and interest the Corporation expects to collect on such loans.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses ("allowance") is presented as a reserve against loans. The allowance represents management’s assessment of probable loan losses inherent in the Corporation’s loan portfolio. Management’s evaluation of the adequacy of the allowance is based on a continuing review of the loan portfolio, actual loan loss experience, the underlying value of the collateral, risk characteristics of the loan portfolio, the level and composition of nonperforming loans, the financial condition of the borrowers, the balance of the loan portfolio, loan growth, economic conditions, employment levels in the Corporation’s local markets, and special factors affecting specific business sectors. The Corporation maintains formal policies and procedures to monitor and control credit risk. Management evaluates the allowance on a quarterly basis in an effort to ensure the level is appropriate to absorb probable losses inherent in the loan portfolio. The allowance provides for probable losses that have been identified with specific customer relationships and for probable losses believed to be incurred in the remainder of the originated loan portfolio, but that have not been specifically identified. The Corporation utilizes its own loss experience to estimate inherent losses on originated loans. Internal risk ratings are assigned to each loan in the commercial loan portfolio (commercial, commercial real estate, real estate construction and land development loans) at the time of origination and are subject to subsequent periodic reviews by senior management. The Corporation performs a detailed credit quality review quarterly on all loans greater than $0.25 million that have deteriorated below certain levels of credit risk, and may allocate a specific portion of the allowance to such loans based upon this review. A portion of the allowance is allocated to the remaining loans by applying projected loss ratios, based on numerous factors. Projected loss ratios incorporate factors such as charge-off experience, trends with respect to adversely risk-rated loans in the commercial loan portfolio, trends with respect to past due and nonaccrual loans, changes in economic conditions and trends, changes in the value of underlying collateral and other credit risk factors. This evaluation involves a high degree of uncertainty. In determining the allowance and the related provision for loan losses, the Corporation considers four principal elements: (i) valuation allowances based upon probable losses identified during the review of impaired loans in the commercial loan portfolio, (ii) reserves established for adversely-rated loans in the commercial loan portfolio and nonaccrual residential mortgage, consumer installment and home equity loans based on loan loss experience of other adversely-rated loans, (iii) reserves, by loan classes, on all other loans based principally on a five -year historical loan loss experience, with equal weighting placed on all of the years, loan loss trends and giving consideration to estimated loss emergence periods, and (iv) a reserve for qualitative factors that take into consideration risks inherent in the originated loan portfolio that differ from historical loan loss experience. Although the Corporation allocates portions of the allowance to specific loans and loan types, the entire allowance attributable to originated loans is available for any loan losses that occur in the originated portfolio. Loans that are deemed not collectible are charged off and reduce the allowance. The provision for loan losses and recoveries on loans previously charged off increase the allowance. Collection efforts may continue and recoveries may occur after a loan is charged off. Acquired loans are aggregated into pools based upon common risk characteristics. An allowance may be recorded related to an acquired loan pool if it experiences a decrease in expected cash flows, as compared to those projected at the acquisition date. On a quarterly basis, the expected future cash flow of each pool is estimated based on various factors, including changes in property values of collateral dependent loans, default rates, loss severities and prepayment speeds. Decreases in estimates of expected cash flows within a pool generally result in a charge to the provision for loan losses and a corresponding increase in the allowance allocated to acquired loans for the particular pool. Increases in estimates of expected cash flows within a pool generally result in a reduction in the allowance allocated to acquired loans for the particular pool, if applicable, and then an adjustment to the accretable yield for the pool, which will increase amounts recognized in interest income in subsequent periods. Various regulatory agencies, as an integral part of their examination process, periodically review the allowance. Such agencies may require additions to the allowance, based on their judgment, reflecting information available to them at the time of their examinations.
Fair Value Measurements	Fair Value Measurements Fair value for assets and liabilities measured at fair value on a recurring or nonrecurring basis refers to the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants in the market in which the reporting entity transacts such sales or transfers based on the assumptions market participants would use when pricing an asset or liability. Assumptions are developed based on prioritizing information within a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data, such as the reporting entity’s own data. The Corporation may choose to measure eligible items at fair value at specified election dates. Unrealized gains and losses on items for which the fair value measurement option has been elected are reported in earnings at each subsequent reporting date. At September 30, 2016 and December 31, 2015 , the Corporation had elected the fair value option on all of its residential mortgage loans held-for-sale. In addition, the Corporation elected to account for loan servicing rights acquired in the merger with Talmer effective August 31, 2016 under the fair value method. The Corporation has not elected the fair value option for any other financial assets or liabilities.
Share-Based Compensation	Share-Based Compensation The Corporation has outstanding share-based compensation, including stock options, stock awards, restricted stock awards, restricted stock performance units and restricted stock service-based units to certain executive and senior management employees. The Corporation accounts for share-based compensation expense using the modified-prospective transition method. Under that method, compensation expense is recognized for stock options based on the estimated grant date fair value as computed using the Black-Scholes option pricing model and the probability of issuance. The Corporation accounts for stock awards based on the closing stock price of the Corporation's common stock on the date the award is granted. The fair values of stock options, stock awards and restricted stock awards are recognized as compensation expense on a straight-line basis over the requisite service period. The Corporation accounts for restricted stock performance units based on the closing stock price of the Corporation's common stock on the date of grant, discounted by the present value of estimated future dividends to be declared over the requisite performance or service period. The fair value of restricted stock performance units is recognized as compensation expense over the expected requisite performance period, or requisite service period for awards with multiple performance and service conditions. The Corporation accounts for restricted stock service-based units based on the closing stock price of the Corporation's common stock on the date of grant, as these awards accrue dividend equivalents equal to the amount of any cash dividends that would have been payable to a shareholder owning the number of shares of the Corporation's common stock represented by the restricted stock service-based units. The fair value of the restricted stock service-based units is recognized as compensation expense over the requisite service period. Cash flows realized from the tax benefits of exercised stock option awards that result from actual tax deductions that are in excess of the recorded tax benefits related to the compensation expense recognized for those options (excess tax benefits) are classified as financing activities on the consolidated statements of cash flows.
Bank-Owned Life Insurance	Bank-Owned Life Insurance The Corporation has life insurance policies on certain key officers of Chemical Bank and Talmer Bank and Trust. The majority of the bank-owned life insurance policies of the Corporation were obtained through its acquisition of Lake Michigan and the merger with Talmer. Bank-owned life insurance is recorded at the cash surrender value, net of surrender charges, and is included within other assets on the consolidated statements of financial position and changes in the cash surrender values are recorded as other noninterest income on the consolidated statements of income.
Earnings Per Share	Earnings Per Share Beginning in the third quarter of 2016, the Corporation applies the two-class method of computing earnings per share as the Corporation acquired unvested restricted stock awards in the merger with Talmer which qualify as participating securities. Under this calculation, all outstanding unvested share-based payment awards that contain rights to nonforfeitable dividends are considered participating securities and earnings per share is determined according to dividends declared and participating rights in undistributed earnings. Basic earnings per common share is net income divided by the weighted average number of common shares outstanding during the period. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights and then are divided by the weighted-average number of common shares outstanding during the period. Diluted earnings per common share include the dilutive effect of additional potential common shares issuable under common stock equivalents.
Income and Other Taxes	Income and Other Taxes The Corporation is subject to the income and other tax laws of the United States, the State of Michigan and any other states where nexus has been created. These laws are complex and are subject to different interpretations by the taxpayer and the various taxing authorities. In determining the provision for income and other taxes, management must make judgments and estimates about the application of these inherently complex laws, related regulations and case law. In the process of preparing the Corporation’s tax returns, management attempts to make reasonable interpretations of enacted tax laws. These interpretations are subject to challenge by the tax authorities upon audit or to reinterpretation based on management’s ongoing assessment of facts and evolving case law. On a quarterly basis, management assesses the reasonableness of its effective federal tax rate based upon its estimate of taxable income and the applicable taxes expected for the full year. Deferred tax assets and liabilities are reassessed on a quarterly basis, including the need for a valuation allowance for deferred tax assets. Uncertain income tax positions are evaluated to determine whether it is more-likely-than-not that a tax position will be sustained upon examination based on the technical merits of the tax position. If a tax position is more-likely-than-not to be sustained, a tax benefit is recognized for the amount that is greater than 50% likely to be realized. Reserves for contingent income tax liabilities attributable to unrecognized tax benefits associated with uncertain tax positions are reviewed quarterly for adequacy based upon developments in tax law and the status of audits or examinations. The Corporation had no contingent income tax liabilities recorded at September 30, 2016 or December 31, 2015 .
Investments in Qualified Affordable Housing Projects, Federal Historic Projects and New Market Tax Credits	Investments in Qualified Affordable Housing Projects, Federal Historic Projects and New Market Tax Credits The Corporation invests in qualified affordable housing projects, federal historic projects, and new market projects for the purpose of community reinvestment and obtaining tax credits. Return on the Corporation's investment in these projects comes in the form of the tax credits and tax losses that pass through to the Corporation. The carrying value of the investments are reflected in other assets on the consolidated statements of financial position. The Corporation utilizes the proportional amortization method to account for investments in qualified affordable housing projects and the equity method to account for investments in other tax credit projects. Under the proportional amortization method, the Corporation amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits. The Corporat ion re cognized additional income tax expense attributable to the amortization of investments in qualified affordable housing projects of $0.4 million and $1.6 million during the three and nine months ended September 30, 2016 , respectively, and $0.6 million and $0.8 million during the three and nine months ended September 30, 2015 , respectively. The Corporation's remaining investment in qualified affordable housing projects accounted for under the proportional amortization method totaled $30.3 million at September 30, 2016 and $21.7 million at December 31, 2015 . Under the equity method, the Corporation's share of the earnings or losses are included in other operating expenses on the consolidated statements of income. The Corporation's remaining investment in new market projects accounted for under the equity method totaled $10.2 million and $1.7 million at September 30, 2016 and December 31, 2015 , respectively. The Corporation's unfunded equity contributions relating to investments in qualified affordable housing projects, federal historic tax projects and new market projects is recorded in other liabilities on the consolidated statements of financial position. The Corporation's remaining unfunded equity contributions totaled $16.8 million and $8.0 million at September 30, 2016 and December 31, 2015 . Management analyzes these investments for potential impairment when events or changes in circumstances indicate that it is more-likely-than-not that the carrying amount of the investment will not be realized. An impairment loss is measured as the amount by which the carrying amount of an investment exceeds its fair value. There were no impairment losses recognized as of September 30, 2016 or December 31, 2015 . The Corporation consolidates variable interest entities ("VIEs") in which it is the primary beneficiary. In general, a VIE is an entity that either (i) has an insufficient amount of equity to carry out its principal activities without additional subordinated financial support, (ii) has a group of equity owners that are unable to make significant decisions about its activities or (iii) has a group of equity owners that do not have the obligation to absorb losses or the right to receive returns as generated by its operations. If any of these characteristics are present, the entity is subject to a variable interests consolidation model, and consolidation is based on variable interests, not on ownership of the entity's outstanding voting stock. Variable interests are defined as contractual, ownership, or other monetary interests in an entity that change with fluctuations in the entity's net asset value. The primary beneficiary consolidates the VIE. The primary beneficiary is defined as the enterprise that has the power to direct the activities and absorb losses or the right to receive benefits. The Corporation is a significant limited partner in the qualified affordable housing, federal historic and new market projects it has invested in . These projects meet the definition of VIEs. However, the Corporation is not the primary beneficiary of any of the VIEs in which it holds a limited partnership interest; therefore, the VIEs are not consolidated in the Corporation's consolidated financial statements.
Shareholders' Equity	Shareholders’ Equity Common Stock Repurchase Programs From time to time, the board of directors of the Corporation approves common stock repurchase programs allowing management to repurchase shares of the Corporation’s common stock in the open market. The repurchased shares are available for later reissuance in connection with potential future stock dividends, the Corporation’s dividend reinvestment plan, employee benefit plans and other general corporate purposes. Under these programs, the timing and actual number of shares subject to repurchase are at the discretion of management and are contingent on a number of factors, including the projected parent company cash flow requirements and the Corporation’s market price per share. In January 2008, the board of directors of the Corporation authorized the repurchase of up to 500,000 shares of the Corporation’s common stock under a stock repurchase program. In November 2011, the board of directors of the Corporation reaffirmed the stock buy-back authorization with the qualification that the shares may only be repurchased if the share price is below the tangible book value per share of the Corporation’s common stock at the time of the repurchase. Since the January 2008 authorization, no shares have been repurchased. At September 30, 2016 , there were 500,000 remaining shares available for repurchase under the Corporation’s stock repurchase program. Shelf Registration On June 12, 2014, the Corporation filed an automatic shelf registration statement on Form S-3 with the Securities and Exchange Commission ("SEC") for an indeterminate amount of securities, which became immediately effective. The shelf registration statement provides the Corporation with the ability to raise capital, subject to SEC rules and limitations, if the board of directors of the Corporation decides to do so. Preferred Stock On April 20, 2015, the shareholders of the Corporation approved an amendment to the restated articles of incorporation which eliminated and replaced the previous class of 200,000 shares of preferred stock, that had been approved by shareholders on April 20, 2009, with a new class of 2,000,000 shares of preferred stock. At September 30, 2016 , no shares of preferred stock were issued and outstanding. Common Stock On July 19, 2016, the shareholders of the Corporation approved an amendment to the restated articles of incorporation to increase the number of authorized shares of common stock from 60,000,000 to 100,000,000 in anticipation of the merger with Talmer.
Legal Matters	Legal Matters On February 22, 2016, two putative class action and derivative complaints were filed in the Circuit Court for Oakland County, Michigan by individuals purporting to be a shareholder of Talmer. The actions are styled Regina Gertel Lee v. Chemical Financial Corporation, et. al. , Case No. 2016-151642-CB and City of Livonia Employees’ Retirement System v. Chemical Financial Corporation et. al., Case No. 2016-151641-CB. These complaints purport to be brought derivatively on behalf of Talmer against the individual defendants, and individually and on behalf of all others similarly situated against Talmer and Chemical. The complaints allege, among other things, that the directors of Talmer breached their fiduciary duties to Talmer’s shareholders in connection with the merger by approving a transaction pursuant to an allegedly inadequate process that undervalues Talmer and includes preclusive deal protection provisions, and that Chemical allegedly aided and abetted the Talmer directors in breaching their duties to Talmer’s shareholders. The complaints also allege that the individual defendants have been unjustly enriched. Both complaints seek various remedies on behalf of the putative class (consisting of all shareholders of Talmer who are not related to or affiliated with any defendant). They request, among other things, that the Court enjoin the merger from being consummated in accordance with its agreed-upon terms, direct the Talmer directors to exercise their fiduciary duties, rescind the merger agreement to the extent that it is already implemented, award the plaintiff all costs and disbursements in each respective action (including reasonable attorneys’ and experts’ fees), and grant such further relief as the court deems just and proper. The City of Livonia plaintiff amended its complaint on April 21, 2016 to add additional factual allegations, including but not limited to allegations that Keefe Bruyette & Woods, Inc. ("KBW") served as a financial advisor for the proposed merger despite an alleged conflict of interest, that Talmer’s board acted under actual or potential conflicts of interest, and that the defendants omitted and/or misrepresented material information about the proposed merger in the Form S-4 Registration Statement relating to the proposed merger. These two cases were consolidated as In re Talmer Bancorp Shareholder Litigation , case number 2016-151641-CB, per an order entered on May 12, 2016. On October 31, 2016, the plaintiffs in this consolidated action again amended their complaint, adding additional factual allegations, adding KBW as a defendant, and asserting that KBW acted in concert with Chemical to aid and abet breaches of fiduciary duty by Talmer's directors. Talmer, Chemical, KBW and the individual defendants all believe that the claims asserted against each of them in the above-described consolidated action are without merit and intend to vigorously defend against these consolidated lawsuits. On March 22, 2016, an additional putative class action and derivative complaint was filed in the Circuit Court for Oakland County, Michigan, by an individual purporting to be a shareholder of Talmer, styled Stephen Bushansky v . Gary Torgow et. al . Case No. 2016-152112-CB. This action contained similar allegations, claims, and requests for relief as the complaints filed in the Lee and City of Livonia lawsuits discussed above. The Bushansky lawsuit was voluntarily dismissed by the plaintiff as to all defendants, without prejudice, on April 18, 2016. On April 27, 2016, Stephen Bushansky filed a new putative class action complaint in the United State District Court for Eastern District of Michigan, styled Stephen Bushansky v. Talmer Bancorp In. et.al., Docket No. 1:16-cv-11511. This lawsuit alleged violations of Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, and named Talmer, Chemical, and several individuals as defendants. The complaint alleged, among other things, that the Defendants issued materially incomplete and misleading disclosures in the preliminary Form S-4 Registration Statement relating to the proposed merger. The Federal Bushansky lawsuit was voluntarily dismissed by the plaintiff as to all defendants, without prejudice, on June 20, 2016. On April 6, 2016, a complaint was filed in the United States District Court for the Eastern District of Michigan by another purported shareholder of Talmer, styled Matthew Sciabacucchi v. Chemical Financial Corporation et. al ., Docket No. 1:16-cv-11261. Mr. Sciabacucchi purports to bring this action “on behalf of himself and all others similarly situated.” This lawsuit alleges violations of Sections 14(a) and 20(a) of the Securities Exchange Act of 1934, naming Talmer, Chemical, and several individuals as defendants. The complaint alleges, among other things, that the Defendants issued materially incomplete and misleading disclosures in the Form S-4 Registration Statement relating to the proposed merger. The Complaint contains requests for relief that include, among other things, that the Court enjoin the proposed transaction, rescind the transaction if it is consummated or award rescissory damages, order the Talmer directors to file a revised Registration Statement, declare that the Defendants violated Sections 14(a) and/or Section 20(a) of the Securities Exchange Act, as well as Rule 14a-9 promulgated thereunder, award the plaintiff all costs associated with bringing the action (including reasonable attorneys’ and experts’ fees), and grant such further relief as the court deems just and proper. Talmer, Chemical and the individual defendants all believe that the claims asserted against each of them in this lawsuit are without merit and intend to vigorously defend against this lawsuit. The Sciabacucchi lawsuit was voluntarily dismissed by the plaintiff as to all defendants, without prejudice, on August 5, 2016. On April 25, 2016, a complaint was filed in the United States District Court for the Eastern District of Michigan by another purported shareholder of Talmer, styled Kevin Nicholl v. Chemical Financial Corporation et. al ., Docket No. 1:16-cv-11482. The plaintiff names Talmer, Chemical, and several individuals as defendants. This lawsuit was styled as a class action and derivative action, and alleged breach of fiduciary duties as well as violations of Sections 14(a) and 20(a) of the Securities Exchange Act of 1934. The Nicholl lawsuit was voluntarily dismissed by the plaintiff as to all defendants, with prejudice, on June 20, 2016. On June 16, 2016, a complaint was filed in the United States District Court for the Eastern District of Michigan by a purported Talmer shareholder, styled City of Livonia Employees’ Retirement System v . Chemical Financial Corporation, et. al., Docket No. 1:16-cv-12229. The plaintiff purports to bring the action “individually and on behalf of all others similarly situated,” and requests certification as a class action. This lawsuit alleges violations of Section 14(a) and 20(a) of the Securities Exchange Act of 1934. The Complaint alleges, among other things, that the Defendants issued materially incomplete and misleading disclosures in the Form S-4 Registration Statement relating to the proposed merger. The Complaint contains requests for relief that include, among other things, that the Court enjoin the proposed transaction unless and until additional information is provided to Talmer’s shareholders, declare that the Defendants violated the securities laws in connection with the proposed merger, award compensatory damages, interest, attorneys’ and experts’ fees, and that the Court grant such other relief as it deems just and proper. Talmer, Chemical, and the individual defendants all believe that the claims asserted against each of them in this lawsuit are without merit and intend to vigorously defend against this lawsuit. On October 18, 2016, the Court entered a stipulated order staying this action until the Oakland County Circuit Court issues rulings on motions to dismiss that the defendants anticipate filing in In re Talmer Bancorp Shareholder Litigation , case number 2016-151641-CB. In addition, the Corporation, Chemical Bank and Talmer Bank and Trust are subject to certain legal actions arising in the ordinary course of business. In the opinion of management, after consultation with legal counsel, the ultimate disposition of these matters is not expected to have a material adverse effect on the consolidated financial condition or results of operations of the Corporation.
Reclassifications	Reclassifications Certain amounts appearing in the consolidated financial statements and notes thereto for prior periods have been reclassified to conform with the current presentation. The reclassification had no effect on net income or shareholders’ equity as previously reported.
Adopted and Pending Accounting Pronouncements	Adopted Accounting Pronouncements Consolidation of Variable Interest Entities In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis ("ASU 2015-02"). ASU 2015-02 is applicable to reporting entities that are required to evaluate whether they should consolidate certain legal entities. Specifically, ASU 2015-02 (i) modifies the evaluation of whether limited partnerships and similar legal entities are VIEs, (ii) eliminates the presumption that a general partner should consolidate a limited partnership, (iii) affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships and (iv) provides a scope exception from consolidation guidance for reporting entities with interests in legal entities that are required to comply with 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 adoption of ASU 2015-02 effective January 1, 2016 did not have a material impact on the Corporation's consolidated financial condition or results of operations. Customer's Accounting for Cloud Computing Fees In April 2015, the FASB issued ASU No. 2015-05, Intangibles - Goodwill and Other - Internal Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement ("ASU 2015-05"). ASU 2015-05 provides guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. ASU 2015-05 does not change the accounting for a customer’s accounting for service contracts. The purpose of ASU 2015-05 is to clarify which fees paid in a cloud computing arrangement should be capitalized and which fees should be expensed as incurred. The adoption of ASU 2015-05 prospectively effective January 1, 2016 did not have a material impact on the Corporation's consolidated financial condition or results of operations. Pending Accounting Pronouncements Revenue Recognition In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”), which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The ASU is intended to clarify and converge the revenue recognition principles under GAAP and International Financial Reporting Standards and to streamline revenue recognition requirements in addition to expanding required revenue recognition disclosures. In March 2016, the FASB issued ASU 2016-08, Principal versus Agent Considerations (Reporting Revenue Gross versus Net), ("ASU 2016-08"), which further clarifies ASU 2014-09 by providing implementation guidance on principal versus agent considerations. In April 2016, the FASB issued ASU 2016-10, Identifying Performance Obligations and Licensing, ("ASU 2016-10"), which provides additional clarification of ASU 2014-09 by amending guidance related to the identification of performance obligations and licensing implementation. ASU 2016-08 and ASU 2016-10 do not change the core principal of ASU 2014-09, but are intended to improve the operations and understanding of principal versus agent considerations, performance obligation identification and licensing implementation. In May 2016, the FASB issued ASU 2016-12, Narrow-Scope Improvements and Practical Expedients, ("ASU 2016-12"), which amends certain aspects of ASU 2014-09, which include collectibility, presentation of sales taxes and other taxes collected from customers, noncash consideration and transition technical corrections. ASU 2016-12 completes the FASB deliberations of clarifications to ASU 2014-09 that have been conducted over the last year. In August 2015, the FASB issued ASU 2015-14, Deferral of the Effective Date ("ASU 2015-14"), which provides a one year deferral to the effective date, therefore, ASU 2014-09 is effective for public companies for annual periods, and interim periods within those annual periods, beginning on or after December 15, 2017. As such, the Corporation will adopt ASU 2014-09 as of January 1, 2018. Under the provision, the Corporation will have the option to adopt the guidance using either a full retrospective method or a modified transition approach. The Corporation is currently evaluating the provisions of ASU 2014-09 on the Corporation's consolidated financial condition and results of operations. Recognition and Measurement In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ("ASU 2016-01"). ASU 2016-01 amends current guidance by: (i) requiring equity investments with readily determinable fair values to be measured at fair value with changes in fair value recognized in net income, (ii) allowing an entity to measure equity investments that do not have readily determinable fair values at either fair value or cost minus impairment, if any, plus or minus changes in observable prices, with changes in measurement recognized in net income, (iii) simplifying the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment, (iv) eliminating the requirement to disclose the methods and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet; (v) requiring use the of exit price notion when measuring the fair value of financial instruments for disclosure purposes; (vi) requiring recognition of changes in the fair value related to instrument-specific credit risk in other comprehensive income if the fair value option for financial liabilities is elected, (vii) requiring separate presentation in the financial statements of financial assets and financial liabilities by measurement category, and (8) clarifying that an entity should evaluate the need for a valuation allowance on deferred tax assets related to available-for-sale securities in combination with the entity’s other deferred tax assets. ASU 2016-01 is effective for interim and annual reporting periods beginning after December 15, 2017. Early application is permitted as of the beginning of the fiscal year of adoption only for items (iv) and (vi) above. Early adoption of the other items mentioned above is not permitted. The adoption of ASU 2016-01 is not expected to have a material impact on the Corporation's consolidated financial condition or results of operations. Leases In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) ("ASU 2016-02"). Under ASU 2016-02, the Corporation will be required to recognize the following for all leases (with the exception of short-term leases): (i) a right to use asset, which is an asset that represents the lessee's right to use, or control the use of, a specified asset for the lease term and (ii) a lease liability, which is a liability that represents lessee's obligation to make lease payments arising from a lease, measured on a discounted basis. ASU 2016-02 requires a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. ASU 2016-02 is effective for public companies for interim and annual periods beginning after December 15, 2018. The adoption of ASU 2016-02 is not expected to have a material impact on the Corporation's consolidated financial condition or results of operations. Stock Compensation In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 allows for simplification of several aspects of the accounting for share-based payment transactions including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Under ASU 2016-09, all excess tax benefits and tax deficiencies (including tax benefits of dividends on share-based payment awards) should be recognized as income tax expense or benefit in the income statement. ASU 2016-09 also requires recognition of excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. ASU 2016-09 further permits the withholding of an amount up to employees' maximum individual tax rate in the relevant jurisdiction without resulting in a liability classification. ASU 2016-09 also requires any excess tax benefits be classified along with other income tax cash flows as an operating activity and cash paid by an employer when directly withholding shares for tax-withholding purposes to be classified as a financing activity. ASU 2016-09 is effective for public companies for interim and annual periods beginning after December 15, 2016. The adoption of ASU 2016-09 is not expected to have a material impact on the Corporation's consolidated financial condition or results of operations. Credit Losses In June, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). ASU 2016-13 changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. ASU 2016-13 requires an entity measure expected credit losses for financial assets over the estimated lifetime of expected credit loss and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The standard includes the following core concepts in determining the expected credit loss estimate: (a) be based on an asset’s amortized cost (including premiums or discounts, net deferred fees and costs, foreign exchange and fair value hedge accounting adjustments), (b) reflect losses expected over the remaining contractual life of an asset (considering the effect of voluntary prepayments), (c) consider available relevant information about the estimated collectability of cash flows (including information about past events, current conditions, and reasonable and supportable forecasts), and (d) reflect the risk of loss, even when that risk is remote. ASU 2016-13 also amends the recording of purchased credit-deteriorated assets. Under the new guidance, an allowance will be recognized at acquisition through a gross-up approach whereby an entity will record as the initial amortized cost the sum of (a) the purchase price and (b) an estimate of credit losses as of the date of acquisition. In addition, the guidance also requires immediate recognition in earnings any subsequent changes, both favorable and unfavorable, in expected cash flows by adjusting this allowance. ASU 2016-13 amends the impairment model for available-for-sale debt securities and requires entities to determine whether all or a portion of the unrealized loss on an available-for-sale debt security is a credit loss. Management may not use the length of time a security has been in an unrealized loss position as a factor in concluding whether a credit loss exists, as is currently permitted. In addition, an entity will recognize an allowance for credit losses on available-for-sale debt securities as a contra-account to the amortized cost basis rather than as a direct reduction of the amortized cost basis of the investment, as is currently required. As a result, entities will recognize improvements to credit losses on available-for-sale debt securities immediately in earnings rather than as interest income over time under current practice. New disclosures required by ASU 2016-13 include: (a) for financial assets measured at amortized cost, an entity will be required to disclose information about how it developed its allowance, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes, (b) for financial receivables and net investments in leases measured at amortized cost, an entity will be required to further disaggregate the information it currently discloses about the credit quality of these assets by year or the asset’s origination or vintage for as many as five annual periods, and (c) for available-for-sale debt securities, an entity will be required to provide a roll-forward of the allowance for credit losses and an aging analysis for securities that are past due. Upon adoption of ASU 2016-13, a cumulative-effect adjustment to retained earnings will be recorded as of the beginning of the first reporting period in which the guidance is effective. ASU 2016-13 is effective for public companies for interim and annual periods beginning after December 15, 2019, with early adoption permitted for annual periods beginning after December 15, 2018. The Corporation is currently evaluating the provisions of ASU 2016-13 to determine the potential impact on the Corporation's consolidated financial condition and results of operations. Statement of Cash Flows In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”), which clarifies guidance on the classification of eight specific cash flow issues. ASU 2016-15 was issued to reduce diversity in practice and prevent financial statement restatements. Cash flow issues include; debt prepayment or debt extinguishment costs, settlement of zero-coupon bonds, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies and bank-owned life insurance policies, distributions received from equity method investees, beneficial interests in securitization transactions and separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for public business entities for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. Under the provision, entities must apply the guidance retrospectively to all periods presented but may apply it prospectively if retrospective application would be impracticable. The Corporation is currently evaluating the provisions of ASU 2016-15.

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Summary of assets acquired and liabilities assumed	(Dollars in thousands) Consideration paid: Stock $ 1,504,811 Cash 107,638 Total consideration 1,612,449 Fair value of identifiable assets acquired: Cash and cash equivalents 433,352 Investment securities: Available-for-sale 808,894 Held-to-maturity 1,657 Loans held-for-sale 244,916 Loans 4,882,864 Premises and equipment 38,793 Loan servicing rights 42,462 Other intangible assets 12,399 Interest receivable and other assets 397,660 Total identifiable assets acquired 6,862,997 Fair value of liabilities assumed: Noninterest-bearing deposits 1,236,902 Interest-bearing deposits 4,057,968 Interest payable and other liabilities 99,176 Securities sold under agreements to repurchase with customers 19,704 Short-term borrowings 387,500 Long-term borrowings 299,597 Total liabilities assumed 6,100,847 Fair value of net identifiable assets acquired 762,150 Goodwill resulting from acquisition $ 850,299
Information regarding acquired loans accounted for under ASC 310-30	Information regarding loans accounted for under ASC 310-30 at the merger date is as follows: (Dollars in thousands) Accounted for under ASC 310-30: Contractual cash flows $ 5,968,950 Contractual cash flows not expected to be collected (nonaccretable difference) 223,959 Expected cash flows 5,744,991 Interest component of expected cash flows (accretable yield) 862,127 Fair value at acquisition $ 4,882,864
Pro forma financial information	The following unaudited pro forma financial information presents the consolidated results of operation of the Corporation and Talmer as if the merger had occurred as of January 1, 2015 with pro forma adjustments to give effect to any change in interest income due to the accretion of the discount (premium) associated with the fair value adjustments to acquired loans, any change in interest expense due to estimated premium amortization/discount accretion associated with the fair value adjustments to acquired time deposits and borrowings and other debt and the amortization of the core deposit intangible that would have resulted had the deposits been acquired as of January 1, 2015. Dollars in thousands For the three months ended, September 30, 2016 September 30, 2015 Net interest and other income $ 176,102 $ 163,933 Net Income 9,320 38,849 Earnings per share: Basic $ 0.13 $ 0.55 Diluted 0.13 0.55 Dollars in thousands For the nine months ended, September 30, 2016 September 30, 2015 Net interest and other income $ 504,831 $ 460,791 Net Income 84,808 93,764 Earnings per share: Basic $ 1.20 $ 1.39 Diluted 1.19 1.37
Activity for accretable yield includes contractually due interest of acquired loans	Activity for the accretable yield, which includes contractually due interest for acquired loans that have been renewed or extended since the date of acquisition and continue to be accounted for in loan pools in accordance with ASC 310-30, follows: (Dollars in thousands) Talmer Lake Michigan Monarch North-western OAK Total Three Months Ended September 30, 2016 Balance at beginning of period $ — $ 125,343 $ 30,859 $ 73,746 $ 26,592 $ 256,540 Addition attributable to acquisitions 862,127 — — — — 862,127 Additions (reductions) (1) — 6,565 114 526 19 7,224 Accretion recognized in interest income (17,415 ) (7,968 ) (1,322 ) (3,890 ) (3,423 ) (34,018 ) Balance at end of period $ 844,712 $ 123,940 $ 29,651 $ 70,382 $ 23,188 $ 1,091,873 Three Months Ended September 30, 2015 Balance at beginning of period $ — $ 188,310 $ 35,805 $ 91,758 $ 32,175 $ 348,048 Additions attributable to acquisitions — — — — — — Additions (reductions) (1) — (747 ) (351 ) (1,337 ) 1,202 (1,233 ) Accretion recognized in interest income — (10,704 ) (2,085 ) (4,376 ) (2,825 ) (19,990 ) Balance at end of period $ — $ 176,859 $ 33,369 $ 86,045 $ 30,552 $ 326,825 (1) Represents additions of estimated contractual interest expected to be collected from acquired loans being renewed or extended, less reductions in contractual interest resulting from the early payoff of acquired loans. (Dollars in thousands) Talmer Lake Michigan Monarch North-western OAK Total Nine Months Ended September 30, 2016 Balance at beginning of period $ — $ 152,999 $ 34,558 $ 82,623 $ 28,077 $ 298,257 Addition attributable to acquisitions 862,127 — — — — 862,127 Additions (reductions) (1) — (3,800 ) (749 ) (5,322 ) (182 ) (10,053 ) Accretion recognized in interest income (17,415 ) (25,259 ) (4,158 ) (11,919 ) (9,707 ) (68,458 ) Reclassification from nonaccretable difference — — — 5,000 5,000 10,000 Balance at end of period $ 844,712 $ 123,940 $ 29,651 $ 70,382 $ 23,188 $ 1,091,873 Nine Months Ended September 30, 2015 Balance at beginning of period $ — $ — $ — $ 104,675 $ 33,286 $ 137,961 Additions attributable to acquisitions — 190,246 37,914 — — 228,160 Additions (reductions) (1) — 803 (1,492 ) (4,196 ) 6,417 1,532 Accretion recognized in interest income — (14,190 ) (3,053 ) (14,434 ) (9,151 ) (40,828 ) Balance at end of period $ — $ 176,859 $ 33,369 $ 86,045 $ 30,552 $ 326,825 (1) Represents additions of estimated contractual interest expected to be collected from acquired loans being renewed or extended, less reductions in contractual interest resulting from the early payoff of acquired loans.

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	The following is a summary of the amortized cost and fair value of investment securities available-for-sale and investment securities held-to-maturity at September 30, 2016 and December 31, 2015 : Investment Securities Available-for-Sale (Dollars in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value September 30, 2016 U.S. Treasury securities $ 5,784 $ 17 $ — $ 5,801 Government sponsored agencies 223,917 535 414 224,038 State and political subdivisions 306,196 384 1,043 305,537 Residential mortgage-backed securities 301,194 2,206 2 303,398 Collateralized mortgage obligations 343,502 629 392 343,739 Corporate bonds 96,283 37 235 96,085 Preferred stock and trust preferred securities 24,381 515 113 24,783 Total $ 1,301,257 $ 4,323 $ 2,199 $ 1,303,381 December 31, 2015 U.S. Treasury securities $ 5,773 $ — $ 8 $ 5,765 Government sponsored agencies 195,711 78 800 194,989 State and political subdivisions 14,731 395 6 15,120 Residential mortgage-backed securities 189,452 538 2,222 187,768 Collateralized mortgage obligations 133,256 111 1,137 132,230 Corporate bonds 14,825 2 200 14,627 Preferred stock and trust preferred securities 2,888 344 — 3,232 Total $ 556,636 $ 1,468 $ 4,373 $ 553,731
Held-to-maturity Securities	Investment Securities Held-to-Maturity (Dollars in thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value September 30, 2016 State and political subdivisions $ 563,221 $ 13,110 $ 1,487 $ 574,844 Trust preferred securities 500 — 200 300 Total $ 563,721 $ 13,110 $ 1,687 $ 575,144 December 31, 2015 State and political subdivisions $ 509,471 $ 7,446 $ 4,512 $ 512,405 Trust preferred securities 500 — 200 300 Total $ 509,971 $ 7,446 $ 4,712 $ 512,705
Proceeds from sales of securities and the associated gains and losses recorded in earnings	Proceeds from sales of securities and the associated gains and losses recorded in earnings are listed below: For the three months ended September 30, For the nine months ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Proceeds $ 2,820 $ 8,000 $ 7,820 $ 37,897 Gross gains 17 5 54 613 Gross losses (1 ) — (1 ) (1 )
Amortized cost and fair value of debt securities by contractual maturity	The following is a summary of the amortized cost and fair value of investment securities at September 30, 2016 , by maturity, for both available-for-sale and held-to-maturity investment securities. The maturities of residential mortgage-backed securities and collateralized mortgage obligations are based on scheduled principal payments. The maturities of all other debt securities are based on final contractual maturity. September 30, 2016 (Dollars in thousands) Amortized Cost Fair Value Investment Securities Available-for-Sale: Due in one year or less $ 303,733 $ 304,279 Due after one year through five years 563,948 565,258 Due after five years through ten years 266,242 266,463 Due after ten years 165,946 165,576 Preferred stock 1,388 1,805 Total $ 1,301,257 $ 1,303,381 Investment Securities Held-to-Maturity: Due in one year or less $ 60,391 $ 60,508 Due after one year through five years 276,065 279,172 Due after five years through ten years 138,202 143,257 Due after ten years 89,063 92,207 Total $ 563,721 $ 575,144
Summary of continuous unrealized loss position of securities	The following schedule summarizes information for both available-for-sale and held-to-maturity investment securities with gross unrealized losses at September 30, 2016 and December 31, 2015 , aggregated by category and length of time that individual securities have been in a continuous unrealized loss position. As of September 30, 2016 , the Corporation’s securities portfolio consisted of 2,473 securities, 598 of which were in an unrealized loss position. Less Than 12 Months 12 Months or More Total (Dollars in thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses September 30, 2016 Government sponsored agencies $ 20,532 $ 29 $ 17,546 $ 385 $ 38,078 $ 414 State and political subdivisions 391,355 2,342 29,379 188 420,734 2,530 Residential mortgage-backed securities 10,607 2 8 — 10,615 2 Collateralized mortgage obligations 112,890 230 20,812 162 133,702 392 Corporate bonds 71,912 156 4,921 79 76,833 235 Preferred stock and trust preferred securities 12,131 113 300 200 12,431 313 Total $ 619,427 $ 2,872 $ 72,966 $ 1,014 $ 692,393 $ 3,886 December 31, 2015 U.S. Treasury securities $ 5,765 $ 8 $ — $ — $ 5,765 $ 8 Government sponsored agencies 114,640 292 21,681 508 136,321 800 State and political subdivisions 195,285 2,891 68,361 1,627 263,646 4,518 Residential mortgage-backed securities 169,226 2,146 3,435 76 172,661 2,222 Collateralized mortgage obligations 60,459 408 39,382 729 99,841 1,137 Corporate bonds 9,532 200 — — 9,532 200 Trust preferred securities — — 300 200 300 200 Total $ 554,907 $ 5,945 $ 133,159 $ 3,140 $ 688,066 $ 9,085

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2016
Receivables [Abstract]
Summary of loans under portfolio	A summary of loans follows: (Dollars in thousands) September 30, December 31, Commercial loan portfolio: Commercial $ 3,159,936 $ 1,905,879 Commercial real estate 3,773,017 2,112,162 Real estate construction and land development 500,494 232,076 Subtotal 7,433,447 4,250,117 Consumer loan portfolio: Residential mortgage 3,046,959 1,429,636 Consumer installment 1,335,707 877,457 Home equity 899,676 713,937 Subtotal 5,282,342 3,021,030 Total loans $ 12,715,789 $ 7,271,147
Recorded investment of loans in the commercial loan portfolio by risk rating categories	The following schedule presents the recorded investment of loans in the commercial loan portfolio by risk rating categories at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Commercial Commercial Real Estate Real Estate Construction and Land Development Total September 30, 2016 Originated Portfolio: Risk Grades 1-5 $ 1,624,836 $ 1,528,013 $ 291,841 $ 3,444,690 Risk Grade 6 49,934 40,710 288 90,932 Risk Grade 7 35,719 15,132 515 51,366 Risk Grade 8 12,612 19,913 80 32,605 Risk Grade 9 1,130 1 — 1,131 Subtotal 1,724,231 1,603,769 292,724 3,620,724 Acquired Portfolio: Risk Grades 1-5 1,331,689 1,988,676 203,159 3,523,524 Risk Grade 6 49,679 94,829 742 145,250 Risk Grade 7 37,813 52,317 886 91,016 Risk Grade 8 16,524 33,426 2,983 52,933 Subtotal 1,435,705 2,169,248 207,770 3,812,723 Total $ 3,159,936 $ 3,773,017 $ 500,494 $ 7,433,447 December 31, 2015 Originated Portfolio: Risk Grades 1-5 $ 1,418,301 $ 1,341,202 $ 183,323 $ 2,942,826 Risk Grade 6 34,727 31,036 180 65,943 Risk Grade 7 39,933 26,658 1,123 67,714 Risk Grade 8 26,459 25,163 521 52,143 Risk Grade 9 2,095 — — 2,095 Subtotal 1,521,515 1,424,059 185,147 3,130,721 Acquired Portfolio: Risk Grades 1-5 340,782 629,430 41,683 1,011,895 Risk Grade 6 28,321 23,926 2,556 54,803 Risk Grade 7 11,607 29,975 1,537 43,119 Risk Grade 8 3,654 4,772 1,153 9,579 Subtotal 384,364 688,103 46,929 1,119,396 Total $ 1,905,879 $ 2,112,162 $ 232,076 $ 4,250,117
Recorded investment of loans in the consumer loan portfolio based on the credit risk profile of loans in a performing and nonperforming status	The following schedule presents the recorded investment of loans in the consumer loan portfolio based on loans in a performing status and loans in a nonperforming status at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Residential Mortgage Consumer Installment Home Equity Total Consumer September 30, 2016 Originated Loans: Performing $ 1,363,819 $ 1,171,759 $ 589,374 $ 3,124,952 Nonperforming 7,185 378 2,692 10,255 Subtotal 1,371,004 1,172,137 592,066 3,135,207 Acquired Loans 1,675,955 163,570 307,610 2,147,135 Total $ 3,046,959 $ 1,335,707 $ 899,676 $ 5,282,342 December 31, 2015 Originated Loans: Performing $ 1,207,945 $ 868,975 $ 587,566 $ 2,664,486 Nonperforming 9,030 451 3,246 12,727 Subtotal 1,216,975 869,426 590,812 2,677,213 Acquired Loans 212,661 8,031 123,125 343,817 Total $ 1,429,636 $ 877,457 $ 713,937 $ 3,021,030
Summary of nonperforming loans	A summary of nonperforming loans follows: (Dollars in thousands) September 30, December 31, Nonaccrual loans: Commercial $ 13,742 $ 28,554 Commercial real estate 19,914 25,163 Real estate construction and land development 80 521 Residential mortgage 5,119 5,557 Consumer installment 378 451 Home equity 2,064 1,979 Total nonaccrual loans 41,297 62,225 Accruing loans contractually past due 90 days or more as to interest or principal payments: Commercial 221 364 Commercial real estate 739 254 Real estate construction and land development 1,439 — Residential mortgage 375 402 Home equity 628 1,267 Total accruing loans contractually past due 90 days or more as to interest or principal payments 3,402 2,287 Nonperforming TDRs: Commercial loan portfolio 15,261 16,297 Consumer loan portfolio 1,691 3,071 Total nonperforming TDRs 16,952 19,368 Total nonperforming loans (1) $ 61,651 $ 83,880 (1) Acquired loans that are not performing in accordance with contractual terms are not reported as nonperforming loans because these loans are recorded in pools at their net realizable value based on the principal and interest the Corporation expects to collect on these loans.
Schedule of Impaired loans by classes	The following schedule presents impaired loans by classes of loans at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Recorded Investment Unpaid Principal Balance Related Valuation Allowance September 30, 2016 Impaired loans with a valuation allowance: Commercial $ 4,906 $ 4,911 $ 2,729 Commercial real estate 2,741 2,741 516 Residential mortgage 19,864 19,864 154 Subtotal 27,511 27,516 3,399 Impaired loans with no related valuation allowance: Commercial 53,542 78,494 — Commercial real estate 69,713 118,751 — Real estate construction and land development 3,362 8,894 — Residential mortgage 34,310 54,414 — Consumer installment 1,004 1,538 — Home equity 7,573 10,245 — Subtotal 169,504 272,336 — Total impaired loans: Commercial 58,448 83,405 2,729 Commercial real estate 72,454 121,492 516 Real estate construction and land development 3,362 8,894 — Residential mortgage 54,174 74,278 154 Consumer installment 1,004 1,538 — Home equity 7,573 10,245 — Total $ 197,015 $ 299,852 $ 3,399 December 31, 2015 Impaired loans with a valuation allowance: Commercial $ 18,898 $ 19,426 $ 5,700 Commercial real estate 4,448 4,688 497 Residential mortgage 21,037 21,037 192 Subtotal 44,383 45,151 6,389 Impaired loans with no related valuation allowance: Commercial 31,039 37,703 — Commercial real estate 53,518 69,130 — Real estate construction and land development 2,136 3,108 — Residential mortgage 7,638 8,644 — Consumer installment 498 512 — Home equity 2,986 3,270 — Subtotal 97,815 122,367 — Total impaired loans: Commercial 49,937 57,129 5,700 Commercial real estate 57,966 73,818 497 Real estate construction and land development 2,136 3,108 — Residential mortgage 28,675 29,681 192 Consumer installment 498 512 — Home equity 2,986 3,270 — Total $ 142,198 $ 167,518 $ 6,389
Schedule presents information related to impaired loans	The following schedule presents information related to impaired loans for the three and nine months ended September 30, 2016 and 2015 , respectively: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Average Recorded Investment Interest Income Recognized While on Impaired Status Average Recorded Investment Interest Income Recognized While on Impaired Status Commercial $ 43,812 $ 1,073 $ 42,478 $ 1,750 Commercial real estate 58,658 1,219 56,779 2,068 Real estate construction and land development 2,400 64 2,243 115 Residential mortgage 35,986 818 30,499 1,540 Consumer installment 601 17 439 19 Home equity 4,466 95 3,504 123 Total $ 145,923 $ 3,286 $ 135,942 $ 5,615 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Average Recorded Investment Interest Income Recognized While on Impaired Status Average Recorded Investment Interest Income Recognized While on Impaired Status Commercial $ 42,847 $ 310 $ 39,387 $ 862 Commercial real estate 59,150 470 59,927 1,453 Real estate construction and land development 2,210 26 2,338 89 Residential mortgage 30,467 387 29,084 1,098 Consumer installment 497 — 474 1 Home equity 3,026 20 2,635 42 Total $ 138,197 $ 1,213 $ 133,845 $ 3,545
Schedule representing the aging status of the recorded investment in loans by classes	The following schedule presents the aging status of the recorded investment in loans by classes of loans at September 30, 2016 and December 31, 2015 : (Dollars in thousands) 31-60 Days Past Due 61-89 Days Past Due Accruing Loans Past Due 90 Days or More Non-accrual Loans Total Past Due Current Total Loans September 30, 2016 Originated Portfolio: Commercial $ 6,313 $ 2,675 $ 221 $ 13,742 $ 22,951 $ 1,701,280 $ 1,724,231 Commercial real estate 11,913 726 739 19,914 33,292 1,570,477 1,603,769 Real estate construction and land development 3,003 — 1,439 80 4,522 288,202 292,724 Residential mortgage 2,627 — 375 5,119 8,121 1,362,883 1,371,004 Consumer installment 2,425 448 — 378 3,251 1,168,886 1,172,137 Home equity 3,097 940 628 2,064 6,729 585,337 592,066 Total $ 29,378 $ 4,789 $ 3,402 $ 41,297 $ 78,866 $ 6,677,065 $ 6,755,931 Acquired Portfolio: Commercial $ 3,116 $ 1,146 $ 11,984 $ — $ 16,246 $ 1,419,459 $ 1,435,705 Commercial real estate 4,315 2,844 25,444 — 32,603 2,136,645 2,169,248 Real estate construction and land development 208 153 2,902 — 3,263 204,507 207,770 Residential mortgage 1,452 2,895 10,719 — 15,066 1,660,889 1,675,955 Consumer installment 1,367 200 203 — 1,770 161,800 163,570 Home equity 1,082 1,143 1,461 — 3,686 303,924 307,610 Total $ 11,540 $ 8,381 $ 52,713 $ — $ 72,634 $ 5,887,224 $ 5,959,858 December 31, 2015 Originated Portfolio: Commercial $ 3,685 $ 1,230 $ 364 $ 28,554 $ 33,833 $ 1,487,682 $ 1,521,515 Commercial real estate 4,168 1,603 254 25,163 31,188 1,392,871 1,424,059 Real estate construction and land development — — — 521 521 184,626 185,147 Residential mortgage 1,737 — 402 5,557 7,696 1,209,279 1,216,975 Consumer installment 3,145 644 — 451 4,240 865,186 869,426 Home equity 1,767 788 1,267 1,979 5,801 585,011 590,812 Total $ 14,502 $ 4,265 $ 2,287 $ 62,225 $ 83,279 $ 5,724,655 $ 5,807,934 Acquired Portfolio: Commercial $ 490 $ 532 $ 3,735 $ — $ 4,757 $ 379,607 $ 384,364 Commercial real estate 3,557 691 4,771 — 9,019 679,084 688,103 Real estate construction and land development — — 1,154 — 1,154 45,775 46,929 Residential mortgage 1,370 — 2,081 — 3,451 209,210 212,661 Consumer installment 55 — 47 — 102 7,929 8,031 Home equity 847 78 1,007 — 1,932 121,193 123,125 Total $ 6,319 $ 1,301 $ 12,795 $ — $ 20,415 $ 1,442,798 $ 1,463,213
Schedule of Corporation's TDRs	The following schedule presents the Corporation’s TDRs at September 30, 2016 and December 31, 2015 : (Dollars in thousands) Performing TDRs Non-Performing TDRs Nonaccrual TDRs Total September 30, 2016 Commercial loan portfolio $ 30,662 $ 15,261 $ 26,340 $ 72,263 Consumer loan portfolio 18,173 1,691 3,165 23,029 Total $ 48,835 $ 16,952 $ 29,505 $ 95,292 December 31, 2015 Commercial loan portfolio $ 29,844 $ 16,297 $ 32,682 $ 78,823 Consumer loan portfolio 17,966 3,071 3,251 24,288 Total $ 47,810 $ 19,368 $ 35,933 $ 103,111
Schedule providing information on TDRs	The following schedule provides information on the Corporation's TDRs that were modified during the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial loan portfolio: Commercial 4 $ 4,160 $ 4,160 32 $ 12,141 $ 12,141 Commercial real estate — — — 6 2,441 2,441 Subtotal – commercial loan portfolio 4 4,160 4,160 38 14,582 14,582 Consumer loan portfolio 2 89 89 23 783 783 Total 6 $ 4,249 $ 4,249 61 $ 15,365 $ 15,365 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Number of Loans Pre- Modification Recorded Investment Post- Modification Recorded Investment Commercial loan portfolio: Commercial 3 $ 882 $ 882 21 $ 5,146 $ 5,146 Commercial real estate 3 2,044 2,044 12 5,105 5,105 Real estate construction and land development — — — 1 305 305 Subtotal – commercial loan portfolio 6 2,926 2,926 34 10,556 10,556 Consumer loan portfolio 15 481 481 54 2,450 2,448 Total 21 $ 3,407 $ 3,407 88 $ 13,006 $ 13,004
Troubled debt restructurings on financing receivables with defaults payment	The following schedule includes TDRs for which there was a payment default during the three and nine months ended September 30, 2016 and 2015 , whereby the borrower was past due with respect to principal and/or interest for 90 days or more, and the loan became a TDR during the twelve-month period prior to the default: Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 (Dollars in thousands) Number of Loans Principal Balance at End of Period Number of Loans Principal Balance at End of Period Commercial loan portfolio: Commercial real estate — $ — 2 $ 1,721 Subtotal – commercial loan portfolio — — 2 1,721 Consumer loan portfolio 1 — 3 — Total 1 $ — 5 $ 1,721 Three Months Ended September 30, 2015 Nine months ended September 30, 2015 (Dollars in thousands) Number of Loans Principal Balance at End of Period Number of Loans Principal Balance at End of Period Commercial loan portfolio: Commercial real estate 1 $ 74 5 $ 1,016 Subtotal – commercial loan portfolio 1 74 5 1,016 Consumer loan portfolio 1 13 2 46 Total 2 $ 87 7 $ 1,062
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment	The following schedule presents, by loan portfolio segment, the changes in the allowance for the three and nine months ended September 30, 2016 and 2015 , respectively, and details regarding the balance in the allowance and the recorded investment in loans at September 30, 2016 by impairment evaluation method. (Dollars in thousands) Commercial Loan Portfolio Consumer Loan Portfolio Unallocated Total Changes in allowance for loan losses for the three months ended September 30, 2016: Beginning balance $ 44,228 $ 27,278 $ — $ 71,506 Provision for loan losses 3,537 566 — 4,103 Charge-offs (824 ) (2,037 ) — (2,861 ) Recoveries 489 538 — 1,027 Ending balance $ 47,430 $ 26,345 $ — $ 73,775 Changes in allowance for loan losses for the nine months ended September 30, 2016: Beginning balance $ 47,234 $ 26,094 $ — $ 73,328 Provision for loan losses 5,437 3,166 — 8,603 Charge-offs (7,262 ) (4,677 ) — (11,939 ) Recoveries 2,021 1,762 — 3,783 Ending balance $ 47,430 $ 26,345 $ — $ 73,775 Changes in allowance for loan losses for the three months ended September 30, 2015: Beginning balance $ 45,527 $ 23,321 $ 6,093 $ 74,941 Provision for loan losses 2,637 (351 ) (786 ) 1,500 Charge-offs (539 ) (1,656 ) — (2,195 ) Recoveries 769 611 — 1,380 Ending balance $ 48,394 $ 21,925 $ 5,307 $ 75,626 Changes in allowance for loan losses for the nine months ended September 30, 2015: Beginning balance $ 44,156 $ 28,803 $ 2,724 $ 75,683 Provision for loan losses 5,604 (3,687 ) 2,583 4,500 Charge-offs (2,958 ) (5,104 ) — (8,062 ) Recoveries 1,592 1,913 — 3,505 Ending balance $ 48,394 $ 21,925 $ 5,307 $ 75,626 Allowance for loan losses balance at September 30, 2016 attributable to: Loans individually evaluated for impairment $ 3,245 $ 154 $ — $ 3,399 Loans collectively evaluated for impairment 44,185 26,191 — 70,376 Loans acquired with deteriorated credit quality — — — — Total $ 47,430 $ 26,345 $ — $ 73,775 Recorded investment (loan balance) at September 30, 2016: Loans individually evaluated for impairment $ 79,659 $ 19,864 $ — $ 99,523 Loans collectively evaluated for impairment 3,541,065 3,115,343 — 6,656,408 Loans acquired with deteriorated credit quality 3,812,723 2,147,135 — 5,959,858 Total $ 7,433,447 $ 5,282,342 $ — $ 12,715,789 The following schedule presents, by loan portfolio segment, details regarding the balance in the allowance and the recorded investment in loans at December 31, 2015 by impairment evaluation method. (Dollars in thousands) Commercial Loan Portfolio Consumer Loan Portfolio Total Allowance for loan losses balance at December 31, 2015 attributable to: Loans individually evaluated for impairment $ 6,197 $ 192 $ 6,389 Loans collectively evaluated for impairment 41,037 25,902 66,939 Loans acquired with deteriorated credit quality — — — Total $ 47,234 $ 26,094 $ 73,328 Recorded investment (loan balance) at December 31, 2015: Loans individually evaluated for impairment $ 100,379 $ 21,037 $ 121,416 Loans collectively evaluated for impairment 3,030,342 2,656,176 5,686,518 Loans acquired with deteriorated credit quality 1,119,396 343,817 1,463,213 Total $ 4,250,117 $ 3,021,030 $ 7,271,147

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Net carrying value of intangible assets	The following table shows the net carrying value of the Corporation’s intangible assets: (Dollars in thousands) September 30, December 31, Goodwill $ 1,137,166 $ 287,393 Loan servicing rights 51,393 11,122 Other intangible assets: Core deposit intangible assets $ 35,618 $ 26,654 Non-compete intangible assets 82 328 Total other intangible assets $ 35,700 $ 26,982
Carrying amount, accumulated amortization and amortization expense of core deposit intangible assets	The following table sets forth the carrying amount and accumulated amortization of core deposit intangible assets that are amortizable and arose from business combinations or other acquisitions: (Dollars in thousands) September 30, December 31, Gross original amount $ 52,454 $ 40,055 Accumulated amortization 16,836 13,401 Net carrying amount $ 35,618 $ 26,654
Activity for loan servicing rights accounted for under fair value method	The following table represents the activity for LSRs accounted for under the fair value method and the related fair value changes: (Dollars in thousands) Three and nine months ended September 30, 2016 Commercial Real Estate Mortgage Total Fair value, beginning of period $ — $ — $ — Acquired in Talmer Bancorp, Inc. merger 365 42,097 42,462 Additions from loans sold with servicing retained — 810 810 Changes in fair value due to: Reductions from pay-offs, pay downs and run-off (2 ) (685 ) (687 ) Changes in estimates of fair value (1) — (657 ) (657 ) Fair value, end of period $ 363 $ 41,565 $ 41,928 Principal balance of loans serviced for others that have servicing capitalized $ 79,405 $ 5,523,423 $ 5,602,828 (1) Represents estimated LSR value change resulting primarily from market-driven changes in interest rates.
Net carrying value, fair value of MSRs and loans Corporation servicing for others	The Corporation continues to account for all other LSRs using the amortization method. The following shows the net carrying value and fair value of LSRs and the total loans that the Corporation is servicing for others accounted for under the amortization method: (Dollars in thousands) September 30, December 31, Net carrying value of LSRs $ 9,465 $ 11,122 Fair value of LSRs $ 12,434 $ 15,542 Valuation allowance $ 214 $ — Loans serviced for others that have servicing rights capitalized $ 1,981,157 $ 2,082,899
Activity for capitalized MSRs	The following table shows the activity for capitalized LSRs accounted for under the amortization method: (Dollars in thousands) Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Balance at beginning of period $ 9,677 $ 12,307 $ 11,122 $ 12,217 Acquired in Monarch acquisition — — — 1,284 Additions 695 303 1,612 1,118 Amortization (1,105 ) (1,070 ) (3,055 ) (3,279 ) Change in valuation allowance 198 — (214 ) 200 Balance at end of period $ 9,465 $ 11,540 $ 9,465 $ 11,540
Assumptions utilized in determining the fair value of loan servicing rights	Expected and actual loan prepayment speeds are the most significant factors driving the fair value of loan servicing rights. The following table presents assumptions utilized in determining the fair value of loan servicing rights as of September 30, 2016 and December 31, 2015 . Commercial Real Estate Mortgage As of September 30, 2016 Prepayment speed 0.00 - 22.47% 0.00 - 38.28% Weighted average (“WA”) discount rate 16.46 % 10.09 % Cost to service/per year $467-$500 $65-$90 Ancillary income/per year N/A $ 28 WA float range 0.53 % 0.68 % As of December 31, 2015 Prepayment speed N/A 6.96 - 17.65% WA discount rate N/A 10.04 % Cost to service/per year N/A $70-$85 Ancillary income/per year N/A $ 20 WA float range N/A 1.72 %

Accumulated Other Comprehensi30

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Components of accumulated other comprehensive loss, net of related tax benefit/expense	The following table summarizes the changes within each component of accumulated other comprehensive income (loss), net of related tax benefit/expense for the three and nine months ended September 30, 2016, and 2015: (Dollars in thousands) Unrealized gains Defined Benefit Pension Plans Total For the three months ended September 30, 2016 Beginning balance $ 2,196 $ (27,894 ) $ (25,698 ) Other comprehensive income (loss) before reclassifications (805 ) (511 ) (1,316 ) Amounts reclassified from accumulated other comprehensive income (10 ) 1,882 1,872 Net current period other comprehensive income (loss) (815 ) 1,371 556 Ending balance $ 1,381 $ (26,523 ) $ (25,142 ) For the three months ended September 30, 2015 Beginning balance $ (274 ) $ (30,830 ) $ (31,104 ) Other comprehensive income before reclassifications 1,214 — 1,214 Amounts reclassified from accumulated other comprehensive income (3 ) 707 704 Net current period other comprehensive income 1,211 707 1,918 Ending balance $ 937 $ (30,123 ) $ (29,186 ) For the nine months ended September 30, 2016 Beginning balance $ (1,888 ) $ (27,144 ) $ (29,032 ) Other comprehensive income (loss) before reclassifications 3,304 (511 ) 2,793 Amounts reclassified from accumulated other comprehensive income (35 ) 1,132 1,097 Net current period other comprehensive income (loss) 3,269 621 3,890 Ending balance $ 1,381 $ (26,523 ) $ (25,142 ) For the nine months ended September 30, 2015 Beginning balance $ (210 ) $ (32,243 ) $ (32,453 ) Other comprehensive income before reclassifications 1,545 — 1,545 Amounts reclassified from accumulated other comprehensive income (398 ) 2,120 1,722 Net current period other comprehensive income 1,147 2,120 3,267 Ending balance $ 937 $ (30,123 ) $ (29,186 )
Summary of amounts reclassified out of accumulated other comprehensive income (loss)	The following table summarizes the amounts reclassified out of each component of accumulated other comprehensive income (loss) for the three and nine months ended September 30, 2016 and 2015: (Dollars in thousands) Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Income Statement Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Gains and losses on available-for-sale securities $ 16 $ 5 $ 53 $ 612 Gain on sale of investment securities (noninterest income) (6 ) (2 ) (18 ) (214 ) Income tax (expense)/benefit $ 10 $ 3 $ 35 $ 398 Net Income Amortization of defined benefit pension plan items $ (2,895 ) $ (1,087 ) $ (1,742 ) $ (3,261 ) Salaries, wages and employee benefits (operating expenses) 1,013 380 610 1,141 Income tax (expense)/benefit $ (1,882 ) $ (707 ) $ (1,132 ) $ (2,120 ) Net Income

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of Other Borrowings	A summary of the Corporation's short- and long-term borrowings follows: September 30, December 31, (Dollars in thousands) Amount Weighted Average Rate (1) Amount Weighted Average Rate (1) Short-term borrowings: FHLB advances: 0.45% - 0.81% fixed-rate notes $ 400,000 0.52 % $ 100,000 0.34 % Long-term borrowings: FHLB advances: 0.59% - 7.44% fixed-rate notes due 2016 to 2027 (2) $ 494,013 1.45 181,394 1.41 Securities sold under agreements to repurchase: 1.48% - 4.30% fixed-rate notes due 2016 to 2017 (3) 42,394 3.61 17,453 0.27 Line-of-credit: floating-rate based on one-month LIBOR plus 1.75% 124,698 2.27 25,000 2.27 Subordinated debt obligations: floating-rate based on three-month LIBOR plus 1.45% - 2.85% due 2034 to 2035 (4) 11,260 3.09 — — Subordinated debt obligations: floating-rate based on three-month LIBOR plus 3.25% due in 2032 (5) 4,247 4.09 — — Subordinated debt obligations — — 18,544 3.99 Total long-term borrowings $ 676,612 1.78 $ 242,391 1.59 (1) Weighted average rate presented is the contractual rate which excludes premiums and discounts related to purchase accounting. (2) The September 30, 2016 balances include advances payable of $492.8 million and purchase accounting premiums of $1.2 million . The December 31, 2015 balance includes advances payable of $181.0 million and purchase accounting premiums of $0.4 million . (3) The September 30, 2016 balance includes advances payable of $42.0 million and purchase accounting premiums of $0.4 million . The December 31, 2015 balance includes advance payable of $17.0 million and purchase accounting premiums of $0.5 million . (4) The September 30, 2016 balance includes advances payable of $15.0 million and purchase accounting discounts of $3.7 million . (5) The September 30, 2016 balance includes advances payable of $5.0 million and purchase accounting discounts of $0.8 million .
Schedule of Securities Sold Under Agreements to Repurchase	The remaining contract maturity, excluding purchase accounting adjustments, of long-term securities under agreement to repurchase, is as follows: September 30, 2016 Remaining Contractual Maturities of the Agreements (Dollars in thousands) Overnight and continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities sold under agreements to repurchase $ — $ 13,000 $ 10,000 $ 19,000 $ 42,000 Total borrowings $ — $ 13,000 $ 10,000 $ 19,000 $ 42,000 Amounts related to securities sold under agreements to repurchase not included in offsetting disclosure in Footnote 14 $ 42,000

Regulatory Capital (Tables)

Regulatory Capital (Tables)	9 Months Ended
	Sep. 30, 2016
Banking and Thrift [Abstract]
Corporation's and Chemical Bank's actual capital amounts and ratios with the quantitative measures established by regulation to ensure capital adequacy	The summary below compares the actual capital amounts and ratios with the quantitative measures established by regulation to ensure capital adequacy: Actual Minimum Required for Capital Adequacy Purposes Minimum Required for Capital Adequacy Purposes Plus Capital Conservation Buffer Required to be Well Capitalized Under Prompt Corrective Action Regulations (Dollars in thousands) Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio Capital Amount Ratio September 30, 2016 Total Capital to Risk-Weighted Assets Corporation $ 1,491,389 11.1 % $ 1,074,506 8.0 % $ 1,155,093 8.6 % N/A N/A Chemical Bank 825,504 10.8 614,281 8.0 660,352 8.6 $ 767,851 10.0 % Talmer Bank and Trust 719,213 12.7 453,090 8.0 487,071 8.6 566,362 10.0 Tier 1 Capital to Risk-Weighted Assets Corporation 1,413,464 10.5 805,879 6.0 886,467 6.6 N/A N/A Chemical Bank 752,957 9.8 460,711 6.0 506,782 6.6 614,281 8.0 Talmer Bank and Trust 713,835 12.6 339,817 6.0 373,799 6.6 453,090 8.0 Common Equity Tier 1 Capital to Risk-Weighted Assets Corporation 1,413,464 10.5 604,409 4.5 684,997 5.1 N/A N/A Chemical Bank 752,957 9.8 345,533 4.5 391,604 5.1 499,103 6.5 Talmer Bank and Trust 713,835 12.6 254,863 4.5 288,845 5.1 368,135 6.5 Leverage Ratio Corporation 1,413,464 12.8 442,317 4.0 442,317 4.0 N/A N/A Chemical Bank 752,957 8.1 373,897 4.0 373,897 4.0 467,371 5.0 Talmer Bank and Trust 713,835 10.9 262,318 4.0 262,318 4.0 327,898 5.0 December 31, 2015 Total Capital to Risk-Weighted Assets Corporation $ 841,257 11.8 % $ 571,509 8.0 % N/A N/A N/A N/A Chemical Bank 830,294 11.7 570,073 8.0 N/A N/A $ 712,591 10.0 % Tier 1 Capital to Risk-Weighted Assets Corporation 767,929 10.7 428,631 6.0 N/A N/A N/A N/A Chemical Bank 756,966 10.6 427,555 6.0 N/A N/A 570,073 8.0 Common Equity Tier 1 Capital to Risk-Weighted Asset Corporation 753,815 10.6 321,474 4.5 N/A N/A N/A N/A Chemical Bank 756,966 10.6 320,666 4.5 N/A N/A 463,184 6.5 Leverage Ratio Corporation 767,929 8.6 356,396 4.0 N/A N/A N/A N/A Chemical Bank 756,966 8.5 355,911 4.0 N/A N/A 444,888 5.0

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Summary of assets measured at fair value on a recurring basis	For assets and liabilities measured at fair value on a recurring basis, quantitative disclosures about the fair value measurements for each major category of assets were as follows: (Dollars in thousands) Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2016 Investment securities – available-for-sale: U.S. Treasury securities $ 5,801 $ — $ — $ 5,801 Government sponsored agencies — 224,038 — 224,038 State and political subdivisions — 305,537 — 305,537 Residential mortgage-backed securities — 303,398 — 303,398 Collateralized mortgage obligations — 343,739 — 343,739 Corporate bonds — 96,085 — 96,085 Preferred stock and trust preferred securities — 24,783 — 24,783 Total investment securities – available-for-sale 5,801 1,297,580 — 1,303,381 Loans held-for-sale — 276,061 — 276,061 Loan servicing rights — — 41,928 41,928 Derivative assets: Customer-initiated derivatives — 12,250 — 12,250 Forward contracts related to mortgage loans to be delivered for sale — 89 — 89 Interest rate lock commitments — 2,674 — 2,674 Power Equity CD — 2,183 — 2,183 Total derivatives — 17,196 — 17,196 Total assets at fair value $ 5,801 $ 1,590,837 $ 41,928 $ 1,638,566 Derivative liabilities: Customer-initiated derivatives — 12,787 — 12,787 Forward contracts related to mortgage loans to be delivered for sale — 944 — 944 Interest rate lock commitments — 56 — 56 Power Equity CD — 2,183 — 2,183 Total derivatives — 15,970 — 15,970 Total liabilities at fair value $ — $ 15,970 $ — $ 15,970 December 31, 2015 Investment securities – available-for-sale: U.S. Treasury securities $ 5,765 $ — $ — $ 5,765 Government sponsored agencies — 194,989 — 194,989 State and political subdivisions — 15,120 — 15,120 Residential mortgage-backed securities — 187,768 — 187,768 Collateralized mortgage obligations — 132,230 — 132,230 Corporate bonds — 14,627 — 14,627 Preferred stock and trust preferred securities — 3,232 — 3,232 Total investment securities – available-for-sale 5,765 547,966 — 553,731 Loans held-for-sale — 10,327 — 10,327 Derivative assets: Forward contracts related to mortgage loans to be delivered for sale — 144 — 144 Interest rate lock commitments — 42 — 42 Power Equity CD — 1,832 — 1,832 Total derivatives — 2,018 — 2,018 Total assets at fair value $ 5,765 $ 560,311 $ — $ 566,076 Derivative liabilities: Forward contracts related to mortgage loans to be delivered for sale — 57 — 57 Interest rate lock commitments — 90 — 90 Power Equity CD — 1,832 — 1,832 Total derivatives — 1,979 — 1,979 Total liabilities at fair value $ — $ 1,979 $ — $ 1,979
Summary of changes in Level 3 assets measured at fair value on a recurring basis	The following table summarizes the changes in Level 3 assets measured at fair value on a recurring basis. (Dollars in thousands) Three and nine months ended September 30, 2016 Loan servicing rights Balance, beginning of period $ — Additions due to acquisition 42,462 Gains (losses): Recorded in earnings (realized): Recorded in “Mortgage banking revenue” (1,344 ) New originations 810 Balance, end of period $ 41,928
Schedule of aggregate fair value contractual balance and gain (loss) for loans held-for-sale	The aggregate fair value, contractual balance (including accrued interest), and gain or loss for loans held-for-sale carried at fair value was as follows: (Dollars in thousands) September 30, 2016 December 31, 2015 Aggregate fair value $ 276,061 $ 10,327 Contractual balance 274,406 10,366 Unrealized gain (loss) 1,655 (39 )
Amount of gains (losses) from loans held for sale included in the Consolidated Statements of Income	The total amount of gains (losses) from loans held for sale included in the Consolidated Statements of Income were as follows: For the three months ended For the nine months ended (Dollars in thousands) 2016 2015 2016 2015 Interest income (1) $ 811 $ 23 $ 849 $ 56 Change in fair value (2) 43 76 199 (15 ) Total included in earnings $ 854 $ 99 $ 1,048 $ 41 (1) Included in "Interest and fees on loans" in the Consolidated Statements of Income. (2) Included in "Mortgage banking revenue" in the Consolidated Statements of Income.
Summary of assets measured at fair value on a nonrecurring basis	For assets measured at fair value on a nonrecurring basis, quantitative disclosures about fair value measurements for each major category of assets were as follows: (Dollars in thousands) Quoted Prices In Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total September 30, 2016 Impaired originated loans $ — $ — $ 25,344 $ 25,344 Other real estate/repossessed assets — — 380 380 Loan servicing rights — — 5,688 5,688 Total $ — $ — $ 31,412 $ 31,412 December 31, 2015 Impaired originated loans $ — $ — $ 42,065 $ 42,065 Other real estate/repossessed assets — — 3,068 3,068 Total $ — $ — $ 45,133 $ 45,133
Additional information about significant unobservable inputs used in the fair value measurement of financial assets	The following table presents additional information about the significant unobservable inputs used in the fair value measurement of financial assets measured on a nonrecurring basis that were categorized within the Level 3 of the fair value hierarchy: (Dollars in thousands) Fair Value at September 30, 2016 Valuation Technique Significant Unobservable Inputs Range Impaired originated loans $ 25,344 Appraisal of collateral Discount for type of collateral and age of appraisal 20%-30% Other real estate/repossessed assets 380 Appraisal of property Discount for type of property and age of appraisal 10%-33% Loan servicing rights 5,688 Discounted cash flow Constant prepayment rate 13%-22% Discount rate 10%-11%
Summary of carrying amounts and estimated fair values of the financial instruments	A summary of carrying amounts and estimated fair values of the Corporation’s financial instruments not recorded at fair value in their entirety on a recurring basis on the Consolidated Statements of Financial Position was as follows: Level in Fair Value Measurement Hierarchy September 30, 2016 December 31, 2015 (Dollars in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Cash and cash equivalents Level 1 $ 556,567 $ 556,567 $ 238,789 $ 238,789 Investment securities: Held-to-maturity Level 2 563,221 574,844 509,471 512,405 Held-to-maturity Level 3 500 300 500 300 Nonmarketable equity securities NA 77,396 77,396 36,907 36,907 Net loans (1) Level 3 12,642,014 12,650,332 7,197,819 7,201,994 Interest receivable Level 2 43,131 43,131 21,953 21,953 Liabilities: Deposits without defined maturities Level 2 $ 9,924,502 $ 9,924,502 $ 5,809,355 $ 5,809,355 Time deposits Level 2 3,348,360 3,348,942 1,647,412 1,647,412 Interest payable Level 2 5,097 5,097 1,578 1,578 Short-term borrowings Level 2 726,789 726,789 397,199 397,199 Long-term borrowings Level 2 676,612 676,750 242,391 242,391 (1) Included $25.3 million and $42.1 million of impaired loans recorded at fair value on a nonrecurring basis at September 30, 2016 and December 31, 2015 , respectively.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Numerator and denominator of the basic and diluted earnings per common share computations	The factors used in the earnings per share computation follow: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share data) 2016 2015 2016 2015 Net income $ 10,732 $ 24,467 $ 59,701 $ 61,326 Net income allocated to participating securities 36 — 78 — Net income allocated to common shareholders (1) $ 10,696 $ 24,467 $ 59,623 $ 61,326 Weighted average common shares - issued 49,107 38,123 41,881 35,384 Average unvested restricted share awards (163 ) — (55 ) — Weighted average common shares outstanding - basic 48,944 38,123 41,826 35,384 Effect of dilutive securities Weighted average common stock equivalents 687 270 493 246 Weighted average common shares outstanding - diluted 49,631 38,393 42,319 35,630 EPS available to common shareholders Basic earnings per common share $ 0.22 $ 0.64 $ 1.43 $ 1.73 Diluted earnings per common share $ 0.21 $ 0.64 $ 1.40 $ 1.72 (1) Net income allocated to common shareholders for basic and diluted earnings per share may differ under the two-class method as a result of adding common share equivalents for options and warrants to dilutive shares outstanding, which alters the ratio used to allocate net income to common shareholders and participating securities for the purposes of calculating diluted earnings per share.

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of activity for Corporation's stock options	A summary of activity for the Corporation’s stock options as of and for the nine months ended September 30, 2016 is presented below: Non-Vested Stock Options Outstanding Stock Options Outstanding Number of Options Weighted- Average Exercise Price Per Share Weighted- Average Grant Date Fair Value Per Share Number of Options Weighted- Average Exercise Price Per Share Outstanding at December 31, 2015 479,755 $ 28.75 $ 8.49 1,054,739 $ 25.38 Acquired — — — 1,466,408 15.08 Granted 441,167 32.81 — 441,167 32.81 Exercised — — — (220,026 ) 24.08 Vested (454,360 ) 28.74 8.49 — — Forfeited/expired (47,286 ) 30.69 7.42 (47,286 ) 30.69 Outstanding at September 30, 2016 419,276 $ 32.81 $ 6.15 2,695,002 $ 21.01 Exercisable/vested at September 30, 2016 2,275,726 $ 18.84
Assumptions of Black-Scholes option pricing model	The fair value of the stock options granted during the nine months ended September 30, 2016 was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions. Expected dividend yield 3.30 % Risk-free interest rate 1.39 % Expected stock price volatility 27.9 % Expected life of options – in years 6.5 Weighted average fair value of options granted $ 6.15
Summary of activity for restricted stock units and awards	The following table provides information regarding nonvested restricted stock awards: Nonvested restricted stock awards Number of Awards Weighted-average acquisition-date Nonvested at January 1, 2016 — $ — Acquired 484,892 46.23 Vested — — Forfeited (508 ) 46.23 Nonvested at September 30, 2016 484,384 $ 46.23 A summary of the activity for restricted stock units as of and for the nine months ended September 30, 2016 is presented below: Number of Units Weighted-average grant date fair value per unit Outstanding at December 31, 2015 207,989 $ 26.41 Granted 133,620 34.75 Converted into shares of common stock (67,207 ) 24.54 Forfeited/expired (5,656 ) 29.30 Outstanding at September 30, 2016 268,746 $ 30.97

Pension and Other Postretirem36

Pension and Other Postretirement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Components of net periodic benefit cost (income) for the Corporation's qualified and nonqualified pension plans and nonqualified postretirement benefits plan	The components of net periodic benefit cost for the Corporation’s qualified and nonqualified pension plans and nonqualified postretirement benefit plan are as follows: Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Defined Benefit Pension Plans Service cost $ 279 $ 273 $ 834 $ 818 Interest cost 1,357 1,331 4,072 3,995 Contractual termination cost 32 — 32 — Expected return on plan assets (2,141 ) (2,161 ) (6,422 ) (6,483 ) Amortization of prior service credit — (2 ) — (4 ) Amortization of unrecognized net loss 585 1,057 1,729 3,169 Net periodic benefit cost $ 112 $ 498 $ 245 $ 1,495 Postretirement Benefit Plan Service cost $ 2 $ 4 $ 7 $ 12 Interest cost 33 33 99 100 Amortization of prior service cost 29 32 88 97 Amortization of unrecognized net gain (24 ) — (75 ) (1 ) Net periodic benefit cost $ 40 $ 69 $ 119 $ 208

Derivative Instruments and Ba37

Derivative Instruments and Balance Sheet Offsetting (Tables)	9 Months Ended
	Sep. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule reflecting the amount and fair value of risk management derivatives and mortgage banking and customer initiated derivatives	The following table presents the notional amount and fair value of the Corporation’s derivative instruments held or issued in connection with customer-initiated and mortgage banking activities. September 30, 2016 December 31, 2015 Fair Value Fair Value (Dollars in thousands) Notional Amount (1) Gross Derivative Assets (2) Gross Derivative Liabilities (2) Notional Amount (1) Gross Derivative Assets (2) Gross Derivative Liabilities (2) Customer-initiated and mortgage banking derivatives: Customer-initiated derivatives $ 559,458 $ 12,250 $ 12,787 $ — $ — $ — Forward contracts related to mortgage loans to be delivered for sale 197,874 89 944 33,787 144 57 Interest rate lock commitments 157,743 2,674 56 23,421 42 90 Power Equity CD 36,372 2,183 2,183 33,703 1,832 1,832 Total gross derivatives $ 951,447 $ 17,196 $ 15,970 $ 90,911 $ 2,018 $ 1,979 (1) Notional or contract amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the Consolidated Statements of Financial Position. (2) Derivative assets are included within “Other assets” and derivative liabilities are included within “Other liabilities” on the Consolidated Statements of Financial Position. Included in the fair value of the derivative assets are credit valuation adjustments for counterparty credit risk totaling $745 thousand at September 30, 2016 and $0 at December 31, 2015 .
Schedule reflecting the net gains (losses) relating to derivative instruments related to the changes in fair value	The following table presents the net gains (losses) related to derivative instruments reflecting the changes in fair value. Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) Location of Gain (Loss) 2016 2015 2016 2015 Forward contracts related to mortgage loans to be delivered for sale Mortgage banking revenue $ (156 ) $ (384 ) $ (798 ) $ (24 ) Interest rate lock commitments Mortgage banking revenue (179 ) 308 307 39 Power Equity CD Other noninterest income — — — — Customer-initiated derivatives Other noninterest income (60 ) — (60 ) — Total gain (loss) recognized in income $ (395 ) $ (76 ) $ (551 ) $ 15
Schedule of the Company's financial instruments eligible for offset, offsetting assets	The tables below present information about the Corporation’s financial instruments that are eligible for offset. There were no financial instruments eligible for offset as of December 31, 2015. Gross amounts not offset in the (Dollars in thousands) Gross Gross amounts Net amounts Financial Collateral Net September 30, 2016 Offsetting derivative assets Derivative assets $ 12,247 $ — $ 12,247 $ — $ — $ 12,247 Offsetting derivative liabilities Derivative liabilities 12,785 — 12,785 — 12,530 255
Schedule of the Company's financial instruments eligible for offset, offsetting liabilities	The tables below present information about the Corporation’s financial instruments that are eligible for offset. There were no financial instruments eligible for offset as of December 31, 2015. Gross amounts not offset in the (Dollars in thousands) Gross Gross amounts Net amounts Financial Collateral Net September 30, 2016 Offsetting derivative assets Derivative assets $ 12,247 $ — $ 12,247 $ — $ — $ 12,247 Offsetting derivative liabilities Derivative liabilities 12,785 — 12,785 — 12,530 255

Other Real Estate Owned and R38

Other Real Estate Owned and Repossessed Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Other Real Estate [Abstract]
Tabular disclosure of the changes in non-covered and covered other real estate on properties owned	Changes in other real estate owned and repossessed assets were as follows: (Dollars in thousands) Other real estate Repossessed Balance at January 1, 2016 $ 9,716 $ 219 Additions due to acquisitions 13,227 313 Other additions (1) 3,945 2,084 Net payments received (171 ) (764 ) Disposals (6,232 ) (1,231 ) Write-downs (376 ) — Balance at September 30, 2016 $ 20,109 $ 621 Balance at January 1, 2015 $ 13,953 $ 252 Additions due to acquisitions 440 — Other additions (1) 5,651 1,761 Net payments made/(received) 8 (13 ) Disposals (8,179 ) (1,739 ) Write-downs (927 ) — Balance at September 30, 2015 $ 10,946 $ 261 (1) Includes loans transferred to other real estate owned and other repossessed assets.
Schedule of income and expenses related to other real estate owned	Income and expenses related to other real estate owned and repossessed assets, recorded as a component of “Other expense” in the Consolidated Statements of Income, were as follows: (Dollars in thousands) Other real estate owned Repossessed assets For the three months ended September 30, 2016 Net gain (loss) on sale $ 788 $ (5 ) Write-downs (145 ) — Net operating expenses (176 ) (8 ) Total $ 467 $ (13 ) For the nine months ended September 30, 2016 Net gain (loss) on sale $ 2,830 $ 696 Write-downs (376 ) — Net operating expenses (588 ) (11 ) Total $ 1,866 $ 685 For the three months ended September 30, 2015 Net gain (loss) on sale $ 1,214 $ — Write-downs (363 ) — Net operating expenses (360 ) (2 ) Total $ 491 $ (2 ) For the nine months ended September 30, 2015 Net gain (loss) on sale $ 3,376 $ (21 ) Write-downs (927 ) — Net operating expenses (1,238 ) (10 ) Total $ 1,211 $ (31 )

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Schedule of reconciliation of expected income tax expense (benefit) at the federal statutory rate to the Company’s provision for income taxes and effective tax rate	The differences between the provision for federal income taxes computed at the federal statutory income tax rate and the amounts recorded in the consolidated financial statements were as follows: Three Months Ended September 30, Nine Months Ended September 30, (Dollars in thousands) 2016 2015 2016 2015 Tax at statutory rate $ 5,016 $ 11,923 $ 29,400 $ 30,844 Changes resulting from: Tax-exempt interest income (1,321 ) (1,033 ) (3,599 ) (2,809 ) State taxes, net of federal benefit (803 ) — (803 ) — Change in valuation allowance (29 ) — (29 ) — Bank-owned life insurance adjustments (169 ) — (524 ) — Director plan change in control (525 ) — (525 ) — Income tax credits, net (413 ) (992 ) (2,428 ) (1,851 ) Nondeductible transaction expenses 2,100 — 2,100 525 Other, net (256 ) (298 ) 708 91 Provision for federal income taxes $ 3,600 $ 9,600 $ 24,300 $ 26,800 Effective federal income tax rate 25.1 % 28.2 % 28.9 % 30.4 %
Significant components of deferred tax assets and liabilities	The significant components of the deferred tax assets and liabilities at September 30, 2016 and December 31, 2015 were as follows: (Dollars in thousands) September 30, December 31, Deferred tax assets: Allowance for loan losses $ 44,233 $ 24,863 Acquisition-related fair value adjustments 65,596 29,280 Accrued stock-based compensation 18,353 3,240 Loss and tax credit carry forwards 55,921 6,850 Acquisition built in loss carry forwards 31,316 — Depreciation 3,900 4,333 Nonaccrual interest 8,064 4,994 Accrued expense 18,400 13,296 Other 17,861 5,951 Total deferred tax assets 263,644 92,807 Deferred tax liabilities: Loan servicing rights 18,021 3,893 Core deposit intangible assets 9,938 7,379 Goodwill 6,350 5,808 Other 7,829 4,742 Total deferred tax liabilities 42,138 21,822 Net deferred tax asset before valuation allowance 221,506 70,985 Valuation allowance (2,502 ) (795 ) Net deferred tax asset $ 219,004 $ 70,190

Significant Accounting Polici40

Significant Accounting Policies (Details)	Nov. 04, 2016USD ($)	Oct. 28, 2016USD ($)	Aug. 31, 2016USD ($)	Feb. 22, 2016claim	Sep. 30, 2016USD ($)shares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)poolBankshares	Sep. 30, 2015USD ($)	Jul. 19, 2016shares	Jul. 18, 2016shares	Dec. 31, 2015USD ($)shares	Apr. 20, 2015shares	Apr. 20, 2009shares	Jan. 31, 2008shares
Business Acquisition
Number of banks through which company operates (in bank) | Bank							2
Number of regional banking units Chemical Bank operates through (in bank) | Bank							7
Goodwill					$ 1,137,166,000		$ 1,137,166,000				$ 287,393,000
Number of minimum days when principal or interest is past due is placed in nonaccrual category							90 days
Number of minimum days in real estate residential loan when principal or interest is past due is placed in nonaccrual category							120 days
Time period in which payments receive consistently and loans are returned to accrual status							6 months
Time period sustained for payment history of principal and interest payments to move them to performing status							6 months
Time period of real estate residential troubled debt restructurings reducing borrower's monthly payments by decreasing the interest rate charged on the loan							24 months
Minimum number of days past due as to interest or principal payments in accruing loans moves to nonperforming loans							90 days
Minimum amount of loan reviewed for detailed credit quality							$ 250,000
Time period for historical loan loss experience							5 years
Minimum percentage of tax benefit is recognized for the amount likely to be realized							50.00%
Reserve for contingent income tax liabilities recorded					0		$ 0
Expense related to qualified affordable housing projects					400,000	$ 600,000	1,600,000	$ 800,000
Remaining investment in qualified affordable housing projects					30,300,000		30,300,000				21,700,000
Equity method investments					10,200,000		10,200,000				1,700,000
Remaining unfunded equity contributions					16,800,000		16,800,000				8,000,000
Impairment on tax credit projects					$ 0		$ 0				$ 0
Number of shares authorized to be repurchased (in shares) | shares														500,000
Stock repurchased (in shares) | shares							0
Number of remaining shares authorized to be repurchased (in shares) | shares					500,000		500,000
Preferred stock, shares authorized (in shares) | shares					2,000,000		2,000,000				2,000,000	2,000,000	200,000
Preferred stock, shares issued (in shares) | shares					0		0				0
Preferred stock, shares outstanding (in shares) | shares					0		0
Common stock, shares authorized (in shares) | shares					100,000,000		100,000,000		100,000,000	60,000,000	60,000,000
Subsequent Event [Member] | Single branch office in Chicago [Member] | Completed sale [Member]
Business Acquisition
Deposits assumed in sale		$ 48,900,000
Loans purchased in sale		233,600,000
Premium in sale transaction		$ 6,500,000
Subsequent Event [Member] | Single branch office in Las Vegas [Member] | Completed sale [Member]
Business Acquisition
Deposits assumed in sale	$ 88,100,000
Loans purchased in sale	100,000
Premium in sale transaction	$ 1,000,000
Pending Litigation [Member] | In re Talmer Bancorp Shareholder Litigation [Member]
Business Acquisition
Number of putative class action and derivative complaints filed (in claim) | claim				2
Talmer [Member]
Business Acquisition
Total consideration			$ 1,612,449,000
Stock consideration			1,504,811,000
Cash consideration			107,638,000
Goodwill			850,299,000
Intangibles acquired			12,399,000
Deposits acquired			$ 5,290,000,000
Talmer [Member]
Business Acquisition
Number of pools of aggregate acquired loans based upon common risk characteristics (in pool) | pool							5
Lake Michigan Financial Corporation [Member]
Business Acquisition
Number of pools of aggregate acquired loans based upon common risk characteristics (in pool) | pool							2
Monarch Community Bancorp [Member]
Business Acquisition
Number of pools of aggregate acquired loans based upon common risk characteristics (in pool) | pool							2
Northwestern Bancorp [Member]
Business Acquisition
Number of pools of aggregate acquired loans based upon common risk characteristics (in pool) | pool							4
O.A.K. Financial Corporation [Member]
Business Acquisition
Number of pools of aggregate acquired loans based upon common risk characteristics (in pool) | pool							14

Mergers and Acquisitions (Textu

Mergers and Acquisitions (Textual) (Details) $ / shares in Units, $ in Thousands	Aug. 31, 2016USD ($)$ / sharesshares	May 31, 2015USD ($)office$ / sharesshares	Apr. 01, 2015USD ($)officeshares	Oct. 31, 2014USD ($)office	Dec. 07, 2012USD ($)branch	Apr. 30, 2010USD ($)office	Sep. 30, 2016USD ($)office	Mar. 31, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)office	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Business Acquisition
Merger and acquisition-related transaction expenses							$ 37,470		$ 900	$ 43,118	$ 5,719
Goodwill							$ 1,137,166			$ 1,137,166		$ 287,393
Talmer [Member]
Business Acquisition
Share price (in dollars per share) | $ / shares	$ 1.61
Exchange ratio of common stock issued	0.4725
Repayments of lines of credit	$ 37,500
Acquisition purchase price	1,612,449
Total assets acquired	$ 762,150
Service provided by acquiree bank through number of branches (in office) | office							81			81
Stock consideration given (in shares) | shares	32,100,000
Goodwill	$ 850,299
Contractual cash flows not expected to be collected (nonaccretable difference)	223,959
Intangibles acquired	12,399
Short-term borrowings	5,290,000
Loans	4,882,864
Lake Michigan Financial Corporation [Member]
Business Acquisition
Share price (in dollars per share) | $ / shares		$ 16.64
Exchange ratio of common stock issued		1.326
Acquisition purchase price		$ 187,400
Total assets acquired		1,240,000
Total loans acquired		985,500
Total deposits acquired		$ 924,700
Service provided by acquiree bank through number of branches (in office) | office		5
Stock consideration given		$ 132,900
Cash consideration given		$ 54,500
Stock consideration given (in shares) | shares		4,300,000
Goodwill		$ 100,900
Core deposits and other intangible assets acquired		8,600
Decrease in goodwill recognized								$ 500
Contractually required principal payments receivable		1,010,000
Contractually required interest payments receivable		190,200
Expected principal cash flows of contractually required acquired loan portfolio		986,100
Expected interest cash flows of contractually required acquired loan portfolio		189,600
Contractual cash flows not expected to be collected (nonaccretable difference)		22,600
Expected credit losses on acquired loan portfolio		22,000
Difference between expected cash flows and fair value, accretable yield		$ 190,200
Outstanding contractual principal balance of acquired loan portfolio							$ 697,400			$ 697,400		864,000
Carrying amount of acquired loan portfolio							675,000			675,000		842,000
Monarch Community Bancorp [Member]
Business Acquisition
Exchange ratio of common stock issued			0.0982
Acquisition purchase price			$ 27,200
Total assets acquired			182,800
Total loans acquired			121,800
Total deposits acquired			$ 144,300
Service provided by acquiree bank through number of branches (in office) | office			5
Stock consideration given (in shares) | shares			860,575
Goodwill			$ 5,300
Contractually required principal payments receivable			128,900
Contractually required interest payments receivable			37,800
Expected principal cash flows of contractually required acquired loan portfolio			122,600
Expected interest cash flows of contractually required acquired loan portfolio			37,100
Contractual cash flows not expected to be collected (nonaccretable difference)			7,100
Expected credit losses on acquired loan portfolio			6,300
Difference between expected cash flows and fair value, accretable yield			37,900
Outstanding contractual principal balance of acquired loan portfolio							97,100			97,100		115,000
Carrying amount of acquired loan portfolio							91,000			91,000		108,000
Purchase accounting fair value adjustment, core deposit intangibles			$ 1,900
Northwestern Bancorp [Member]
Business Acquisition
Acquisition purchase price				$ 121,000
Total assets acquired				815,000
Total loans acquired				475,000
Total deposits acquired				$ 794,000
Service provided by acquiree bank through number of branches (in office) | office				25
Goodwill				$ 60,300
Contractually required principal payments receivable				507,000
Contractually required interest payments receivable				112,000
Expected principal cash flows of contractually required acquired loan portfolio				481,000
Expected interest cash flows of contractually required acquired loan portfolio				104,000
Contractual cash flows not expected to be collected (nonaccretable difference)				34,000
Expected credit losses on acquired loan portfolio				26,000
Difference between expected cash flows and fair value, accretable yield				110,000
Outstanding contractual principal balance of acquired loan portfolio							296,700			296,700		361,000
Carrying amount of acquired loan portfolio							266,700			266,700		330,000
Intangibles acquired				$ 12,900
Independent Bank [Member]
Business Acquisition
Acquisition purchase price					$ 8,100
Goodwill					$ 6,800
Number of branches acquired (branch) | branch					21
Short-term borrowings					$ 404,000
Loans					44,000
Premium paid on deposits purchased					$ 11,500
Premium paid as a percentage of deposits purchased (percent)					2.85%
Discount on loans purchased (percent)					1.75%
Independent Bank [Member] | Core deposit intangible assets [Member]
Business Acquisition
Intangibles acquired					$ 5,600
O.A.K. Financial Corporation [Member]
Business Acquisition
Acquisition purchase price						$ 83,700
Total assets acquired						820,000
Total deposits acquired						693,000
Brokered deposits acquired						$ 193,000
Service provided by acquiree bank through number of branches (in office) | office						14
Outstanding contractual principal balance of acquired loan portfolio							165,300			165,300		204,000
Carrying amount of acquired loan portfolio							150,400			150,400		183,000
Loans						$ 627,000
Contractually required principal payments of loan portfolio, acquisition date						683,000
Acquired loan portfolio acquisition date fair value						$ 627,000
Northwestern and OAK [Member]
Business Acquisition
Reclassification from nonaccretable difference to the accretable yield										5,000
Line of Credit [Member]
Business Acquisition
Long-term borrowings, Amount	125,000						$ 124,698			$ 124,698		$ 25,000
Repayments of lines of credit	$ 25,000

Mergers and Acquisitions (Asset

Mergers and Acquisitions (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Aug. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair value of liabilities assumed:
Goodwill		$ 1,137,166	$ 287,393
Talmer Bank [Member]
Consideration paid:
Stock	$ 1,504,811
Cash	107,638
Total consideration	1,612,449
Fair value of identifiable assets acquired:
Cash and cash equivalents	433,352
Investment securities - AFS	808,894
Investment securities - HTM	1,657
Loans held-for-sale	244,916
Loans	4,882,864
Premises and equipment	38,793
Loan servicing rights	42,462
Other intangible assets	12,399
Interest receivable and other assets	397,660
Total identifiable assets acquired	6,862,997
Fair value of liabilities assumed:
Noninterest-bearing deposits	1,236,902
Interest-bearing deposits	4,057,968
Interest payable and other liabilities	99,176
Securities sold under agreements to repurchase with customers	19,704
Short-term borrowings	387,500
Long-term borrowings	299,597
Total liabilities assumed	6,100,847
Fair value of net identifiable assets acquired	762,150
Goodwill	$ 850,299

Mergers and Acquisitions (Loans

Mergers and Acquisitions (Loans Accounted for Under ASC 310-30) (Details) - Talmer Bank [Member] $ in Thousands	Aug. 31, 2016USD ($)
Accounted for under ASC 310-30:
Contractual cash flows	$ 5,968,950
Contractual cash flows not expected to be collected (nonaccretable difference)	223,959
Expected cash flows	5,744,991
Interest component of expected cash flows (accretable yield)	862,127
Fair value at acquisition	$ 4,882,864

Mergers and Acquisitions (Pro F

Mergers and Acquisitions (Pro Forma Information) (Details) - Talmer Bank [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Business Acquisition
Net interest and other income	$ 176,102	$ 163,933	$ 504,831	$ 460,791
Net Income	$ 9,320	$ 38,849	$ 84,808	$ 93,764
Earnings per share:
Basic (in dollars per share)	$ 0.13	$ 0.55	$ 1.20	$ 1.39
Diluted (in dollars per share)	$ 0.13	$ 0.55	$ 1.19	$ 1.37

Mergers and Acquisitions (Activ

Mergers and Acquisitions (Activity for Acquired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	$ 256,540	$ 348,048	$ 298,257	$ 137,961
Additions attributable to acquisitions	862,127	0	862,127	228,160
Additions (reductions)	7,224	(1,233)	(10,053)	1,532
Accretion recognized in interest income	(34,018)	(19,990)	(68,458)	(40,828)
Reclassification from nonaccretable difference			10,000
Balance at end of period	1,091,873	326,825	1,091,873	326,825
Talmer [Member]
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	0	0	0	0
Additions attributable to acquisitions	862,127	0	862,127	0
Additions (reductions)	0	0	0	0
Accretion recognized in interest income	(17,415)	0	(17,415)	0
Reclassification from nonaccretable difference			0
Balance at end of period	844,712	0	844,712	0
Lake Michigan [Member]
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	125,343	188,310	152,999	0
Additions attributable to acquisitions	0	0	0	190,246
Additions (reductions)	6,565	(747)	(3,800)	803
Accretion recognized in interest income	(7,968)	(10,704)	(25,259)	(14,190)
Reclassification from nonaccretable difference			0
Balance at end of period	123,940	176,859	123,940	176,859
Monarch [Member]
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	30,859	35,805	34,558	0
Additions attributable to acquisitions	0	0	0	37,914
Additions (reductions)	114	(351)	(749)	(1,492)
Accretion recognized in interest income	(1,322)	(2,085)	(4,158)	(3,053)
Reclassification from nonaccretable difference			0
Balance at end of period	29,651	33,369	29,651	33,369
Northwestern [Member]
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	73,746	91,758	82,623	104,675
Additions attributable to acquisitions	0	0	0	0
Additions (reductions)	526	(1,337)	(5,322)	(4,196)
Accretion recognized in interest income	(3,890)	(4,376)	(11,919)	(14,434)
Reclassification from nonaccretable difference			5,000
Balance at end of period	70,382	86,045	70,382	86,045
OAK [Member]
Activity for accretable yield includes contractually due interest of acquired loans
Balance at beginning of period	26,592	32,175	28,077	33,286
Additions attributable to acquisitions	0	0	0	0
Additions (reductions)	19	1,202	(182)	6,417
Accretion recognized in interest income	(3,423)	(2,825)	(9,707)	(9,151)
Reclassification from nonaccretable difference			5,000
Balance at end of period	$ 23,188	$ 30,552	$ 23,188	$ 30,552

Investment Securities (Summary

Investment Securities (Summary of Amortized Cost and Fair Value of Available-For-Sale Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Available-for-sale Securities
Amortized Cost	$ 1,301,257	$ 556,636
Unrealized Gains	4,323	1,468
Unrealized Losses	2,199	4,373
Available-for-sale, at fair value	1,303,381	553,731
US Treasury securities [Member]
Available-for-sale Securities
Amortized Cost	5,784	5,773
Unrealized Gains	17	0
Unrealized Losses	0	8
Available-for-sale, at fair value	5,801	5,765
Government sponsored agencies [Member]
Available-for-sale Securities
Amortized Cost	223,917	195,711
Unrealized Gains	535	78
Unrealized Losses	414	800
Available-for-sale, at fair value	224,038	194,989
State and political subdivisions [Member]
Available-for-sale Securities
Amortized Cost	306,196	14,731
Unrealized Gains	384	395
Unrealized Losses	1,043	6
Available-for-sale, at fair value	305,537	15,120
Residential mortgage-backed securities [Member]
Available-for-sale Securities
Amortized Cost	301,194	189,452
Unrealized Gains	2,206	538
Unrealized Losses	2	2,222
Available-for-sale, at fair value	303,398	187,768
Collateralized mortgage obligations [Member]
Available-for-sale Securities
Amortized Cost	343,502	133,256
Unrealized Gains	629	111
Unrealized Losses	392	1,137
Available-for-sale, at fair value	343,739	132,230
Corporate bonds [Member]
Available-for-sale Securities
Amortized Cost	96,283	14,825
Unrealized Gains	37	2
Unrealized Losses	235	200
Available-for-sale, at fair value	96,085	14,627
Preferred stock and trust preferred securities[Member]
Available-for-sale Securities
Amortized Cost	24,381	2,888
Unrealized Gains	515	344
Unrealized Losses	113	0
Available-for-sale, at fair value	$ 24,783	$ 3,232

Investment Securities (Summar47

Investment Securities (Summary of Amortized Cost and Fair Value of Held-To-Maturity Investment Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Held-to-maturity Securities
Amortized Cost	$ 563,721	$ 509,971
Unrealized Gains	13,110	7,446
Unrealized Losses	1,687	4,712
Held-to-maturity, fair value	575,144	512,705
State and political subdivisions [Member]
Held-to-maturity Securities
Amortized Cost	563,221	509,471
Unrealized Gains	13,110	7,446
Unrealized Losses	1,487	4,512
Held-to-maturity, fair value	574,844	512,405
Trust preferred securities [Member]
Held-to-maturity Securities
Amortized Cost	500	500
Unrealized Gains	0	0
Unrealized Losses	200	200
Held-to-maturity, fair value	$ 300	$ 300

Investment Securities (Gains an

Investment Securities (Gains and (Losses) Recognized in Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 2,820	$ 8,000	$ 7,820	$ 37,897
Gross gains	17	5	54	613
Gross losses	$ (1)	$ 0	$ (1)	$ (1)

Investment Securities (Maturiti

Investment Securities (Maturities of Debt Securities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Securities with amortized cost pledged to secure borrowings and deposits	$ 838,000	$ 530,800
Investment Securities Available-for-Sale:
Due in one year or less, Amortized Cost	303,733
Due after one year through five years, Amortized Cost	563,948
Due after five years through ten years, Amortized Cost	266,242
Due after ten years, Amortized Cost	165,946
Preferred stock, Amortized Cost	1,388
Total Available-for-sale Securities, Debt Maturities, Amortized Cost	1,301,257
Due in one year or less , Fair Value	304,279
Due after one year through five years, Fair Value	565,258
Due after five years through ten years, Fair Value	266,463
Due after ten years, Fair Value	165,576
Preferred stock, Fair Value	1,805
Total Available-for-sale securities, Debt maturities, Fair Value	1,303,381
Investment Securities Held-to-Maturity:
Due in one year or less, Amortized Cost	60,391
Due after one year through five years, Amortized Cost	276,065
Due after five years through ten years, Amortized Cost	138,202
Due after ten years, Amortized Cost	89,063
Total Held-to-maturity securities, Debt maturities, Amortized Cost	563,721	509,971
Due in one year or less , Fair Value	60,508
Due after one year through five years, Fair Value	279,172
Due after five years through ten years, Fair Value	143,257
Due after ten years, Fair Value	92,207
Total Held-to-maturity securities, Debt maturities, Fair Value	$ 575,144	$ 512,705

Investment Securities (Summar50

Investment Securities (Summary of Investment Securities with Gross Unrealized Losses) (Details) $ in Thousands	Sep. 30, 2016USD ($)security	Dec. 31, 2015USD ($)
Schedule of Investments [Line Items]
Total number of securities, available-for-sale and held-to-maturity | security	2,473
Securities in unrealized loss positions, qualitative disclosure, number of positions | security	598
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	$ 619,427	$ 554,907
Less Than 12 Months, Gross Unrealized Losses	2,872	5,945
12 Months or More, Fair Value	72,966	133,159
12 Months or More, Gross Unrealized Losses	1,014	3,140
Total, Fair Value	692,393	688,066
Total, Gross Unrealized Losses	3,886	9,085
Government sponsored agencies [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	20,532	114,640
Less Than 12 Months, Gross Unrealized Losses	29	292
12 Months or More, Fair Value	17,546	21,681
12 Months or More, Gross Unrealized Losses	385	508
Total, Fair Value	38,078	136,321
Total, Gross Unrealized Losses	414	800
State and political subdivisions [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	391,355	195,285
Less Than 12 Months, Gross Unrealized Losses	2,342	2,891
12 Months or More, Fair Value	29,379	68,361
12 Months or More, Gross Unrealized Losses	188	1,627
Total, Fair Value	420,734	263,646
Total, Gross Unrealized Losses	2,530	4,518
Residential mortgage-backed securities [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	10,607	169,226
Less Than 12 Months, Gross Unrealized Losses	2	2,146
12 Months or More, Fair Value	8	3,435
12 Months or More, Gross Unrealized Losses	0	76
Total, Fair Value	10,615	172,661
Total, Gross Unrealized Losses	2	2,222
Collateralized mortgage obligations [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	112,890	60,459
Less Than 12 Months, Gross Unrealized Losses	230	408
12 Months or More, Fair Value	20,812	39,382
12 Months or More, Gross Unrealized Losses	162	729
Total, Fair Value	133,702	99,841
Total, Gross Unrealized Losses	392	1,137
Corporate bonds [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	71,912	9,532
Less Than 12 Months, Gross Unrealized Losses	156	200
12 Months or More, Fair Value	4,921	0
12 Months or More, Gross Unrealized Losses	79	0
Total, Fair Value	76,833	9,532
Total, Gross Unrealized Losses	235	200
Preferred stock and trust preferred securities[Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value	12,131
Less Than 12 Months, Gross Unrealized Losses	113
12 Months or More, Fair Value	300
12 Months or More, Gross Unrealized Losses	200
Total, Fair Value	12,431
Total, Gross Unrealized Losses	$ 313
US Treasury securities [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value		5,765
Less Than 12 Months, Gross Unrealized Losses		8
12 Months or More, Fair Value		0
12 Months or More, Gross Unrealized Losses		0
Total, Fair Value		5,765
Total, Gross Unrealized Losses		8
Trust preferred securities [Member]
Summary of continuous unrealized loss position of securities
Less Than 12 Months, Fair Value		0
Less Than 12 Months, Gross Unrealized Losses		0
12 Months or More, Fair Value		300
12 Months or More, Gross Unrealized Losses		200
Total, Fair Value		300
Total, Gross Unrealized Losses		$ 200

Loans (Textual) (Details)

Loans (Textual) (Details)	9 Months Ended
	Sep. 30, 2016USD ($)class_of_loansegmentdirectortenantexecutive	Dec. 31, 2015USD ($)
Loans (Textual) [Abstract]
Number of portfolio segment (in segment) | segment	2
Number of classes of loans (in class of loan) | class_of_loan	6
Number of minimum tenants under lease of non-owner occupied commercial real estate (in tenant) | tenant	1
Loans	$ 12,715,789,000	$ 7,271,147,000
Minimum due period of loans consider in a nonperforming status	90 days
Total nonaccrual TDR loans	$ 29,500,000	35,900,000
Residential mortgage loans in process of foreclosure	8,100,000	2,900,000
Difference between recorded investment and unpaid principal balance of loan	102,800,000	25,300,000
Confirmed losses (partial charge-offs)	17,400,000	17,100,000
Fair value of discount adjustment	85,400,000	8,200,000
Acquired impaired loans	89,900,000	12,800,000
Performing trouble debt restructuring under impaired loans	48,800,000	47,800,000
Consumer loan portfolio [Member]
Loans (Textual) [Abstract]
Loans	$ 5,282,342,000	3,021,030,000
Maximum due period of loans consider in performing status	90 days
Minimum due period of loans consider in a nonperforming status	90 days
Commercial loan portfolio [Member]
Loans (Textual) [Abstract]
Loans	$ 7,433,447,000	4,250,117,000
Land development loans [Member]
Loans (Textual) [Abstract]
Maximum period for payment of loan	12 months
Residential mortgage [Member]
Loans (Textual) [Abstract]
Period for loan secured under real estate residential security	15 years
Loan-to-value ratio at the time of origination (as a percent)	80.00%
Residential mortgage [Member] | Consumer loan portfolio [Member]
Loans (Textual) [Abstract]
Loans	$ 3,046,959,000	1,429,636,000
Commercial [Member] | Commercial loan portfolio [Member]
Loans (Textual) [Abstract]
Loans	3,159,936,000	$ 1,905,879,000
Minimum value of loan requires group loan authority approval	$ 1,000,000
Number of bank executives and senior officers with credit decision limits similar to group loan authorities (in executive) | executive	6
Minimum value of loan requires executive and senior officer approval	$ 1,500,000
Maximum value of loan requires executive and senior officer approval	3,500,000
Minimum value of loan requires group loan authority approval	1,000,000
Maximum value of loan requires group loan authority approval	$ 10,000,000
Number of members of the board of directors in loan committee (in director) | director	8
Maximum [Member] | Residential mortgage [Member]
Loans (Textual) [Abstract]
Upper limit of number of family residential properties (in tenant) | tenant	4
Maximum [Member] | Commercial [Member] | Commercial loan portfolio [Member]
Loans (Textual) [Abstract]
Other loans requiring director loan committee approval depending on risk rating and credit action required	$ 10,000,000
Minimum [Member] | Residential mortgage [Member]
Loans (Textual) [Abstract]
Lower limit of number of family residential properties (in tenant) | tenant	1
Minimum [Member] | Commercial [Member] | Commercial loan portfolio [Member]
Loans (Textual) [Abstract]
Minimum value of loans requiring only director loan committee approval	$ 10,000,000
Minimum value of loans depending on risk rating and requires credit action from board of directors	15,000,000
Foreign [Member]
Loans (Textual) [Abstract]
Loans	$ 0

Loans (Summary of Loans) (Detai

Loans (Summary of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Summary of loans under portfolio
Total loans	$ 12,715,789	$ 7,271,147
Commercial loan portfolio [Member]
Summary of loans under portfolio
Total loans	7,433,447	4,250,117
Commercial loan portfolio [Member] | Commercial [Member]
Summary of loans under portfolio
Total loans	3,159,936	1,905,879
Commercial loan portfolio [Member] | Commercial real estate [Member]
Summary of loans under portfolio
Total loans	3,773,017	2,112,162
Commercial loan portfolio [Member] | Real estate construction and land development [Member]
Summary of loans under portfolio
Total loans	500,494	232,076
Consumer loan portfolio [Member]
Summary of loans under portfolio
Total loans	5,282,342	3,021,030
Consumer loan portfolio [Member] | Residential mortgage [Member]
Summary of loans under portfolio
Total loans	3,046,959	1,429,636
Consumer loan portfolio [Member] | Consumer installment [Member]
Summary of loans under portfolio
Total loans	1,335,707	877,457
Consumer loan portfolio [Member] | Home equity [Member]
Summary of loans under portfolio
Total loans	$ 899,676	$ 713,937

Loans (Summary of Recorded Inve

Loans (Summary of Recorded Investment of Commercial Loans by Risk Rating Categories) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	$ 12,715,789	$ 7,271,147
Commercial loan portfolio [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	7,433,447	4,250,117
Commercial loan portfolio [Member] | Commercial [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,159,936	1,905,879
Commercial loan portfolio [Member] | Commercial real estate [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,773,017	2,112,162
Commercial loan portfolio [Member] | Real estate construction and land development [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	500,494	232,076
Originated Portfolio [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,620,724	3,130,721
Originated Portfolio [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,444,690	2,942,826
Originated Portfolio [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	90,932	65,943
Originated Portfolio [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	51,366	67,714
Originated Portfolio [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	32,605	52,143
Originated Portfolio [Member] | Risk Grade 9 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,131	2,095
Originated Portfolio [Member] | Commercial [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,724,231	1,521,515
Originated Portfolio [Member] | Commercial [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,624,836	1,418,301
Originated Portfolio [Member] | Commercial [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	49,934	34,727
Originated Portfolio [Member] | Commercial [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	35,719	39,933
Originated Portfolio [Member] | Commercial [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	12,612	26,459
Originated Portfolio [Member] | Commercial [Member] | Risk Grade 9 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,130	2,095
Originated Portfolio [Member] | Commercial real estate [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,603,769	1,424,059
Originated Portfolio [Member] | Commercial real estate [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,528,013	1,341,202
Originated Portfolio [Member] | Commercial real estate [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	40,710	31,036
Originated Portfolio [Member] | Commercial real estate [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	15,132	26,658
Originated Portfolio [Member] | Commercial real estate [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	19,913	25,163
Originated Portfolio [Member] | Commercial real estate [Member] | Risk Grade 9 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1	0
Originated Portfolio [Member] | Real estate construction and land development [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	292,724	185,147
Originated Portfolio [Member] | Real estate construction and land development [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	291,841	183,323
Originated Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	288	180
Originated Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	515	1,123
Originated Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	80	521
Originated Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 9 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	0	0
Acquired Portfolio [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,812,723	1,119,396
Acquired Portfolio [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	3,523,524	1,011,895
Acquired Portfolio [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	145,250	54,803
Acquired Portfolio [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	91,016	43,119
Acquired Portfolio [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	52,933	9,579
Acquired Portfolio [Member] | Commercial [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,435,705	384,364
Acquired Portfolio [Member] | Commercial [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,331,689	340,782
Acquired Portfolio [Member] | Commercial [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	49,679	28,321
Acquired Portfolio [Member] | Commercial [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	37,813	11,607
Acquired Portfolio [Member] | Commercial [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	16,524	3,654
Acquired Portfolio [Member] | Commercial real estate [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	2,169,248	688,103
Acquired Portfolio [Member] | Commercial real estate [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	1,988,676	629,430
Acquired Portfolio [Member] | Commercial real estate [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	94,829	23,926
Acquired Portfolio [Member] | Commercial real estate [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	52,317	29,975
Acquired Portfolio [Member] | Commercial real estate [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	33,426	4,772
Acquired Portfolio [Member] | Real estate construction and land development [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	207,770	46,929
Acquired Portfolio [Member] | Real estate construction and land development [Member] | Risk Grades 1-5 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	203,159	41,683
Acquired Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 6 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	742	2,556
Acquired Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 7 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	886	1,537
Acquired Portfolio [Member] | Real estate construction and land development [Member] | Risk Grade 8 [Member]
Recorded investment of loans in commercial loan portfolio by risk rating categories
Total loans	$ 2,983	$ 1,153

Loans (Summary of Recorded In54

Loans (Summary of Recorded Investment of Consumer Loans by Risk Rating Categories) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	$ 12,715,789	$ 7,271,147
Nonperforming [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	61,651	83,880
Consumer loan portfolio [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	5,282,342	3,021,030
Consumer loan portfolio [Member] | Residential mortgage [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	3,046,959	1,429,636
Consumer loan portfolio [Member] | Consumer installment [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,335,707	877,457
Consumer loan portfolio [Member] | Home equity [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	899,676	713,937
Originated Portfolio [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	3,135,207	2,677,213
Originated Portfolio [Member] | Residential mortgage [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,371,004	1,216,975
Originated Portfolio [Member] | Consumer installment [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,172,137	869,426
Originated Portfolio [Member] | Home equity [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	592,066	590,812
Originated Portfolio [Member] | Performing [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	3,124,952	2,664,486
Originated Portfolio [Member] | Performing [Member] | Residential mortgage [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,363,819	1,207,945
Originated Portfolio [Member] | Performing [Member] | Consumer installment [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,171,759	868,975
Originated Portfolio [Member] | Performing [Member] | Home equity [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	589,374	587,566
Originated Portfolio [Member] | Nonperforming [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	10,255	12,727
Originated Portfolio [Member] | Nonperforming [Member] | Residential mortgage [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	7,185	9,030
Originated Portfolio [Member] | Nonperforming [Member] | Consumer installment [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	378	451
Originated Portfolio [Member] | Nonperforming [Member] | Home equity [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	2,692	3,246
Acquired Portfolio [Member] | Performing [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	2,147,135	343,817
Acquired Portfolio [Member] | Performing [Member] | Residential mortgage [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	1,675,955	212,661
Acquired Portfolio [Member] | Performing [Member] | Consumer installment [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	163,570	8,031
Acquired Portfolio [Member] | Performing [Member] | Home equity [Member]
Recorded investment of loans in consumer loan portfolio based on credit risk profile of loans in performing and nonperforming status
Total loans	$ 307,610	$ 123,125

Loans (Summary of Nonperforming

Loans (Summary of Nonperforming Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Summary of nonperforming loans
Total TDRs	$ 95,292	$ 103,111
Total loans	12,715,789	7,271,147
Commercial Loan Portfolio [Member]
Summary of nonperforming loans
Total TDRs	72,263	78,823
Total loans	7,433,447	4,250,117
Consumer Loan Portfolio [Member]
Summary of nonperforming loans
Total TDRs	23,029	24,288
Total loans	5,282,342	3,021,030
Commercial [Member] | Commercial Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	3,159,936	1,905,879
Commercial real estate [Member] | Commercial Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	3,773,017	2,112,162
Real estate construction and land development [Member] | Commercial Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	500,494	232,076
Residential mortgage [Member] | Consumer Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	3,046,959	1,429,636
Consumer Installment Loans [Member] | Consumer Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	1,335,707	877,457
Home Equity Loans [Member] | Consumer Loan Portfolio [Member]
Summary of nonperforming loans
Total loans	899,676	713,937
Nonperforming [Member]
Summary of nonperforming loans
Total nonaccrual loans	41,297	62,225
Total accruing loans contractually past due 90 days or more as to interest or principal payments	3,402	2,287
Total TDRs	16,952	19,368
Total loans	61,651	83,880
Nonperforming [Member] | Commercial Loan Portfolio [Member]
Summary of nonperforming loans
Total TDRs	15,261	16,297
Nonperforming [Member] | Consumer Loan Portfolio [Member]
Summary of nonperforming loans
Total TDRs	1,691	3,071
Nonperforming [Member] | Commercial [Member]
Summary of nonperforming loans
Total nonaccrual loans	13,742	28,554
Total accruing loans contractually past due 90 days or more as to interest or principal payments	221	364
Nonperforming [Member] | Commercial real estate [Member]
Summary of nonperforming loans
Total nonaccrual loans	19,914	25,163
Total accruing loans contractually past due 90 days or more as to interest or principal payments	739	254
Nonperforming [Member] | Real estate construction and land development [Member]
Summary of nonperforming loans
Total nonaccrual loans	80	521
Total accruing loans contractually past due 90 days or more as to interest or principal payments	1,439	0
Nonperforming [Member] | Residential mortgage [Member]
Summary of nonperforming loans
Total nonaccrual loans	5,119	5,557
Total accruing loans contractually past due 90 days or more as to interest or principal payments	375	402
Nonperforming [Member] | Consumer Installment Loans [Member]
Summary of nonperforming loans
Total nonaccrual loans	378	451
Nonperforming [Member] | Home Equity Loans [Member]
Summary of nonperforming loans
Total nonaccrual loans	2,064	1,979
Total accruing loans contractually past due 90 days or more as to interest or principal payments	$ 628	$ 1,267

Loans (Summary of Impaired Loan

Loans (Summary of Impaired Loans by Classes of Loans) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	$ 27,511	$ 44,383
Unpaid Principal Balance	27,516	45,151
Related Valuation Allowance	3,399	6,389
Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	169,504	97,815
Unpaid Principal Balance	272,336	122,367
Related Valuation Allowance	0	0
Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	197,015	142,198
Unpaid Principal Balance	299,852	167,518
Related Valuation Allowance	3,399	6,389
Commercial [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	4,906	18,898
Unpaid Principal Balance	4,911	19,426
Related Valuation Allowance	2,729	5,700
Commercial [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	53,542	31,039
Unpaid Principal Balance	78,494	37,703
Related Valuation Allowance	0	0
Commercial [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	58,448	49,937
Unpaid Principal Balance	83,405	57,129
Related Valuation Allowance	2,729	5,700
Commercial real estate [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	2,741	4,448
Unpaid Principal Balance	2,741	4,688
Related Valuation Allowance	516	497
Commercial real estate [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	69,713	53,518
Unpaid Principal Balance	118,751	69,130
Related Valuation Allowance	0	0
Commercial real estate [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	72,454	57,966
Unpaid Principal Balance	121,492	73,818
Related Valuation Allowance	516	497
Real estate construction and land development [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	3,362	2,136
Unpaid Principal Balance	8,894	3,108
Related Valuation Allowance	0	0
Real estate construction and land development [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	3,362	2,136
Unpaid Principal Balance	8,894	3,108
Related Valuation Allowance	0	0
Residential mortgage [Member] | Impaired loans with a valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	19,864	21,037
Unpaid Principal Balance	19,864	21,037
Related Valuation Allowance	154	192
Residential mortgage [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	34,310	7,638
Unpaid Principal Balance	54,414	8,644
Related Valuation Allowance	0	0
Residential mortgage [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	54,174	28,675
Unpaid Principal Balance	74,278	29,681
Related Valuation Allowance	154	192
Consumer installment [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,004	498
Unpaid Principal Balance	1,538	512
Related Valuation Allowance	0	0
Consumer installment [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	1,004	498
Unpaid Principal Balance	1,538	512
Related Valuation Allowance	0	0
Home equity [Member] | Impaired loans with no valuation allowance [Member]
Schedule of Impaired loans by classes
Recorded Investment	7,573	2,986
Unpaid Principal Balance	10,245	3,270
Related Valuation Allowance	0	0
Home equity [Member] | Total Impaired Loans [Member]
Schedule of Impaired loans by classes
Recorded Investment	7,573	2,986
Unpaid Principal Balance	10,245	3,270
Related Valuation Allowance	$ 0	$ 0

Loans (Summary of Information R

Loans (Summary of Information Related to Impaired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	$ 145,923	$ 138,197	$ 135,942	$ 133,845
Interest income recognized related to loans with impaired status	3,286	1,213	5,615	3,545
Commercial [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	43,812	42,847	42,478	39,387
Interest income recognized related to loans with impaired status	1,073	310	1,750	862
Commercial real estate [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	58,658	59,150	56,779	59,927
Interest income recognized related to loans with impaired status	1,219	470	2,068	1,453
Real estate construction and land development [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	2,400	2,210	2,243	2,338
Interest income recognized related to loans with impaired status	64	26	115	89
Residential mortgage [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	35,986	30,467	30,499	29,084
Interest income recognized related to loans with impaired status	818	387	1,540	1,098
Consumer installment [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	601	497	439	474
Interest income recognized related to loans with impaired status	17	0	19	1
Home equity [Member]
Schedule representing information related to impaired loans
Average recorded investment related to impaired loans	4,466	3,026	3,504	2,635
Interest income recognized related to loans with impaired status	$ 95	$ 20	$ 123	$ 42

Loans (Summary of the Aging Sta

Loans (Summary of the Aging Status of the Recorded Investment in Loans by Portfolio Segment/Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Originated Portfolio [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	$ 41,297	$ 62,225
Financing receivable recorded investment, Total past due	78,866	83,279
Financing receivable, recorded investment, current	6,677,065	5,724,655
Financing receivable, recorded investment, Total loans	6,755,931	5,807,934
Originated Portfolio [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	29,378	14,502
Originated Portfolio [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	4,789	4,265
Originated Portfolio [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	3,402	2,287
Originated Portfolio [Member] | Commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	13,742	28,554
Financing receivable recorded investment, Total past due	22,951	33,833
Financing receivable, recorded investment, current	1,701,280	1,487,682
Financing receivable, recorded investment, Total loans	1,724,231	1,521,515
Originated Portfolio [Member] | Commercial [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	6,313	3,685
Originated Portfolio [Member] | Commercial [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,675	1,230
Originated Portfolio [Member] | Commercial [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	221	364
Originated Portfolio [Member] | Commercial real estate [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	19,914	25,163
Financing receivable recorded investment, Total past due	33,292	31,188
Financing receivable, recorded investment, current	1,570,477	1,392,871
Financing receivable, recorded investment, Total loans	1,603,769	1,424,059
Originated Portfolio [Member] | Commercial real estate [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	11,913	4,168
Originated Portfolio [Member] | Commercial real estate [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	726	1,603
Originated Portfolio [Member] | Commercial real estate [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	739	254
Originated Portfolio [Member] | Real estate construction and land development [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	80	521
Financing receivable recorded investment, Total past due	4,522	521
Financing receivable, recorded investment, current	288,202	184,626
Financing receivable, recorded investment, Total loans	292,724	185,147
Originated Portfolio [Member] | Real estate construction and land development [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	3,003	0
Originated Portfolio [Member] | Real estate construction and land development [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	0	0
Originated Portfolio [Member] | Real estate construction and land development [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,439	0
Originated Portfolio [Member] | Residential mortgage [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	5,119	5,557
Financing receivable recorded investment, Total past due	8,121	7,696
Financing receivable, recorded investment, current	1,362,883	1,209,279
Financing receivable, recorded investment, Total loans	1,371,004	1,216,975
Originated Portfolio [Member] | Residential mortgage [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,627	1,737
Originated Portfolio [Member] | Residential mortgage [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	0	0
Originated Portfolio [Member] | Residential mortgage [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	375	402
Originated Portfolio [Member] | Consumer installment [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	378	451
Financing receivable recorded investment, Total past due	3,251	4,240
Financing receivable, recorded investment, current	1,168,886	865,186
Financing receivable, recorded investment, Total loans	1,172,137	869,426
Originated Portfolio [Member] | Consumer installment [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,425	3,145
Originated Portfolio [Member] | Consumer installment [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	448	644
Originated Portfolio [Member] | Consumer installment [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	0	0
Originated Portfolio [Member] | Home equity [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	2,064	1,979
Financing receivable recorded investment, Total past due	6,729	5,801
Financing receivable, recorded investment, current	585,337	585,011
Financing receivable, recorded investment, Total loans	592,066	590,812
Originated Portfolio [Member] | Home equity [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	3,097	1,767
Originated Portfolio [Member] | Home equity [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	940	788
Originated Portfolio [Member] | Home equity [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	628	1,267
Acquired Portfolio [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	72,634	20,415
Financing receivable, recorded investment, current	5,887,224	1,442,798
Financing receivable, recorded investment, Total loans	5,959,858	1,463,213
Acquired Portfolio [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	11,540	6,319
Acquired Portfolio [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	8,381	1,301
Acquired Portfolio [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	52,713	12,795
Acquired Portfolio [Member] | Commercial [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	16,246	4,757
Financing receivable, recorded investment, current	1,419,459	379,607
Financing receivable, recorded investment, Total loans	1,435,705	384,364
Acquired Portfolio [Member] | Commercial [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	3,116	490
Acquired Portfolio [Member] | Commercial [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,146	532
Acquired Portfolio [Member] | Commercial [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	11,984	3,735
Acquired Portfolio [Member] | Commercial real estate [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	32,603	9,019
Financing receivable, recorded investment, current	2,136,645	679,084
Financing receivable, recorded investment, Total loans	2,169,248	688,103
Acquired Portfolio [Member] | Commercial real estate [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	4,315	3,557
Acquired Portfolio [Member] | Commercial real estate [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,844	691
Acquired Portfolio [Member] | Commercial real estate [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	25,444	4,771
Acquired Portfolio [Member] | Real estate construction and land development [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	3,263	1,154
Financing receivable, recorded investment, current	204,507	45,775
Financing receivable, recorded investment, Total loans	207,770	46,929
Acquired Portfolio [Member] | Real estate construction and land development [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	208	0
Acquired Portfolio [Member] | Real estate construction and land development [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	153	0
Acquired Portfolio [Member] | Real estate construction and land development [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,902	1,154
Acquired Portfolio [Member] | Residential mortgage [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	15,066	3,451
Financing receivable, recorded investment, current	1,660,889	209,210
Financing receivable, recorded investment, Total loans	1,675,955	212,661
Acquired Portfolio [Member] | Residential mortgage [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,452	1,370
Acquired Portfolio [Member] | Residential mortgage [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	2,895	0
Acquired Portfolio [Member] | Residential mortgage [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	10,719	2,081
Acquired Portfolio [Member] | Consumer installment [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	1,770	102
Financing receivable, recorded investment, current	161,800	7,929
Financing receivable, recorded investment, Total loans	163,570	8,031
Acquired Portfolio [Member] | Consumer installment [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,367	55
Acquired Portfolio [Member] | Consumer installment [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	200	0
Acquired Portfolio [Member] | Consumer installment [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	203	47
Acquired Portfolio [Member] | Home equity [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Nonaccrual loans	0	0
Financing receivable recorded investment, Total past due	3,686	1,932
Financing receivable, recorded investment, current	303,924	121,193
Financing receivable, recorded investment, Total loans	307,610	123,125
Acquired Portfolio [Member] | Home equity [Member] | 31-60 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,082	847
Acquired Portfolio [Member] | Home equity [Member] | 61-89 Days Past Due [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	1,143	78
Acquired Portfolio [Member] | Home equity [Member] | Accruing Loans Past Due 90 Days or More [Member]
Schedule representing the aging status of the recorded investment in loans by classes
Financing receivable, recorded investment, Loans past due	$ 1,461	$ 1,007

Loans (Summary of TDRs) (Detail

Loans (Summary of TDRs) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of corporation's TDRs
Total TDRs	$ 95,292	$ 103,111
Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	72,263	78,823
Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	23,029	24,288
Performing Financial Instruments [Member]
Schedule of corporation's TDRs
Total TDRs	48,835	47,810
Performing Financial Instruments [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	30,662	29,844
Performing Financial Instruments [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	18,173	17,966
Nonperforming Financial Instruments [Member]
Schedule of corporation's TDRs
Total TDRs	16,952	19,368
Nonperforming Financial Instruments [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	15,261	16,297
Nonperforming Financial Instruments [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	1,691	3,071
Nonaccrual TDRs [Member]
Schedule of corporation's TDRs
Total TDRs	29,505	35,933
Nonaccrual TDRs [Member] | Commercial Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	26,340	32,682
Nonaccrual TDRs [Member] | Consumer Loan Portfolio [Member]
Schedule of corporation's TDRs
Total TDRs	$ 3,165	$ 3,251

Loans (Summary of TDRs Modified

Loans (Summary of TDRs Modified During the Period) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan	6	21	61	88
Modified TDRs, Pre-modification recorded investment	$ 4,249	$ 3,407	$ 15,365	$ 13,006
Modified TDRs, Post-modification recorded investment	$ 4,249	$ 3,407	$ 15,365	$ 13,004
Commercial Loan Portfolio [Member]
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan	4	6	38	34
Modified TDRs, Pre-modification recorded investment	$ 4,160	$ 2,926	$ 14,582	$ 10,556
Modified TDRs, Post-modification recorded investment	$ 4,160	$ 2,926	$ 14,582	$ 10,556
Commercial Loan Portfolio [Member] | Commercial [Member]
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan	4	3	32	21
Modified TDRs, Pre-modification recorded investment	$ 4,160	$ 882	$ 12,141	$ 5,146
Modified TDRs, Post-modification recorded investment	$ 4,160	$ 882	$ 12,141	$ 5,146
Commercial Loan Portfolio [Member] | Commercial real estate [Member]
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan	0	3	6	12
Modified TDRs, Pre-modification recorded investment	$ 0	$ 2,044	$ 2,441	$ 5,105
Modified TDRs, Post-modification recorded investment	$ 0	$ 2,044	$ 2,441	$ 5,105
Commercial Loan Portfolio [Member] | Real estate construction and land development [Member]
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan		0		1
Modified TDRs, Pre-modification recorded investment		$ 0		$ 305
Modified TDRs, Post-modification recorded investment		$ 0		$ 305
Consumer loan portfolio [Member]
Schedule providing information on TDRs
Modified TDRs, Number of loans (in loan) | loan	2	15	23	54
Modified TDRs, Pre-modification recorded investment	$ 89	$ 481	$ 783	$ 2,450
Modified TDRs, Post-modification recorded investment	$ 89	$ 481	$ 783	$ 2,448

Loans (Summary of TDRs with a P

Loans (Summary of TDRs with a Payment Default During the Period) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan	Sep. 30, 2016USD ($)loan	Sep. 30, 2015USD ($)loan
Troubled debt restructurings on financing receivables with defaults payment
Financing receivable modifications subsequent default number of contract (in loan) | loan	1	2	5	7
Financing receivable modifications subsequent default recorded investment | $	$ 0	$ 87	$ 1,721	$ 1,062
Commercial Loan Portfolio [Member]
Troubled debt restructurings on financing receivables with defaults payment
Financing receivable modifications subsequent default number of contract (in loan) | loan	0	1	2	5
Financing receivable modifications subsequent default recorded investment | $	$ 0	$ 74	$ 1,721	$ 1,016
Commercial Loan Portfolio [Member] | Commercial real estate [Member]
Troubled debt restructurings on financing receivables with defaults payment
Financing receivable modifications subsequent default number of contract (in loan) | loan	0	1	2	5
Financing receivable modifications subsequent default recorded investment | $	$ 0	$ 74	$ 1,721	$ 1,016
Consumer loan portfolio [Member]
Troubled debt restructurings on financing receivables with defaults payment
Financing receivable modifications subsequent default number of contract (in loan) | loan	1	1	3	2
Financing receivable modifications subsequent default recorded investment | $	$ 0	$ 13	$ 0	$ 46

Loans (Schedule of the Allowanc

Loans (Schedule of the Allowance for Loan Losses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Dec. 31, 2015
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	$ 71,506	$ 74,941	$ 73,328	$ 75,683
Provision for loan losses	4,103	1,500	8,603	4,500
Charge-offs	(2,861)	(2,195)	(11,939)	(8,062)
Recoveries	1,027	1,380	3,783	3,505
Ending balance	73,775	75,626	73,775	75,626
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses					$ 3,399	$ 6,389
Loans collectively evaluated for impairment related to allowance for loan losses					70,376	66,939
Loans acquired with deteriorated credit quality					0	0
Total allowance for loan losses	71,506	74,941	73,328	75,683	73,775	73,328
Loans individually evaluated for impairment related to recorded investment (loan balance)					99,523	121,416
Loans collectively evaluated for impairment related to recorded investment (loan balance)					6,656,408	5,686,518
Loans acquired with deteriorated credit quality					5,959,858	1,463,213
Total loans					12,715,789	7,271,147
Commercial Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	44,228	45,527	47,234	44,156
Provision for loan losses	3,537	2,637	5,437	5,604
Charge-offs	(824)	(539)	(7,262)	(2,958)
Recoveries	489	769	2,021	1,592
Ending balance	47,430	48,394	47,430	48,394
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses					3,245	6,197
Loans collectively evaluated for impairment related to allowance for loan losses					44,185	41,037
Loans acquired with deteriorated credit quality					0	0
Total allowance for loan losses	44,228	45,527	47,234	44,156	47,430	47,234
Loans individually evaluated for impairment related to recorded investment (loan balance)					79,659	100,379
Loans collectively evaluated for impairment related to recorded investment (loan balance)					3,541,065	3,030,342
Loans acquired with deteriorated credit quality					3,812,723	1,119,396
Total loans					7,433,447	4,250,117
Consumer Loan Portfolio [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	27,278	23,321	26,094	28,803
Provision for loan losses	566	(351)	3,166	(3,687)
Charge-offs	(2,037)	(1,656)	(4,677)	(5,104)
Recoveries	538	611	1,762	1,913
Ending balance	26,345	21,925	26,345	21,925
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses					154	192
Loans collectively evaluated for impairment related to allowance for loan losses					26,191	25,902
Loans acquired with deteriorated credit quality					0	0
Total allowance for loan losses	27,278	23,321	26,094	28,803	26,345	26,094
Loans individually evaluated for impairment related to recorded investment (loan balance)					19,864	21,037
Loans collectively evaluated for impairment related to recorded investment (loan balance)					3,115,343	2,656,176
Loans acquired with deteriorated credit quality					2,147,135	343,817
Total loans					5,282,342	3,021,030
Unallocated [Member]
Schedule of allowance and recorded investment related to financing receivables segregated by portfolio segment
Beginning balance	0	6,093	0	2,724
Provision for loan losses	0	(786)	0	2,583
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	0	5,307	0	5,307
Allowance for loan losses
Loans individually evaluated for impairment related to allowance for loan losses					0
Loans collectively evaluated for impairment related to allowance for loan losses					0
Loans acquired with deteriorated credit quality					0
Total allowance for loan losses	$ 0	$ 6,093	$ 0	$ 2,724	0	$ 0
Loans individually evaluated for impairment related to recorded investment (loan balance)					0
Loans collectively evaluated for impairment related to recorded investment (loan balance)					0
Loans acquired with deteriorated credit quality					0
Total loans					$ 0

Intangible Assets (Textual) (De

Intangible Assets (Textual) (Details) - USD ($)	Aug. 31, 2016	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Goodwill acquired during period			$ 500,000
Amortization of intangible assets					$ 6,736,000	$ 9,405,000
Estimated Future Amortization Expense, Fiscal Year Maturity [Abstract]
Impairment valuation allowance		$ 200,000			200,000
Loan servicing fee income		2,100,000		$ 1,400,000	4,700,000	4,100,000
Core deposit intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets		1,200,000		1,200,000	3,400,000	2,900,000
Estimated Future Amortization Expense, Fiscal Year Maturity [Abstract]
2,016		1,400,000			1,400,000
2,017		5,200,000			5,200,000
2,018		5,000,000			5,000,000
2,019		4,800,000			4,800,000
2,020		4,200,000			4,200,000
2021 and thereafter		15,000,000			15,000,000
Impairment valuation allowance		0			0
Loan Servicing Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets		1,105,000		$ 1,070,000	3,055,000	$ 3,279,000
Estimated Future Amortization Expense, Fiscal Year Maturity [Abstract]
Impairment valuation allowance		$ 214,000			$ 214,000		$ 0
Talmer [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill acquired during period	$ 850,300,000

Intangible Assets (Net Carrying

Intangible Assets (Net Carrying Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Net carrying value of intangible assets
Goodwill	$ 1,137,166		$ 287,393
Loan servicing rights	51,393		11,122
Other intangible assets:
Total other intangible assets	35,700		26,982
Loan Servicing Rights [Member]
Net carrying value of intangible assets
Loan servicing rights	51,393		11,122
Other intangible assets:
Total other intangible assets	9,465	$ 9,677	11,122	$ 11,540	$ 12,307	$ 12,217
Core deposit intangible assets [Member]
Other intangible assets:
Total other intangible assets	35,618		26,654
Noncompete Agreements [Member]
Other intangible assets:
Total other intangible assets	$ 82		$ 328

Intangible Assets (Amortization

Intangible Assets (Amortization Expense of Core Deposit Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Carrying amount, accumulated amortization and amortization expense of core deposit intangible assets
Total intangible assets	$ 35,700	$ 26,982
Core deposit intangible assets [Member]
Carrying amount, accumulated amortization and amortization expense of core deposit intangible assets
Gross original amount	52,454	40,055
Accumulated amortization	16,836	13,401
Total intangible assets	$ 35,618	$ 26,654

Intangible Assets (Loan Servici

Intangible Assets (Loan Servicing Rights at Fair Value) (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2016USD ($)
Activity for Loan Servicing Rights Accounted for Under Fair Value Method
Fair value, beginning of period	$ 0	$ 0
Acquired in Talmer Bancorp, Inc. merger	42,462	42,462
Additions from loans sold with servicing retained	810	810
Reductions from pay-offs, pay downs and run-off	(687)	(687)
Changes in estimates of fair value	(657)	(657)
Fair value, end of period	41,928	41,928
Principal balance of loans serviced	5,602,828	5,602,828
Commercial Real Estate [Member]
Activity for Loan Servicing Rights Accounted for Under Fair Value Method
Fair value, beginning of period	0	0
Acquired in Talmer Bancorp, Inc. merger	365	365
Additions from loans sold with servicing retained	0	0
Reductions from pay-offs, pay downs and run-off	(2)	(2)
Changes in estimates of fair value	0	0
Fair value, end of period	363	363
Principal balance of loans serviced	79,405	79,405
Mortgage [Member]
Activity for Loan Servicing Rights Accounted for Under Fair Value Method
Fair value, beginning of period	0	0
Acquired in Talmer Bancorp, Inc. merger	42,097	42,097
Additions from loans sold with servicing retained	810	810
Reductions from pay-offs, pay downs and run-off	(685)	(685)
Changes in estimates of fair value	(657)	(657)
Fair value, end of period	41,565	41,565
Principal balance of loans serviced	$ 5,523,423	$ 5,523,423

Intangible Assets (Carrying and

Intangible Assets (Carrying and Fair Value of LSRs) (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Net carrying value, fair value of LSRs and loans Corporation servicing for others
Valuation allowance	$ 200,000
Loan Servicing Rights [Member]
Net carrying value, fair value of LSRs and loans Corporation servicing for others
Net carrying value of LSRs	9,465,000	$ 11,122,000
Loan servicing rights	12,434,000	15,542,000
Valuation allowance	214,000	0
Loans serviced for others that have servicing rights capitalized	$ 1,981,157,000	$ 2,082,899,000

Intangible Assets (Activity for

Intangible Assets (Activity for Capitalized LSRs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Capitalized MSRs [Roll Forward]
Balance at beginning of period			$ 26,982
Amortization			(6,736)	$ (9,405)
Balance at end of period	$ 35,700		35,700
Loan Servicing Rights [Member]
Capitalized MSRs [Roll Forward]
Balance at beginning of period	9,677	$ 12,307	11,122	12,217
Acquired in Monarch acquisition	0	0	0	1,284
Additions	695	303	1,612	1,118
Amortization	(1,105)	(1,070)	(3,055)	(3,279)
Change in valuation allowance	198	0	(214)	200
Balance at end of period	$ 9,465	$ 11,540	$ 9,465	$ 11,540

Intangible Assets (Fair Value A

Intangible Assets (Fair Value Assumptions) (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
WA float range (as a percent)		1.72%
Commercial Real Estate [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average (“WA”) discount rate (as a percent)	16.46%
WA float range (as a percent)	0.53%
Commercial Real Estate [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Prepayment speed (as a percent)	0.00%
WA cost to service/per year (in dollars)	$ 467
Commercial Real Estate [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Prepayment speed (as a percent)	50.00%
WA cost to service/per year (in dollars)	$ 500
Mortgage [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average (“WA”) discount rate (as a percent)	10.09%	10.04%
WA ancillary income/per year (in dollars)	$ 28	$ 20
WA float range (as a percent)	0.68%
Mortgage [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Prepayment speed (as a percent)	0.00%	6.96%
WA cost to service/per year (in dollars)	$ 65	$ 70
Mortgage [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Prepayment speed (as a percent)	38.38%	17.65%
WA cost to service/per year (in dollars)	$ 90	$ 85

Accumulated Other Comprehensi70

Accumulated Other Comprehensive Loss (Changes in Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Components of accumulated other comprehensive income (loss), net of related tax benefit/expense
Beginning Balance			$ 1,015,974	$ 797,133
Other comprehensive income (loss) before reclassifications	$ (1,316)	$ 1,214	2,793	1,545
Amounts reclassified from accumulated other comprehensive income	1,872	704	1,097	1,722
Other comprehensive income, net of tax	556	1,918	3,890	3,267
Ending Balance	2,563,666	998,363	2,563,666	998,363
Unrealized gains (losses) on securities available-for-sale, net of tax [Member]
Components of accumulated other comprehensive income (loss), net of related tax benefit/expense
Beginning Balance	2,196	(274)	(1,888)	(210)
Other comprehensive income (loss) before reclassifications	(805)	1,214	3,304	1,545
Amounts reclassified from accumulated other comprehensive income	(10)	(3)	(35)	(398)
Other comprehensive income, net of tax	(815)	1,211	3,269	1,147
Ending Balance	1,381	937	1,381	937
Defined Benefit Pension Plans [Member]
Components of accumulated other comprehensive income (loss), net of related tax benefit/expense
Beginning Balance	(27,894)	(30,830)	(27,144)	(32,243)
Other comprehensive income (loss) before reclassifications	(511)	0	(511)	0
Amounts reclassified from accumulated other comprehensive income	1,882	707	1,132	2,120
Other comprehensive income, net of tax	1,371	707	621	2,120
Ending Balance	(26,523)	(30,123)	(26,523)	(30,123)
Total [Member]
Components of accumulated other comprehensive income (loss), net of related tax benefit/expense
Beginning Balance	(25,698)	(31,104)	(29,032)	(32,453)
Ending Balance	$ (25,142)	$ (29,186)	$ (25,142)	$ (29,186)

Accumulated Other Comprehensi71

Accumulated Other Comprehensive Loss (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gain on sale of investment securities	$ 16	$ 5	$ 53	$ 612
Income tax (expense)/benefit	(3,600)	(9,600)	(24,300)	(26,800)
Net income	10,732	24,467	59,701	61,326
Net Income (Loss)	(1,882)	(707)	(1,132)	(2,120)
Unrealized gains (losses) on securities available-for-sale, net of tax [Member] | Reclassification out of accumulated other comprehensive income (loss) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net gain on sale of investment securities	16	5	53	612
Income tax (expense)/benefit	(6)	(2)	(18)	(214)
Net income	10	3	35	398
Amortization of defined benefit pension plan items [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries, wages and employee benefits (operating expenses)	(2,895)	(1,087)	(1,742)	(3,261)
Income tax (expense)/benefit	$ 1,013	$ 380	$ 610	$ 1,141

Borrowings Schedule of Other Bo

Borrowings Schedule of Other Borrowings (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Aug. 31, 2016	Dec. 31, 2015
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Weighted Average Rate (as a percent)	1.78%		1.59%
Total long-term borrowings	$ 676,612		$ 242,391
Long-term debt, gross	$ 5,000
FHLB advances: 0.45% - 0.81% fixed-rate notes | Minimum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	0.45%
FHLB advances: 0.45% - 0.81% fixed-rate notes | Maximum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	0.81%
Federal Home Loan Bank Advances [Member] | FHLB advances: 0.59% - 7.44% fixed-rate notes due 2016 to 2027 (2)
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 494,013		$ 181,394
Long-term borrowings, Weighted Average Rate (as a percent)	1.45%		1.41%
Advances payable from Federal Home Loan Banks	$ 492,800		$ 181,000
Purchase accounting premiums	$ 1,200		400
Federal Home Loan Bank Advances [Member] | FHLB advances: 0.59% - 7.44% fixed-rate notes due 2016 to 2027 (2) | Minimum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	0.59%
Federal Home Loan Bank Advances [Member] | FHLB advances: 0.59% - 7.44% fixed-rate notes due 2016 to 2027 (2) | Maximum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	7.44%
Securities sold under agreements to repurchase | Securities sold under agreements to repurchase: 1.48% - 4.30% fixed-rate notes due 2016 to 2017 (3)
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 42,394		$ 17,453
Long-term borrowings, Weighted Average Rate (as a percent)	3.61%		0.27%
Purchase accounting premiums	$ 400		$ 500
Debt carrying amount after mater netting	$ 42,000		17,000
Securities sold under agreements to repurchase | Securities sold under agreements to repurchase: 1.48% - 4.30% fixed-rate notes due 2016 to 2017 (3) | Minimum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	1.48%
Securities sold under agreements to repurchase | Securities sold under agreements to repurchase: 1.48% - 4.30% fixed-rate notes due 2016 to 2017 (3) | Maximum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	4.30%
Line of Credit [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 124,698	$ 125,000	$ 25,000
Long-term borrowings, Weighted Average Rate (as a percent)	2.27%		2.27%
Stated interest rate	1.75%
Subordinated Debt Obligations [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 0		$ 18,544
Long-term borrowings, Weighted Average Rate (as a percent)	0.00%		3.99%
Subordinated Debt Obligations [Member] | Subordinated debt obligations: floating-rate based on three-month LIBOR plus 1.45% - 2.85% due 2034 to 2035 (4)
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 11,260		$ 0
Long-term borrowings, Weighted Average Rate (as a percent)	3.09%		0.00%
Purchase accounting discounts	$ 3,700
Long-term debt, gross	$ 15,000
Subordinated Debt Obligations [Member] | Subordinated debt obligations: floating-rate based on three-month LIBOR plus 1.45% - 2.85% due 2034 to 2035 (4) | Minimum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	1.45%
Subordinated Debt Obligations [Member] | Subordinated debt obligations: floating-rate based on three-month LIBOR plus 1.45% - 2.85% due 2034 to 2035 (4) | Maximum [Member]
Short Term Borrowings and Long Term Debt [Line Items]
Stated interest rate	2.85%
Subordinated Debt Obligations [Member] | Subordinated debt obligations: floating-rate based on three-month LIBOR plus 3.25% due in 2032 (5)
Short Term Borrowings and Long Term Debt [Line Items]
Long-term borrowings, Amount	$ 4,247		$ 0
Long-term borrowings, Weighted Average Rate (as a percent)	4.09%		0.00%
Stated interest rate	3.25%
Purchase accounting discounts	$ 800
Federal Home Loan Bank Advances [Member] | FHLB advances: 0.45% - 0.81% fixed-rate notes
Short Term Borrowings and Long Term Debt [Line Items]
Short-term borrowings, Amount	$ 400,000		$ 100,000
Short-term borrowings, Weighted Average Rate (as a percent)	0.52%		0.34%

Borrowings Textuals (Details)

Borrowings Textuals (Details) - USD ($)	Aug. 31, 2016	Sep. 30, 2016	Dec. 31, 2015	May 31, 2015
Debt Disclosure [Abstract]
FHLB advances		$ 5,100,000,000
Debt Instrument [Line Items]
Subordinated debt obligations: floating-rate based on three-month LIBOR plus 3.25 % due in 2032 (5)				$ 18,600,000
Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 145,000,000
Long-term borrowings, Amount	125,000,000	124,698,000	$ 25,000,000
Repayment of debt	25,000,000
Line of Credit [Member] | Term Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	125,000,000
Line of Credit [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	20,000,000
Line of Credit Acquired in Merger With Talmer [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Repayment of debt	37,500,000
Talmer Bank [Member]
Debt Instrument [Line Items]
Debt assumed in acquisition	$ 687,100,000
Repayment of assumed debt		$ 142,200,000

Borrowings (Details)

Borrowings (Details) $ in Thousands	Sep. 30, 2016USD ($)
Short-term Debt [Line Items]
Amounts related to securities sold under agreements to repurchase not included in offsetting disclosure in Footnote 14	$ 42,000
Securities sold under agreements to repurchase
Short-term Debt [Line Items]
Overnight and continuous	0
Up to 30 Days	13,000
30-90 Days	10,000
Greater than 90 Days	19,000
Total	$ 42,000

Regulatory Capital (Details)

Regulatory Capital (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Regulatory Capital
Risk weighted assets	$ 13,430,000	$ 7,140,000
Corporation [Member]
Total Capital to Risk-Weighted Assets
Actual Amount	$ 1,491,389	$ 841,257
Actual Ratio	11.10%	11.80%
For Capital Adequacy Purposes Amount	$ 1,074,506	$ 571,509
For Capital Adequacy Purposes Ratio	8.00%	8.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 1,155,093
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	8.60%
Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 1,413,464	$ 767,929
Actual Ratio	10.50%	10.70%
For Capital Adequacy Purposes Amount	$ 805,879	$ 428,631
For Capital Adequacy Purposes Ratio	6.00%	6.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 886,467
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	6.60%
Common Equity Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 1,413,464	$ 753,815
Actual Ratio	10.50%	10.60%
For Capital Adequacy Purposes Amount	$ 604,409	$ 321,474
For Capital Adequacy Purposes Ratio	4.50%	4.50%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 684,997
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	5.10%
Leverage Ratio
Actual Amount	$ 1,413,464	$ 767,929
Actual Ratio	12.80%	8.60%
For Capital Adequacy Purposes Amount	$ 442,317	$ 356,396
For Capital Adequacy Purposes Ratio	4.00%	4.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 442,317
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	4.00%
Chemical Bank [Member]
Total Capital to Risk-Weighted Assets
Actual Amount	$ 825,504	$ 830,294
Actual Ratio	10.80%	11.70%
For Capital Adequacy Purposes Amount	$ 614,281	$ 570,073
For Capital Adequacy Purposes Ratio	8.00%	8.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 660,352
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	8.60%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 767,851	$ 712,591
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 752,957	$ 756,966
Actual Ratio	9.80%	10.60%
For Capital Adequacy Purposes Amount	$ 460,711	$ 427,555
For Capital Adequacy Purposes Ratio	6.00%	6.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 506,782
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	6.60%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 614,281	$ 570,073
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Common Equity Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 752,957	$ 756,966
Actual Ratio	9.80%	10.60%
For Capital Adequacy Purposes Amount	$ 345,533	$ 320,666
For Capital Adequacy Purposes Ratio	4.50%	4.50%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 391,604
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	5.10%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 499,103	$ 463,184
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.50%	6.50%
Leverage Ratio
Actual Amount	$ 752,957	$ 756,966
Actual Ratio	8.10%	8.50%
For Capital Adequacy Purposes Amount	$ 373,897	$ 355,911
For Capital Adequacy Purposes Ratio	4.00%	4.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 373,897
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 467,371	$ 444,888
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%	5.00%
Talmer Bank [Member]
Total Capital to Risk-Weighted Assets
Actual Amount	$ 719,213
Actual Ratio	12.70%
For Capital Adequacy Purposes Amount	$ 453,090
For Capital Adequacy Purposes Ratio	8.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 487,071
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	8.60%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 566,362
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%
Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 713,835
Actual Ratio	12.60%
For Capital Adequacy Purposes Amount	$ 339,817
For Capital Adequacy Purposes Ratio	6.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 373,799
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	6.60%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 453,090
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%
Common Equity Tier 1 Capital to Risk-Weighted Assets
Actual Amount	$ 713,835
Actual Ratio	12.60%
For Capital Adequacy Purposes Amount	$ 254,863
For Capital Adequacy Purposes Ratio	4.50%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 288,845
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	5.10%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 368,135
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.50%
Leverage Ratio
Actual Amount	$ 713,835
Actual Ratio	10.90%
For Capital Adequacy Purposes Amount	$ 262,318
For Capital Adequacy Purposes Ratio	4.00%
For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 262,318
For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 327,898
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value of Assets on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	$ 1,303,381		$ 553,731
Loan servicing rights	41,928	$ 0	0
US Treasury securities [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	5,801		5,765
Government sponsored agencies [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	224,038		194,989
State and political subdivisions [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	305,537		15,120
Residential mortgage-backed securities [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	303,398		187,768
Collateralized mortgage obligations [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	343,739		132,230
Corporate bonds [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	96,085		14,627
Preferred stock and trust preferred securities[Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	24,783		3,232
Recurring [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	1,303,381		553,731
Loans held-for-sale	276,061		10,327
Loan servicing rights	41,928
Total derivatives	17,196		2,018
Total assets measured at fair value on a recurring basis	1,638,566		566,076
Total derivatives	15,970		1,979
Total liabilities at fair value	15,970		1,979
Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	5,801		5,765
Loans held-for-sale	0		0
Loan servicing rights	0
Total derivatives	0		0
Total assets measured at fair value on a recurring basis	5,801		5,765
Total derivatives	0		0
Total liabilities at fair value	0		0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	1,297,580		547,966
Loans held-for-sale	276,061		10,327
Loan servicing rights	0
Total derivatives	17,196		2,018
Total assets measured at fair value on a recurring basis	1,590,837		560,311
Total derivatives	15,970		1,979
Total liabilities at fair value	15,970		1,979
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Loans held-for-sale	0		0
Loan servicing rights	41,928
Total derivatives	0		0
Total assets measured at fair value on a recurring basis	41,928		0
Total derivatives	0		0
Total liabilities at fair value	0		0
Recurring [Member] | Customer-initiated derivatives [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	12,250
Total derivatives	12,787
Recurring [Member] | Customer-initiated derivatives [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0
Total derivatives	0
Recurring [Member] | Customer-initiated derivatives [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	12,250
Total derivatives	12,787
Recurring [Member] | Customer-initiated derivatives [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0
Total derivatives	0
Recurring [Member] | Forward contracts related to mortgage loans to be delivered for sale [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	89		144
Total derivatives	944		57
Recurring [Member] | Forward contracts related to mortgage loans to be delivered for sale [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | Forward contracts related to mortgage loans to be delivered for sale [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	89		144
Total derivatives	944		57
Recurring [Member] | Forward contracts related to mortgage loans to be delivered for sale [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | Interest rate lock commitments [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	2,674		42
Total derivatives	56		90
Recurring [Member] | Interest rate lock commitments [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | Interest rate lock commitments [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	2,674		42
Total derivatives	56		90
Recurring [Member] | Interest rate lock commitments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | Power Equity CD [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	2,183		1,832
Total derivatives	2,183		1,832
Recurring [Member] | Power Equity CD [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | Power Equity CD [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	2,183		1,832
Total derivatives	2,183		1,832
Recurring [Member] | Power Equity CD [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total derivatives	0		0
Total derivatives	0		0
Recurring [Member] | US Treasury securities [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	5,801		5,765
Recurring [Member] | US Treasury securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	5,801		5,765
Recurring [Member] | US Treasury securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | US Treasury securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Government sponsored agencies [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	224,038		194,989
Recurring [Member] | Government sponsored agencies [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Government sponsored agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	224,038		194,989
Recurring [Member] | Government sponsored agencies [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | State and political subdivisions [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	305,537		15,120
Recurring [Member] | State and political subdivisions [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | State and political subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	305,537		15,120
Recurring [Member] | State and political subdivisions [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Residential mortgage-backed securities [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	303,398		187,768
Recurring [Member] | Residential mortgage-backed securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Residential mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	303,398		187,768
Recurring [Member] | Residential mortgage-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Collateralized mortgage obligations [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	343,739		132,230
Recurring [Member] | Collateralized mortgage obligations [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Collateralized mortgage obligations [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	343,739		132,230
Recurring [Member] | Collateralized mortgage obligations [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Corporate bonds [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	96,085		14,627
Recurring [Member] | Corporate bonds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	96,085		14,627
Recurring [Member] | Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Preferred stock and trust preferred securities[Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	24,783		3,232
Recurring [Member] | Preferred stock and trust preferred securities[Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	0		0
Recurring [Member] | Preferred stock and trust preferred securities[Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	24,783		3,232
Recurring [Member] | Preferred stock and trust preferred securities[Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Available-for-sale, at fair value	$ 0		$ 0

Fair Value Measurements (Change

Fair Value Measurements (Changes in Level 3 Assets) (Details) - Recurring [Member] - Loans Servicing Rights [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 0
New originations	810
Balance, end of period	41,928
Mortgage banking revenue [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Additions due to acquisition	42,462
Gains (losses): Recorded in earnings (realized)	$ (1,344)

Fair Value Measurements (Aggreg

Fair Value Measurements (Aggregate Fair Value, Contractual Balance, and Gain or Loss for Loans Held-For-Sale) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Aggregate fair value	$ 276,061	$ 10,327
Contractual balance	274,406	10,366
Unrealized gain (loss)	$ 1,655	$ (39)

Fair Value Measurements (Gains

Fair Value Measurements (Gains (Losses) from Loans Held-for-Sale Included in the Consolidated Statements of Income) (Details) - Loans Held For Sale [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total included in earnings	$ 854	$ 99	$ 1,048	$ 41
Interest income [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total included in earnings	811	23	849	56
Change in fair value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total included in earnings	$ 43	$ 76	$ 199	$ (15)

Fair Value Measurements (Textua

Fair Value Measurements (Textual) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value Measurements (Textual) [Abstract]
Impairment of goodwill	$ 0	$ 0
Impairment valuation allowance	200,000
Core deposit intangible assets [Member]
Fair Value Measurements (Textual) [Abstract]
Impairment valuation allowance	0
Impairment identified for intangible assets		0
Loan Servicing Rights [Member]
Fair Value Measurements (Textual) [Abstract]
Impairment valuation allowance	$ 214,000	0
Minimum [Member]
Fair Value Measurements (Textual) [Abstract]
Expected life of intangible assets	10 years
Maximum [Member]
Fair Value Measurements (Textual) [Abstract]
Expected life of intangible assets	15 years
Loans Held For Sale [Member]
Fair Value Measurements (Textual) [Abstract]
Loans held for sale that were on nonaccrual status	$ 0	0
Loans held for sale that were 90 days past due and on accrual status	$ 0	0
Total Impaired Loans [Member] | Minimum [Member]
Fair Value Measurements (Textual) [Abstract]
Percentage of discount factors used to determine fair value	70.00%
Total Impaired Loans [Member] | Maximum [Member]
Fair Value Measurements (Textual) [Abstract]
Percentage of discount factors used to determine fair value	80.00%
Other Real Estate and Repossessed Assets [Member] | Minimum [Member]
Fair Value Measurements (Textual) [Abstract]
Percentage of discount factors used to determine fair value	67.00%
Other Real Estate and Repossessed Assets [Member] | Maximum [Member]
Fair Value Measurements (Textual) [Abstract]
Percentage of discount factors used to determine fair value	90.00%
Measured on a Recurring Basis [Member]
Fair Value Measurements (Textual) [Abstract]
Liabilities recorded at fair value	$ 15,970,000	1,979,000
Measured on a Nonrecurring Basis [Member]
Fair Value Measurements (Textual) [Abstract]
Liabilities recorded at fair value	0	0
Total assets measured at fair value on a nonrecurring basis	31,412,000	45,133,000
Measured on a Nonrecurring Basis [Member] | Impaired originated loans [Member]
Fair Value Measurements (Textual) [Abstract]
Total assets measured at fair value on a nonrecurring basis	25,344,000	$ 42,065,000
Measured on a Nonrecurring Basis [Member] | Loan Servicing Rights [Member]
Fair Value Measurements (Textual) [Abstract]
Total assets measured at fair value on a nonrecurring basis	$ 5,688,000

Fair Value Measurements (Fair81

Fair Value Measurements (Fair Value of Assets on a Nonrecurring Basis) (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	$ 31,412	$ 45,133
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	31,412	45,133
Impaired originated loans [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	25,344	42,065
Impaired originated loans [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Impaired originated loans [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Impaired originated loans [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	25,344	42,065
Other real estate/repossessed assets [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	380	3,068
Other real estate/repossessed assets [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Other real estate/repossessed assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0	0
Other real estate/repossessed assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	380	$ 3,068
Loan servicing rights [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	5,688
Loan servicing rights [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0
Loan servicing rights [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	0
Loan servicing rights [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a nonrecurring basis
Total assets measured at fair value on a nonrecurring basis	$ 5,688

Fair Value Measurements (Level

Fair Value Measurements (Level 3 Assets Measured on a Nonrecurring Basis) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Impaired originated loans [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	20.00%
Impaired originated loans [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	30.00%
Other Real Estate and Repossessed Assets [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	10.00%
Other Real Estate and Repossessed Assets [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	33.00%
Prepayment speed (as a percent)	22.00%
Loan servicing rights [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	10.00%
Prepayment speed (as a percent)	13.00%
Loan servicing rights [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate (as a percent)	11.00%
Nonrecurring [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	$ 31,412	$ 45,133
Nonrecurring [Member] | Impaired originated loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	25,344	42,065
Nonrecurring [Member] | Other real estate/repossessed assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	380	3,068
Nonrecurring [Member] | Loan servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	5,688
Nonrecurring [Member] | Level 3 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	31,412	45,133
Nonrecurring [Member] | Level 3 [Member] | Impaired originated loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	25,344	42,065
Nonrecurring [Member] | Level 3 [Member] | Other real estate/repossessed assets [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	380	$ 3,068
Nonrecurring [Member] | Level 3 [Member] | Loan servicing rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Total assets measured at fair value on a nonrecurring basis	$ 5,688

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Carrying Amounts and Estimated Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investment securities:
Held-to-maturity	$ 575,144	$ 512,705
Carrying Amount [Member]
Investment securities:
Nonmarketable equity securities	77,396	36,907
Carrying Amount [Member] | Level 1[Member]
Assets:
Cash and cash equivalents	556,567	238,789
Carrying Amount [Member] | Level 2 [Member]
Investment securities:
Held-to-maturity	563,221	509,471
Interest receivable	43,131	21,953
Liabilities:
Deposits without defined maturities	9,924,502	5,809,355
Time deposits	3,348,360	1,647,412
Interest payable	5,097	1,578
Short-term borrowings	726,789	397,199
Long-term borrowings	676,612	242,391
Carrying Amount [Member] | Level 3 [Member]
Investment securities:
Held-to-maturity	500	500
Net loans	12,642,014	7,197,819
Fair Value [Member]
Investment securities:
Nonmarketable equity securities	77,396	36,907
Fair Value [Member] | Level 1[Member]
Assets:
Cash and cash equivalents	556,567	238,789
Fair Value [Member] | Level 2 [Member]
Investment securities:
Held-to-maturity	574,844	512,405
Interest receivable	43,131	21,953
Liabilities:
Deposits without defined maturities	9,924,502	5,809,355
Time deposits	3,348,942	1,647,412
Interest payable	5,097	1,578
Short-term borrowings	726,789	397,199
Long-term borrowings	676,750	242,391
Fair Value [Member] | Level 3 [Member]
Investment securities:
Held-to-maturity	300	300
Net loans	$ 12,650,332	$ 7,201,994

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income	$ 10,732	$ 24,467	$ 59,701	$ 61,326
Net income allocated to participating securities	36	0	78	0
Net income allocated to common shareholders	$ 10,696	$ 24,467	$ 59,623	$ 61,326
Weighted average common shares - issued (in shares)	49,107,000	38,123,000	41,881,000	35,384,000
Average unvested restricted share awards (in shares)	(163,000)	0	(55,000)	0
Weighted average common shares outstanding - basic (in shares)	48,944,000	38,123,000	41,826,000	35,384,000
Effect of dilutive securities
Weighted average common stock equivalents (in shares)	687,000	270,000	493,000	246,000
Denominator for diluted earnings per common share (in shares)	49,631,000	38,393,000	42,319,000	35,630,000
EPS available to common shareholders
Basic earnings per common share (dollars per share)	$ 0.22	$ 0.64	$ 1.43	$ 1.73
Diluted earnings per common share (dollars per share)	$ 0.21	$ 0.64	$ 1.40	$ 1.72
Stock Option [Member]
Earnings Per Common Share (Textual)
Average number of exercisable employee stock option awards that were not included in the computation of diluted earnings per common share (in shares)	0	17,333	0	73,028

(Textual) (Details)

(Textual) (Details) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2015USD ($)	Apr. 20, 2015shares
Share-based Compensation Plans (Textual)
Share-based compensation expense | $	$ 4.7	$ 1.2	$ 6.5	$ 2.7
Corporation granted shares of common stock (in shares) | shares			940
Common stock available for future grants under share-based compensation plans (in shares) | shares					1,300,000
Stock Incentive Plans After 2012 [Member]
Share-based Compensation Plans (Textual)
Vesting period			5 years
Stock Incentive Plans Prior To 2013 [Member]
Share-based Compensation Plans (Textual)
Vesting period			3 years
Employee Stock Option [Member]
Share-based Compensation Plans (Textual)
Corporation acquired stock options (in shares | shares			1,466,408
Stock option award vesting period			10 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Plans (Textual)
Corporation granted options to purchase restricted stock performance units (in shares) | shares			133,620
Unrecognized compensation expense | $	$ 5.6		$ 5.6
Unrecognized compensation expense, period for recognition			2 years 7 months 6 days
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Plans (Textual)
Restricted stock performance units eligible to vest as a multiple of number of units granted			0.5
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Plans (Textual)
Restricted stock performance units eligible to vest as a multiple of number of units granted			1.5
Equity Option [Member]
Share-based Compensation Plans (Textual)
Common stock available for future grants under share-based compensation plans (in shares) | shares	669,081		669,081
Weighted-average remaining contractual terms for outstanding stock options			6 years 2 months 12 days
Weighted-average remaining contractual terms for exercisable stock options			5 years 8 months 15 days
Outstanding in-the-money stock options, intrinsic value | $	$ 62.3		$ 62.3
Exercisable in-the-money stock options, intrinsic value | $	$ 57.6		$ 57.6
Closing price of common stock (dollars per share) | $ / shares	$ 44.13		$ 44.13
Unrecognized compensation expense | $	$ 2.3		$ 2.3
Unrecognized compensation expense, period for recognition			4 years 4 months 24 days
Restricted Stock Awards [Member]
Share-based Compensation Plans (Textual)
Corporation acquired restricted stock awards (in shares | shares			484,892
Unrecognized compensation expense | $	$ 14.8		$ 14.8
Unrecognized compensation expense, period for recognition			1 year 6 months

Share-Based Compensation (Stock

Share-Based Compensation (Stock Option Activity) (Details)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Grant Date Fair Value [Roll Forward]
Granted, Weighted Average Grant Date Fair Value (dollars per share)	$ 6.15
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Acquired, Number of Options (in shares) | shares	1,466,408
Stock Options [Member] | Non Vested [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Number of Options (in shares) | shares	479,755
Acquired, Number of Options (in shares) | shares	0
Granted, Number of Options (in shares) | shares	441,167
Exercised, Number of Options (in shares) | shares	0
Vested, Number of Options (in shares) | shares	(454,360)
Forfeited/expired, Number of Options (in shares) | shares	(47,286)
Ending balance, Number of Options (in shares) | shares	419,276
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Beginning balance, Weighted Average Exercise Price (dollars per share)	$ 28.75
Acquired, Weighted Average Exercise Price (dollars per share)	0
Granted, Weighted Average Exercise Price (dollars per share)	32.81
Exercised, Weighted Average Exercise Price (dollars per share)	0
Vested, Weighted Average Exercise Price (dollars per share)	28.74
Forfeited/expired, Weighted Average Exercise Price (dollars per share)	30.69
Ending balance, Weighted Average Exercise Price (dollars per share)	32.81
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning balance, Weighted average grant date fair value (dollars per share)	8.49
Acquired, Weighted Average Grant Date Fair Value (dollars per share)	0
Granted, Weighted Average Grant Date Fair Value (dollars per share)	0
Exercised, Weighted Average Grant Date Fair Value (dollars per share)	0
Vested, Weighted Average Grant Date Fair Value (dollars per share)	8.49
Forfeited/expired, Weighted Average Grant Date Fair Value (dollars per share)	7.42
Ending balance, Weighted average grant date fair value (dollars per share)	$ 6.15
Stock Options [Member] | Vested & Nonvested [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance, Number of Options (in shares) | shares	1,054,739
Acquired, Number of Options (in shares) | shares	1,466,408
Granted, Number of Options (in shares) | shares	441,167
Exercised, Number of Options (in shares) | shares	(220,026)
Vested, Number of Options (in shares) | shares	0
Forfeited/expired, Number of Options (in shares) | shares	(47,286)
Ending balance, Number of Options (in shares) | shares	2,695,002
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Beginning balance, Weighted Average Exercise Price (dollars per share)	$ 25.38
Acquired, Weighted Average Exercise Price (dollars per share)	15.08
Granted, Weighted Average Exercise Price (dollars per share)	32.81
Exercised, Weighted Average Exercise Price (dollars per share)	24.08
Vested, Weighted Average Exercise Price (dollars per share)	0
Forfeited/expired, Weighted Average Exercise Price (dollars per share)	30.69
Ending balance, Weighted Average Exercise Price (dollars per share)	$ 21.01
Stock Options [Member] | Vested [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Grant Date Fair Value [Roll Forward]
Exercisable/vested, Number of Options (in shares) | shares	2,275,726
Exercisable/vested, Weighted Average Exercise Price (dollars per share)	$ 18.84

Share-Based Compensation (Black

Share-Based Compensation (Black-Scholes Pricing Model Assumptions) (Details)	9 Months Ended
	Sep. 30, 2016$ / shares
Assumptions of Black-Scholes option pricing model
Expected dividend yield	3.30%
Risk-free interest rate	1.39%
Expected stock price volatility	27.90%
Expected life of options - in years	6 years 6 months
Weighted average fair value of options granted (dollars per share)	$ 6.15

Share-Based Compensation (Restr

Share-Based Compensation (Restricted Stock Unit and Award Activity) (Details)	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Restricted Stock Units (RSUs) [Member]
Number of shares
Beginning balance, Number of shares (in shares) | shares	207,989
Granted, Number of shares (in shares) | shares	133,620
Converted into shares of common stock, Number of shares (in shares) | shares	(67,207)
Forfeited/expired, Number of shares (in shares) | shares	(5,656)
Ending balance, Number of shares (in shares) | shares	268,746
Weighted-average grant-date fair value
Beginning balance, Weighted average grant date fair value (dollars per share) | $ / shares	$ 26.41
Granted, Weighted average grant date fair value (dollars per share) | $ / shares	34.75
Converted into shares of common stock, Weighted average grant date fair value (dollars per share) | $ / shares	24.54
Forfeited/expired, Weighted average grant date fair value (dollars per share) | $ / shares	29.30
Ending balance, Weighted average grant date fair value (dollars per share) | $ / shares	$ 30.97
Restricted Stock Awards [Member]
Number of shares
Beginning balance, Number of shares (in shares) | shares	0
Acquired, Number of shares (in shares) | shares	484,892
Vested, Number of shares (in shares) | shares	0
Forfeited/expired, Number of shares (in shares) | shares	(508)
Ending balance, Number of shares (in shares) | shares	484,384
Weighted-average grant-date fair value
Beginning balance, Weighted average grant date fair value (dollars per share) | $ / shares	$ 0
Acquired, Weighted average grant date fair value (dollars per share) | $ / shares	46.23
Converted into shares of common stock, Weighted average grant date fair value (dollars per share) | $ / shares	0
Vested, Weighted average grant date fair value (dollars per share) | $ / shares	46.23
Ending balance, Weighted average grant date fair value (dollars per share) | $ / shares	$ 46.23

Pension and Other Postretirem89

Pension and Other Postretirement Benefit Plans (Components of Net Periodic Benefit Cost (Income)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Pension Plans
Components of net periodic benefit cost (income) for the Corporation's qualified and nonqualified pension plans and nonqualified postretirement benefits plan
Service cost	$ 279	$ 273	$ 834	$ 818
Interest cost	1,357	1,331	4,072	3,995
Contractual termination cost	32	0	32	0
Expected return on plan assets	(2,141)	(2,161)	(6,422)	(6,483)
Amortization of prior service cost	0	(2)	0	(4)
Amortization of unrecognized net loss (gain)	585	1,057	1,729	3,169
Net periodic benefit cost	112	498	245	1,495
Postretirement Benefit Plan
Components of net periodic benefit cost (income) for the Corporation's qualified and nonqualified pension plans and nonqualified postretirement benefits plan
Service cost	2	4	7	12
Interest cost	33	33	99	100
Amortization of prior service cost	29	32	88	97
Amortization of unrecognized net loss (gain)	(24)	0	(75)	(1)
Net periodic benefit cost	$ 40	$ 69	$ 119	$ 208

Pension and Other Postretirem90

Pension and Other Postretirement Benefit Plans (Textual) (Details) - USD ($)	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Aug. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to Pentegra DB Plan		$ 0	$ 0		$ 0
Chemical Financial Corporation [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of eligible pay contribution to certain employees (as a percent)					4.00%
Employer total contribution amount		$ 1,700,000	$ 1,400,000		$ 4,400,000	$ 3,800,000
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit pension plan					$ 0		$ 0
Discount rate for pension plan expense (as a percent)	2.87%			4.55%
Increase in pension liability from remeasurement	$ 786,000
Non-Qualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Discount rate for pension plan expense (as a percent)				4.51%

Financial Guarantees (Textual)

Financial Guarantees (Textual) (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Financial Guarantees (Textual) [Abstract]
Potential losses from standby letters of credit	$ 0	$ 0
Liability related to financial guarantees	950,000
Performance Guarantee [Member]
Financial Guarantees (Textual) [Abstract]
Recorded liability	6,900,000	4,000,000
Financial and Performance Standby Letters of Credit [Member]
Financial Guarantees (Textual) [Abstract]
Letters of credit outstanding	117,300,000	38,800,000
Liability related to financial guarantees		0
Commitments to Extend Credit [Member]
Financial Guarantees (Textual) [Abstract]
Loan commitments under financial guarantee	3,250,000,000	1,590,000,000
Loan Commitments [Member]
Financial Guarantees (Textual) [Abstract]
Loan commitments under financial guarantee	480,000,000	293,600,000
Certain Loans with Limited Recourse [Member]
Financial Guarantees (Textual) [Abstract]
Principal amount outstanding on loans	22,600,000	1,500,000
Maximum undiscounted potential future payments	21,600,000	1,500,000
Recorded liability	$ 200,000	$ 100,000

Derivative Instruments and Ba92

Derivative Instruments and Balance Sheet Offsetting (Notional Amount and Fair Value) (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Derivative instruments
Notional Amount	$ 951,447,000	$ 90,911,000
Gross Derivative Assets	17,196,000	2,018,000
Gross Derivative Liabilities	15,970,000	1,979,000
Credit valuation adjustments for counterparty credit risk	745,000	0
Not designated as hedging | Customer-initiated derivatives [Member]
Derivative instruments
Notional Amount	559,458,000	0
Gross Derivative Assets	12,250,000	0
Gross Derivative Liabilities	12,787,000	0
Not designated as hedging | Forward contracts related to mortgage loans to be delivered for sale [Member]
Derivative instruments
Notional Amount	197,874,000	33,787,000
Gross Derivative Assets	89,000	144,000
Gross Derivative Liabilities	944,000	57,000
Not designated as hedging | Interest rate lock commitments [Member]
Derivative instruments
Notional Amount	157,743,000	23,421,000
Gross Derivative Assets	2,674,000	42,000
Gross Derivative Liabilities	56,000	90,000
Not designated as hedging | Power Equity CD [Member]
Derivative instruments
Notional Amount	36,372,000	33,703,000
Gross Derivative Assets	2,183,000	1,832,000
Gross Derivative Liabilities	$ 2,183,000	$ 1,832,000

Derivative Instruments and Ba93

Derivative Instruments and Balance Sheet Offsetting (Net Gains (Losses) Related to Changes in Fair Value) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative instruments
Net gains (losses) relating to derivative instruments	$ (395)	$ (76)	$ (551)	$ 15
Forward contracts related to mortgage loans to be delivered for sale [Member] | Net gain on sales of loans [Member]
Derivative instruments
Net gains (losses) relating to derivative instruments	(156)	(384)	(798)	(24)
Interest rate lock commitments [Member] | Net gain on sales of loans [Member]
Derivative instruments
Net gains (losses) relating to derivative instruments	(179)	308	307	39
Power Equity CD [Member] | Other noninterest income [Member]
Derivative instruments
Net gains (losses) relating to derivative instruments	0	0	0	0
Customer-initiated derivatives [Member] | Other noninterest income [Member]
Derivative instruments
Net gains (losses) relating to derivative instruments	$ (60)	$ 0	$ (60)	$ 0

Derivative Instruments and Ba94

Derivative Instruments and Balance Sheet Offsetting (Balance Sheet Offsetting) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Offsetting derivative assets
Gross amounts recognized	$ 17,196	$ 2,018
Offsetting derivative liabilities
Gross amounts recognized	15,970	$ 1,979
Interest rate swaps and customer-initiated derivatives
Offsetting derivative assets
Gross amounts recognized	12,247
Financial instruments	0
Net amounts presented in the statement of financial position	12,247
Gross amounts not offset in the statement of financial position
Financial Instruments	0
Collateral (received)/posted	0
Net Amount	12,247
Offsetting derivative liabilities
Gross amounts recognized	12,785
Financial instruments	0
Net amounts presented in the statement of financial position	12,785
Gross amounts not offset in the statement of financial position
Financial Instruments	0
Collateral (received)/posted	12,530
Net Amount	$ 255

Other Real Estate Owned and R95

Other Real Estate Owned and Repossessed Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Changes in other real estate owned
Balance at the beginning of the period	$ 9,716	$ 13,953
Additions due to acquisitions	13,227	440
Other additions	3,945	5,651
Net payments received	(171)	8
Disposals	(6,232)	(8,179)
Write-downs	(376)	(927)
Balance at the end of the period	20,109	10,946
Changes in repossessed assets
Balance at the beginning of the period	219	252
Additions due to acquisitions	313	0
Other additions	2,084	1,761
Net payments received	(764)	(13)
Disposals	(1,231)	(1,739)
Write-downs	0	0
Balance at the end of the period	$ 621	$ 261

Other Real Estate Owned and R96

Other Real Estate Owned and Repossessed Assets (Textuals) (Details) $ in Thousands	Sep. 30, 2016USD ($)
Other Real Estate [Abstract]
Other real estate owned and repossessed assets acquired in accordance with ASU 2014-04	$ 893
Real estate properties for which formal foreclosure proceedings are in process	$ 8,100

Other Real Estate Owned and R97

Other Real Estate Owned and Repossessed Assets - Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income and expenses related to other real estate owned
Net gain (loss) on sale	$ 788	$ 1,214	$ 2,830	$ 3,376
Write-downs	(145)	(363)	(376)	(927)
Net operating expenses	(176)	(360)	(588)	(1,238)
Total	467	491	1,866	1,211
Income and expenses related to repossessed assets
Net gain (loss) on sale	(5)	0	696	(21)
Write-downs	0	0	0	0
Net operating expenses	(8)	(2)	(11)	(10)
Total	$ (13)	$ (2)	$ 685	$ (31)

Income Taxes (Effective Income

Income Taxes (Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Amount
Tax at statutory rate	$ 5,016	$ 11,923	$ 29,400	$ 30,844
Changes resulting from:
Tax-exempt interest income	(1,321)	(1,033)	(3,599)	(2,809)
State taxes, net of federal benefit	(803)	0	(803)	0
Change in valuation allowance	(29)	0	(29)	0
Bank-owned life insurance adjustments	(169)	0	(524)	0
Director plan change in control	(525)	0	(525)	0
Income tax credits, net	(413)	(992)	(2,428)	(1,851)
Nondeductible transaction expenses	2,100	0	2,100	525
Other, net	(256)	(298)	708	91
Income tax provision (benefit)	$ 3,600	$ 9,600	$ 24,300	$ 26,800
Effective federal income tax rate (as a percent)	25.10%	28.20%	28.90%	30.40%

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Aug. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Allowance for loan losses	$ 44,233		$ 24,863
Acquisition-related fair value adjustments	65,596		29,280
Accrued stock-based compensation	18,353		3,240
Loss and tax credit carry forwards	55,921		6,850
Acquisition built in loss carry forwards	31,316		0
Depreciation	3,900		4,333
Nonaccrual interest	8,064		4,994
Accrued expense	18,400		13,296
Other	17,861		5,951
Total deferred tax assets	263,644		92,807
Deferred tax liabilities:
Loan servicing rights	18,021		3,893
Core deposit intangible assets	9,938		7,379
Goodwill	6,350		5,808
Other	7,829		4,742
Total deferred tax liabilities	42,138		21,822
Net deferred tax asset before valuation allowance	221,506		70,985
Valuation allowance	(2,502)		(795)
Net deferred tax asset	$ 219,004	$ 155,900	$ 70,190

Income Taxes (Textual) (Details

Income Taxes (Textual) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Aug. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Net deferred tax asset	$ 219,004	$ 155,900	$ 70,190
Operating loss carryforwards, subject to expiration		1,000
Operating loss carryforwards, not subject to expiration		16,700
Valuation allowance for deferred tax assets	2,502		$ 795
Capital Loss Carry Forwards [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance for deferred tax assets	800
Talmer [Member]
Operating Loss Carryforwards [Line Items]
Realized built-in losses		88,700
Valuation allowance for deferred tax assets	$ 1,700	1,800
Talmer [Member] | Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		$ 91,800