MB Financial 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 30, 2013
Entity Registrant Name	MB FINANCIAL INC /MD
Entity Central Index Key	1139812
Document Type	10-Q
Document Period End Date	30-Sep-13
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		54,961,540
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q3

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS
Cash and due from banks	$215,017	$176,010
Interest earning deposits with banks	41,700	111,533
Total cash and cash equivalents	256,717	287,543
Federal funds sold	47,500	0
Investment securities:
Securities available for sale, at fair value	1,090,123	1,868,171
Securities held to maturity, at amortized cost ($1,212,748 and $535,681 fair value at September 30, 2013 and December 31, 2012, respectively)	1,193,544	493,421
Non-marketable securities - FHLB and FRB stock	50,870	55,385
Total investment securities	2,334,537	2,416,977
Loans held for sale	1,120	7,492
Loans:
Total loans, excluding covered loans	5,313,235	5,317,080
Covered loans	273,497	449,850
Total loans	5,586,732	5,766,930
Less: Allowance for loan losses	118,031	124,204
Net loans	5,468,701	5,642,726
Lease investment, net	112,491	129,823
Premises and equipment, net	220,574	221,533
Cash surrender value of life insurance	129,332	128,879
Goodwill	423,369	423,369
Other intangibles	24,917	29,512
Other real estate owned, net	31,356	36,977
Other real estate owned related to FDIC-assisted transactions	24,792	22,478
FDIC indemnification asset	11,074	39,345
Other assets	171,138	185,151
Total assets	9,257,618	9,571,805
Deposits:
Noninterest bearing	2,269,367	2,164,547
Interest bearing	5,029,319	5,378,150
Total	7,298,686	7,542,697
Short-term borrowings	240,600	220,602
Long-term borrowings	62,428	116,050
Junior subordinated notes issued to capital trusts	152,065	152,065
Accrued expenses and other liabilities	194,371	264,621
Total liabilities	7,948,150	8,296,035
STOCKHOLDERS’ EQUITY
Common stock, ($0.01 par value; authorized 70,000,000 shares at September 30, 2013 and December 31, 2012; issued 55,141,834 shares at September 30, 2013 and 54,955,284 shares at December 31, 2012)	551	550
Additional paid-in capital	736,294	732,771
Retained earnings	564,779	507,933
Accumulated other comprehensive income	9,918	36,326
Less: 180,296 and 170,567 shares of treasury stock, at cost, at September 30, 2013 and December 31, 2012, respectively	-3,525	-3,293
Controlling interest stockholders’ equity	1,308,017	1,274,287
Noncontrolling interest	1,451	1,483
Total stockholders’ equity	1,309,468	1,275,770
Total liabilities and stockholders’ equity	$9,257,618	$9,571,805

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Securities held to maturity, at amortized cost, fair value (in dollars)	$1,212,748	$535,681
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, authorized shares	70,000,000	70,000,000
Common stock, issued shares	55,141,834	54,955,284
Treasury stock, shares	180,296	170,567

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Interest income:
Loans	$60,115	$67,482	$180,489	$208,380
Investment securities:
Taxable	6,330	7,287	18,749	27,053
Nontaxable	8,175	7,582	24,399	21,624
Federal funds sold	7	0	9	0
Other interest earning accounts	193	312	420	639
Total interest income	74,820	82,663	224,066	257,696
Interest expense:
Deposits	4,433	7,374	15,274	24,192
Short-term borrowings	112	342	395	910
Long-term borrowings and junior subordinated notes	1,367	2,872	4,324	9,322
Total interest expense	5,912	10,588	19,993	34,424
Net interest income	68,908	72,075	204,073	223,272
Provision for credit losses	-3,304	-13,000	-2,804	-9,900
Net interest income after provision for credit losses	72,212	85,075	206,877	233,172
Non-interest income:
Capital markets and international banking fees	972	1,400	2,719	2,700
Commercial deposit and treasury management fees	6,327	5,860	18,322	17,541
Lease financing, net	14,070	9,671	45,435	23,963
Trust and asset management fees	4,799	4,428	14,167	13,367
Card fees	2,745	2,388	8,175	6,863
Loan service fees	1,427	1,075	4,349	3,409
Consumer and other deposit service fees	3,648	3,786	10,487	10,773
Brokerage fees	1,289	1,185	3,680	3,704
Net gain on investment securities	1	281	14	244
Increase in cash surrender value of life insurance	851	890	2,537	2,677
Net loss on sale of assets	0	-12	0	-37
Accretion of FDIC indemnification asset	64	204	307	901
Net (loss) gain recognized on other real estate owned	-791	-3,938	894	-15,968
Net gain on sale of loans	177	575	1,322	1,503
Other operating income	1,337	760	3,835	3,674
Total non-interest income	36,916	28,553	116,243	75,314
Non-interest expenses:
Salaries and employee benefits	44,918	42,083	132,341	122,658
Occupancy and equipment expense	8,797	8,274	27,609	27,032
Computer services and telecommunication expense	4,870	3,777	13,374	11,339
Advertising and marketing expense	1,917	1,936	6,187	5,848
Professional and legal expense	3,102	1,554	5,750	4,470
Other intangibles amortization expense	1,513	1,251	4,595	3,759
Branch impairment charges	0	758	0	758
Other real estate expense, net	240	874	572	2,541
Prepayment fees on interest bearing liabilities	0	12,682	0	12,682
Other operating expenses	10,117	7,976	28,413	24,243
Total non-interest expenses	75,474	81,165	218,841	215,330
Income before income taxes	33,654	32,463	104,279	93,156
Income tax expense	9,254	9,330	29,680	26,794
Net income	24,400	23,133	74,599	66,362
Dividends and discount accretion on preferred shares	0	0	0	3,269
Net income available to common stockholders	$24,400	$23,133	$74,599	$63,093
Common share data:
Basic earnings per common share	$0.45	$0.43	$1.37	$1.16
Diluted earnings per common share	$0.44	$0.42	$1.36	$1.16
Weighted average common shares outstanding for basic earnings per common share	54,565,089	54,346,827	54,471,541	54,226,241
Diluted weighted average common shares outstanding for diluted earnings per common share	55,130,653	54,556,517	54,912,352	54,472,617

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$24,400	$23,133	$74,599	$66,362
Unrealized holding (losses) gains on investment securities, net of tax and reclassification adjustments	-3,701	2,118	-25,788	1,981
Reclassification adjustment for amortization of unrealized gains on investment securities transferred to held to maturity from available for sale, net of tax	-612	0	-612	0
Reclassification adjustments for gains included in net income, net of tax	0	-168	-8	-146
Other comprehensive (loss) income, net of tax	-4,313	1,950	-26,408	1,835
Comprehensive income	$20,087	$25,083	$48,191	$68,197

CONSOLIDATED_STATEMENTS_OF_CHA

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $)	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock	Noncontrolling Interest
In Thousands, unless otherwise specified
Balance at Dec. 31, 2011	$1,393,027	$194,719	$548	$731,248	$427,956	$39,150	($3,044)	$2,450
Increase (Decrease) in Stockholders' Equity
Net income	66,546				66,362			184
Other comprehensive loss, net of tax	1,835					1,835
Cash dividends declared on common stock	-1,643				-1,643
Dividends and discount accretion on preferred shares	-1,988	1,281			-3,269
Repurchase of preferred shares and warrant	-197,518	-196,000	0	-1,518	0	0	0	0
Restricted common stock activity, net of tax	1,071		2	-722	17		1,774
Stock option activity, net of tax	-277			-625	3		345
Repurchase of common shares in connection with employee benefit plans and held in trust for deferred compensation plan	-1,928			451			-2,379
Stock-based compensation expense	3,581			3,581
Adjustments To Additional Paid In Capital Investment In Subsidiary	-1,640	0	0	-736	0	0	0	-904
Distributions to noncontrolling interest	-236							-236
Balance at Sep. 30, 2012	1,260,830	0	550	731,679	489,426	40,985	-3,304	1,494
Balance at Dec. 31, 2012	1,275,770		550	732,771	507,933	36,326	-3,293	1,483
Increase (Decrease) in Stockholders' Equity
Net income	74,736				74,599			137
Other comprehensive loss, net of tax	-26,408					-26,408
Cash dividends declared on common stock	-17,653				-17,653
Restricted common stock activity, net of tax	869		1	-757	-100		1,725
Stock option activity, net of tax	616			117			499
Repurchase of common shares in connection with employee benefit plans and held in trust for deferred compensation plan	-2,153			303			-2,456
Stock-based compensation expense	3,860			3,860
Distributions to noncontrolling interest	-169							-169
Balance at Sep. 30, 2013	$1,309,468	$0	$551	$736,294	$564,779	$9,918	($3,525)	$1,451

CONSOLIDATED_STATEMENTS_OF_CHA1

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash dividends declared	$0.32	$0.03

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash Flows From Operating Activities
Net income (loss)	$74,599	$66,362
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment	13,165	11,450
Depreciation of leased equipment	24,933	28,107
Impairment charges on branch facilities	0	758
Compensation expense for restricted stock awards	3,013	2,586
Compensation expense for stock option grants	847	995
Gain on sales of premises and equipment and leased equipment	-192	-2,746
Amortization of other intangibles	4,595	3,759
Provision for credit losses	-2,804	-9,900
Deferred income tax expense	13,067	19,763
Amortization of premiums and discounts on investment securities, net	35,364	31,838
Accretion of premiums and discounts on loans, net	-5,462	-13,000
Accretion of FDIC indemnification asset	-307	-901
Net gain on sale of investment securities available for sale	-14	-244
Proceeds from sale of loans held for sale	74,395	64,124
Origination of loans held for sale	-66,667	-64,980
Net gain on sale of loans held for sale	-1,322	-1,503
Net gain on sales of other real estate owned	-977	-1,264
Fair value adjustments on other real estate owned	-80	13,919
Net loss on sales of other real estate owned related to FDIC-assisted transactions	163	3,313
Increase in cash surrender value of life insurance	-2,537	-2,677
Decrease (increase) in other assets, net	30,976	-45,242
(Decrease) increase in other liabilities, net	-68,428	7,944
Net cash provided by operating activities	126,327	112,461
Cash Flows From Investing Activities
Increase in federal funds sold	-47,500	0
Proceeds from sales of investment securities available for sale	989	12,573
Proceeds from maturities and calls of investment securities available for sale	415,780	432,162
Purchases of investment securities available for sale	-364,550	-350,669
Proceeds from maturities and calls of investment securities held to maturity	5,079	960
Purchases of investment securities held to maturity	-55,409	-1,923
Purchases of non-marketable securities - FHLB and FRB stock	0	-24
Redemption of non-marketable securities - FHLB and FRB stock	4,515	23,203
Net decrease in loans	170,586	329,773
Purchases of premises and equipment	-11,342	-16,952
Purchases of leased equipment	-18,359	-19,836
Proceeds from sales of premises and equipment		1,498
Proceeds from sales of leased equipment	6,672	11,108
Capital improvements on other real estate owned	-53	-2,304
Proceeds from sale of other real estate owned	12,791	28,398
Proceeds from sale of other real estate owned related to FDIC-assisted transactions	7,535	29,008
Principal paid on lease investments	-1,127	-1,878
Life insurance death benefit	2,083
Net proceeds from FDIC related covered assets	11,347	79,247
Net cash provided by investing activities	139,037	554,344
Cash Flows From Financing Activities
Net decrease in deposits	-244,011	-168,260
Net increase in short-term borrowings	19,998	69,659
Proceeds from long-term borrowings	5,457	5,740
Principal paid on long-term borrowings	-59,079	-153,206
Redemption of junior subordinated notes issued to capital trusts		-6,186
Repurchase of preferred stock	0	-197,518
Treasury stock transactions, net	-1,653	-260
Stock options exercised	1,014	154
Excess tax benefits from share-based payment arrangements	-402
Dividends paid on preferred stock		-3,239
Dividends paid on common stock	-17,514	-1,627
Net cash used in financing activities	-296,190	-454,743
Net (decrease) increase in cash and cash equivalents	-30,826	212,062
Cash and cash equivalents:
Beginning of period	287,543	244,565
End of period	256,717	456,627
Cash payments for:
Interest paid to depositors and other borrowed funds	20,913	36,156
Net income tax payments, net	35,141	4,230
Supplemental Schedule of Noncash Investing Activities:
Investment securities available for sale purchased not settled	1,797	3,919
Transfer of investment securities available for sale to investment securities held to maturity	656,617	0
Loans transferred to other real estate owned	6,060	2,724
Loans transferred to other real estate owned related to FDIC-assisted transactions	11,580	17,923
Loans transferred to repossessed vehicles	606	607
Operating leases rewritten as direct finance leases included as loans	$6,541	$7,593

Basis_of_Presentation_Notes

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Basis of Presentation
	These unaudited consolidated financial statements include the accounts of MB Financial, Inc., a Maryland corporation (the “Company”), and its subsidiaries, including its wholly owned national bank subsidiary, MB Financial Bank, N.A. (“MB Financial Bank”), based in Chicago, Illinois. In the opinion of management, all normal recurring adjustments necessary for a fair presentation of the financial position, results of operations and cash flows for the interim periods have been made. The results of operations for the three and nine months ended September 30, 2013 are not necessarily indicative of the results to be expected for the entire fiscal year.
	These unaudited interim financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) and industry practice. Certain information in footnote disclosure normally included in financial statements prepared in accordance with U.S. GAAP and industry practice has been condensed or omitted pursuant to rules and regulations of the Securities and Exchange Commission. These financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s December 31, 2012 audited financial statements filed on Form 10-K.
	The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions which affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of income and expenses during the reported periods. Actual results could differ from those estimates.
	Certain prior period amounts have been reclassified to conform to current period presentation. These reclassifications did not result in any changes to previously reported net income or stockholders’ equity.

New_Authoritative_Accounting_G

New Authoritative Accounting Guidance (Notes)	9 Months Ended
	Sep. 30, 2013
New Authoritative Accounting Guidance [Abstract]
New Authoritative Accounting Guidance	New Authoritative Accounting Guidance
	ASC Topic 805 “Business Combinations.” New authoritative accounting guidance under ASC Topic 805, “Business Combinations” amended prior guidance on the subsequent accounting for an indemnification asset recognized at the acquisition date as a result of a government-assisted (Federal Deposit Insurance Corporation) acquisition of a financial institution that includes a loss-sharing agreement. The new authoritative guidance requires that at each subsequent reporting date, an acquirer measure an indemnification asset on the same basis as the indemnified liability or asset, subject to any contractual limitations on its amount, and, for an indemnification asset that is not subsequently measured at fair value, management's assessment of the collectability of the indemnification asset. Any amortization of changes in value should be limited to the contractual term of the indemnification agreement (that is, the lesser of the term of the indemnification agreement and the remaining life of the indemnified assets). The Company adopted this new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition.
	ASC Topic 210 “Disclosures about Offsetting Assets and Liabilities.” New authoritative accounting guidance under ASC Topic 210, “Disclosures about Offsetting Assets and Liabilities” amended prior guidance to require an entity to disclose both gross and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an agreement similar to a master netting arrangement. The instruments and transactions would include derivatives, sale and repurchase agreements and reverse sale and repurchase agreements, and securities borrowing and securities lending arrangements. This new authoritative guidance was further amended to clarify the scope of offsetting disclosures. The Company adopted the new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition. See disclosures in Note 15.
	ASC Topic 220 “Comprehensive Income.” New authoritative accounting guidance under ASC Topic 220, “Comprehensive Income” amended prior guidance to improve the reporting of reclassifications out of accumulated other comprehensive income by requiring an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income if the amount reclassified is required under U.S. GAAP. The Company adopted this new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition.
	ASC Topic 815 “Derivatives and Hedging.” New authoritative accounting guidance under ASC Topic 815, “Derivatives and Hedging” amended prior guidance to permit the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge accounting purposes, in addition to U.S. government treasury obligation rates and London Interbank Offered Rate swap rate. The amendments also remove the restriction on using different benchmark rates for similar hedges. The new authoritative guidance will be effective prospectively for new and redesignated hedging relationships entered into on or after July 17, 2013 and is not expected to have an impact on the Company's statements of operations and financial condition.
	ASC Topic 740 “Income Taxes.” New authoritative accounting guidance under ASC Topic 740, “Income Taxes” amended prior guidance to include explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as follows. To the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The new authoritative guidance will be for reporting periods after January 1, 2014 and is not expected to have an impact on the Company's statements of operations and financial condition.

Earnings_Per_Common_Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]
Earnings Per Common Share	Earnings Per Common Share
	Earnings per common share is computed using the two-class method. Basic earnings per common share is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding participating securities. Participating securities include non-vested restricted stock awards and restricted stock units, though no actual shares of common stock related to restricted stock units are issued until the settlement of such units, to the extent holders of these securities receive non-forfeitable dividends or dividend equivalents at the same rate as holders of the Company's common stock. Diluted earnings per common share is computed using the weighted-average number of shares determined for the basic earnings per common share computation plus the dilutive effect of stock compensation using the treasury stock method.
	The following table presents a reconciliation of the number of shares used in the calculation of basic and diluted earnings per common share (amounts in thousands, except share and per share data).
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Distributed earnings allocated to common stock	$	6,636	$	548	$	17,653	$	1,643
	Undistributed earnings	17,764		22,585		56,946		64,719
	Net income	24,400		23,133		74,599		66,362
	Less: preferred stock dividends and discount accretion	—		—		—		3,269
	Net income available to common stockholders	24,400		23,133		74,599		63,093
	Less: earnings allocated to participating securities	1		1		2		2
	Earnings allocated to common stockholders	$	24,399	$	23,132	$	74,597	$	63,091
	Weighted average shares outstanding for basic earnings per common share	54,565,089		54,346,827		54,471,541		54,226,241
	Dilutive effect of equity awards	565,564		209,690		440,811		246,376
	Weighted average shares outstanding for diluted earnings per common share	55,130,653		54,556,517		54,912,352		54,472,617
	Basic earnings per common share	$	0.45	$	0.43	$	1.37	$	1.16
	Diluted earnings per common share	0.44		0.42		1.36		1.16

Business_Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]
Business Combinations	Business Combinations
	The following business combination was accounted for under the acquisition method of accounting.  Accordingly, the results of operations of the acquired company have been included in the Company’s results of operations since the date of acquisition.  Under this method of accounting, assets and liabilities acquired are recorded at their estimated fair values, net of applicable income tax effects.  The excess cost over fair value of net assets acquired is recorded as goodwill.  In the event that the fair value of net assets acquired exceeds the cost, the Company will record a gain on the acquisition.
	On December 28, 2012, MB Financial Bank acquired a 100% equity interest in Celtic Leasing Corp. (“Celtic”), a privately held, mid-ticket equipment leasing company. Celtic specializes in solutions for the health care, legal, technology, and manufacturing industries. MB Financial Bank estimated contingent consideration related to the transaction which may be paid out at future dates. This consideration is based on the performance of lease residual values which will be determined in future years over an earn-out period. As the consideration paid for Celtic exceeded the net assets acquired, goodwill was recorded on the acquisition. Goodwill recorded in the transaction is not tax deductible. The purchase accounting entries are preliminary for lease loans, goodwill and other intangibles, as MB Financial Bank continues to analyze the portfolios and the underlying risks and collateral values of the assets. After the purchase accounting is finalized, the impact of any future changes to the amount of contingent consideration will be reflected in the statement of operations.
	Estimated fair values of the assets acquired and liabilities assumed in the Celtic transaction, as of the closing date of the transaction were as follows (in thousands):
	Assets Acquired and Liabilities Assumed
	(Dollar Amounts in Thousands)
		Celtic
		December 28,
		2012
	ASSETS
	Cash and cash equivalents	$	31,647
	Investment securities available for sale	635
	Loans and leases	32,933
	Premises and equipment	81
	Goodwill	36,300
	Other intangibles	5,028
	Other assets	27,323
	Total assets	$	133,947
	LIABILITIES
	Accrued expenses and other liabilities	$	75,290
	Total liabilities	$	75,290
	Cash paid on acquisition	$	58,657
	Net gain recorded on acquisition	$	—
	On July 14, 2013, the Company and Taylor Capital Group, Inc. (“Taylor Capital”) entered into an Agreement and Plan of Merger (the "Merger Agreement") whereby the Company will acquire Taylor Capital. The Merger Agreement provides that, upon the terms and subject to the conditions set forth therein, Taylor Capital will merge with and into the Company, with the Company as the surviving corporation in the merger. Immediately following the Merger, Taylor Capital's wholly owned subsidiary bank, Cole Taylor Bank, will merge with the Company's wholly owned subsidiary bank, MB Financial Bank. Cole Taylor Bank is a commercial bank headquartered in Chicago with $5.9 billion in assets, $3.3 billion in loans and $3.7 billion in deposits as of June 30, 2013.
	Subject to the terms and conditions of the Merger Agreement, at the effective time of the Merger (the "Effective Time"), each share of Taylor Capital common stock and each share of Taylor Capital nonvoting convertible preferred stock ("non-voting preferred stock") will be converted into the right to receive, promptly following the Effective Time, (1) 0.64318 of a share of the Company's common stock and (2) $4.08 in cash. All "in-the-money" Taylor Capital stock options and warrants outstanding immediately prior to the Effective Time will be canceled in exchange for a cash payment as provided in the Merger Agreement, as will all then-outstanding unvested restricted stock awards of Taylor Capital; however, the cash consideration paid for such restricted stock awards will remain subject to vesting or other lapse restrictions. Each share of Taylor Capital's Perpetual Non-Cumulative Preferred Stock, Series A, will be exchanged for a share of a series of preferred stock of the Company with substantially identical terms. The Merger Agreement provides that any shares of Taylor Capital's Fixed Rate Cumulative Perpetual Preferred Stock, Series B, that are not repurchased or redeemed by Taylor Capital prior to the Merger will be exchanged for a series of preferred stock of the Company with substantially identical terms and repurchased or redeemed by the Company at or promptly after the Effective Time.
	The merger is subject to regulatory approvals, approval by the Company's stockholders, approval by Taylor Capital stockholders and certain other customary closing conditions and is expected to close in the first half of 2014. In addition, it is a condition to the Company's obligation to complete the Merger that the shares of Taylor Capital common stock and Taylor Capital nonvoting preferred stock whose holders have perfected appraisal rights under Delaware law represent less than nine percent of the total number of outstanding shares of Taylor Capital common stock and Taylor Capital nonvoting preferred stock.

Investment_Securities

Investment Securities	9 Months Ended
	Sep. 30, 2013
Investments Securities [Abstract]
Investment Securities	Investment Securities
	Carrying amounts and fair values of investment securities were as follows (in thousands):
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	30-Sep-13
	Available for Sale
	U.S. Government sponsored agencies and enterprises	$	50,678	$	1,849		$	—		$	52,527
	States and political subdivisions	19,461		52			(201		)	19,312
	Residential mortgage-backed securities	685,126		8,659			(2,509		)	691,276
	Commercial mortgage-backed securities	50,944		2,502			—			53,446
	Corporate bonds	265,293		927			(3,199		)	263,021
	Equity securities	10,574		—			(33		)	10,541
		1,082,076		13,989			(5,942		)	1,090,123
	Held to Maturity
	States and political subdivisions	941,273		8,517			(3,481		)	946,309
	Residential mortgage-backed securities	252,271		14,168			—			266,439
		1,193,544		22,685			(3,481		)	1,212,748
	Total	$	2,275,620	$	36,674		$	(9,423	)	$	2,302,871
	December 31, 2012
	Available for Sale
	U.S. Government sponsored agencies and enterprises	$	38,605	$	2,710		$	—		$	41,315
	States and political subdivisions	679,991		45,571			(543		)	725,019
	Residential mortgage-backed securities	930,413		14,038			(5,249		)	939,202
	Commercial mortgage-backed securities	51,100		3,026			—			54,126
	Corporate bonds	97,014		213			(553		)	96,674
	Equity securities	11,398		447			(10		)	11,835
		1,808,521		66,005			(6,355		)	1,868,171
	Held to Maturity
	States and political subdivisions	237,563		21,039			—			258,602
	Residential mortgage-backed securities	255,858		21,221			—			277,079
		493,421		42,260			—			535,681
	Total	$	2,301,942	$	108,265		$	(6,355	)	$	2,403,852
	Securities of states and political subdivisions with a fair value of $656.6 million were transferred from available for sale to held to maturity during the third quarter of 2013, which is the new cost basis. As of the date of the transfer, the resulting unrealized holding gain continues to be reported as a separate component of stockholders’ equity as accumulated other comprehensive income, net of tax. This unrealized gain will be amortized over the remaining life of the securities as a yield adjustment.
	We do not have any meaningful direct or indirect holdings of subprime residential mortgage loans, home equity lines of credit, or any Fannie Mae or Freddie Mac preferred or common equity securities in our investment portfolio.
	The Company has no direct exposure to the State of Illinois, but approximately 27% of the state and political subdivisions portfolio consists of securities issued by municipalities located in Illinois as of September 30, 2013. Approximately 90% of such securities were general obligation issues as of September 30, 2013.
	Unrealized losses on investment securities and the fair value of the related securities at September 30, 2013 were as follows (in thousands):
		Less Than 12 Months					12 Months or More						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Available for Sale
	States and political subdivisions	$	9,050	$	(201	)	$	—		$	—		$	9,050	$	(201	)
	Residential mortgage-backed securities	206,562		(2,040		)	49,104			(469		)	255,666		(2,509		)
	Corporate bonds	147,181		(3,199		)	—			—			147,181		(3,199		)
	Equity securities	10,541		(33		)	—			—			10,541		(33		)
		373,334		(5,473		)	49,104			(469		)	422,438		(5,942		)
	Held to Maturity
	States and political subdivisions	207,613		(3,481		)	—			—			207,613		(3,481		)
		207,613		(3,481		)	—			—			207,613		(3,481		)
	Totals	$	580,947	$	(8,954	)	$	49,104		$	(469	)	$	630,051	$	(9,423	)
	Unrealized losses on investment securities and the fair value of the related securities at December 31, 2012 were as follows (in thousands):
		Less Than 12 Months					12 Months or More						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Available for Sale
	States and political subdivisions	$	57,540	$	(543	)	$	—		$	—		$	57,540	$	(543	)
	Residential mortgage-backed securities	270,539		(5,083		)	16,434			(166		)	286,973		(5,249		)
	Corporate bonds	58,241		(553		)	—			—			58,241		(553		)
	Equity securities	30		(10		)	—			—			30		(10		)
	Totals	$	386,350	$	(6,189	)	$	16,434		$	(166	)	$	402,784	$	(6,355	)
	The total number of security positions in the investment portfolio in an unrealized loss position at September 30, 2013 was 353 compared to 117 at December 31, 2012. Declines in the fair value of available for sale securities below their cost that are deemed to be other than temporary are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in other comprehensive income. In estimating other-than-temporary impairment losses, management considers, among other things, (i) the length of time and the extent to which the fair value has been less than cost, (ii) the financial condition and near-term prospects of the issuer, and (iii) whether or not the Company is more likely than not to sell the security before recovery of its cost basis.
	As of September 30, 2013, management does not have the intent to sell any of the securities in the table above and believes that it is more likely than not that the Company will not have to sell any such securities before a recovery of cost. The fair value is expected to recover as the bonds approach their maturity date or repricing date or if market yields for such investments decline. Accordingly, as of September 30, 2013, management believes the impairments detailed in the table above are temporary.
	Changes in market interest rates can significantly influence the fair value of securities, and the fair value of our municipal security portfolio would decline substantially if interest rates increase materially.
	Net gains (losses) recognized on investment securities available for sale were as follows (in thousands):
	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2013		2012			2013			2012
Realized gains	$	1	$	282		$	15		$	472
Realized losses	—		(1		)	(1		)	(4		)
Impairment charges	—		—			—			(224		)
Net gains (losses)	$	1	$	281		$	14		$	244
The amortized cost and fair value of investment securities as of September 30, 2013 by contractual maturity are shown below. Maturities may differ from contractual maturities in mortgage-backed securities because the mortgages underlying the securities may be called or repaid without any penalties. Therefore, mortgage-backed securities are not included in the maturity categories in the following maturity summary.
	Amortized		Fair
(In thousands)	Cost		Value
Available for sale:
Due in one year or less	$	—	$	—
Due after one year through five years	319,032		318,598
Due after five years through ten years	7,695		7,711
Due after ten years	8,705		8,551
Equity securities	10,574		10,541
Residential and commercial mortgage-backed securities	736,070		744,722
	1,082,076		1,090,123
Held to maturity:
Due in one year or less	28,222		28,221
Due after one year through five years	245,125		245,545
Due after five years through ten years	122,547		122,533
Due after ten years	545,379		550,010
Residential mortgage-backed securities	252,271		266,439
	1,193,544		1,212,748
Total	$	2,275,620	$	2,302,871
Investment securities available for sale with carrying amounts of $1.0 billion and $989.6 million at September 30, 2013 and December 31, 2012, respectively, were pledged as collateral on public deposits and for other purposes as required or permitted by law.

Loans

Loans	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]
Loans	Loans
	Loans consist of the following at (in thousands):
			September 30,				December 31, 2012
			2013
	Commercial loans		$	1,169,009			$	1,220,472
	Commercial loans collateralized by assignment of lease payments		1,468,814				1,303,020
	Commercial real estate		1,638,368				1,761,832
	Residential real estate		311,256				314,359
	Construction real estate		136,146				110,261
	Indirect vehicle		257,740				208,633
	Home equity		274,484				305,186
	Other consumer loans		57,418				93,317
	Gross loans, excluding covered loans		5,313,235				5,317,080
	Covered loans		273,497				449,850
	Total loans(1)		$	5,586,732			$	5,766,930
	(1)          Gross loan balances at September 30, 2013 and December 31, 2012 are net of unearned income, including net deferred loan fees of $1.5 million and $1.1 million, respectively.
	Loans are made to individuals as well as commercial and tax exempt entities. Specific loan terms vary as to interest rate, repayment, and collateral requirements based on the type of loan requested and the credit worthiness of the prospective borrower. Credit risk tends to be geographically concentrated in that a majority of the loan customers are located in the markets serviced by MB Financial Bank.
	The Company's extension of credit is governed by its Credit Risk Policy which was established to control the quality of the Company's loans. These policies and procedures are reviewed and approved by the Board of Directors on a regular basis.
	Commercial Loans. Commercial credit is extended primarily to middle market customers. Such credits are typically comprised of working capital loans, loans for physical asset expansion, asset acquisition loans and other business loans. Loans to closely held businesses will generally be guaranteed in full or for a significant amount by the businesses' principal owners. Commercial loans are made based primarily on the historical and projected cash flow of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not behave as forecasted and collateral securing loans may fluctuate in value due to economic or individual performance factors. Minimum standards and underwriting guidelines have been established for all commercial loan types.
	Lease Loans. The Company makes lease loans to both investment grade and non-investment grade companies. Investment grade lessees are companies rated in one of the four highest categories by Moody's Investor Services or Standard & Poor's Rating Services or, in the event the related lessee has not received any such rating, where the related lessee would be viewed under the underwriting polices of the Company as an investment grade company. Whether or not companies fall into this category, each lease loan is considered on its individual merit based on financial information available at the time of underwriting.
	Commercial Real Estate Loans. Commercial real estate loans are subject to underwriting standards and processes similar to commercial loans. These loans are viewed primarily as cash flow loans and the repayment of these loans is largely dependent on the successful operation of the property. Loan performance may be adversely affected by factors impacting the general economy or conditions specific to the real estate market such as geographic location and/or property type.
	Construction Real Estate Loans. The Company defines construction loans as loans where the loan proceeds are controlled by the Company and used exclusively for the improvement of real estate in which the Company holds a mortgage. Due to the inherent risk in this type of loan, they are subject to other industry specific policy guidelines outlined in the Company's Credit Risk Policy.
	Consumer Related Loans. The Company originates direct and indirect consumer loans, including primarily residential real estate, home equity lines and loans, credit cards, and indirect motorcycle loans, using a matrix-based credit analysis as part of the underwriting process. Each loan type has a separate matrix which consists of several factors including debt to income, type of collateral and loan to collateral value, credit history and Company relationship with the borrower. Indirect loan and credit card underwriting involves the use of risk-based pricing in the underwriting process.
	The following table presents the contractual aging of the recorded investment in past due loans by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
			Current				30-59 Days				60-89 Days				Loans Past Due				Total				Total
							Past Due				Past Due				90 Days or More				Past Due
	30-Sep-13
	Commercial		$	1,158,326			$	2,392			$	2,580			$	5,711			$	10,683			$	1,169,009
	Commercial collateralized by assignment of lease payments		1,455,296				10,761				1,816				941				13,518				1,468,814
	Commercial real estate
	Healthcare		212,659				—				—				3,164				3,164				215,823
	Industrial		371,940				161				2,101				1,394				3,656				375,596
	Multifamily		316,495				2,808				—				2,387				5,195				321,690
	Retail		344,390				236				449				8,632				9,317				353,707
	Office		139,251				412				579				2,106				3,097				142,348
	Other		223,385				3,443				229				2,147				5,819				229,204
	Residential real estate		298,878				1,103				1,059				10,216				12,378				311,256
	Construction real estate		133,742				—				89				2,315				2,404				136,146
	Indirect vehicle		255,177				1,638				687				238				2,563				257,740
	Home equity		260,055				4,505				2,911				7,013				14,429				274,484
	Other consumer		57,357				54				1				6				61				57,418
	Gross loans, excluding covered loans		5,226,951				27,513				12,501				46,270				86,284				5,313,235
	Covered loans		138,876				12,091				5,681				116,849				134,621				273,497
	Total loans (1)		$	5,365,827			$	39,604			$	18,182			$	163,119			$	220,905			$	5,586,732
	Nonperforming loan aging		$	53,271			$	3,596			$	6,111			$	39,474			$	49,181			$	102,452
	Non-covered loans related to FDIC transactions (2)		$	11,339			$	222			$	146			$	6,796			$	7,164			$	18,503
	December 31, 2012
	Commercial		$	1,215,957			$	639			$	754			$	3,122			$	4,515			$	1,220,472
	Commercial collateralized by assignment of lease payments		1,288,341				11,252				2,847				580				14,679				1,303,020
	Commercial real estate
	Healthcare		192,039				—				—				3,238				3,238				195,277
	Industrial		402,813				548				424				7,700				8,672				411,485
	Multifamily		353,966				1,282				—				3,103				4,385				358,351
	Retail		375,900				6,933				518				9,331				16,782				392,682
	Office		186,665				742				280				1,125				2,147				188,812
	Other		210,456				851				1,837				2,081				4,769				215,225
	Residential real estate		306,927				382				1,248				5,802				7,432				314,359
	Construction real estate		106,158				1,139				97				2,867				4,103				110,261
	Indirect vehicle		206,126				1,588				498				421				2,507				208,633
	Home equity		291,737				3,557				1,888				8,004				13,449				305,186
	Other consumer		93,266				47				—				4				51				93,317
	Gross loans, excluding covered loans		5,230,351				28,960				10,391				47,378				86,729				5,317,080
	Covered loans		301,260				5,831				7,478				135,281				148,590				449,850
	Total loans (1)		$	5,531,611			$	34,791			$	17,869			$	182,659			$	235,319			$	5,766,930
Nonperforming loan aging		$	69,836			$	3,171			$	3,718			$	40,261			$	47,150			$	116,986
Non-covered loans related to FDIC transactions (2)		$	12,752			$	312			$	1,542			$	7,115			$	8,969			$	21,721
(1)          Includes loans related to the InBank FDIC-assisted transaction completed by MB Financial Bank in 2009.
(2)          Loans related to the InBank FDIC-assisted transaction completed by MB Financial Bank in 2009.
The following table presents the recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
		September 30, 2013								December 31, 2012
						Loans past due								Loans past due
		Nonaccrual				90 days or more				Nonaccrual				90 days or more
						and still accruing								and still accruing
Commercial		$	19,948			$	—			$	23,886			$	229
Commercial collateralized by assignment of lease payments		2,130				215				1,180				222
Commercial real estate:
Healthcare		3,164				—				3,238				—
Industrial		9,754				—				19,179				147
Multifamily		5,087				195				7,225				—
Office		10,916				—				3,263				—
Retail		3,740				—				17,019				—
Other		21,420				—				9,437				—
Residential real estate		13,041				—				10,943				—
Construction real estate		496				—				1,028				—
Indirect vehicle		1,516				—				1,494				—
Home equity		10,818				—				17,486				1,000
Other consumer		12				—				9				1
Total		$	102,042			$	410			$	115,387			$	1,599
The Company utilizes an internal asset classification system as a means of reporting problem and potential problem loans. Under the Company's risk rating system, the Company classifies potential problem and problem loans as “Special Mention,” “Substandard,” and “Doubtful.” Substandard loans include those characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Loans classified as Doubtful have all the weaknesses inherent in those classified as Substandard with the added characteristic that the weaknesses present make collection or liquidation in full, on the basis of currently existing facts, conditions and values, highly questionable and improbable. Loans that do not currently expose the Company to sufficient risk to warrant classification in one of the aforementioned categories but possess weaknesses that deserve management's close attention are deemed to be Special Mention. Risk ratings are updated at least annually and any time the situation warrants.
Loans listed as not rated are included in groups of homogeneous loans with similar risk and loss characteristics. The following tables present the risk category of loans by class of loans based on the most recent analysis performed as of September 30, 2013 and December 31, 2012 (in thousands):
		Pass				Special				Substandard				Doubtful				Total
						Mention
30-Sep-13
Commercial		$	1,091,129			$	17,720			$	60,160			$	—			$	1,169,009
Commercial collateralized by assignment of lease payments		1,457,577				4,814				6,423				—				1,468,814
Commercial real estate
Healthcare		188,946				21,556				2,157				3,164				215,823
Industrial		335,274				7,384				32,938				—				375,596
Multifamily		306,691				—				14,999				—				321,690
Retail		324,558				10,373				18,776				—				353,707
Office		132,490				2,732				7,126				—				142,348
Other		201,971				3,088				24,145				—				229,204
Construction real estate		126,902				6,264				2,980				—				136,146
Total		$	4,165,538			$	73,931			$	169,704			$	3,164			$	4,412,337
December 31, 2012
Commercial		$	1,136,294			$	33,068			$	50,895			$	215			$	1,220,472
Commercial collateralized by assignment of lease payments		1,292,241				3,322				7,457				—				1,303,020
Commercial real estate
Healthcare		170,265				21,774				—				3,238				195,277
Industrial		355,218				15,243				41,024				—				411,485
Multifamily		318,991				25,297				14,063				—				358,351
Retail		340,919				25,096				26,667				—				392,682
Office		159,056				7,120				22,636				—				188,812
Other		193,824				2,553				18,848				—				215,225
Construction real estate		97,724				552				11,985				—				110,261
Total		$	4,064,532			$	134,025			$	193,575			$	3,453			$	4,395,585
Approximately $76.5 million and $85.5 million of the substandard and doubtful loans were non-performing as of September 30, 2013 and December 31, 2012, respectively.
For residential real estate, home equity, indirect vehicle and other consumer loan classes, the Company also evaluates credit quality based on the aging status of the loan, which was previously presented, and by payment activity. The following table presents the recorded investment in those loan classes based on payment activity as of September 30, 2013 and December 31, 2012 (in thousands):
		Performing				Non-performing				Total
30-Sep-13
Residential real estate		$	298,215			$	13,041			$	311,256
Indirect vehicle		256,224				1,516				257,740
Home equity		263,666				10,818				274,484
Other consumer		57,406				12				57,418
Total		$	875,511			$	25,387			$	900,898
December 31, 2012
Residential real estate		$	303,416			$	10,943			$	314,359
Indirect vehicle		207,139				1,494				208,633
Home equity		286,700				18,486				305,186
Other consumer		93,307				10				93,317
Total		$	890,562			$	30,933			$	921,495
The following tables present loans individually evaluated for impairment by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
		30-Sep-13
																		Three Months Ended							Nine Months Ended
		Unpaid				Recorded				Partial				Allowance for				Average				Interest			Average			Interest
		Principal				Investment				Charge-offs				Loan Losses				Recorded				Income			Recorded			Income
		Balance												Allocated				Investment				Recognized			Investment			Recognized
With no related allowance recorded:
Commercial		$	6,236			$	5,364			$	872			$	—			$	6,509			$	—		$	7,378		$	—
Commercial collateralized by assignment of lease payments		681				681				—				—				666				6			256			6
Commercial real estate:
Healthcare		—				—				—				—				—				—			3,608			—
Industrial		7,547				6,927				620				—				7,902				—			9,316			—
Multifamily		546				546				—				—				665				—			739			—
Retail		3,002				3,002				—				—				3,233				—			3,123			—
Office		685				527				158				—				705				—			986			—
Other		3,149				3,139				10				—				3,353				—			4,785			—
Residential real estate		4,174				3,788				386				—				4,082				—			2,835			—
Construction real estate		—				—				—				—				—				—			—			—
Indirect vehicle		—				—				—				—				—				—			—			—
Home equity		577				577				—				—				577				—			872			—
Other consumer		—				—				—				—				—				—			—			—
With an allowance recorded:
Commercial		14,472				14,472				—				4,389				15,680				—			14,839			—
Commercial collateralized by assignment of lease payments		1,649				1,649				—				285				1,659				109			1,347			158
Commercial real estate:
Healthcare		10,868				3,164				7,704				495				10,869				—			7,302			—
Industrial		2,826				2,826				—				1,047				3,078				—			3,611			—
Multifamily		6,334				5,944				390				1,876				6,408				115			6,642			224
Retail		15,323				13,031				2,292				1,855				13,778				—			13,572			—
Office		3,607				3,214				393				1,047				3,735				—			4,391			—
Other		18,493				18,280				213				1,144				19,790				8			11,104			16
Residential real estate		12,690				12,063				627				3,033				12,494				—			12,965			—
Construction real estate		3,990				1,622				2,368				240				1,736				—			1,938			—
Indirect vehicle		138				106				32				—				146				—			54			—
Home equity		23,171				22,701				470				781				23,558				—			24,341			—
Other consumer		—				—				—				—				—				—			—			—
Total		$	140,158			$	123,623			$	16,535			$	16,192			$	140,623			$	238		$	136,004		$	404
		December 31, 2012
		Unpaid				Recorded				Partial				Allowance for				Average				Interest
		Principal				Investment				Charge-offs				Loan Losses				Recorded				Income
		Balance												Allocated				Investment				Recognized
With no related allowance recorded:
Commercial		$	10,993			$	9,505			$	1,488			$	—			$	14,089			$	105
Commercial collateralized by assignment of lease payments		390				390				—				—				278				9
Commercial real estate:
Healthcare		10,943				3,238				7,705				—				2,751				—
Industrial		16,891				14,940				1,951				—				16,374				29
Multifamily		800				800				—				—				1,340				14
Retail		5,372				4,917				455				—				9,241				—
Office		1,568				1,568				—				—				1,151				—
Other		4,860				4,860				—				—				6,005				—
Residential real estate		3,097				2,711				386				—				6,476				—
Construction real estate		—				—				—				—				577				—
Indirect vehicle		—				—				—				—				—				—
Home equity		2,558				2,558				—				—				8,976				—
Other consumer		—				—				—				—				182				—
With an allowance recorded:
Commercial		14,484				14,381				103				3,620				8,455				—
Commercial collateralized by assignment of lease payments		885				885				—				188				1,130				73
Commercial real estate:
Healthcare		—				—				—				—				3,901				—
Industrial		5,525				4,238				1,287				1,255				2,443				—
Multifamily		8,233				7,249				984				2,284				5,847				130
Retail		23,144				17,257				5,887				3,604				10,058				—
Office		1,706				1,695				11				522				1,904				—
Other		4,661				4,577				84				1,263				6,082				16
Residential real estate		10,565				10,565				—				2,858				3,417				—
Construction real estate		4,552				2,167				2,385				497				3,775				—
Indirect vehicle		—				—				—				—				—				—
Home equity		13,765				13,763				2				850				4,800				—
Other consumer		—				—				—				—				—				—
Total		$	144,992			$	122,264			$	22,728			$	16,941			$	119,252			$	376
Impaired loans included accruing restructured loans of $29.9 million and $21.3 million that have been modified and are performing in accordance with those modified terms as of September 30, 2013 and December 31, 2012, respectively.  In addition, impaired loans included $22.3 million and $28.4 million of non-performing, restructured loans as of September 30, 2013 and December 31, 2012, respectively.
Loans may be restructured in an effort to maximize collections from financially distressed borrowers. We use various restructuring techniques, including, but not limited to, deferring past due interest or principal, implementing an A/B note structure, redeeming past due taxes, reducing interest rates, extending maturities and modifying amortization schedules. Residential real estate loans are restructured in an effort to minimize losses while allowing borrowers to remain in their primary residences when possible. Programs that we offer to residential real estate borrowers include the Home Affordable Refinance Program (“HARP”), a restructuring program similar to the Home Affordable Modification Program (“HAMP”) for first mortgage borrowers, the Second Lien Modification Program (“2MP”) and similar programs for home equity borrowers in keeping with the restructuring techniques discussed above.
Periodically, the Company will restructure a note into two separate notes (A/B structure), charging off the entire B portion of the note. The A note is structured with appropriate loan-to-value and cash flow coverage ratios that provide for a high likelihood of repayment. The A note is classified as a non-performing note until the borrower has displayed a historical payment performance for a reasonable time prior to and subsequent to the restructuring. A period of sustained repayment for at least six months generally is required to return the note to accrual status provided that management has determined that the performance is reasonably expected to continue. The A note will be classified as a restructured note (either performing or nonperforming) through the calendar year of the restructuring that the historical payment performance has been established. As of September 30, 2013, there were no A/B structures. As of December 31, 2012 there was approximately $3.1 million in recorded investment in relation to one A/B structure.
A loan classified as a troubled debt restructuring will no longer be included in the troubled debt restructuring disclosures in the years after the restructuring if the loan performs in accordance with the terms specified by the restructuring agreement and the interest rate specified in the restructuring agreement represents a market rate at the time of modification. The specified interest rate is considered a market rate when the interest rate is equal to or greater than the rate the Company is willing to accept at the time of restructuring for a new loan with comparable risk. If there are concerns that the borrower will not be able to meet the modified terms of the loan, the loan will continue to be included in the troubled debt restructuring disclosures.
Impairment analyses on commercial-related loans classified as troubled debt restructurings are performed in conjunction with the normal allowance for loan loss process. Consumer loans classified as troubled debt restructurings are aggregated in two pools that share common risk characteristics, home equity and residential real estate loans, with impairment measured on a quarterly basis based on the present value of expected future cash flows discounted at the loan's effective interest rate.
The following table presents loans that have been restructured during the three months ended September 30, 2013 (dollars in thousands):
		30-Sep-13
		Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
		Loans		Investment				Investment				Specific Reserves
Performing:
Residential real estate		1		$	95			$	95			$	—
Home equity		1		19				19				—
Total		2		$	114			$	114			$	—
Non-Performing:
Commercial real estate:
Healthcare		1		$	3,164			$	3,164			$	496
Multifamily		1		436				436				119
Retail		1		205				205				56
Residential real estate		1		394				394				—
Indirect vehicle		17		113				89				24
Home equity		5		397				397				—
Total		26		$	4,709			$	4,685			$	695
The following table presents loans that have been restructured during the nine months ended September 30, 2013 (dollars in thousands):
		30-Sep-13
		Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
		Loans		Investment				Investment				Specific Reserves
Performing:
Commercial real estate:
Multifamily		1		$	601			$	601			$	—
Residential real estate		5		854				854				—
Home equity		7		723				723				—
Total		13		$	2,178			$	2,178			$	—
Non-Performing:
Commercial		2		$	1,251			$	1,251			$	673
Commercial real estate:
Healthcare		1		3,164				3,164				496
Industrial		4		2,570				2,570				1,425
Multifamily		2		623				623				169
Retail		3		862				862				235
Other		1		84				84				23
Residential real estate		6		1,149				1,149				—
Indirect vehicle		20		127				103				24
Home equity		25		3,333				3,333				—
Total		64		$	13,163			$	13,139			$	3,045
The following table presents loans that have been restructured during the three months ended September 30, 2012 (dollars in thousands):
		30-Sep-12
		Number of			Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
		Loans			Investment				Investment				Specific Reserves
Performing:
Home equity		7			$	401			$	325			$	76
Total		7			$	401			$	325			$	76
Non-Performing:
Commercial collateralized by assignment of lease payments		1			$	202			$	202			$	168
Commercial real estate:
Retail		1			202				202				200
Residential real estate		7			173				68				105
Home equity		5			347				232				115
Total		14			$	924			$	704			$	588
The following table presents loans that have been restructured during the nine months ended September 30, 2012 (dollars in thousands):
		30-Sep-12
		Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
		Loans		Investment				Investment				Specific Reserves
Performing:
Commercial real estate:
Multifamily		1		$	155			$	155			$	—
Retail		1		236				236				—
Residential real estate		2		808				808				—
Home equity		38		6,009				5,933				76
Total		42		$	7,208			$	7,132			$	76
Non-Performing:
Commercial		4		$	292			$	292			$	96
Commercial collateralized by assignment of lease payments		1		202				202				168
Commercial real estate:
Multifamily		1		149				149				40
Retail		4		923				923				232
Other		1		157				157				50
Residential real estate		13		637				401				236
Home equity		34		5,324				4,899				425
Total		58		$	7,684			$	7,023			$	1,247
Of the troubled debt restructurings entered into during the past twelve months, none subsequently defaulted during the nine months ended September 30, 2013.  Performing troubled debt restructurings are considered to have defaulted when they become 90 days or more past due post restructuring or are placed on non-accrual status.
The following tables present the troubled debt restructurings activity during the nine months ended September 30, 2013 (dollars in thousands):
		Performing				Non-performing
Beginning balance		$	21,256			$	28,418
Additions		2,178				13,163
Charge-offs		—				(3,127		)
Principal payments, net		(883		)		(8,008		)
Removals		—				(565		)
Transfer to other real estate owned		—				(206		)
Transfer from/to performing		8,458				1,098
Transfer from/to nonperforming		(1,098		)		(8,458		)
Ending balance		$	29,911			$	22,315
Approximately $8.5 million of non-performing troubled debt restructurings were transferred to performing status. A majority of these loans were identified as non-performing troubled debt restructurings during the first half of 2012 and have performed in accordance with the modified terms. The loans continue to be reported as performing troubled debt restructurings. The loans transferred to nonperforming in the table above were restructured in 2010 and 2011.
Loans removed from troubled debt restructuring status are those that were restructured in a previous calendar year at a market rate of interest and have performed in compliance with the modified terms.
The following table presents the type of modification for loans that have been restructured and the pre-modification recorded investment during the nine months ended September 30, 2013 (dollars in thousands):
	30-Sep-13
	Extended				Extended								Extended
	Maturity,				Maturity, Delay				Extended				Maturity, Delay								Delay in
	Amortization				in Payments and				Maturity and				in Payments and								Payments or
	and Reduction				Reduction of				Reduction of				Reduction of				Extended				Reduction of
	of Interest Rate				Interest Rate				Interest Rate				Amount				Maturity				Interest Rate			Total
Commercial	$	42			$	—			$	1,209			$	—			$	—			$	—		$	1,251
Commercial collateralized by assignment of lease payments	—				—				—				—				—				—			—
Commercial real estate:
Healthcare	—				—				—				3,164				—				—			3,164
Industrial	—				—				—				—				2,570				—			2,570
Multifamily	187				—				—				—				601				436			1,224
Retail	256				205				401				—				—				—			862
Office	—				—				—				—				—				—			—
Other	84				—				—				—				—				—			84
Residential real estate	1,386				—				—				—				—				618			2,004
Construction real estate	—				—				—				—				—				—			—
Indirect vehicle	—				—				—				—				—				127			127
Home equity	1,509				—				708				—				227				1,611			4,055
Other consumer	—				—				—				—				—				—			—
Total	$	3,464			$	205			$	2,318			$	3,164			$	3,398			$	2,792		$	15,341
The following table presents the activity in the allowance for credit losses, balance in allowance for credit losses and recorded investment in loans by portfolio segment and based on impairment method as of September 30, 2013 and 2012 (in thousands):
		Commercial				Commercial				Commercial				Residential				Construction				Indirect			Home			Other consumer		Unfunded			Total
						collateralized  by				real estate				real estate				real estate				vehicle			equity					commitments
						assignment of
						lease payments
30-Sep-13
Allowance for credit losses:
Three Months Ended
Beginning balance		$	27,277			$	8,529			$	60,014			$	8,121			$	8,695			$	1,537		$	8,206		$	1,306	$	1,812		$	125,497
Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				—				—			—			—		—			—
Charge-offs		1,686				—				1,236				713				26				572			437			485		—			5,155
Recoveries		579				—				966				48				420				372			228			74		—			2,687
Provision		(45		)		721				(3,983		)		347				(735		)		293			(152		)	368		(118		)	(3,304		)
Ending balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
Nine Months Ended
Beginning balance		$	24,943			$	7,755			$	61,056			$	6,941			$	11,222			$	1,324		$	9,401		$	1,562	$	4,075		$	128,279
Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				500				—			—			—		(500		)	—
Charge-offs		3,030				—				5,131				2,074				855				1,930			2,547			1,501		—			17,068
Recoveries		1,808				1,131				5,353				461				827				1,111			442			185		—			11,318
Provision		2,404				364				(5,517		)		2,475				(3,340		)		1,125			549			1,017		(1,881		)	(2,804		)
Ending balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
Ending allowance balance attributable to loans:
Individually evaluated for impairment		$	4,389			$	285			$	7,464			$	3,033			$	240			$	—		$	781		$	—	$	657		$	16,849
Collectively evaluated for impairment		20,871				8,965				46,412				4,663				8,114				1,630			7,064			1,263		1,037			100,019
Acquired and accounted for under ASC 310-30 (1)		865				—				1,885				107				—				—			—			—		—			2,857
Total ending allowance balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
Loans:
Individually evaluated for impairment		$	19,836			$	2,330			$	60,600			$	15,851			$	1,622			$	106		$	23,278		$	—	$	—		$	123,623
Collectively evaluated for impairment		1,134,376				1,466,484				1,577,768				291,699				134,524				257,634			251,206			57,418		—			5,171,109
Acquired and accounted for under ASC 310-30 (1)		35,649				—				159,799				5,982				61,446				—			110			29,014		—			292,000
Total ending loans balance		$	1,189,861			$	1,468,814			$	1,798,167			$	313,532			$	197,592			$	257,740		$	274,594		$	86,432	$	—		$	5,586,732
		Commercial				Commercial				Commercial				Residential				Construction				Indirect			Home			Other consumer		Unfunded			Total
						collateralized  by				real estate				real estate				real estate				vehicle			equity					commitments
						assignment of
						lease payments
30-Sep-12
Allowance for credit losses:
Three Months Ended
Beginning balance		$	20,789			$	7,490			$	68,713			$	3,592			$	10,586			$	1,941		$	7,617		$	1,028	$	7,084		$	128,840
Charge-offs		75				—				2,994				474				71				433			1,209			332		—			5,588
Recoveries		306				111				12,893				8				752				224			303			77		—			14,674
Provision		1,181				(149		)		(12,253		)		738				(393		)		288			370			558		(3,340		)	(13,000		)
Ending balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
Nine Months Ended
Beginning balance		$	21,106			$	7,561			$	68,695			$	3,935			$	15,639			$	1,834		$	7,333		$	695	$	9,177		$	135,975
Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				1,132				—			—			—		(1,132		)	—
Charge-offs		2,065				1,720				8,412				1,876				3,951				1,636			3,157			864		—			23,681
Recoveries		2,730				460				16,116				230				1,458				835			423			280		—			22,532
Provision		430				1,151				(10,040		)		1,575				(3,404		)		987			2,482			1,220		(4,301		)	(9,900		)
Ending balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
Ending allowance balance attributable to loans:
Individually evaluated for impairment		$	2,570			$	180			$	7,567			$	401			$	582			$	—		$	—		$	—	$	1,726		$	13,026
Collectively evaluated for impairment		19,345				7,272				56,851				3,144				10,292				2,020			7,081			1,331		2,018			109,354
Acquired and accounted for under ASC 310-30 (1)		286				—				1,941				319				—				—			—			—		—			2,546
Total ending allowance balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
Loans:
Individually evaluated for impairment		$	21,537			$	1,168			$	56,037			$	11,127			$	2,372			$	—		$	10,280		$	248	$	—		$	102,769
Collectively evaluated for impairment		1,033,534				1,218,193				1,714,224				293,787				147,500				206,973			304,438			84,403		—			5,003,052
Acquired and accounted for under ASC 310-30 (1)		78,275				—				269,348				7,116				125,515				—			568			38,202		—			519,024
Total ending loans balance		$	1,133,346			$	1,219,361			$	2,039,609			$	312,030			$	275,387			$	206,973		$	315,286		$	122,853	$	—		$	5,624,845
(1)  Loans acquired in FDIC-assisted transactions and accounted for under ASC Subtopic 310-30 “Receivables — Loans and Debt Securities Acquired with Deteriorated Credit Quality.”
Purchased loans acquired in a business combination are recorded at estimated fair value on their purchase date without a carryover of the related allowance for loan losses.  These acquired loans are segregated into three types: pass rated loans with no discount attributable to credit quality, non-impaired loans with a discount attributable at least in part to credit quality and impaired loans with evidence of significant credit deterioration.
•	Pass rated loans (typically performing loans) are accounted in accordance with ASC 310-30 "Nonrefundable Fees and Other Costs" as these loans do not have evidence of credit deterioration since origination.
•	Non-impaired loans (typically past-due loans, special mention loans and performing substandard loans) are accounted for in accordance with ASC 310-30 as they display at least some level of credit deterioration since origination.
•	Impaired loans (typically substandard loans on non-accrual status) are accounted for in accordance with ASC 310-30 as they display significant credit deterioration since origination.
In accordance with ASC 310-30, for both purchased non-impaired loans and purchased impaired loans, the difference between contractually required payments at acquisition and the cash flows expected to be collected is referred to as the non-accretable difference. Further, any excess of cash flows expected at acquisition over the estimated fair value is referred to as the accretable yield and is recognized into interest income over the remaining life of the loan when there is a reasonable expectation about the amount and timing of such cash flows.
Substantially all of the loans acquired in transactions with the FDIC displayed at least some level of credit deterioration and as such are included as non-impaired and impaired loans as described immediately above.
During the three and nine months ended September 30, 2013 there was a negative provision for credit losses of $1.5 million and $2.5 million, respectively, and net recoveries of $677 thousand and $830 thousand, respectively, in relation to 15 pools of purchased loans with a total carrying amount of $219.1 million as of September 30, 2013. There was $2.9 million in allowance for loan losses related to these purchased loans at September 30, 2013 and $4.5 million at December 31, 2012.  The provision for credit losses and accompanying charge-offs are included in the table above.
Changes in the accretable yield for loans acquired in FDIC-assisted transactions and accounted for under ASC 310-30 were as follows for the three and nine months ended September 30, 2013 and 2012 (in thousands):
		Three Months Ended								Nine Months Ended
		September 30,								September 30,
		2013				2012				2013				2012
Balance at beginning of period		$	6,360			$	9,411			$	5,685			$	18,703
Accretion		(2,427		)		(3,406		)		(2,859		)		(12,812		)
Other		—				403				1,107				517
Balance at end of period		$	3,933			$	6,408			$	3,933			$	6,408
In our FDIC-assisted transactions, the fair value of purchased impaired loans, on the acquisition date, was determined based on assigned risk ratings, expected cash flows and the fair value of loan collateral. The fair value of loans that were non-impaired was determined based on estimates of losses on defaults and other market factors. Due to the loss-share agreements with the FDIC, MB Financial Bank recorded a receivable (FDIC indemnification asset) from the FDIC equal to the present value of the corresponding reimbursement percentages on the estimated losses embedded in the loan portfolio.
When cash flow estimates are adjusted downward for a particular loan pool, the FDIC indemnification asset is increased. An allowance for loan losses is established for the impairment of the loans. A provision for loan losses is recognized for the difference between the increase in the FDIC indemnification asset and the decrease in cash flows.
When cash flow estimates are adjusted upward for a particular loan pool, the FDIC indemnification asset is decreased. The difference between the decrease in the FDIC indemnification asset and the increase in cash flows is accreted over the estimated life of the loan pool.
When cash flow estimates are adjusted downward for covered foreclosed real estate, the FDIC indemnification asset is increased. A charge is recognized for the difference between the increase in the FDIC indemnification asset and the decrease in cash flows.
When cash flow estimates are adjusted upward for covered foreclosed real estate, the FDIC indemnification asset is decreased. Any write-down after the transfer to covered foreclosed real estate is reversed.
In both scenarios, the clawback liability (the amount the FDIC requires MB Financial Bank to pay back if certain thresholds are met) will increase or decrease accordingly.
The carrying amount of covered loans and other purchased non-covered loans at September 30, 2013 consisted of loans as shown in the following table (in thousands):
30-Sep-13		Purchased				Purchased Non-Impaired				Total
		Impaired				Loans
		Loans
Covered loans:
Commercial related (1)		$	11,130			$	5,738			$	16,868
Commercial		457				3,527				3,984
Commercial real estate		62,576				97,223				159,799
Construction real estate		53,444				8,002				61,446
Other		2,982				28,418				31,400
Total covered loans		$	130,589			$	142,908			$	273,497
Estimated receivable amount from the FDIC under the loss-share agreement (2)		$	36			$	10,013			$	10,049
Non covered loans:
Commercial related (3)		$	4,357			$	10,440			$	14,797
Other		89				3,617				3,706
Total non-covered loans		$	4,446			$	14,057			$	18,503
-1	Covered commercial related loans include commercial, commercial real estate and construction real estate loans acquired in connection with the Heritage and Benchmark FDIC-assisted transactions.
-2	Estimated reimbursable amounts from the FDIC under the loss-share agreement exclude $1.0 million in reimbursable amounts related to covered other real estate owned.
-3	Non covered commercial related loans include commercial, commercial real estate and construction real estate for InBank.
Outstanding balances on purchased loans from the FDIC were $305.0 million and $515.7 million as of September 30, 2013 and December 31, 2012, respectively.  The related carrying amount on loans purchased from the FDIC was $292.0 million and $471.6 million as of September 30, 2013 and December 31, 2012, respectively.

Goodwill_and_Intangibles

Goodwill and Intangibles	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	Goodwill and Intangibles
	The excess of the cost of an acquisition over the fair value of the net assets acquired consists of goodwill, and core deposit and client relationship intangibles. Under ASC Topic 350, goodwill is subject to at least annual assessments for impairment by applying a fair value based test. The Company reviews goodwill to determine potential impairment annually, or more frequently if events and circumstances indicate that goodwill might be impaired, by comparing the carrying value of the reporting unit with the fair value of the reporting unit.
	The Company's annual assessment date is as of December 31. No impairment losses were recognized during the three or nine months ended September 30, 2013 or 2012. Goodwill is tested for impairment at the reporting unit level. All of our goodwill is allocated to MB Financial, Inc., which is the Company's only applicable reporting unit for purposes of testing goodwill impairment.  The carrying amount of goodwill was $423.4 million at September 30, 2013 and December 31, 2012.
	The Company has other intangible assets consisting of core deposit and client relationship intangibles that had a remaining weighted average amortization period of approximately four years as of September 30, 2013.
	The following table presents the changes in the carrying amount of core deposit and client relationship intangibles, gross carrying amount, accumulated amortization, and net book value as of September 30, 2013 (in thousands):
			Nine Months Ended
			September 30,
			2013
	Balance at beginning of period		$	29,512
	Amortization expense		(4,595		)
	Balance at end of period		$	24,917
	Gross carrying amount		$	61,429
	Accumulated amortization		(36,512		)
	Net book value		$	24,917
	The following presents the estimated future amortization expense of other intangible assets (in thousands):
	Year ending December 31,	Amount
	2013	$	1,489
	2014	4,748
	2015	4,030
	2016	3,418
	2017	3,071
	Thereafter	8,161
		$	24,917

Deposits

Deposits	9 Months Ended
	Sep. 30, 2013
Deposits [Abstract]
Deposits	Deposits
	The composition of deposits was as follows (in thousands):
		September 30,		December 31,
		2013		2012
	Demand deposit accounts, noninterest bearing	$	2,269,367	$	2,164,547
	NOW and money market accounts	2,680,127		2,747,273
	Savings accounts	843,671		811,333
	Certificates of deposit, $100,000 or more	838,606		1,020,033
	Other certificates of deposit	666,915		799,511
	Total	$	7,298,686	$	7,542,697
	Certificates of deposit of $100,000 or more included $238.5 million and $294.2 million of brokered deposits at September 30, 2013 and December 31, 2012, respectively.  Brokered deposits typically consist of smaller individual time certificates that have the same liquidity characteristics and yields consistent with time certificates of $100,000 or more.

ShortTerm_Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2013
Short-term Debt [Abstract]
Short-Term Borrowings	Short-Term Borrowings
	Short-term borrowings were as follows as of September 30, 2013 and December 31, 2012 (dollars in thousands):
		30-Sep-13				December 31, 2012
		Weighted				Weighted
		Average				Average
		Cost		Amount		Cost		Amount
	Customer repurchase agreements	0.22	%	$	240,600	0.23	%	$	208,242
	Federal Home Loan Bank advances	—	%	—		3.58	%	12,360
		0.22	%	$	240,600	0.42	%	$	220,602
	Securities sold under agreements to repurchase are agreements in which the Company acquires funds by selling assets to another party under a simultaneous agreement to repurchase the same assets at a specified price and date.  The Company enters into repurchase agreements and also offers a demand deposit account product to customers that sweeps their balances in excess of an agreed upon target amount into overnight repurchase agreements.  All securities sold under agreements to repurchase are recorded on the face of the balance sheet.
	The Company had a Federal Home Loan Bank fixed rate advance with a maturity date less than one year of $12.4 million in fixed rate advances at December 31, 2012.
	On March 9, 2012, the Company entered into a $35.0 million unsecured line of credit with a correspondent bank. Interest is payable at a rate of one month LIBOR + 2.00%. As of September 30, 2013, no amount was outstanding. The line originally matured on March 8, 2013, was renewed and is scheduled to mature on March 7, 2014.

Longterm_Borrowings

Long-term Borrowings	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]
Long-term Borrowings	Long-term Borrowings
	The Company had Federal Home Loan Bank advances with remaining contractual maturities greater than one year of $4.3 million at September 30, 2013 and December 31, 2012. As of September 30, 2013, the advances had fixed terms with effective interest rates, net of discounts, ranging from 3.23% to 5.87% and maturities ranging from April 2021 to April 2035.
	A collateral pledge agreement exists whereby at all times, the Company must keep on hand, free of all other pledges, liens, and encumbrances, first mortgage loans and home equity loans with unpaid principal balances aggregating no less than 133% for first mortgage loans and 250% for home equity loans of the outstanding advances from the Federal Home Loan Bank.  The Company may also pledge certain investment securities as collateral for advances based on market value.  As of September 30, 2013 and December 31, 2012, the Company had $7.3 million and $28.4 million, respectively, of loans pledged as collateral for long-term Federal Home Loan Bank advances.  Additionally, as of September 30, 2013 and December 31, 2012, the Company had $29.2 million and $32.1 million, respectively, of investment securities pledged as collateral for advances from the Federal Home Loan Bank.
	The Company had notes payable to banks totaling $17.7 million and $21.1 million at September 30, 2013 and December 31, 2012, respectively, which as of September 30, 2013, were accruing interest at rates ranging from 2.50% to 12.00%.  Lease investments includes equipment with an amortized cost of $25.9 million and $29.7 million at September 30, 2013 and December 31, 2012, respectively, that is pledged as collateral on these notes.
	The Company had a $40.0 million 10-year structured repurchase agreement as of September 30, 2013, which bears interest at a fixed rate borrowing of 4.75% and expires in 2016.
	During the first quarter of 2013, MB Financial Bank pre-paid a $50.0 million subordinated debt facility.  Interest was payable at a rate of 3-month LIBOR +1.70%.

Junior_Subordinated_Notes_Issu

Junior Subordinated Notes Issued to Capital Trusts	9 Months Ended
	Sep. 30, 2013
JUNIOR SUBORDINATED NOTES ISSUED TO CAPITAL TRUSTS
Junior Subordinated Notes Issued to Capital Trusts	Junior Subordinated Notes Issued to Capital Trusts
	The Company has established statutory trusts for the sole purpose of issuing trust preferred securities and related trust common securities.  The proceeds from such issuances were used by the trusts to purchase junior subordinated notes of the Company, which are the sole assets of each trust.  Concurrently with the issuance of the trust preferred securities, the Company issued guarantees for the benefit of the holders of the trust preferred securities.  The Company’s outstanding trust preferred securities qualify, and are treated by the Company, as Tier 1 regulatory capital.  The Company owns all of the common securities of each trust.  The trust preferred securities issued by each trust rank equally with the common securities in right of payment, except that if an event of default under the indenture governing the notes has occurred and is continuing, the preferred securities will rank senior to the common securities in right of payment.
	The table below summarizes the outstanding junior subordinated notes and the related trust preferred securities issued by each trust as of September 30, 2013 (in thousands):
			Coal City		MB Financial		MB Financial		MB Financial
			Capital Trust I		Capital Trust II		Capital Trust III		Capital Trust IV
	Junior Subordinated Notes:
	Principal balance		$	25,774	$	36,083	$	10,310	$	20,619
	Annual interest rate		3-mo LIBOR + 1.80%		3-mo LIBOR + 1.40%		3-mo LIBOR + 1.50%		3-mo LIBOR + 1.52%
	Stated maturity date		September 1, 2028		September 15, 2035		September 23, 2036		September 15, 2036
	Call date		September 1, 2008		December 15, 2010		September 23, 2011		September 15, 2011
	Trust Preferred Securities:
	Face Value		$	25,000	$	35,000	$	10,000	$	20,000
	Annual distribution rate		3-mo LIBOR + 1.80%		3-mo LIBOR + 1.40%		3-mo LIBOR + 1.50%		3-mo LIBOR + 1.52%
	Issuance date		July 1998		August 2005		July 2006		August 2006
	Distribution dates (1)		Quarterly		Quarterly		Quarterly		Quarterly
			MB Financial		MB Financial		FOBB
			Capital Trust V		Capital Trust VI		Statutory Trust III (2)
	Junior Subordinated Notes:
	Principal balance		$	30,928	$	23,196	$	5,155
	Annual interest rate		3-mo LIBOR + 1.30%		3-mo LIBOR + 1.30%		3-mo LIBOR + 2.80%
	Stated maturity date		December 15, 2037		October 30, 2037		January 23, 2034
	Call date		December 15, 2012		October 30, 2012		January 23, 2009
	Trust Preferred Securities:
	Face Value		$	30,000	$	22,500	$	5,000
	Annual distribution rate		3-mo LIBOR + 1.30%		3-mo LIBOR + 1.30%		3-mo LIBOR + 2.80%
	Issuance date		September 2007		October 2007		December 2003
	Distribution dates (1)		Quarterly		Quarterly		Quarterly
	-1	All distributions are cumulative and paid in cash.
	-2	FOBB Statutory Trust III was established by First Oak Brook Bancshares, Inc. (“FOBB”) prior to the Company's acquisition of FOBB, and the junior subordinated note issued by FOBB to FOBB Statutory Trust III was assumed by the Company upon completion of the acquisition.
	The trust preferred securities are subject to mandatory redemption, in whole or in part, upon repayment of the junior subordinated notes at the stated maturity date or upon redemption on a date no earlier than the call dates noted in the table above.  Prior to these respective redemption dates, the junior subordinated notes could have been redeemed by the Company (in which case the trust preferred securities would also be redeemed) after the occurrence of: certain events that would have a negative tax effect on the Company or the trusts, would cause the trust preferred securities to no longer qualify as Tier 1 capital, or would result in a trust being treated as an investment company.  Each trust’s ability to pay amounts due on the trust preferred securities is solely dependent upon the Company making payment on the related junior subordinated notes.  The Company’s obligation under the junior subordinated notes and other relevant trust agreements, in aggregate, constitutes a full and unconditional guarantee by the Company of each trust’s obligations under the trust preferred securities issued by each trust.  The Company has the right to defer payment of interest on the notes and, therefore, distributions on the trust preferred securities, for up to five years, but not beyond the stated maturity date in the table above.  During any such deferral period the Company may not pay cash dividends on its stock and generally may not repurchase its stock.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Commitments: The Company is a party to credit-related financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers.  These financial instruments include commitments to extend credit, standby letters of credit and commercial letters of credit.  Such commitments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the consolidated balance sheets.
	The Company’s exposure to credit loss is represented by the contractual amount of these commitments.  The Company follows the same credit policies in making commitments as it does for on-balance-sheet instruments.
	At September 30, 2013 and December 31, 2012, the following financial instruments were outstanding, the contractual amounts of which represent off-balance sheet credit risk (in thousands):
		Contractual Amount
		September 30, 2013		December 31, 2012
	Commitments to extend credit:
	Home equity lines	$	216,992	$	239,771
	Other commitments	1,139,255		911,166
	Letters of credit:
	Standby	70,720		66,247
	Commercial	2,705		465
	Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the contract.  Commitments generally have fixed expiration dates or other termination clauses and may require a payment of a fee.  The commitments for home equity lines of credit may expire without being drawn upon.  Therefore, the total commitment amounts do not necessarily represent future cash requirements.  The amount of collateral obtained, if it is deemed necessary by the Company, is based on management’s credit evaluation of the customer.
	The Company, in the normal course of its business, regularly offers standby and commercial letters of credit to its bank customers.  Standby and commercial letters of credit are a conditional but irrevocable form of guarantee.  Under letters of credit, the Company typically guarantees payment to a third party beneficiary upon the default of payment or nonperformance by the bank customer and upon receipt of complying documentation from that beneficiary.
	Both standby and commercial letters of credit may be issued for any length of time, but normally do not exceed a period of five years.  These letters of credit may also be extended or amended from time to time depending on the bank customer’s needs.  As of September 30, 2013, the maximum remaining term for any standby letters of credit was December 31, 2020.  A fee is charged to the bank customer and is recognized as income over the life of the letter of credit, unless considered non-rebatable under the terms of a letter of credit application.
	At September 30, 2013, the aggregate contractual amount of these letters of credit, which represents the maximum potential amount of future payments that the Company would be obligated to pay, increased $6.7 million to $73.4 million from $66.7 million at December 31, 2012.  Of the $73.4 million in commitments outstanding at September 30, 2013, approximately $52.6 million of the letters of credit have been issued or renewed since December 31, 2012.
	Letters of credit issued on behalf of bank customers may be done on either a secured, partially secured or an unsecured basis.  If a letter of credit is secured or partially secured, the collateral can take various forms including bank accounts, investments, fixed assets, inventory, accounts receivable or real estate, among other things.  The Company takes the same care in making credit decisions and obtaining collateral when it issues letters of credit on behalf of its customers as it does when making other types of loans.
	As of September 30, 2013, the Company had approximately $1.4 million in capital expenditure commitments outstanding which relate to various projects to renovate existing branches.
	Concentrations of credit risk:  The majority of the loans, commitments to extend credit and standby letters of credit have been granted to customers in the Company’s market area.  As of September 30, 2013, approximately 27% of our investments in securities issued by states and political subdivisions were within the state of Illinois.  We did not hold any direct exposure to the state of Illinois as of September 30, 2013. The distribution of commitments to extend credit approximates the distribution of loans outstanding.  Standby letters of credit are granted primarily to commercial borrowers. Lease banking provides banking services to lessors located throughout the United States. Our leasing subsidiaries originate leases to companies located through the United States.
	Contingencies: In the normal course of business, the Company is involved in various legal proceedings.  In the opinion of management, any liability resulting from pending proceedings would not be expected to have a material adverse effect on the Company’s consolidated financial statements.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	ASC Topic 820 defines fair value as 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 shall not be 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 marketing 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.
	ASC Topic 820 requires the use of valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities. The income approach uses valuation techniques to convert expected future amounts, such as cash flows or earnings, to a single present value amount on a discounted basis. The cost approach is based on the amount that currently would be required to replace the service capacity of an asset (replacement cost). Valuation techniques should be consistently applied. Inputs to valuation techniques refer to the assumptions that market participants would use in pricing the asset or liability. Inputs may be observable, meaning those that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from independent sources, or unobservable, meaning those that reflect the reporting entity's own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. In that regard, ASC Topic 820 establishes a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows:
	Level 1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that the entity has the ability to access as of the measurement date.
	Level 2: Significant other observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data.
	Level 3: Significant unobservable inputs that reflect a reporting entity's own assumptions about the assumptions that market participants would use in pricing an asset or liability.
	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.
	In general, fair value is based upon quoted market prices, where available. If such quoted market prices are not available, fair value is based upon internally developed models that primarily use, as inputs, observable market-based parameters. Valuation adjustments may be made to ensure that financial instruments are recorded at fair value. These adjustments may include amounts to reflect counterparty credit quality, the Company's creditworthiness, among other things, as well as unobservable parameters. Any such valuation adjustments are applied consistently over time. Our 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 Company'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. Transfers between levels of the fair value hierarchy are recognized on the actual date of the event or circumstances that caused the transfer, which generally coincides with the Company's monthly and/or quarterly valuation process.
	Financial Instruments Recorded at Fair Value on a Recurring Basis
	Securities Available for Sale. The fair values of securities available for sale are determined by quoted prices in active markets, when available, and classified as Level 1. If quoted market prices are not available, the fair value is determined by a matrix pricing, which is a mathematical technique widely used in the industry to value debt securities without relying exclusively on quoted prices for the specific securities but rather by relying on the securities' relationship to other benchmark quoted securities and classified as Level 2. In cases where significant credit valuation adjustments are incorporated into the estimation of fair value, reported amounts are classified as Level 3.
	Loans Held for Sale. The fair value of loans held for sale is determined using quoted secondary market prices and classified as level 2.
	Assets Held in Trust for Deferred Compensation and Associated Liabilities. Assets held in trust for deferred compensation are recorded at fair value and included in “Other Assets” on the consolidated balance sheets. These assets are invested in mutual funds and classified as Level 1. Deferred compensation liabilities, also classified as Level 1, are carried at the fair value of the obligation to the employee, which corresponds to the fair value of the invested assets.
	Derivatives. Currently, we use interest rate swaps to manage our interest rate risk. The valuation of these instruments is determined using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative and classified as Level 2. This analysis reflects the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including LIBOR rate curves. We also obtain dealer quotations for these derivatives for comparative purposes to assess the reasonableness of the model valuations. We also offer other derivatives, including foreign currency forward contracts and interest rate lock commitments, to our customers and offset our exposure from such contracts by purchasing other financial contracts, which are valued using market consensus prices.
	The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands):
			Total				Quoted Prices in				Significant Other				Significant
							Active Markets for				Observable Inputs				Unobservable Inputs
							Identical Assets				(Level 2)				(Level 3)
							(Level 1)
	30-Sep-13
	Financial assets
	Securities available for sale:
	U.S Government sponsored agencies and enterprises		$	52,527			$	—			$	52,527			$	—
	States and political subdivisions		19,312				—				19,312				—
	Residential mortgage-backed securities		691,276				—				690,546				730
	Commercial mortgage-backed securities		53,446				—				53,446				—
	Corporate bonds		263,021				—				257,857				5,164
	Equity securities		10,541				10,541				—				—
	Loans held for sale		1,120				—				1,120				—
	Assets held in trust for deferred compensation		10,077				10,077				—				—
	Derivative financial instruments		19,112				—				19,112				—
	Financial liabilities
	Other liabilities (1)		9,892				9,892				—				—
	Derivative financial instruments		19,060				—				19,060				—
	December 31, 2012
	Financial assets
	Securities available for sale:
	U.S. Government sponsored agencies and enterprises		$	41,315			$	—			$	41,315			$	—
	States and political subdivisions		725,019				—				725,019				—
	Residential mortgage-backed securities		939,202				—				938,354				848
	Commercial mortgage-backed securities		54,126				—				54,126				—
	Corporate bonds		96,674				—				91,451				5,223
	Equity securities		11,835				11,835				—				—
	Loans held for sale		7,492				—				7,492				—
	Assets held in trust for deferred compensation		7,746				7,746				—				—
	Derivative financial instruments		29,096				—				29,096				—
	Financial liabilities
	Other liabilities (1)		7,746				7,746				—				—
	Derivative financial instruments		29,055				—				29,055				—
	(1) Liabilities associated with assets held in trust for deferred compensation
	The following table presents additional information about the unobservable inputs used in the fair value measurement of financial assets measured on a recurring basis that were categorized within the Level 3 of the fair value hierarchy:
		Fair Value at			Valuation	Unobservable
		September 30, 2013			Technique	Input	Range
	Residential mortgage-backed securities	$	730		Discounted cash flows	Constant pre-payment rates
						(CPR) assumption	1% - 3% CPR
	Corporate bonds	5,164			Discounted cash flows	Credit assumption	20% Loss
	The Company did not have any transfers between Level 1 and Level 2 of the fair value hierarchy during the three and nine months ended September 30, 2013. The Company's policy for determining transfers between levels occurs at the end of the reporting period when circumstances in the underlying valuation criteria change and result in transfer between levels.
	The following table presents additional information about financial assets measured at fair value on a recurring basis for which the Company used significant unobservable inputs (Level 3):
			Nine Months Ended
			September 30,
	(in thousands)		2013				2012
	Balance, beginning of period		$	6,071			$	6,992
	Other comprehensive income		(59		)		89
	Principal payments		(118		)		(846		)
	Impairment charge		—				(117		)
Balance, ending of period		$	5,894			$	6,118
Financial Instruments Recorded at Fair Value on a Nonrecurring Basis
The Company may be required, from time to time, to measure certain financial assets and financial liabilities at fair value on a nonrecurring basis in accordance with U.S. GAAP. These include assets that are measured at the lower of cost or fair value that were recognized at fair value below cost at the end of the period.
Impaired Loans. 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. Once a loan is identified as individually impaired, management measures impairment in accordance with ASC Topic 310. The fair value of impaired loans is estimated using one of several methods, including collateral value, market value of similar debt, enterprise value, liquidation value and discounted cash flows. Those impaired loans not requiring an allowance represent loans for which the fair value of the expected repayments or collateral exceed the recorded investments in such loans. In accordance with ASC Topic 820, impaired loans where an allowance is established based on the fair value of collateral require classification in the fair value hierarchy. Collateral values are estimated using Level 3 inputs based on customized discounting criteria. For a majority of impaired real estate loans where an allowance is established based on the fair value of collateral (approximately 85%), the Company obtains a current external appraisal. Other valuation techniques are used as well, including internal valuations, comparable property analysis and contractual sales information.
Non-Financial Assets and Non-Financial Liabilities Recorded at Fair Value
The Company has no non-financial assets or non-financial liabilities measured at fair value on a recurring basis. Certain non-financial assets and non-financial liabilities measured at fair value on a non-recurring basis include foreclosed assets and non-financial long-lived assets.
Other Real Estate and Repossessed Vehicles Owned (Foreclosed Assets). Foreclosed assets, upon initial recognition, are measured and reported at fair value through a charge-off to the allowance for loan losses based upon the fair value of the foreclosed asset. The fair value of foreclosed assets, upon initial recognition, are estimated using Level 3 inputs based on customized discounting criteria.
Non-Financial Long-Lived Assets.  Non-financial long-lived assets, when determined to be impaired, are measured and reported at fair value using Level 3 inputs based on customized discounting criteria.
Assets measured at fair value on a nonrecurring basis as of September 30, 2013 and December 31, 2012 are included in the table below (in thousands):
		Total				Quoted Prices in Active				Significant Other				Significant
						Markets for Identical				Observable Inputs				Unobservable Inputs
						Assets (Level 1)				(Level 2)				(Level 3)
30-Sep-13
Financial assets:
Impaired loans		$	84,500			$	—			$	—			$	84,500
Non-financial assets:
Foreclosed assets		57,009				—				—				57,009
December 31, 2012
Financial assets:
Impaired loans		$	62,258			$	—			$	—			$	62,258
Non-financial assets:
Foreclosed assets		60,228				—				—				60,228
Long-lived assets		2,314				—				—				2,314
The following table presents additional information about the 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:
	Fair Value at			Valuation	Unobservable
	September 30, 2013			Technique	Input	Range
Impaired loans	$	84,500		Appraisal of collateral	Appraisal adjustments - sales costs	5% - 10%
Foreclosed assets	57,009			Appraisal of collateral	Appraisal adjustments - sales costs	5% - 10%
ASC Topic 825 requires disclosure of the fair value of financial assets and financial liabilities, including those financial assets and financial liabilities that are not measured and reported at fair value on a recurring basis or non-recurring basis. The methodologies for estimating the fair value of financial assets and financial liabilities that are measured at fair value on a recurring or non-recurring basis are discussed above. The estimated fair value approximates carrying value for cash and cash equivalents, accrued interest and the cash surrender value of life insurance policies. The methodologies for other financial assets and financial liabilities are discussed below:
The following methods and assumptions were used by the Company in estimating the fair values of its other financial instruments:
Cash and due from banks and interest bearing deposits with banks: The carrying amounts reported in the balance sheet approximate fair value.
Securities held to maturity: The fair values of securities held to maturity are determined by quoted prices in active markets, when available, and classified as Level 1. If quoted market prices are not available, the fair value is determined by a matrix pricing, which is a mathematical technique widely used in the industry to value debt securities without relying exclusively on quoted prices for the specific securities but rather by relying on the securities' relationship to other benchmark quoted securities and classified as Level 2. In cases where significant credit valuation adjustments are incorporated into the estimation of fair value, reported amounts are classified as Level 3.
Non-marketable securities - FHLB and FRB Stock: The carrying amounts reported in the balance sheet approximate fair value.
Loans Held for Sale: The fair value of the loans held for sale is determined using quoted secondary market prices and classified as level 2.
Loans: The fair values for loans are estimated using discounted cash flow analyses, using the corporate bond curve adjusted for liquidity for commercial loans and the swap curve adjusted for liquidity for retail loans.
Non-interest bearing deposits: The fair values disclosed are equal to their balance sheet carrying amounts, which represent the amount payable on demand.
Interest bearing deposits: The fair values disclosed for deposits with no defined maturities are equal to their carrying amounts, which represent the amounts payable on demand. Fair values for certificates of deposit are estimated using a discounted cash flow calculation that applies the Company's current incremental borrowing rates for similar terms.
Short-term borrowings: The carrying amounts of federal funds purchased, borrowings under repurchase agreements and other short-term borrowings with maturities of 90 days or less approximate their fair values.  The fair value of short-term borrowings greater than 90 days is based on the discounted value of contractual cash flows.
Long-term borrowings: The fair values of the Company's long-term borrowings (other than deposits) are estimated using discounted cash flow analyses, based on the Company's current incremental borrowing rates for similar types of borrowing arrangements.
Junior subordinated notes issued to capital trusts: The fair values of the Company's junior subordinated notes issued to capital trusts are estimated based on the quoted market prices, when available, of the related trust preferred security instruments or are estimated based on the quoted market prices of comparable trust preferred securities.
Accrued interest: The carrying amount of accrued interest receivable and payable approximate their fair values.
Off-balance-sheet instruments: Fair values for the Company’s off-balance-sheet lending commitments (guarantees, letters of credit and commitments to extend credit) are based on fees currently charged to enter into similar agreements, taking into account the remaining terms of the agreements.
The estimated fair values of financial instruments are as follows (in thousands):
		30-Sep-13
		Carrying Amount				Estimated Fair Value			Quoted Prices in Active			Significant Other			Significant
									Markets for Identical			Observable Inputs			Unobservable Inputs
									Assets (Level 1)			(Level 2)			(Level 3)
Financial Assets:
Cash and due from banks		$	215,017			$	215,017		$	215,017		$	—		$	—
Interest bearing deposits with banks		41,700				41,700			41,700			—			—
Investment securities available for sale		1,090,123				1,090,123			10,541			1,073,688			5,894
Investment securities held to maturity		1,193,544				1,212,748			—			1,212,748			—
Non-marketable securities - FHLB and FRB stock		50,870				50,870			—			—			50,870
Loans held for sale		1,120				1,120			—			1,120			—
Loans, net		5,468,701				5,470,567			—			—			5,470,567
Accrued interest receivable		35,938				35,938			35,938			—			—
Derivative financial instruments		19,112				19,112			—			19,112			—
Financial Liabilities:
Noninterest bearing deposits		$	2,269,367			$	2,269,367		$	2,269,367		$	—		$	—
Interest bearing deposits		5,029,319				5,039,175			—			—			5,039,175
Short-term borrowings		240,600				240,595			—			—			240,595
Long-term borrowings		62,428				67,425			—			—			67,425
Junior subordinated notes issued to capital trusts		152,065				105,967			—			—			105,967
Accrued interest payable		1,908				1,908			1,908			—			—
Derivative financial instruments		19,060				19,060			—			19,060			—
		December 31, 2012
		Carrying Amount				Estimated Fair Value			Quoted Prices in Active			Significant Other			Significant
									Markets for Identical			Observable Inputs			Unobservable Inputs
									Assets (Level 1)			(Level 2)			(Level 3)
Financial Assets:
Cash and due from banks		$	176,010			$	176,010		$	176,010		$	—		$	—
Interest bearing deposits with banks		111,533				111,533			111,533			—			—
Investment securities available for sale		1,868,171				1,868,171			11,835			1,850,265			6,071
Investment securities held to maturity		493,421				535,681			—			535,681			—
Non-marketable securities - FHLB and FRB stock		55,385				55,385			—			—			55,385
Loans held for sale		7,492				7,492			—			7,492			—
Loans, net		5,642,726				5,659,598			—			—			5,659,598
Accrued interest receivable		36,040				36,040			36,040			—			—
Derivative financial instruments		29,096				29,096			—			29,096			—
Financial Liabilities:
Non-interest bearing deposits		$	2,164,547			$	2,164,547		$	2,164,547		$	—		$	—
Interest bearing deposits		5,378,150				5,399,709			—			—			5,399,709
Short-term borrowings		220,602				220,683			—			—			220,683
Long-term borrowings		116,050				117,809			—			—			117,809
Junior subordinated notes issued to capital trusts		152,065				104,009			—			—			104,009
Accrued interest payable		2,828				2,828			2,828			—			—
Derivative financial instruments		29,055				29,055			—			29,055			—

Stock_Incentive_Plans

Stock Incentive Plans	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Incentive Plans	Stock Incentive Plans
	ASC Topic 718 requires that the grant date fair value of equity awards to employees be recognized as compensation expense over the period during which an employee is required to provide service in exchange for such award.
	The following table summarizes the impact of the Company’s share-based payment plans in the financial statements for the periods shown (in thousands):
		Three Months Ended							Nine Months Ended
		September 30,							September 30,
		2013				2012			2013			2012
	Total cost of share-based payment plans during the period	$	1,388			$	1,080		$	3,860		$	3,581
	Amount of related income tax benefit recognized in income	548				430			1,530			$	1,431
	The Company adopted the Omnibus Incentive Plan (the “Omnibus Plan”) in 1997.  In June 2011, the Company’s stockholders approved an amendment and restatement of the Omnibus Plan to add 2,300,000 authorized shares for a total of 8,300,000 shares of common stock for issuance to directors, officers, and employees of the Company or any of its subsidiaries.  Equity grants under the Omnibus Plan can be in the form of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, and other stock-based awards.  Shares awarded in the form of restricted stock, restricted stock units, performance shares, performance units, or other stock-based awards generally will reduce the shares available under the Omnibus Plan on a 2-for-1 basis.  As of September 30, 2013, there were 1,617,262 shares available for future grants.
	Annual equity-based incentive awards are typically granted to selected officers and employees mid-year.  Options are granted with an exercise price equal to no less than the market price of the Company’s shares at the date of grant; those option awards generally vest over four years of service and have 10-year contractual terms.  Restricted shares and units typically vest over a two to four year period.  Equity awards may also be granted at other times throughout the year in connection with the recruitment and retention of officers and employees.  Directors currently may elect, in lieu of cash, to receive up to 70% of their fees in stock options with a five year term, which are fully vested on the grant date (provided that the director may not sell the underlying shares for at least six months after the grant date), and up to 100% of their fees in restricted shares, which vest one year after the grant date.
	The following table summarizes stock options outstanding for the nine months ended September 30, 2013:
		Number of			Weighted			Weighted		Aggregate
		Options			Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual		(in thousands)
								Term
								(In Years)
	Options outstanding as of December 31, 2012	2,739,753			$	27.34
	Granted	211,501			27.03
	Exercised	(330,832	)		25.51
	Expired or cancelled	(113,290	)		30.91
	Forfeited	(17,857	)		20.18
	Options outstanding as of September 30, 2013	2,489,275			$	27.44		4.94		$	9,407
	Options exercisable as of September 30, 2013	1,809,183			$	29.72		3.67		$	4,764
	The fair value of each option award is estimated on the date of grant using the Black-Scholes option pricing model based on certain assumptions.  Expected volatility is based on historical volatility and the expectations of future volatility of Company shares.  The risk free interest rate for periods within the contractual term of the option is based on the U.S. Treasury yield curve in effect at the time of the grant.  The expected life of options is estimated based on historical employee behavior and represents the period of time that options granted are expected to remain outstanding.
	The following assumptions were used for options granted during the nine months ended September 30, 2013:
		September 30,
		2013
	Risk-free interest rate	1.96		%
	Expected volatility of Company’s stock	25.6		%
	Expected dividend yield	1.74		%
	Expected life of options	5.6 years
	Weighted average fair value per option of options granted during the year	$	5.97
	The total intrinsic value of options exercised during the nine months ended September 30, 2013 and 2012 was $929 thousand and $203 thousand, respectively.
	The following is a summary of changes in restricted shares and units for the nine months ended September 30, 2013:
		Number of			Weighted
		Shares and Units			Average
					Grant Date
					Fair Value
	Shares Outstanding at December 31, 2012	634,211			$	18.82
	Granted	270,983			26.91
	Vested	(201,178	)		16.79
	Forfeited	(13,983	)		20.52
	Shares Outstanding at September 30, 2013	690,033			$	22.55
	The Company issued 56,752 and 65,333 market-based restricted stock units in 2013 and 2012, respectively, which entitle recipients to shares of common stock at the end of a three year vesting period. Recipients will earn shares, totaling between 0% and 175% of the number of units issued, based on the Company's total stockholder return relative to a specified peer group of financial institutions over the three year period. The market-based restricted stock units are included in the preceding table as if the recipients earned shares equal to 100% of the units issued. A Monte Carlo simulation model was used to value the market-based restricted stock units at the time of issuance.
	The Company issued 92,717 shares and 66,193 shares of market-based restricted stock in 2011 and 2010, respectively.  The market component of the vesting terms for each award requires that, for ten consecutive trading days, the closing price of the Company’s stock be at least $27.00 for awards issued in 2011 and $25.80 for awards issued in 2010.  The market components for awards issued in 2011 and 2010 have been satisfied as of September 30, 2013. Awards issued in 2011 will vest in full in 2014, on the third anniversary of the grant date. Awards issued in 2010 vested in full in 2013. A Monte Carlo simulation model was used to value the market-based restricted stock awards at the time of issuance.
	Effective January 1, 2010, the Company began issuing shares of common stock under the Omnibus Plan as Salary Stock, classified as other stock-based awards, to certain executive officers. This stock is fully vested as of the grant date and the related expense is included in salaries and employee benefits on the Consolidated Statements of Operations. Holders of Salary Stock have all of the rights of a stockholder, including the right to vote the shares and the right to receive any dividends that may be paid thereon. As a condition of receiving the Salary Stock, the holders entered into agreements with the Company providing that they may not sell or otherwise transfer the shares of Salary Stock for two years, except in the event of disability or death.  During the three months ended March 31, 2013, the Company issued 876 shares of Salary Stock at a weighted average issuance price of $22.39 and subsequently ended the issuance of new shares of Salary Stock.
	As of September 30, 2013, there was $14.2 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements (including share option and nonvested share awards) granted under the Omnibus Plan.  At September 30, 2013, the weighted-average period over which the unrecognized compensation expense is expected to be recognized was approximately 2.9 years.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments
	The Company offers various derivatives, including interest rate swaps and foreign currency forward contracts, to our customers which can mitigate our exposure to market risk through the execution of off-setting positions with inter-bank dealer counterparties. This also permits the Company to offer customized risk management solutions to our customers. These customer accommodations and any offsetting financial contracts are treated as non-designated derivative instruments and carried at fair value through an adjustment to the income statement.
	Interest rate swap and foreign currency forward contracts involve the risk of dealing with counterparties and their ability to meet contractual terms. The net amount payable or receivable under interest rate swaps is accrued as an adjustment to interest income.  The net amount payable as of September 30, 2013 was approximately $24 thousand, and the net amount payable as of December 31, 2012 was approximately $30 thousand.  The Company's credit exposure on interest rate swaps is limited to the Company's net favorable value and interest payments of all swaps to each counterparty. In such cases, collateral is generally required from the counterparties involved if the net value of the swaps exceeds a nominal amount.  At September 30, 2013, the Company’s credit exposure relating to interest rate swaps was approximately $17.9 million, which is secured by the underlying collateral on customer loans.
	The Company also enters into mortgage banking derivatives which are classified as non-designated derivatives. These derivatives include interest rate lock commitments provided to customers to fund certain mortgage loans to be sold into the secondary market and forward commitments for the future delivery of such loans. It is the Company's practice to enter into forward commitments for the future delivery of residential mortgage loans when interest rate lock commitments are entered into in order to economically hedge the effect of future changes in interest rates on its commitments to fund the loans as well as on its portfolio of mortgage loans held-for-sale.
	The Company had fair value commercial loan interest rate swaps, to hedge its interest rate risk, with an aggregate notional amount of $248 thousand at September 30, 2013.  For fair value hedges, the changes in fair values of both the hedging derivative and the hedged item were recorded in current earnings as other income.
	The Company’s derivative financial instruments are summarized below as of September 30, 2013 and December 31, 2012 (in thousands):
		Asset Derivatives												Liability Derivatives
		30-Sep-13						December 31, 2012						30-Sep-13					December 31, 2012
		Notional			Estimated			Notional			Estimated			Notional		Estimated			Notional			Estimated
		Amount			Fair Value			Amount			Fair Value			Amount		Fair Value			Amount			Fair Value
	Derivative instruments designated as hedges of fair value:
	Interest rate swap contracts (1)	$	—		$	—		$	—		$	—		$	248	$	(26	)	$	3,707		$	(94	)
	Stand-alone derivative instruments (2)
	Interest rate swap contracts	570,472			17,813			460,956			27,740			571,445		(17,875		)	462,012			(27,832		)
	Interest rate options contracts	84,095			307			70,346			157			84,095		(307		)	70,346			(157		)
	Foreign exchange contracts	16,112			912			20,033			1,062			15,536		(818		)	19,337			(961		)
	Mortgage banking derivatives	4,794			80			11,400			137			2,603		(34		)	4,000			(11		)
	Total non-hedging derivative instruments	675,473			19,112			562,735			29,096			673,679		(19,034		)	555,695			(28,961		)
	Total	$	675,473		$	19,112		$	562,735		$	29,096		$	673,927	$	(19,060	)	$	559,402		$	(29,055	)
	(1) Hedged fixed-rate commercial real estate loans
	(2) These portfolio swaps are not designated as hedging instruments under ASC Topic 815.
	Amounts included in the other income in the consolidated statements of operations related to derivative financial instruments were as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Derivative instruments designated as hedges of fair value:
	Interest rate swap contracts	$	(1	)	$	—		$	9		$	(36	)
	Stand-alone derivative instruments
	Interest rate swap contracts	7			6			30			19
	Interest rate options contracts	—			—			—			—
	Foreign exchange contracts	(12		)	14			(7		)	44
	Mortgage banking derivatives	(16		)	9			(80		)	79
	Total non-hedging derivative instruments	(21		)	29			(57		)	142
	Total	$	(22	)	$	29		$	(48	)	$	106
	Methods and assumptions used by the Company in estimating the fair value of its interest rate swaps are discussed in Note 13 to consolidated financial statements.
	Certain instruments and transactions subject to an agreement similar to a master netting arrangement are eligible for offset in the consolidated balance sheet. The instruments and transactions would include derivatives, sale and repurchase agreements and reverse sale and repurchase agreements, and securities borrowing and securities lending arrangements. The Company’s derivative transactions with financial institution counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. Under these agreements, there is generally a legally enforceable right to offset recognized amounts, and there may be an intention to settle such amounts on a net basis. The Company, however, does not generally offset such financial instruments for financial reporting purposes.
	Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of September 30, 2013 is summarized below (in thousands):
		Financial Assets									Financial Liabilities
		Gross Amount Recognized			Gross Amount Offset			Net Amount Recognized			Gross Amount Recognized			Gross Amount Offset		Net Amount Recognized
	Derivatives:
	Interest rate swaps, caps and floors	$	3,483		$	—		$	3,483		$	14,724		$	—	$	14,724
	Foreign currency forward contracts	67			—			67			764			—		764
	Mortgage banking derivatives	—			—			—			34			—		34
	Total derivatives	3,550			—			3,550			15,522			—		15,522
	Repurchase agreements	—			—			—			240,600			—		240,600
	Total	$	3,550		$	—		$	3,550		$	256,122		$	—	$	256,122
		Financial Assets												Financial Liabilities
		Net Amount Recognized			Financial Instruments			Collateral			Net Amount			Net Amount Recognized		Financial Instruments			Collateral			Net Amount
	Derivatives:
	Counterparty A	$	440		$	(440	)	$	—		$	—		$	12,976	$	(440	)	$	(12,536	)	$	—
	Counterparty B	1,090			(551		)	—			539			551		(551		)	—			—
	Counterparty C	1,570			(1,570		)	—			—			1,949		(1,570		)	(379		)	—
	Other counterparties	450			(1		)	—			449			46		(1		)	—			45
	Total derivatives	3,550			(2,562		)	—			988			15,522		(2,562		)	(12,915		)	45
	Repurchase agreements	—			—			—			—			240,600		—			(240,600		)	—
	Total	$	3,550		$	(2,562	)	$	—		$	988		$	256,122	$	(2,562	)	$	(253,515	)	$	45
	Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2012 is summarized below (in thousands):
		Financial Assets									Financial Liabilities
		Gross Amount Recognized			Gross Amount Offset			Net Amount Recognized			Gross Amount Recognized			Gross Amount Offset		Net Amount Recognized
	Derivatives:
	Interest rate swaps, caps and floors	$	192		$	—		$	192		$	27,890		$	—	$	27,890
	Foreign currency forward contracts	43			—			43			929			—		929
	Mortgage banking derivatives	1			—			1			11			—		11
	Total derivatives	236			—			236			28,830			—		28,830
Repurchase agreements	—			—			—			208,242			—		208,242
Total	$	236		$	—		$	236		$	237,072		$	—	$	237,072
	Financial Assets												Financial Liabilities
	Net Amount Recognized			Financial Instruments			Collateral			Net Amount			Net Amount Recognized		Financial Instruments			Collateral			Net Amount
Derivatives:
Counterparty A	$	68		$	(68	)	$	—		$	—		$	25,497	$	(68	)	$	(25,429	)	$	—
Counterparty B	84			(84		)	—			—			633		(84		)	(549		)	—
Counterparty C	36			(36		)	—			—			2,305		(36		)	(2,269		)	—
Other counterparties	48			(42		)	—			6			395		(42		)	(298		)	55
Total derivatives	236			(230		)	—			6			28,830		(230		)	(28,545		)	55
Repurchase agreements	—			—			—			—			208,242		—			(208,242		)	—
Total	$	236		$	(230	)	$	—		$	6		$	237,072	$	(230	)	$	(236,787	)	$	55

Common_and_Preferred_Stock

Common and Preferred Stock	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]
Common and Preferred Stock	Common and Preferred Stock
	In 2008, the Company issued 196,000 shares of Fixed Rate Cumulative Perpetual Preferred Stock, Series A ("the Series A Preferred Stock"), liquidation amount $1,000 per share, for an aggregate purchase price of $196.0 million as part of the Troubled Asset Relief Program (“TARP”) Capital Purchase Program of the United States Department of the Treasury (the “Treasury”).  The Series A Preferred Stock qualified as Tier 1 capital and provided for cumulative dividends on the liquidation preference amount on a quarterly basis at a rate of 5% per annum for the first five years, and 9% per annum thereafter.  Concurrent with issuing the Series A Preferred Stock, the Company issued to the Treasury a 10 year warrant (the “Warrant”) to purchase 1,012,048 shares (subsequently reduced to 506,024 shares, as described below) of the Company’s Common Stock at an exercise price of $29.05 per share.
	On September 17, 2009, the Company completed a public offering of its common stock by issuing 12,578,125 shares of common stock for aggregate gross proceeds of $201.3 million.  The net proceeds to the Company after deducting underwriting discounts and commissions and offering expenses were approximately $190.9 million.  With the proceeds from this offering and the proceeds received by the Company from issuances pursuant to its Dividend Reinvestment and Stock Purchase Plan, the Company received aggregate gross proceeds from “Qualified Equity Offerings” in excess of the $196.0 million aggregate liquidation preference amount of the Series A Preferred Stock.  As a result, the number of shares of the Company’s common stock underlying the Warrant was reduced by 50%, from 1,012,048 shares to 506,024 shares.
	On March 14, 2012, the Company repurchased all $196.0 million of the Series A Preferred Stock. On May 2, 2012, the Company repurchased the Warrant in full for approximately $1.5 million.

New_Authoritative_Accounting_G1

New Authoritative Accounting Guidance (Policies)	9 Months Ended
	Sep. 30, 2013
New Authoritative Accounting Guidance [Abstract]
New Authoritative Accounting Pronouncements	ASC Topic 805 “Business Combinations.” New authoritative accounting guidance under ASC Topic 805, “Business Combinations” amended prior guidance on the subsequent accounting for an indemnification asset recognized at the acquisition date as a result of a government-assisted (Federal Deposit Insurance Corporation) acquisition of a financial institution that includes a loss-sharing agreement. The new authoritative guidance requires that at each subsequent reporting date, an acquirer measure an indemnification asset on the same basis as the indemnified liability or asset, subject to any contractual limitations on its amount, and, for an indemnification asset that is not subsequently measured at fair value, management's assessment of the collectability of the indemnification asset. Any amortization of changes in value should be limited to the contractual term of the indemnification agreement (that is, the lesser of the term of the indemnification agreement and the remaining life of the indemnified assets). The Company adopted this new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition.
	ASC Topic 210 “Disclosures about Offsetting Assets and Liabilities.” New authoritative accounting guidance under ASC Topic 210, “Disclosures about Offsetting Assets and Liabilities” amended prior guidance to require an entity to disclose both gross and net information about both instruments and transactions eligible for offset in the statement of financial position and instruments and transactions subject to an agreement similar to a master netting arrangement. The instruments and transactions would include derivatives, sale and repurchase agreements and reverse sale and repurchase agreements, and securities borrowing and securities lending arrangements. This new authoritative guidance was further amended to clarify the scope of offsetting disclosures. The Company adopted the new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition. See disclosures in Note 15.
	ASC Topic 220 “Comprehensive Income.” New authoritative accounting guidance under ASC Topic 220, “Comprehensive Income” amended prior guidance to improve the reporting of reclassifications out of accumulated other comprehensive income by requiring an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income if the amount reclassified is required under U.S. GAAP. The Company adopted this new authoritative guidance on January 1, 2013, and it did not have an impact on the Company's statements of operations and financial condition.
	ASC Topic 815 “Derivatives and Hedging.” New authoritative accounting guidance under ASC Topic 815, “Derivatives and Hedging” amended prior guidance to permit the Fed Funds Effective Swap Rate (OIS) to be used as a U.S. benchmark interest rate for hedge accounting purposes, in addition to U.S. government treasury obligation rates and London Interbank Offered Rate swap rate. The amendments also remove the restriction on using different benchmark rates for similar hedges. The new authoritative guidance will be effective prospectively for new and redesignated hedging relationships entered into on or after July 17, 2013 and is not expected to have an impact on the Company's statements of operations and financial condition.
	ASC Topic 740 “Income Taxes.” New authoritative accounting guidance under ASC Topic 740, “Income Taxes” amended prior guidance to include explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except as follows. To the extent a net operating loss carryforward, a similar tax loss, or a tax credit carryforward is not available at the reporting date under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position or the tax law of the applicable jurisdiction does not require the entity to use, and the entity does not intend to use, the deferred tax asset for such purpose, the unrecognized tax benefit should be presented in the financial statements as a liability and should not be combined with deferred tax assets. The new authoritative guidance will be for reporting periods after January 1, 2014 and is not expected to have an impact on the Company's statements of operations and financial condition.

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]
Reconciliation of the number of shares used in the calculation of basic and diluted earnings (loss) per common share, net income available to common stockholders, and earnings per share	The following table presents a reconciliation of the number of shares used in the calculation of basic and diluted earnings per common share (amounts in thousands, except share and per share data).
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Distributed earnings allocated to common stock	$	6,636	$	548	$	17,653	$	1,643
	Undistributed earnings	17,764		22,585		56,946		64,719
	Net income	24,400		23,133		74,599		66,362
	Less: preferred stock dividends and discount accretion	—		—		—		3,269
	Net income available to common stockholders	24,400		23,133		74,599		63,093
	Less: earnings allocated to participating securities	1		1		2		2
	Earnings allocated to common stockholders	$	24,399	$	23,132	$	74,597	$	63,091
	Weighted average shares outstanding for basic earnings per common share	54,565,089		54,346,827		54,471,541		54,226,241
	Dilutive effect of equity awards	565,564		209,690		440,811		246,376
	Weighted average shares outstanding for diluted earnings per common share	55,130,653		54,556,517		54,912,352		54,472,617
	Basic earnings per common share	$	0.45	$	0.43	$	1.37	$	1.16
	Diluted earnings per common share	0.44		0.42		1.36		1.16

Business_Combinations_Tables

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]
Assets Acquired and Liabilities Assumed	Estimated fair values of the assets acquired and liabilities assumed in the Celtic transaction, as of the closing date of the transaction were as follows (in thousands):
	Assets Acquired and Liabilities Assumed
	(Dollar Amounts in Thousands)
		Celtic
		December 28,
		2012
	ASSETS
	Cash and cash equivalents	$	31,647
	Investment securities available for sale	635
	Loans and leases	32,933
	Premises and equipment	81
	Goodwill	36,300
	Other intangibles	5,028
	Other assets	27,323
	Total assets	$	133,947
	LIABILITIES
	Accrued expenses and other liabilities	$	75,290
	Total liabilities	$	75,290
	Cash paid on acquisition	$	58,657
	Net gain recorded on acquisition	$	—

Investment_Securities_Tables

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2013
Investments Securities [Abstract]
Summary investment holdings	Carrying amounts and fair values of investment securities were as follows (in thousands):
		Amortized		Gross			Gross			Fair
		Cost		Unrealized			Unrealized			Value
				Gains			Losses
	30-Sep-13
	Available for Sale
	U.S. Government sponsored agencies and enterprises	$	50,678	$	1,849		$	—		$	52,527
	States and political subdivisions	19,461		52			(201		)	19,312
	Residential mortgage-backed securities	685,126		8,659			(2,509		)	691,276
	Commercial mortgage-backed securities	50,944		2,502			—			53,446
	Corporate bonds	265,293		927			(3,199		)	263,021
	Equity securities	10,574		—			(33		)	10,541
		1,082,076		13,989			(5,942		)	1,090,123
	Held to Maturity
	States and political subdivisions	941,273		8,517			(3,481		)	946,309
	Residential mortgage-backed securities	252,271		14,168			—			266,439
		1,193,544		22,685			(3,481		)	1,212,748
	Total	$	2,275,620	$	36,674		$	(9,423	)	$	2,302,871
	December 31, 2012
	Available for Sale
	U.S. Government sponsored agencies and enterprises	$	38,605	$	2,710		$	—		$	41,315
	States and political subdivisions	679,991		45,571			(543		)	725,019
	Residential mortgage-backed securities	930,413		14,038			(5,249		)	939,202
	Commercial mortgage-backed securities	51,100		3,026			—			54,126
	Corporate bonds	97,014		213			(553		)	96,674
	Equity securities	11,398		447			(10		)	11,835
		1,808,521		66,005			(6,355		)	1,868,171
	Held to Maturity
	States and political subdivisions	237,563		21,039			—			258,602
	Residential mortgage-backed securities	255,858		21,221			—			277,079
		493,421		42,260			—			535,681
	Total	$	2,301,942	$	108,265		$	(6,355	)	$	2,403,852
Unrealized losses on investment securities and the fair value of the related securities	Unrealized losses on investment securities and the fair value of the related securities at December 31, 2012 were as follows (in thousands):
		Less Than 12 Months					12 Months or More						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Available for Sale
	States and political subdivisions	$	57,540	$	(543	)	$	—		$	—		$	57,540	$	(543	)
	Residential mortgage-backed securities	270,539		(5,083		)	16,434			(166		)	286,973		(5,249		)
	Corporate bonds	58,241		(553		)	—			—			58,241		(553		)
	Equity securities	30		(10		)	—			—			30		(10		)
	Totals	$	386,350	$	(6,189	)	$	16,434		$	(166	)	$	402,784	$	(6,355	)
	Unrealized losses on investment securities and the fair value of the related securities at September 30, 2013 were as follows (in thousands):
		Less Than 12 Months					12 Months or More						Total
		Fair		Unrealized			Fair			Unrealized			Fair		Unrealized
		Value		Losses			Value			Losses			Value		Losses
	Available for Sale
	States and political subdivisions	$	9,050	$	(201	)	$	—		$	—		$	9,050	$	(201	)
	Residential mortgage-backed securities	206,562		(2,040		)	49,104			(469		)	255,666		(2,509		)
	Corporate bonds	147,181		(3,199		)	—			—			147,181		(3,199		)
	Equity securities	10,541		(33		)	—			—			10,541		(33		)
		373,334		(5,473		)	49,104			(469		)	422,438		(5,942		)
	Held to Maturity
	States and political subdivisions	207,613		(3,481		)	—			—			207,613		(3,481		)
		207,613		(3,481		)	—			—			207,613		(3,481		)
	Totals	$	580,947	$	(8,954	)	$	49,104		$	(469	)	$	630,051	$	(9,423	)
Summary of realized gains on the sale of investment securities available for sale	Net gains (losses) recognized on investment securities available for sale were as follows (in thousands):
		Three Months Ended					Nine Months Ended
		September 30,					September 30,
		2013		2012			2013			2012
	Realized gains	$	1	$	282		$	15		$	472
	Realized losses	—		(1		)	(1		)	(4		)
	Impairment charges	—		—			—			(224		)
	Net gains (losses)	$	1	$	281		$	14		$	244
Schedule of remaining contractual maturities of securities included in the securities portfolio	The amortized cost and fair value of investment securities as of September 30, 2013 by contractual maturity are shown below. Maturities may differ from contractual maturities in mortgage-backed securities because the mortgages underlying the securities may be called or repaid without any penalties. Therefore, mortgage-backed securities are not included in the maturity categories in the following maturity summary.
		Amortized		Fair
	(In thousands)	Cost		Value
	Available for sale:
	Due in one year or less	$	—	$	—
	Due after one year through five years	319,032		318,598
	Due after five years through ten years	7,695		7,711
	Due after ten years	8,705		8,551
	Equity securities	10,574		10,541
	Residential and commercial mortgage-backed securities	736,070		744,722
		1,082,076		1,090,123
	Held to maturity:
	Due in one year or less	28,222		28,221
	Due after one year through five years	245,125		245,545
	Due after five years through ten years	122,547		122,533
	Due after ten years	545,379		550,010
	Residential mortgage-backed securities	252,271		266,439
		1,193,544		1,212,748
	Total	$	2,275,620	$	2,302,871

Loans_Tables

Loans (Tables)	9 Months Ended
	Sep. 30, 2013
Receivables [Abstract]
Schedule of composition of loans	Loans consist of the following at (in thousands):
			September 30,				December 31, 2012
			2013
	Commercial loans		$	1,169,009			$	1,220,472
	Commercial loans collateralized by assignment of lease payments		1,468,814				1,303,020
	Commercial real estate		1,638,368				1,761,832
	Residential real estate		311,256				314,359
	Construction real estate		136,146				110,261
	Indirect vehicle		257,740				208,633
	Home equity		274,484				305,186
	Other consumer loans		57,418				93,317
	Gross loans, excluding covered loans		5,313,235				5,317,080
	Covered loans		273,497				449,850
	Total loans(1)		$	5,586,732			$	5,766,930
	(1)          Gross loan balances at September 30, 2013 and December 31, 2012 are net of unearned income, including net deferred loan fees of $1.5 million and $1.1 million, respectively.
Contractual aging of the recorded investment in past due loans by class of loans	The following table presents the contractual aging of the recorded investment in past due loans by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
			Current				30-59 Days				60-89 Days				Loans Past Due				Total				Total
							Past Due				Past Due				90 Days or More				Past Due
	30-Sep-13
	Commercial		$	1,158,326			$	2,392			$	2,580			$	5,711			$	10,683			$	1,169,009
	Commercial collateralized by assignment of lease payments		1,455,296				10,761				1,816				941				13,518				1,468,814
	Commercial real estate
	Healthcare		212,659				—				—				3,164				3,164				215,823
	Industrial		371,940				161				2,101				1,394				3,656				375,596
	Multifamily		316,495				2,808				—				2,387				5,195				321,690
	Retail		344,390				236				449				8,632				9,317				353,707
	Office		139,251				412				579				2,106				3,097				142,348
	Other		223,385				3,443				229				2,147				5,819				229,204
	Residential real estate		298,878				1,103				1,059				10,216				12,378				311,256
	Construction real estate		133,742				—				89				2,315				2,404				136,146
	Indirect vehicle		255,177				1,638				687				238				2,563				257,740
	Home equity		260,055				4,505				2,911				7,013				14,429				274,484
	Other consumer		57,357				54				1				6				61				57,418
	Gross loans, excluding covered loans		5,226,951				27,513				12,501				46,270				86,284				5,313,235
	Covered loans		138,876				12,091				5,681				116,849				134,621				273,497
	Total loans (1)		$	5,365,827			$	39,604			$	18,182			$	163,119			$	220,905			$	5,586,732
	Nonperforming loan aging		$	53,271			$	3,596			$	6,111			$	39,474			$	49,181			$	102,452
	Non-covered loans related to FDIC transactions (2)		$	11,339			$	222			$	146			$	6,796			$	7,164			$	18,503
	December 31, 2012
	Commercial		$	1,215,957			$	639			$	754			$	3,122			$	4,515			$	1,220,472
	Commercial collateralized by assignment of lease payments		1,288,341				11,252				2,847				580				14,679				1,303,020
	Commercial real estate
	Healthcare		192,039				—				—				3,238				3,238				195,277
	Industrial		402,813				548				424				7,700				8,672				411,485
	Multifamily		353,966				1,282				—				3,103				4,385				358,351
	Retail		375,900				6,933				518				9,331				16,782				392,682
	Office		186,665				742				280				1,125				2,147				188,812
	Other		210,456				851				1,837				2,081				4,769				215,225
	Residential real estate		306,927				382				1,248				5,802				7,432				314,359
	Construction real estate		106,158				1,139				97				2,867				4,103				110,261
	Indirect vehicle		206,126				1,588				498				421				2,507				208,633
	Home equity		291,737				3,557				1,888				8,004				13,449				305,186
	Other consumer		93,266				47				—				4				51				93,317
	Gross loans, excluding covered loans		5,230,351				28,960				10,391				47,378				86,729				5,317,080
	Covered loans		301,260				5,831				7,478				135,281				148,590				449,850
	Total loans (1)		$	5,531,611			$	34,791			$	17,869			$	182,659			$	235,319			$	5,766,930
	Nonperforming loan aging		$	69,836			$	3,171			$	3,718			$	40,261			$	47,150			$	116,986
	Non-covered loans related to FDIC transactions (2)		$	12,752			$	312			$	1,542			$	7,115			$	8,969			$	21,721
	(1)          Includes loans related to the InBank FDIC-assisted transaction completed by MB Financial Bank in 2009.
	(2)          Loans related to the InBank FDIC-assisted transaction completed by MB Financial Bank in 2009.
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing by class of loans	The following table presents the recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
			September 30, 2013								December 31, 2012
							Loans past due								Loans past due
			Nonaccrual				90 days or more				Nonaccrual				90 days or more
							and still accruing								and still accruing
	Commercial		$	19,948			$	—			$	23,886			$	229
	Commercial collateralized by assignment of lease payments		2,130				215				1,180				222
	Commercial real estate:
	Healthcare		3,164				—				3,238				—
	Industrial		9,754				—				19,179				147
	Multifamily		5,087				195				7,225				—
	Office		10,916				—				3,263				—
	Retail		3,740				—				17,019				—
	Other		21,420				—				9,437				—
	Residential real estate		13,041				—				10,943				—
	Construction real estate		496				—				1,028				—
	Indirect vehicle		1,516				—				1,494				—
	Home equity		10,818				—				17,486				1,000
	Other consumer		12				—				9				1
	Total		$	102,042			$	410			$	115,387			$	1,599
Risk category of loans by class of loans	The following tables present the risk category of loans by class of loans based on the most recent analysis performed as of September 30, 2013 and December 31, 2012 (in thousands):
			Pass				Special				Substandard				Doubtful				Total
							Mention
	30-Sep-13
	Commercial		$	1,091,129			$	17,720			$	60,160			$	—			$	1,169,009
	Commercial collateralized by assignment of lease payments		1,457,577				4,814				6,423				—				1,468,814
	Commercial real estate
	Healthcare		188,946				21,556				2,157				3,164				215,823
	Industrial		335,274				7,384				32,938				—				375,596
	Multifamily		306,691				—				14,999				—				321,690
	Retail		324,558				10,373				18,776				—				353,707
	Office		132,490				2,732				7,126				—				142,348
	Other		201,971				3,088				24,145				—				229,204
	Construction real estate		126,902				6,264				2,980				—				136,146
	Total		$	4,165,538			$	73,931			$	169,704			$	3,164			$	4,412,337
	December 31, 2012
	Commercial		$	1,136,294			$	33,068			$	50,895			$	215			$	1,220,472
	Commercial collateralized by assignment of lease payments		1,292,241				3,322				7,457				—				1,303,020
	Commercial real estate
	Healthcare		170,265				21,774				—				3,238				195,277
	Industrial		355,218				15,243				41,024				—				411,485
	Multifamily		318,991				25,297				14,063				—				358,351
	Retail		340,919				25,096				26,667				—				392,682
	Office		159,056				7,120				22,636				—				188,812
	Other		193,824				2,553				18,848				—				215,225
	Construction real estate		97,724				552				11,985				—				110,261
	Total		$	4,064,532			$	134,025			$	193,575			$	3,453			$	4,395,585
Recorded investment in loan classes based on payment activity	The following table presents the recorded investment in those loan classes based on payment activity as of September 30, 2013 and December 31, 2012 (in thousands):
			Performing				Non-performing				Total
	30-Sep-13
	Residential real estate		$	298,215			$	13,041			$	311,256
	Indirect vehicle		256,224				1,516				257,740
	Home equity		263,666				10,818				274,484
	Other consumer		57,406				12				57,418
	Total		$	875,511			$	25,387			$	900,898
	December 31, 2012
	Residential real estate		$	303,416			$	10,943			$	314,359
	Indirect vehicle		207,139				1,494				208,633
	Home equity		286,700				18,486				305,186
	Other consumer		93,307				10				93,317
	Total		$	890,562			$	30,933			$	921,495
Loans individually evaluated for impairment by class of loans	The following tables present loans individually evaluated for impairment by class of loans as of September 30, 2013 and December 31, 2012 (in thousands):
			30-Sep-13
																			Three Months Ended							Nine Months Ended
			Unpaid				Recorded				Partial				Allowance for				Average				Interest			Average			Interest
			Principal				Investment				Charge-offs				Loan Losses				Recorded				Income			Recorded			Income
			Balance												Allocated				Investment				Recognized			Investment			Recognized
	With no related allowance recorded:
	Commercial		$	6,236			$	5,364			$	872			$	—			$	6,509			$	—		$	7,378		$	—
	Commercial collateralized by assignment of lease payments		681				681				—				—				666				6			256			6
	Commercial real estate:
	Healthcare		—				—				—				—				—				—			3,608			—
	Industrial		7,547				6,927				620				—				7,902				—			9,316			—
	Multifamily		546				546				—				—				665				—			739			—
	Retail		3,002				3,002				—				—				3,233				—			3,123			—
	Office		685				527				158				—				705				—			986			—
	Other		3,149				3,139				10				—				3,353				—			4,785			—
	Residential real estate		4,174				3,788				386				—				4,082				—			2,835			—
	Construction real estate		—				—				—				—				—				—			—			—
	Indirect vehicle		—				—				—				—				—				—			—			—
	Home equity		577				577				—				—				577				—			872			—
	Other consumer		—				—				—				—				—				—			—			—
	With an allowance recorded:
	Commercial		14,472				14,472				—				4,389				15,680				—			14,839			—
	Commercial collateralized by assignment of lease payments		1,649				1,649				—				285				1,659				109			1,347			158
	Commercial real estate:
	Healthcare		10,868				3,164				7,704				495				10,869				—			7,302			—
	Industrial		2,826				2,826				—				1,047				3,078				—			3,611			—
	Multifamily		6,334				5,944				390				1,876				6,408				115			6,642			224
	Retail		15,323				13,031				2,292				1,855				13,778				—			13,572			—
	Office		3,607				3,214				393				1,047				3,735				—			4,391			—
	Other		18,493				18,280				213				1,144				19,790				8			11,104			16
	Residential real estate		12,690				12,063				627				3,033				12,494				—			12,965			—
	Construction real estate		3,990				1,622				2,368				240				1,736				—			1,938			—
	Indirect vehicle		138				106				32				—				146				—			54			—
	Home equity		23,171				22,701				470				781				23,558				—			24,341			—
	Other consumer		—				—				—				—				—				—			—			—
	Total		$	140,158			$	123,623			$	16,535			$	16,192			$	140,623			$	238		$	136,004		$	404
			December 31, 2012
			Unpaid				Recorded				Partial				Allowance for				Average				Interest
			Principal				Investment				Charge-offs				Loan Losses				Recorded				Income
			Balance												Allocated				Investment				Recognized
	With no related allowance recorded:
	Commercial		$	10,993			$	9,505			$	1,488			$	—			$	14,089			$	105
	Commercial collateralized by assignment of lease payments		390				390				—				—				278				9
	Commercial real estate:
	Healthcare		10,943				3,238				7,705				—				2,751				—
	Industrial		16,891				14,940				1,951				—				16,374				29
	Multifamily		800				800				—				—				1,340				14
	Retail		5,372				4,917				455				—				9,241				—
	Office		1,568				1,568				—				—				1,151				—
	Other		4,860				4,860				—				—				6,005				—
	Residential real estate		3,097				2,711				386				—				6,476				—
	Construction real estate		—				—				—				—				577				—
	Indirect vehicle		—				—				—				—				—				—
	Home equity		2,558				2,558				—				—				8,976				—
	Other consumer		—				—				—				—				182				—
	With an allowance recorded:
	Commercial		14,484				14,381				103				3,620				8,455				—
	Commercial collateralized by assignment of lease payments		885				885				—				188				1,130				73
	Commercial real estate:
	Healthcare		—				—				—				—				3,901				—
	Industrial		5,525				4,238				1,287				1,255				2,443				—
	Multifamily		8,233				7,249				984				2,284				5,847				130
	Retail		23,144				17,257				5,887				3,604				10,058				—
Office		1,706				1,695				11				522				1,904				—
Other		4,661				4,577				84				1,263				6,082				16
Residential real estate		10,565				10,565				—				2,858				3,417				—
Construction real estate		4,552				2,167				2,385				497				3,775				—
Indirect vehicle		—				—				—				—				—				—
Home equity		13,765				13,763				2				850				4,800				—
Other consumer		—				—				—				—				—				—
Total		$	144,992			$	122,264			$	22,728			$	16,941			$	119,252			$	376
Schedule of loans that have been restructured classified as performing and non-performing	The following table presents loans that have been restructured during the three months ended September 30, 2012 (dollars in thousands):
			30-Sep-12
			Number of			Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
			Loans			Investment				Investment				Specific Reserves
	Performing:
	Home equity		7			$	401			$	325			$	76
	Total		7			$	401			$	325			$	76
	Non-Performing:
	Commercial collateralized by assignment of lease payments		1			$	202			$	202			$	168
	Commercial real estate:
	Retail		1			202				202				200
	Residential real estate		7			173				68				105
	Home equity		5			347				232				115
	Total		14			$	924			$	704			$	588
	The following table presents loans that have been restructured during the nine months ended September 30, 2012 (dollars in thousands):
			30-Sep-12
			Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
			Loans		Investment				Investment				Specific Reserves
	Performing:
	Commercial real estate:
	Multifamily		1		$	155			$	155			$	—
	Retail		1		236				236				—
	Residential real estate		2		808				808				—
	Home equity		38		6,009				5,933				76
	Total		42		$	7,208			$	7,132			$	76
	Non-Performing:
	Commercial		4		$	292			$	292			$	96
	Commercial collateralized by assignment of lease payments		1		202				202				168
	Commercial real estate:
	Multifamily		1		149				149				40
	Retail		4		923				923				232
	Other		1		157				157				50
	Residential real estate		13		637				401				236
	Home equity		34		5,324				4,899				425
	Total		58		$	7,684			$	7,023			$	1,247
	The following table presents loans that have been restructured during the three months ended September 30, 2013 (dollars in thousands):
			30-Sep-13
			Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
			Loans		Investment				Investment				Specific Reserves
	Performing:
	Residential real estate		1		$	95			$	95			$	—
	Home equity		1		19				19				—
	Total		2		$	114			$	114			$	—
	Non-Performing:
	Commercial real estate:
	Healthcare		1		$	3,164			$	3,164			$	496
	Multifamily		1		436				436				119
	Retail		1		205				205				56
	Residential real estate		1		394				394				—
	Indirect vehicle		17		113				89				24
	Home equity		5		397				397				—
	Total		26		$	4,709			$	4,685			$	695
	The following table presents loans that have been restructured during the nine months ended September 30, 2013 (dollars in thousands):
			30-Sep-13
			Number of		Pre-Modification Recorded				Post-Modification Recorded				Charge-offs and
			Loans		Investment				Investment				Specific Reserves
	Performing:
	Commercial real estate:
	Multifamily		1		$	601			$	601			$	—
	Residential real estate		5		854				854				—
	Home equity		7		723				723				—
	Total		13		$	2,178			$	2,178			$	—
	Non-Performing:
	Commercial		2		$	1,251			$	1,251			$	673
Commercial real estate:
Healthcare		1		3,164				3,164				496
Industrial		4		2,570				2,570				1,425
Multifamily		2		623				623				169
Retail		3		862				862				235
Other		1		84				84				23
Residential real estate		6		1,149				1,149				—
Indirect vehicle		20		127				103				24
Home equity		25		3,333				3,333				—
Total		64		$	13,163			$	13,139			$	3,045
Troubled debt restructuring activity rollforward	The following tables present the troubled debt restructurings activity during the nine months ended September 30, 2013 (dollars in thousands):
			Performing				Non-performing
	Beginning balance		$	21,256			$	28,418
	Additions		2,178				13,163
	Charge-offs		—				(3,127		)
	Principal payments, net		(883		)		(8,008		)
	Removals		—				(565		)
	Transfer to other real estate owned		—				(206		)
	Transfer from/to performing		8,458				1,098
	Transfer from/to nonperforming		(1,098		)		(8,458		)
	Ending balance		$	29,911			$	22,315
Type of financing receivable modifications and restructuring	The following table presents the type of modification for loans that have been restructured and the pre-modification recorded investment during the nine months ended September 30, 2013 (dollars in thousands):
		30-Sep-13
		Extended				Extended								Extended
		Maturity,				Maturity, Delay				Extended				Maturity, Delay								Delay in
		Amortization				in Payments and				Maturity and				in Payments and								Payments or
		and Reduction				Reduction of				Reduction of				Reduction of				Extended				Reduction of
		of Interest Rate				Interest Rate				Interest Rate				Amount				Maturity				Interest Rate			Total
	Commercial	$	42			$	—			$	1,209			$	—			$	—			$	—		$	1,251
	Commercial collateralized by assignment of lease payments	—				—				—				—				—				—			—
	Commercial real estate:
	Healthcare	—				—				—				3,164				—				—			3,164
	Industrial	—				—				—				—				2,570				—			2,570
	Multifamily	187				—				—				—				601				436			1,224
	Retail	256				205				401				—				—				—			862
	Office	—				—				—				—				—				—			—
	Other	84				—				—				—				—				—			84
	Residential real estate	1,386				—				—				—				—				618			2,004
	Construction real estate	—				—				—				—				—				—			—
	Indirect vehicle	—				—				—				—				—				127			127
	Home equity	1,509				—				708				—				227				1,611			4,055
	Other consumer	—				—				—				—				—				—			—
	Total	$	3,464			$	205			$	2,318			$	3,164			$	3,398			$	2,792		$	15,341
Allowance activity for loan losses by portfolio segment based on impairment method	The following table presents the activity in the allowance for credit losses, balance in allowance for credit losses and recorded investment in loans by portfolio segment and based on impairment method as of September 30, 2013 and 2012 (in thousands):
			Commercial				Commercial				Commercial				Residential				Construction				Indirect			Home			Other consumer		Unfunded			Total
							collateralized  by				real estate				real estate				real estate				vehicle			equity					commitments
							assignment of
							lease payments
	30-Sep-13
	Allowance for credit losses:
	Three Months Ended
	Beginning balance		$	27,277			$	8,529			$	60,014			$	8,121			$	8,695			$	1,537		$	8,206		$	1,306	$	1,812		$	125,497
	Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				—				—			—			—		—			—
	Charge-offs		1,686				—				1,236				713				26				572			437			485		—			5,155
	Recoveries		579				—				966				48				420				372			228			74		—			2,687
	Provision		(45		)		721				(3,983		)		347				(735		)		293			(152		)	368		(118		)	(3,304		)
	Ending balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
	Nine Months Ended
	Beginning balance		$	24,943			$	7,755			$	61,056			$	6,941			$	11,222			$	1,324		$	9,401		$	1,562	$	4,075		$	128,279
	Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				500				—			—			—		(500		)	—
	Charge-offs		3,030				—				5,131				2,074				855				1,930			2,547			1,501		—			17,068
	Recoveries		1,808				1,131				5,353				461				827				1,111			442			185		—			11,318
	Provision		2,404				364				(5,517		)		2,475				(3,340		)		1,125			549			1,017		(1,881		)	(2,804		)
	Ending balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
	Ending allowance balance attributable to loans:
	Individually evaluated for impairment		$	4,389			$	285			$	7,464			$	3,033			$	240			$	—		$	781		$	—	$	657		$	16,849
	Collectively evaluated for impairment		20,871				8,965				46,412				4,663				8,114				1,630			7,064			1,263		1,037			100,019
	Acquired and accounted for under ASC 310-30 (1)		865				—				1,885				107				—				—			—			—		—			2,857
	Total ending allowance balance		$	26,125			$	9,250			$	55,761			$	7,803			$	8,354			$	1,630		$	7,845		$	1,263	$	1,694		$	119,725
	Loans:
	Individually evaluated for impairment		$	19,836			$	2,330			$	60,600			$	15,851			$	1,622			$	106		$	23,278		$	—	$	—		$	123,623
	Collectively evaluated for impairment		1,134,376				1,466,484				1,577,768				291,699				134,524				257,634			251,206			57,418		—			5,171,109
	Acquired and accounted for under ASC 310-30 (1)		35,649				—				159,799				5,982				61,446				—			110			29,014		—			292,000
	Total ending loans balance		$	1,189,861			$	1,468,814			$	1,798,167			$	313,532			$	197,592			$	257,740		$	274,594		$	86,432	$	—		$	5,586,732
			Commercial				Commercial				Commercial				Residential				Construction				Indirect			Home			Other consumer		Unfunded			Total
							collateralized  by				real estate				real estate				real estate				vehicle			equity					commitments
							assignment of
							lease payments
	30-Sep-12
	Allowance for credit losses:
	Three Months Ended
	Beginning balance		$	20,789			$	7,490			$	68,713			$	3,592			$	10,586			$	1,941		$	7,617		$	1,028	$	7,084		$	128,840
	Charge-offs		75				—				2,994				474				71				433			1,209			332		—			5,588
	Recoveries		306				111				12,893				8				752				224			303			77		—			14,674
	Provision		1,181				(149		)		(12,253		)		738				(393		)		288			370			558		(3,340		)	(13,000		)
	Ending balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
	Nine Months Ended
	Beginning balance		$	21,106			$	7,561			$	68,695			$	3,935			$	15,639			$	1,834		$	7,333		$	695	$	9,177		$	135,975
	Transfer to (from) allowance for unfunded credit commitments		—				—				—				—				1,132				—			—			—		(1,132		)	—
	Charge-offs		2,065				1,720				8,412				1,876				3,951				1,636			3,157			864		—			23,681
	Recoveries		2,730				460				16,116				230				1,458				835			423			280		—			22,532
	Provision		430				1,151				(10,040		)		1,575				(3,404		)		987			2,482			1,220		(4,301		)	(9,900		)
	Ending balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
	Ending allowance balance attributable to loans:
	Individually evaluated for impairment		$	2,570			$	180			$	7,567			$	401			$	582			$	—		$	—		$	—	$	1,726		$	13,026
	Collectively evaluated for impairment		19,345				7,272				56,851				3,144				10,292				2,020			7,081			1,331		2,018			109,354
	Acquired and accounted for under ASC 310-30 (1)		286				—				1,941				319				—				—			—			—		—			2,546
	Total ending allowance balance		$	22,201			$	7,452			$	66,359			$	3,864			$	10,874			$	2,020		$	7,081		$	1,331	$	3,744		$	124,926
	Loans:
	Individually evaluated for impairment		$	21,537			$	1,168			$	56,037			$	11,127			$	2,372			$	—		$	10,280		$	248	$	—		$	102,769
	Collectively evaluated for impairment		1,033,534				1,218,193				1,714,224				293,787				147,500				206,973			304,438			84,403		—			5,003,052
	Acquired and accounted for under ASC 310-30 (1)		78,275				—				269,348				7,116				125,515				—			568			38,202		—			519,024
	Total ending loans balance		$	1,133,346			$	1,219,361			$	2,039,609			$	312,030			$	275,387			$	206,973		$	315,286		$	122,853	$	—		$	5,624,845
	(1)  Loans acquired in FDIC-assisted transactions and accounted for under ASC Subtopic 310-30 “Receivables — Loans and Debt Securities Acquired with Deteriorated Credit Quality.”
Changes in the accretable yield for purchased credit-impaired loans	Changes in the accretable yield for loans acquired in FDIC-assisted transactions and accounted for under ASC 310-30 were as follows for the three and nine months ended September 30, 2013 and 2012 (in thousands):
			Three Months Ended								Nine Months Ended
			September 30,								September 30,
			2013				2012				2013				2012
	Balance at beginning of period		$	6,360			$	9,411			$	5,685			$	18,703
	Accretion		(2,427		)		(3,406		)		(2,859		)		(12,812		)
	Other		—				403				1,107				517
	Balance at end of period		$	3,933			$	6,408			$	3,933			$	6,408
Purchased loans disclosures	The carrying amount of covered loans and other purchased non-covered loans at September 30, 2013 consisted of loans as shown in the following table (in thousands):
	30-Sep-13		Purchased				Purchased Non-Impaired				Total
			Impaired				Loans
			Loans
	Covered loans:
	Commercial related (1)		$	11,130			$	5,738			$	16,868
	Commercial		457				3,527				3,984
	Commercial real estate		62,576				97,223				159,799
	Construction real estate		53,444				8,002				61,446
	Other		2,982				28,418				31,400
	Total covered loans		$	130,589			$	142,908			$	273,497
	Estimated receivable amount from the FDIC under the loss-share agreement (2)		$	36			$	10,013			$	10,049
	Non covered loans:
	Commercial related (3)		$	4,357			$	10,440			$	14,797
	Other		89				3,617				3,706
	Total non-covered loans		$	4,446			$	14,057			$	18,503
	-1	Covered commercial related loans include commercial, commercial real estate and construction real estate loans acquired in connection with the Heritage and Benchmark FDIC-assisted transactions.
	-2	Estimated reimbursable amounts from the FDIC under the loss-share agreement exclude $1.0 million in reimbursable amounts related to covered other real estate owned.
	-3	Non covered commercial related loans include commercial, commercial real estate and construction real estate for InBank.

Goodwill_and_Intangibles_Table

Goodwill and Intangibles (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in the carrying amount of core deposit and client relationship intangibles	The following table presents the changes in the carrying amount of core deposit and client relationship intangibles, gross carrying amount, accumulated amortization, and net book value as of September 30, 2013 (in thousands):
			Nine Months Ended
			September 30,
			2013
	Balance at beginning of period		$	29,512
	Amortization expense		(4,595		)
	Balance at end of period		$	24,917
	Gross carrying amount		$	61,429
	Accumulated amortization		(36,512		)
	Net book value		$	24,917
Estimated future amortization expense of other intangible assets	The following presents the estimated future amortization expense of other intangible assets (in thousands):
	Year ending December 31,	Amount
	2013	$	1,489
	2014	4,748
	2015	4,030
	2016	3,418
	2017	3,071
	Thereafter	8,161
		$	24,917

Deposits_Tables

Deposits (Tables)	9 Months Ended
	Sep. 30, 2013
Deposits [Abstract]
Schedule of composition of deposits	The composition of deposits was as follows (in thousands):
		September 30,		December 31,
		2013		2012
	Demand deposit accounts, noninterest bearing	$	2,269,367	$	2,164,547
	NOW and money market accounts	2,680,127		2,747,273
	Savings accounts	843,671		811,333
	Certificates of deposit, $100,000 or more	838,606		1,020,033
	Other certificates of deposit	666,915		799,511
	Total	$	7,298,686	$	7,542,697

ShortTerm_Borrowings_Tables

Short-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2013
Short-term Debt [Abstract]
Summary of short-term borrowings	Short-term borrowings were as follows as of September 30, 2013 and December 31, 2012 (dollars in thousands):
		30-Sep-13				December 31, 2012
		Weighted				Weighted
		Average				Average
		Cost		Amount		Cost		Amount
	Customer repurchase agreements	0.22	%	$	240,600	0.23	%	$	208,242
	Federal Home Loan Bank advances	—	%	—		3.58	%	12,360
		0.22	%	$	240,600	0.42	%	$	220,602

Junior_Subordinated_Notes_Issu1

Junior Subordinated Notes Issued to Capital Trusts (Tables)	9 Months Ended
	Sep. 30, 2013
JUNIOR SUBORDINATED NOTES ISSUED TO CAPITAL TRUSTS
Outstanding junior subordinated notes and the related trust preferred securities issued by each trust	The table below summarizes the outstanding junior subordinated notes and the related trust preferred securities issued by each trust as of September 30, 2013 (in thousands):
			Coal City		MB Financial		MB Financial		MB Financial
			Capital Trust I		Capital Trust II		Capital Trust III		Capital Trust IV
	Junior Subordinated Notes:
	Principal balance		$	25,774	$	36,083	$	10,310	$	20,619
	Annual interest rate		3-mo LIBOR + 1.80%		3-mo LIBOR + 1.40%		3-mo LIBOR + 1.50%		3-mo LIBOR + 1.52%
	Stated maturity date		September 1, 2028		September 15, 2035		September 23, 2036		September 15, 2036
	Call date		September 1, 2008		December 15, 2010		September 23, 2011		September 15, 2011
	Trust Preferred Securities:
	Face Value		$	25,000	$	35,000	$	10,000	$	20,000
	Annual distribution rate		3-mo LIBOR + 1.80%		3-mo LIBOR + 1.40%		3-mo LIBOR + 1.50%		3-mo LIBOR + 1.52%
	Issuance date		July 1998		August 2005		July 2006		August 2006
	Distribution dates (1)		Quarterly		Quarterly		Quarterly		Quarterly
			MB Financial		MB Financial		FOBB
			Capital Trust V		Capital Trust VI		Statutory Trust III (2)
	Junior Subordinated Notes:
	Principal balance		$	30,928	$	23,196	$	5,155
	Annual interest rate		3-mo LIBOR + 1.30%		3-mo LIBOR + 1.30%		3-mo LIBOR + 2.80%
	Stated maturity date		December 15, 2037		October 30, 2037		January 23, 2034
	Call date		December 15, 2012		October 30, 2012		January 23, 2009
	Trust Preferred Securities:
	Face Value		$	30,000	$	22,500	$	5,000
	Annual distribution rate		3-mo LIBOR + 1.30%		3-mo LIBOR + 1.30%		3-mo LIBOR + 2.80%
	Issuance date		September 2007		October 2007		December 2003
	Distribution dates (1)		Quarterly		Quarterly		Quarterly
	-1	All distributions are cumulative and paid in cash.
	-2	FOBB Statutory Trust III was established by First Oak Brook Bancshares, Inc. (“FOBB”) prior to the Company's acquisition of FOBB, and the junior subordinated note issued by FOBB to FOBB Statutory Trust III was assumed by the Company upon completion of the acquisition.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Schedule of outstanding financial instruments, contractual amounts of off-balance sheet credit risk	At September 30, 2013 and December 31, 2012, the following financial instruments were outstanding, the contractual amounts of which represent off-balance sheet credit risk (in thousands):
		Contractual Amount
		September 30, 2013		December 31, 2012
	Commitments to extend credit:
	Home equity lines	$	216,992	$	239,771
	Other commitments	1,139,255		911,166
	Letters of credit:
	Standby	70,720		66,247
	Commercial	2,705		465

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Financial assets and financial liabilities measured at fair value on a recurring basis	The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands):
			Total				Quoted Prices in				Significant Other				Significant
							Active Markets for				Observable Inputs				Unobservable Inputs
							Identical Assets				(Level 2)				(Level 3)
							(Level 1)
	30-Sep-13
	Financial assets
	Securities available for sale:
	U.S Government sponsored agencies and enterprises		$	52,527			$	—			$	52,527			$	—
	States and political subdivisions		19,312				—				19,312				—
	Residential mortgage-backed securities		691,276				—				690,546				730
	Commercial mortgage-backed securities		53,446				—				53,446				—
	Corporate bonds		263,021				—				257,857				5,164
	Equity securities		10,541				10,541				—				—
	Loans held for sale		1,120				—				1,120				—
	Assets held in trust for deferred compensation		10,077				10,077				—				—
	Derivative financial instruments		19,112				—				19,112				—
	Financial liabilities
	Other liabilities (1)		9,892				9,892				—				—
	Derivative financial instruments		19,060				—				19,060				—
	December 31, 2012
	Financial assets
	Securities available for sale:
	U.S. Government sponsored agencies and enterprises		$	41,315			$	—			$	41,315			$	—
	States and political subdivisions		725,019				—				725,019				—
	Residential mortgage-backed securities		939,202				—				938,354				848
	Commercial mortgage-backed securities		54,126				—				54,126				—
	Corporate bonds		96,674				—				91,451				5,223
	Equity securities		11,835				11,835				—				—
	Loans held for sale		7,492				—				7,492				—
	Assets held in trust for deferred compensation		7,746				7,746				—				—
	Derivative financial instruments		29,096				—				29,096				—
	Financial liabilities
	Other liabilities (1)		7,746				7,746				—				—
	Derivative financial instruments		29,055				—				29,055				—
	(1) Liabilities associated with assets held in trust for deferred compensation
Financial assest measured at fair value on a recurring and non-recurring basis, unobservable inputs used	The following table presents additional information about the unobservable inputs used in the fair value measurement of financial assets measured on a recurring basis that were categorized within the Level 3 of the fair value hierarchy:
		Fair Value at			Valuation	Unobservable
		September 30, 2013			Technique	Input	Range
	Residential mortgage-backed securities	$	730		Discounted cash flows	Constant pre-payment rates
						(CPR) assumption	1% - 3% CPR
	Corporate bonds	5,164			Discounted cash flows	Credit assumption	20% Loss
	The following table presents additional information about the 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:
		Fair Value at			Valuation	Unobservable
		September 30, 2013			Technique	Input	Range
	Impaired loans	$	84,500		Appraisal of collateral	Appraisal adjustments - sales costs	5% - 10%
	Foreclosed assets	57,009			Appraisal of collateral	Appraisal adjustments - sales costs	5% - 10%
Financial assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)	The following table presents additional information about financial assets measured at fair value on a recurring basis for which the Company used significant unobservable inputs (Level 3):
			Nine Months Ended
			September 30,
	(in thousands)		2013				2012
	Balance, beginning of period		$	6,071			$	6,992
	Other comprehensive income		(59		)		89
	Principal payments		(118		)		(846		)
	Impairment charge		—				(117		)
	Balance, ending of period		$	5,894			$	6,118
Assets measured at fair value on a nonrecurring basis	Assets measured at fair value on a nonrecurring basis as of September 30, 2013 and December 31, 2012 are included in the table below (in thousands):
			Total				Quoted Prices in Active				Significant Other				Significant
							Markets for Identical				Observable Inputs				Unobservable Inputs
							Assets (Level 1)				(Level 2)				(Level 3)
	30-Sep-13
	Financial assets:
	Impaired loans		$	84,500			$	—			$	—			$	84,500
	Non-financial assets:
	Foreclosed assets		57,009				—				—				57,009
	December 31, 2012
	Financial assets:
	Impaired loans		$	62,258			$	—			$	—			$	62,258
	Non-financial assets:
	Foreclosed assets		60,228				—				—				60,228
	Long-lived assets		2,314				—				—				2,314
Estimated fair values of financial instruments	The estimated fair values of financial instruments are as follows (in thousands):
			30-Sep-13
			Carrying Amount				Estimated Fair Value			Quoted Prices in Active			Significant Other			Significant
										Markets for Identical			Observable Inputs			Unobservable Inputs
										Assets (Level 1)			(Level 2)			(Level 3)
	Financial Assets:
	Cash and due from banks		$	215,017			$	215,017		$	215,017		$	—		$	—
	Interest bearing deposits with banks		41,700				41,700			41,700			—			—
	Investment securities available for sale		1,090,123				1,090,123			10,541			1,073,688			5,894
	Investment securities held to maturity		1,193,544				1,212,748			—			1,212,748			—
	Non-marketable securities - FHLB and FRB stock		50,870				50,870			—			—			50,870
	Loans held for sale		1,120				1,120			—			1,120			—
	Loans, net		5,468,701				5,470,567			—			—			5,470,567
	Accrued interest receivable		35,938				35,938			35,938			—			—
	Derivative financial instruments		19,112				19,112			—			19,112			—
	Financial Liabilities:
	Noninterest bearing deposits		$	2,269,367			$	2,269,367		$	2,269,367		$	—		$	—
	Interest bearing deposits		5,029,319				5,039,175			—			—			5,039,175
	Short-term borrowings		240,600				240,595			—			—			240,595
	Long-term borrowings		62,428				67,425			—			—			67,425
	Junior subordinated notes issued to capital trusts		152,065				105,967			—			—			105,967
	Accrued interest payable		1,908				1,908			1,908			—			—
	Derivative financial instruments		19,060				19,060			—			19,060			—
			December 31, 2012
			Carrying Amount				Estimated Fair Value			Quoted Prices in Active			Significant Other			Significant
										Markets for Identical			Observable Inputs			Unobservable Inputs
										Assets (Level 1)			(Level 2)			(Level 3)
	Financial Assets:
	Cash and due from banks		$	176,010			$	176,010		$	176,010		$	—		$	—
	Interest bearing deposits with banks		111,533				111,533			111,533			—			—
	Investment securities available for sale		1,868,171				1,868,171			11,835			1,850,265			6,071
	Investment securities held to maturity		493,421				535,681			—			535,681			—
	Non-marketable securities - FHLB and FRB stock		55,385				55,385			—			—			55,385
	Loans held for sale		7,492				7,492			—			7,492			—
	Loans, net		5,642,726				5,659,598			—			—			5,659,598
	Accrued interest receivable		36,040				36,040			36,040			—			—
	Derivative financial instruments		29,096				29,096			—			29,096			—
	Financial Liabilities:
	Non-interest bearing deposits		$	2,164,547			$	2,164,547		$	2,164,547		$	—		$	—
	Interest bearing deposits		5,378,150				5,399,709			—			—			5,399,709
	Short-term borrowings		220,602				220,683			—			—			220,683
	Long-term borrowings		116,050				117,809			—			—			117,809
	Junior subordinated notes issued to capital trusts		152,065				104,009			—			—			104,009
	Accrued interest payable		2,828				2,828			2,828			—			—
	Derivative financial instruments		29,055				29,055			—			29,055			—

Stock_Incentive_Plans_Tables

Stock Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the impact of share-based payment plans in the financial statements	The following table summarizes the impact of the Company’s share-based payment plans in the financial statements for the periods shown (in thousands):
		Three Months Ended							Nine Months Ended
		September 30,							September 30,
		2013				2012			2013			2012
	Total cost of share-based payment plans during the period	$	1,388			$	1,080		$	3,860		$	3,581
	Amount of related income tax benefit recognized in income	548				430			1,530			$	1,431
Additional information related to options outstanding	The following table summarizes stock options outstanding for the nine months ended September 30, 2013:
		Number of			Weighted			Weighted		Aggregate
		Options			Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual		(in thousands)
								Term
								(In Years)
	Options outstanding as of December 31, 2012	2,739,753			$	27.34
	Granted	211,501			27.03
	Exercised	(330,832	)		25.51
	Expired or cancelled	(113,290	)		30.91
	Forfeited	(17,857	)		20.18
	Options outstanding as of September 30, 2013	2,489,275			$	27.44		4.94		$	9,407
	Options exercisable as of September 30, 2013	1,809,183			$	29.72		3.67		$	4,764
Assumptions used for options granted	The expected life of options is estimated based on historical employee behavior and represents the period of time that options granted are expected to remain outstanding.
	The following assumptions were used for options granted during the nine months ended September 30, 2013:
		September 30,
		2013
	Risk-free interest rate	1.96		%
	Expected volatility of Company’s stock	25.6		%
	Expected dividend yield	1.74		%
	Expected life of options	5.6 years
	Weighted average fair value per option of options granted during the year	$	5.97
Summary of changes in restricted shares	The following is a summary of changes in restricted shares and units for the nine months ended September 30, 2013:
		Number of			Weighted
		Shares and Units			Average
					Grant Date
					Fair Value
	Shares Outstanding at December 31, 2012	634,211			$	18.82
	Granted	270,983			26.91
	Vested	(201,178	)		16.79
	Forfeited	(13,983	)		20.52
	Shares Outstanding at September 30, 2013	690,033			$	22.55

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of derivative financial instruments	The Company’s derivative financial instruments are summarized below as of September 30, 2013 and December 31, 2012 (in thousands):
		Asset Derivatives												Liability Derivatives
		30-Sep-13						December 31, 2012						30-Sep-13					December 31, 2012
		Notional			Estimated			Notional			Estimated			Notional		Estimated			Notional			Estimated
		Amount			Fair Value			Amount			Fair Value			Amount		Fair Value			Amount			Fair Value
	Derivative instruments designated as hedges of fair value:
	Interest rate swap contracts (1)	$	—		$	—		$	—		$	—		$	248	$	(26	)	$	3,707		$	(94	)
	Stand-alone derivative instruments (2)
	Interest rate swap contracts	570,472			17,813			460,956			27,740			571,445		(17,875		)	462,012			(27,832		)
	Interest rate options contracts	84,095			307			70,346			157			84,095		(307		)	70,346			(157		)
	Foreign exchange contracts	16,112			912			20,033			1,062			15,536		(818		)	19,337			(961		)
	Mortgage banking derivatives	4,794			80			11,400			137			2,603		(34		)	4,000			(11		)
	Total non-hedging derivative instruments	675,473			19,112			562,735			29,096			673,679		(19,034		)	555,695			(28,961		)
	Total	$	675,473		$	19,112		$	562,735		$	29,096		$	673,927	$	(19,060	)	$	559,402		$	(29,055	)
	(1) Hedged fixed-rate commercial real estate loans
	(2) These portfolio swaps are not designated as hedging instruments under ASC Topic 815.
Schedule of the amount of gains and losses on derivative contracts designated as hedges and not designated as hedges	Amounts included in the other income in the consolidated statements of operations related to derivative financial instruments were as follows (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Derivative instruments designated as hedges of fair value:
	Interest rate swap contracts	$	(1	)	$	—		$	9		$	(36	)
	Stand-alone derivative instruments
	Interest rate swap contracts	7			6			30			19
	Interest rate options contracts	—			—			—			—
	Foreign exchange contracts	(12		)	14			(7		)	44
	Mortgage banking derivatives	(16		)	9			(80		)	79
	Total non-hedging derivative instruments	(21		)	29			(57		)	142
	Total	$	(22	)	$	29		$	(48	)	$	106
Schedule of Derivative Instruments [Table Text Block]
		Financial Assets												Financial Liabilities
		Net Amount Recognized			Financial Instruments			Collateral			Net Amount			Net Amount Recognized		Financial Instruments			Collateral			Net Amount
	Derivatives:
	Counterparty A	$	440		$	(440	)	$	—		$	—		$	12,976	$	(440	)	$	(12,536	)	$	—
	Counterparty B	1,090			(551		)	—			539			551		(551		)	—			—
	Counterparty C	1,570			(1,570		)	—			—			1,949		(1,570		)	(379		)	—
	Other counterparties	450			(1		)	—			449			46		(1		)	—			45
	Total derivatives	3,550			(2,562		)	—			988			15,522		(2,562		)	(12,915		)	45
	Repurchase agreements	—			—			—			—			240,600		—			(240,600		)	—
	Total	$	3,550		$	(2,562	)	$	—		$	988		$	256,122	$	(2,562	)	$	(253,515	)	$	45
		Financial Assets												Financial Liabilities
		Net Amount Recognized			Financial Instruments			Collateral			Net Amount			Net Amount Recognized		Financial Instruments			Collateral			Net Amount
	Derivatives:
	Counterparty A	$	68		$	(68	)	$	—		$	—		$	25,497	$	(68	)	$	(25,429	)	$	—
	Counterparty B	84			(84		)	—			—			633		(84		)	(549		)	—
	Counterparty C	36			(36		)	—			—			2,305		(36		)	(2,269		)	—
	Other counterparties	48			(42		)	—			6			395		(42		)	(298		)	55
	Total derivatives	236			(230		)	—			6			28,830		(230		)	(28,545		)	55
	Repurchase agreements	—			—			—			—			208,242		—			(208,242		)	—
	Total	$	236		$	(230	)	$	—		$	6		$	237,072	$	(230	)	$	(236,787	)	$	55
	Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2012 is summarized below (in thousands):
		Financial Assets									Financial Liabilities
		Gross Amount Recognized			Gross Amount Offset			Net Amount Recognized			Gross Amount Recognized			Gross Amount Offset		Net Amount Recognized
	Derivatives:
	Interest rate swaps, caps and floors	$	192		$	—		$	192		$	27,890		$	—	$	27,890
	Foreign currency forward contracts	43			—			43			929			—		929
	Mortgage banking derivatives	1			—			1			11			—		11
	Total derivatives	236			—			236			28,830			—		28,830
	Repurchase agreements	—			—			—			208,242			—		208,242
	Total	$	236		$	—		$	236		$	237,072		$	—	$	237,072
	Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of September 30, 2013 is summarized below (in thousands):
		Financial Assets									Financial Liabilities
		Gross Amount Recognized			Gross Amount Offset			Net Amount Recognized			Gross Amount Recognized			Gross Amount Offset		Net Amount Recognized
	Derivatives:
	Interest rate swaps, caps and floors	$	3,483		$	—		$	3,483		$	14,724		$	—	$	14,724
	Foreign currency forward contracts	67			—			67			764			—		764
	Mortgage banking derivatives	—			—			—			34			—		34
	Total derivatives	3,550			—			3,550			15,522			—		15,522
	Repurchase agreements	—			—			—			240,600			—		240,600
	Total	$	3,550		$	—		$	3,550		$	256,122		$	—	$	256,122

Earnings_Per_Common_Share_Deta

Earnings Per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic and diluted earnings per common share:
Net income (loss)	$24,400	$23,133	$74,599	$66,362
Less: preferred stock dividends and discount accretion	0	0	0	3,269
Net income available to common stockholders	24,400	23,133	74,599	63,093
Earnings allocated to common stockholders	24,399	23,132	74,597	63,091
Weighted average shares outstanding for basic earnings per common share	54,565,089	54,346,827	54,471,541	54,226,241
Weighted average shares outstanding for diluted earnings per common share	55,130,653	54,556,517	54,912,352	54,472,617
Basic earnings per common share	$0.45	$0.43	$1.37	$1.16
Diluted earnings per common share	$0.44	$0.42	$1.36	$1.16
Common Stock
Basic and diluted earnings per common share:
Distributed earnings allocated to common stock	6,636	548	17,653	1,643
Undistributed earnings	17,764	22,585	56,946	64,719
Net income (loss)	24,400	23,133	74,599	66,362
Net income available to common stockholders	24,400	23,133	74,599	63,093
Dilutive effect of equity awards	565,564	209,690	440,811	246,376
Participating Securities
Basic and diluted earnings per common share:
Less: earnings allocated to participating securities	$1	$1	$2	$2

Business_Combinations_Details

Business Combinations (Details) (USD $)	6 Months Ended	0 Months Ended
	Jun. 30, 2013	Dec. 28, 2012
		Celtic [Member]
Assets Acquired and Liabilities Assumed
Cash and cash equivalents		$31,647,000
Investment securities available for sale		635,000
Loans and leases		32,933,000
Premises and equipment		81,000
Goodwill		36,300,000
Other intangible		5,028,000
Other assets		27,323,000
Total assets		133,947,000
Accrued expenses and other liabilities		75,290,000
Total liabilities		75,290,000
Cash paid (received) on acquisition		58,657,000
Net gain recorded on acquisition		0
Business combination, assets to be acquired	5,900,000,000
Business combination, loans to be acquired	3,300,000,000
Business combination, deposits to be acquired	$3,700,000,000
Business combination, share conversion	0.64318
Business combination, amount per share	$4.08

Investment_Securities_Details

Investment Securities (Details) (USD $)	3 Months Ended	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Available for Sale
Amortized Cost	$1,082,076	$1,082,076		$1,808,521
Gross Unrealized Gains	13,989	13,989		66,005
Gross Unrealized Losses	-5,942	-5,942		-6,355
Fair Value	1,090,123	1,090,123		1,868,171
Held to Maturity
Investment securities held to maturity	1,193,544	1,193,544		493,421
Gross Unrealized Gains	22,685	22,685		42,260
Gross Unrealized Losses	-3,481	-3,481		0
Investment Securities held to maturity	1,212,748	1,212,748		535,681
Total Available for Sale and Held to Maturity Investment Securities
Amortized Cost	2,275,620	2,275,620		2,301,942
Gross Unrealized Gains	36,674	36,674		108,265
Gross Unrealized Losses	-9,423	-9,423		-6,355
Fair Value	2,302,871	2,302,871		2,403,852
Transfer of investment securities available for sale to investment securities held to maturity	656,600	656,617	0
U.S. Government sponsored agencies and enterprises
Available for Sale
Amortized Cost	50,678	50,678		38,605
Gross Unrealized Gains	1,849	1,849		2,710
Gross Unrealized Losses	0	0		0
Fair Value	52,527	52,527		41,315
States and political subdivisions
Available for Sale
Amortized Cost	19,461	19,461		679,991
Gross Unrealized Gains	52	52		45,571
Gross Unrealized Losses	-201	-201		-543
Fair Value	19,312	19,312		725,019
Held to Maturity
Investment securities held to maturity	941,273	941,273		237,563
Gross Unrealized Gains	8,517	8,517		21,039
Gross Unrealized Losses	-3,481	-3,481		0
Investment Securities held to maturity	946,309	946,309		258,602
Total Available for Sale and Held to Maturity Investment Securities
Percentage of securities consisting general obligation issues		90.00%
States and political subdivisions | State of Illinois
Total Available for Sale and Held to Maturity Investment Securities
Percentage of investments issued by states and political subdivisions that were within the state of Illinois		27.00%
Residential mortgage-backed securities
Available for Sale
Amortized Cost	685,126	685,126		930,413
Gross Unrealized Gains	8,659	8,659		14,038
Gross Unrealized Losses	-2,509	-2,509		-5,249
Fair Value	691,276	691,276		939,202
Held to Maturity
Investment securities held to maturity	252,271	252,271		255,858
Gross Unrealized Gains	14,168	14,168		21,221
Gross Unrealized Losses	0	0		0
Investment Securities held to maturity	266,439	266,439		277,079
Commercial mortgage-backed securities
Available for Sale
Amortized Cost	50,944	50,944		51,100
Gross Unrealized Gains	2,502	2,502		3,026
Gross Unrealized Losses	0	0		0
Fair Value	53,446	53,446		54,126
Corporate bonds
Available for Sale
Amortized Cost	265,293	265,293		97,014
Gross Unrealized Gains	927	927		213
Gross Unrealized Losses	-3,199	-3,199		-553
Fair Value	263,021	263,021		96,674
Equity securities
Available for Sale
Amortized Cost	10,574	10,574		11,398
Gross Unrealized Gains	0	0		447
Gross Unrealized Losses	-33	-33		-10
Fair Value	$10,541	$10,541		$11,835

Investment_Securities_Details_

Investment Securities (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Security_Position	Security_Position
Available for Sale
Less Than 12 Months, Fair Value	$373,334
Less Than 12 Months, Unrealized Losses	-5,473
12 Months or More, Fair Value	49,104
12 Months or More, Unrealized Losses	-469
Total Fair Value	422,438
Total Unrealized Losses	-5,942
Held to maturity
Less Than 12 Months, Fair Value	207,613
Less Than 12 Months, Unrealized Losses	-3,481
Total Fair Value	207,613
Total Unrealized Losses	-3,481
Total
Less Than 12 Months, Fair Value	580,947	386,350
Less Than 12 Months, Unrealized Losses	-8,954	-6,189
12 Months or More, Fair Value	49,104	16,434
12 Months or More, Unrealized Losses	-469	-166
Total Fair Value	630,051	402,784
Total Unrealized Losses	9,423	6,355
Number of security positions in the investment portfolio in an unrealized loss position	353	117
States and political subdivisions
Available for Sale
Less Than 12 Months, Fair Value	9,050	57,540
Less Than 12 Months, Unrealized Losses	-201	-543
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	9,050	57,540
Total Unrealized Losses	-201	-543
Held to maturity
Less Than 12 Months, Fair Value	207,613
Less Than 12 Months, Unrealized Losses	-3,481
Total Fair Value	207,613
Total Unrealized Losses	-3,481
Residential mortgage-backed securities
Available for Sale
Less Than 12 Months, Fair Value	206,562	270,539
Less Than 12 Months, Unrealized Losses	-2,040	-5,083
12 Months or More, Fair Value	49,104	16,434
12 Months or More, Unrealized Losses	-469	-166
Total Fair Value	255,666	286,973
Total Unrealized Losses	-2,509	-5,249
Corporate bonds
Available for Sale
Less Than 12 Months, Fair Value	147,181	58,241
Less Than 12 Months, Unrealized Losses	-3,199	-553
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	147,181	58,241
Total Unrealized Losses	-3,199	-553
Equity securities
Available for Sale
Less Than 12 Months, Fair Value	10,541	30
Less Than 12 Months, Unrealized Losses	-33	-10
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	10,541	30
Total Unrealized Losses	($33)	($10)

Investment_Securities_Details_1

Investment Securities (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Amortized cost and fair value of investment securities by contractual maturity
Realized gains	$1,000	$282,000	$15,000	$472,000
Realized losses	0	-1,000	-1,000	-4,000
Impairment charges	0	0	0	-224,000
Net gains (losses)	1,000	281,000	14,000	244,000
Amortized Cost, Available for sale
Due in one year or less	0		0
Due after one year through five years	319,032,000		319,032,000
Due after five years through ten years	7,695,000		7,695,000
Due after ten years	8,705,000		8,705,000
Amortized Cost	1,082,076,000		1,082,076,000		1,808,521,000
Fair Value, Available for sale
Due in one year or less	0		0
Due after one year through five years	318,598,000		318,598,000
Due after five years through ten years	7,711,000		7,711,000
Due after ten years	8,551,000		8,551,000
Fair Value	1,090,123,000		1,090,123,000		1,868,171,000
Amortized Cost, Held to maturity
Due in one year or less	28,222,000		28,222,000
Due in after one year through five years	245,125,000		245,125,000
Due after five years through ten years	122,547,000		122,547,000
Due after ten years	545,379,000		545,379,000
Investment securities held to maturity	1,193,544,000		1,193,544,000		493,421,000
Fair value, Held to maturity
Due in one year or less	28,221,000		28,221,000
Due in after one year through five years	245,545,000		245,545,000
Due after five years through ten years	122,533,000		122,533,000
Due after ten years	550,010,000		550,010,000
Investment Securities held to maturity	1,212,748,000		1,212,748,000		535,681,000
Total Available for Sale and Held to Maturity Investment Securities
Amortized Cost	2,275,620,000		2,275,620,000		2,301,942,000
Fair Value	2,302,871,000		2,302,871,000		2,403,852,000
Carrying amounts of investment securities available for sale pledged as collateral	1,000,000,000		1,000,000,000		989,600,000
Equity securities
Amortized Cost, Available for sale
Amortized Cost	10,574,000		10,574,000		11,398,000
Fair Value, Available for sale
Fair Value	10,541,000		10,541,000		11,835,000
Residential and commercial mortgage-backed securities
Amortized Cost, Available for sale
Amortized Cost	736,070,000		736,070,000
Fair Value, Available for sale
Fair Value	744,722,000		744,722,000
Residential mortgage-backed securities
Amortized Cost, Available for sale
Amortized Cost	685,126,000		685,126,000		930,413,000
Fair Value, Available for sale
Fair Value	691,276,000		691,276,000		939,202,000
Amortized Cost, Held to maturity
Investment securities held to maturity	252,271,000		252,271,000		255,858,000
Fair value, Held to maturity
Investment Securities held to maturity	$266,439,000		$266,439,000		$277,079,000

Loans_Details

Loans (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
	investmentrating
Loans
Total loans, excluding covered loans	$5,313,235,000	$5,317,080,000
Covered loans	273,497,000	449,850,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	5,586,732,000	5,766,930,000	5,624,845,000
Net unearned income, including net deferred loan fees	1,500,000	1,100,000
Number of highest rating categories by rating services company	1
Number of highest rating categories to be achieved for classification as investment grade companies	4
Commercial loans
Loans
Total loans, excluding covered loans	1,169,009,000	1,220,472,000
Covered loans	3,984,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,189,861,000		1,133,346,000
Commercial loans collateralized by assignment of lease payments
Loans
Total loans, excluding covered loans	1,468,814,000	1,303,020,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,468,814,000		1,219,361,000
Commercial real estate
Loans
Total loans, excluding covered loans	1,638,368,000	1,761,832,000
Covered loans	159,799,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,798,167,000		2,039,609,000
Residential real estate
Loans
Total loans, excluding covered loans	311,256,000	314,359,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	313,532,000		312,030,000
Construction real estate
Loans
Total loans, excluding covered loans	136,146,000	110,261,000
Covered loans	61,446,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	197,592,000		275,387,000
Indirect vehicle
Loans
Total loans, excluding covered loans	257,740,000	208,633,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	257,740,000		206,973,000
Home equity lines
Loans
Total loans, excluding covered loans	274,484,000	305,186,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	274,594,000		315,286,000
Other consumer
Loans
Total loans, excluding covered loans	57,418,000	93,317,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	$86,432,000		$122,853,000

Loans_Details_2

Loans (Details 2) (USD $)	9 Months Ended
	Sep. 30, 2013		Dec. 31, 2012		Sep. 30, 2012
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	$5,313,235,000		$5,317,080,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	5,586,732,000		5,766,930,000		5,624,845,000
Period past due of recorded investment in loans (in days)	90 days
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Non-performing substandard and doubtful loans	76,500,000		85,500,000
Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	4,165,538,000		4,064,532,000
Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	73,931,000		134,025,000
Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	169,704,000		193,575,000
Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	3,164,000		3,453,000
Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	4,412,337,000		4,395,585,000
Non-performing
Contractual aging of the recorded investment in loans
Current	53,271,000		69,836,000
30-59 days, past due	3,596,000		3,171,000
60-89 days, past due	6,111,000		3,718,000
Loans past due, 90 days or more	39,474,000		40,261,000
Total, past due	49,181,000		47,150,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	102,452,000		116,986,000
Commercial loans
Contractual aging of the recorded investment in loans
Current	1,158,326,000		1,215,957,000
30-59 days, past due	2,392,000		639,000
60-89 days, past due	2,580,000		754,000
Loans past due, 90 days or more	5,711,000		3,122,000
Total, past due	10,683,000		4,515,000
Total loans, excluding covered loans	1,169,009,000		1,220,472,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,189,861,000				1,133,346,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	19,948,000		23,886,000
Loans past due 90 days or more and still accruing	0		229,000
Commercial loans | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,091,129,000		1,136,294,000
Commercial loans | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	17,720,000		33,068,000
Commercial loans | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	60,160,000		50,895,000
Commercial loans | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		215,000
Commercial loans | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,169,009,000		1,220,472,000
Commercial loans collateralized by assignment of lease payments
Contractual aging of the recorded investment in loans
Current	1,455,296,000		1,288,341,000
30-59 days, past due	10,761,000		11,252,000
60-89 days, past due	1,816,000		2,847,000
Loans past due, 90 days or more	941,000		580,000
Total, past due	13,518,000		14,679,000
Total loans, excluding covered loans	1,468,814,000		1,303,020,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,468,814,000				1,219,361,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	2,130,000		1,180,000
Loans past due 90 days or more and still accruing	215,000		222,000
Commercial loans collateralized by assignment of lease payments | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,457,577,000		1,292,241,000
Commercial loans collateralized by assignment of lease payments | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	4,814,000		3,322,000
Commercial loans collateralized by assignment of lease payments | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	6,423,000		7,457,000
Commercial loans collateralized by assignment of lease payments | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Commercial loans collateralized by assignment of lease payments | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,468,814,000		1,303,020,000
Commercial real estate
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,638,368,000		1,761,832,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	1,798,167,000				2,039,609,000
Healthcare
Contractual aging of the recorded investment in loans
Current	212,659,000		192,039,000
30-59 days, past due	0		0
60-89 days, past due	0		0
Loans past due, 90 days or more	3,164,000		3,238,000
Total, past due	3,164,000		3,238,000
Total loans, excluding covered loans	215,823,000		195,277,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	3,164,000		3,238,000
Loans past due 90 days or more and still accruing	0		0
Healthcare | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	188,946,000		170,265,000
Healthcare | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	21,556,000		21,774,000
Healthcare | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	2,157,000		0
Healthcare | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	3,164,000		3,238,000
Healthcare | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	215,823,000		195,277,000
Industrial
Contractual aging of the recorded investment in loans
Current	371,940,000		402,813,000
30-59 days, past due	161,000		548,000
60-89 days, past due	2,101,000		424,000
Loans past due, 90 days or more	1,394,000		7,700,000
Total, past due	3,656,000		8,672,000
Total loans, excluding covered loans	375,596,000		411,485,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	9,754,000		19,179,000
Loans past due 90 days or more and still accruing	0		147,000
Industrial | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	335,274,000		355,218,000
Industrial | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	7,384,000		15,243,000
Industrial | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	32,938,000		41,024,000
Industrial | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Industrial | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	375,596,000		411,485,000
Multifamily
Contractual aging of the recorded investment in loans
Current	316,495,000		353,966,000
30-59 days, past due	2,808,000		1,282,000
60-89 days, past due	0		0
Loans past due, 90 days or more	2,387,000		3,103,000
Total, past due	5,195,000		4,385,000
Total loans, excluding covered loans	321,690,000		358,351,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	5,087,000		7,225,000
Loans past due 90 days or more and still accruing	195,000		0
Multifamily | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	306,691,000		318,991,000
Multifamily | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		25,297,000
Multifamily | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	14,999,000		14,063,000
Multifamily | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Multifamily | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	321,690,000		358,351,000
Retail
Contractual aging of the recorded investment in loans
Current	344,390,000		375,900,000
30-59 days, past due	236,000		6,933,000
60-89 days, past due	449,000		518,000
Loans past due, 90 days or more	8,632,000		9,331,000
Total, past due	9,317,000		16,782,000
Total loans, excluding covered loans	353,707,000		392,682,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	3,740,000		17,019,000
Loans past due 90 days or more and still accruing	0		0
Retail | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	324,558,000		340,919,000
Retail | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	10,373,000		25,096,000
Retail | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	18,776,000		26,667,000
Retail | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Retail | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	353,707,000		392,682,000
Office
Contractual aging of the recorded investment in loans
Current	139,251,000		186,665,000
30-59 days, past due	412,000		742,000
60-89 days, past due	579,000		280,000
Loans past due, 90 days or more	2,106,000		1,125,000
Total, past due	3,097,000		2,147,000
Total loans, excluding covered loans	142,348,000		188,812,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	10,916,000		3,263,000
Loans past due 90 days or more and still accruing	0		0
Office | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	132,490,000		159,056,000
Office | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	2,732,000		7,120,000
Office | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	7,126,000		22,636,000
Office | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Office | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	142,348,000		188,812,000
Other
Contractual aging of the recorded investment in loans
Current	223,385,000		210,456,000
30-59 days, past due	3,443,000		851,000
60-89 days, past due	229,000		1,837,000
Loans past due, 90 days or more	2,147,000		2,081,000
Total, past due	5,819,000		4,769,000
Total loans, excluding covered loans	229,204,000		215,225,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	21,420,000		9,437,000
Loans past due 90 days or more and still accruing	0		0
Other | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	201,971,000		193,824,000
Other | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	3,088,000		2,553,000
Other | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	24,145,000		18,848,000
Other | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Other | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	229,204,000		215,225,000
Residential real estate
Contractual aging of the recorded investment in loans
Current	298,878,000		306,927,000
30-59 days, past due	1,103,000		382,000
60-89 days, past due	1,059,000		1,248,000
Loans past due, 90 days or more	10,216,000		5,802,000
Total, past due	12,378,000		7,432,000
Total loans, excluding covered loans	311,256,000		314,359,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	313,532,000				312,030,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	13,041,000		10,943,000
Loans past due 90 days or more and still accruing	0		0
Residential real estate | Performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	298,215,000		303,416,000
Residential real estate | Non-performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	13,041,000		10,943,000
Construction real estate
Contractual aging of the recorded investment in loans
Current	133,742,000		106,158,000
30-59 days, past due	0		1,139,000
60-89 days, past due	89,000		97,000
Loans past due, 90 days or more	2,315,000		2,867,000
Total, past due	2,404,000		4,103,000
Total loans, excluding covered loans	136,146,000		110,261,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	197,592,000				275,387,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	496,000		1,028,000
Loans past due 90 days or more and still accruing	0		0
Construction real estate | Pass
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	126,902,000		97,724,000
Construction real estate | Special Mention
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	6,264,000		552,000
Construction real estate | Substandard
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	2,980,000		11,985,000
Construction real estate | Doubtful
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	0		0
Construction real estate | Total risk rated category
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	136,146,000		110,261,000
Indirect vehicle
Contractual aging of the recorded investment in loans
Current	255,177,000		206,126,000
30-59 days, past due	1,638,000		1,588,000
60-89 days, past due	687,000		498,000
Loans past due, 90 days or more	238,000		421,000
Total, past due	2,563,000		2,507,000
Total loans, excluding covered loans	257,740,000		208,633,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	257,740,000				206,973,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	1,516,000		1,494,000
Loans past due 90 days or more and still accruing	0		0
Indirect vehicle | Performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	256,224,000		207,139,000
Indirect vehicle | Non-performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	1,516,000		1,494,000
Home equity lines
Contractual aging of the recorded investment in loans
Current	260,055,000		291,737,000
30-59 days, past due	4,505,000		3,557,000
60-89 days, past due	2,911,000		1,888,000
Loans past due, 90 days or more	7,013,000		8,004,000
Total, past due	14,429,000		13,449,000
Total loans, excluding covered loans	274,484,000		305,186,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	274,594,000				315,286,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	10,818,000		17,486,000
Loans past due 90 days or more and still accruing	0		1,000,000
Home equity lines | Performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	263,666,000		286,700,000
Home equity lines | Non-performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	10,818,000		18,486,000
Other consumer
Contractual aging of the recorded investment in loans
Current	57,357,000		93,266,000
30-59 days, past due	54,000		47,000
60-89 days, past due	1,000		0
Loans past due, 90 days or more	6,000		4,000
Total, past due	61,000		51,000
Total loans, excluding covered loans	57,418,000		93,317,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	86,432,000				122,853,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	12,000		9,000
Loans past due 90 days or more and still accruing	0		1,000
Other consumer | Performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	57,406,000		93,307,000
Other consumer | Non-performing
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	12,000		10,000
Gross loans, excluding covered loans
Contractual aging of the recorded investment in loans
Current	5,226,951,000		5,230,351,000
30-59 days, past due	27,513,000		28,960,000
60-89 days, past due	12,501,000		10,391,000
Loans past due, 90 days or more	46,270,000		47,378,000
Total, past due	86,284,000		86,729,000
Total loans, excluding covered loans	5,313,235,000		5,317,080,000
Covered loans
Contractual aging of the recorded investment in loans
Current	138,876,000		301,260,000
30-59 days, past due	12,091,000		5,831,000
60-89 days, past due	5,681,000		7,478,000
Loans past due, 90 days or more	116,849,000		135,281,000
Total, past due	134,621,000		148,590,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	273,497,000		449,850,000
Loans
Contractual aging of the recorded investment in loans
Current	5,365,827,000		5,531,611,000
30-59 days, past due	39,604,000		34,791,000
60-89 days, past due	18,182,000		17,869,000
Loans past due, 90 days or more	163,119,000		182,659,000
Total, past due	220,905,000		235,319,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	5,586,732,000		5,766,930,000
Recorded investment in nonaccrual loans and loans past due ninety days or more and still accruing
Nonaccrual	102,042,000		115,387,000
Loans past due 90 days or more and still accruing	410,000		1,599,000
Non-covered loans related to FDIC transactions
Contractual aging of the recorded investment in loans
Current	11,339,000	[1]	12,752,000	[1]
30-59 days, past due	222,000	[1]	312,000	[1]
60-89 days, past due	146,000	[1]	1,542,000	[1]
Loans past due, 90 days or more	6,796,000	[1]	7,115,000	[1]
Total, past due	7,164,000		8,969,000
Loans and Leases Receivable, Net of Deferred Income Including Covered Loans	$18,503,000		$21,721,000
[1]	Loans related to the InBank FDIC-assisted transaction completed by MB Financial Bank in 2009.

Loans_Details_3

Loans (Details 3) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	$5,313,235	$5,313,235	$5,317,080
Unpaid Principal Balance	140,158	140,158	144,992
Recorded Investment	123,623	123,623	122,264
Partial Charge-Offs	16,535	16,535	22,728
Allowance for Loan Losses Allocated	16,192	16,192	16,941
Impaired Financing Receivable, Average Recorded Investment	140,623	136,004	119,252
Interest Income Recognized	238	404	376
Restructured loans	15,341	15,341
Performing
Loans individually evaluated for impairment by class of loans
Restructured loans	29,900	29,900	21,300
Non-performing
Loans individually evaluated for impairment by class of loans
Restructured loans	22,300	22,300	28,400
Commercial loans
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	1,169,009	1,169,009	1,220,472
Restructured loans	1,251	1,251
Commercial loans collateralized by assignment of lease payments
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	1,468,814	1,468,814	1,303,020
Restructured loans	0	0
Commercial real estate
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	1,638,368	1,638,368	1,761,832
Healthcare
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	215,823	215,823	195,277
Restructured loans	3,164	3,164
Industrial
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	375,596	375,596	411,485
Restructured loans	2,570	2,570
Multifamily
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	321,690	321,690	358,351
Restructured loans	1,224	1,224
Retail
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	353,707	353,707	392,682
Restructured loans	862	862
Office
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	142,348	142,348	188,812
Restructured loans	0	0
Other
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	229,204	229,204	215,225
Restructured loans	84	84
Residential real estate
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	311,256	311,256	314,359
Restructured loans	2,004	2,004
Residential real estate | Performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	298,215	298,215	303,416
Residential real estate | Non-performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	13,041	13,041	10,943
Construction real estate
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	136,146	136,146	110,261
Restructured loans	0	0
Indirect vehicle
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	257,740	257,740	208,633
Restructured loans	127	127
Indirect vehicle | Performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	256,224	256,224	207,139
Indirect vehicle | Non-performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	1,516	1,516	1,494
Home equity lines
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	274,484	274,484	305,186
Restructured loans	4,055	4,055
Home equity lines | Performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	263,666	263,666	286,700
Home equity lines | Non-performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	10,818	10,818	18,486
Other consumer
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	57,418	57,418	93,317
Restructured loans	0	0
Other consumer | Performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	57,406	57,406	93,307
Other consumer | Non-performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	12	12	10
Other loans
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	900,898	900,898	921,495
Other loans | Performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	875,511	875,511	890,562
Other loans | Non-performing
Loans individually evaluated for impairment by class of loans
Total loans, excluding covered loans	25,387	25,387	30,933
Impaired financing receivable with no allowance | Commercial loans
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	6,236	6,236	10,993
Recorded Investment	5,364	5,364	9,505
Partial Charge-Offs	872	872	1,488
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	6,509	7,378	14,089
Interest Income Recognized	0	0	105
Impaired financing receivable with no allowance | Commercial loans collateralized by assignment of lease payments
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	681	681	390
Recorded Investment	681	681	390
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	666	256	278
Interest Income Recognized	6	6	9
Impaired financing receivable with no allowance | Healthcare
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	0	0	10,943
Recorded Investment	0	0	3,238
Partial Charge-Offs	0	0	7,705
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	0	3,608	2,751
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Industrial
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	7,547	7,547	16,891
Recorded Investment	6,927	6,927	14,940
Partial Charge-Offs	620	620	1,951
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	7,902	9,316	16,374
Interest Income Recognized	0	0	29
Impaired financing receivable with no allowance | Multifamily
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	546	546	800
Recorded Investment	546	546	800
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	665	739	1,340
Interest Income Recognized	0	0	14
Impaired financing receivable with no allowance | Retail
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	3,002	3,002	5,372
Recorded Investment	3,002	3,002	4,917
Partial Charge-Offs	0	0	455
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	3,233	3,123	9,241
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Office
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	685	685	1,568
Recorded Investment	527	527	1,568
Partial Charge-Offs	158	158	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	705	986	1,151
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Other
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	3,149	3,149	4,860
Recorded Investment	3,139	3,139	4,860
Partial Charge-Offs	10	10	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	3,353	4,785	6,005
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Residential real estate
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	4,174	4,174	3,097
Recorded Investment	3,788	3,788	2,711
Partial Charge-Offs	386	386	386
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	4,082	2,835	6,476
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Construction real estate
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	0	0	0
Recorded Investment	0	0	0
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	0	0	577
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Indirect vehicle
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	0	0	0
Recorded Investment	0	0	0
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Home equity lines
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	577	577	2,558
Recorded Investment	577	577	2,558
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	577	872	8,976
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Other consumer
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	0	0	0
Recorded Investment	0	0	0
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	0	0	182
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial loans
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	14,472	14,472	14,484
Recorded Investment	14,472	14,472	14,381
Partial Charge-Offs	0	0	103
Allowance for Loan Losses Allocated	4,389	4,389	3,620
Impaired Financing Receivable, Average Recorded Investment	15,680	14,839	8,455
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial loans collateralized by assignment of lease payments
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	1,649	1,649	885
Recorded Investment	1,649	1,649	885
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	285	285	188
Impaired Financing Receivable, Average Recorded Investment	1,659	1,347	1,130
Interest Income Recognized	109	158	73
Impaired financing receivable with allowance | Healthcare
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	10,868	10,868	0
Recorded Investment	3,164	3,164	0
Partial Charge-Offs	7,704	7,704	0
Allowance for Loan Losses Allocated	495	495	0
Impaired Financing Receivable, Average Recorded Investment	10,869	7,302	3,901
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Industrial
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	2,826	2,826	5,525
Recorded Investment	2,826	2,826	4,238
Partial Charge-Offs	0	0	1,287
Allowance for Loan Losses Allocated	1,047	1,047	1,255
Impaired Financing Receivable, Average Recorded Investment	3,078	3,611	2,443
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Multifamily
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	6,334	6,334	8,233
Recorded Investment	5,944	5,944	7,249
Partial Charge-Offs	390	390	984
Allowance for Loan Losses Allocated	1,876	1,876	2,284
Impaired Financing Receivable, Average Recorded Investment	6,408	6,642	5,847
Interest Income Recognized	115	224	130
Impaired financing receivable with allowance | Retail
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	15,323	15,323	23,144
Recorded Investment	13,031	13,031	17,257
Partial Charge-Offs	2,292	2,292	5,887
Allowance for Loan Losses Allocated	1,855	1,855	3,604
Impaired Financing Receivable, Average Recorded Investment	13,778	13,572	10,058
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Office
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	3,607	3,607	1,706
Recorded Investment	3,214	3,214	1,695
Partial Charge-Offs	393	393	11
Allowance for Loan Losses Allocated	1,047	1,047	522
Impaired Financing Receivable, Average Recorded Investment	3,735	4,391	1,904
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Other
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	18,493	18,493	4,661
Recorded Investment	18,280	18,280	4,577
Partial Charge-Offs	213	213	84
Allowance for Loan Losses Allocated	1,144	1,144	1,263
Impaired Financing Receivable, Average Recorded Investment	19,790	11,104	6,082
Interest Income Recognized	8	16	16
Impaired financing receivable with allowance | Residential real estate
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	12,690	12,690	10,565
Recorded Investment	12,063	12,063	10,565
Partial Charge-Offs	627	627	0
Allowance for Loan Losses Allocated	3,033	3,033	2,858
Impaired Financing Receivable, Average Recorded Investment	12,494	12,965	3,417
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Construction real estate
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	3,990	3,990	4,552
Recorded Investment	1,622	1,622	2,167
Partial Charge-Offs	2,368	2,368	2,385
Allowance for Loan Losses Allocated	240	240	497
Impaired Financing Receivable, Average Recorded Investment	1,736	1,938	3,775
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Indirect vehicle
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	138	138	0
Recorded Investment	106	106	0
Partial Charge-Offs	32	32	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	146	54	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Home equity lines
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	23,171	23,171	13,765
Recorded Investment	22,701	22,701	13,763
Partial Charge-Offs	470	470	2
Allowance for Loan Losses Allocated	781	781	850
Impaired Financing Receivable, Average Recorded Investment	23,558	24,341	4,800
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Other consumer
Loans individually evaluated for impairment by class of loans
Unpaid Principal Balance	0	0	0
Recorded Investment	0	0	0
Partial Charge-Offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Impaired Financing Receivable, Average Recorded Investment	0	0	0
Interest Income Recognized	$0	$0	$0

Loans_Details_4

Loans (Details 4) (USD $)	3 Months Ended	9 Months Ended		12 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			9 Months Ended			3 Months Ended		3 Months Ended	9 Months Ended		9 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended				9 Months Ended			3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended				3 Months Ended	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013
	note	loan	loan	loan	Performing	Performing	Performing	Performing	Non-performing	Non-performing	Non-performing	Non-performing	Commercial loans	Commercial loans	Commercial loans	Commercial loans collateralized by assignment of lease payments	Commercial loans collateralized by assignment of lease payments	Healthcare	Healthcare	Healthcare	Industrial	Industrial	Multifamily	Multifamily	Multifamily	Multifamily	Multifamily	Multifamily	Retail	Retail	Retail	Retail	Retail	Retail	Office	Other	Other	Other	Residential real estate	Residential real estate	Residential real estate	Residential real estate	Residential real estate	Residential real estate	Residential real estate	Residential real estate	Construction real estate	Indirect vehicle	Indirect vehicle	Indirect vehicle	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Home equity lines	Other consumer
					loan	loan	loan	loan	loan	loan	loan	loan		Non-performing	Non-performing		Non-performing		Non-performing	Non-performing		Non-performing		Performing	Performing	Non-performing	Non-performing	Non-performing		Performing	Non-performing	Non-performing	Non-performing	Non-performing			Non-performing	Non-performing		Performing	Performing	Performing	Non-performing	Non-performing	Non-performing	Non-performing			Non-performing	Non-performing		Performing	Performing	Performing	Performing	Non-performing	Non-performing	Non-performing	Non-performing
														loan	loan		loan		loan	loan		loan		loan	loan	loan	loan	loan		loan	loan	loan	loan	loan			loan	loan		loan	loan	loan	loan	loan	loan	loan			loan	loan		loan	loan	loan	loan	loan	loan	loan	loan
Restructured loans
Number of separate notes restructured into A/B by the company	2
Minimum period of sustained repayment required to return the note to accrual status (in months)		6 months
Restructured loans representing A/B structures				$3,100,000
Number of A/B structures represented by restructured loans		0		1
Number of loans			1		2	7	13	42	26	14	64	58		2	4		1		1	1		4		1	1	1	2	1		1	1	1	3	4			1	1		1	5	2	1	7	6	13			17	20		1	7	7	38	5	5	25	34
Pre-Modification Recorded Investment			202,000		114,000	401,000	2,178,000	7,208,000	4,709,000	924,000	13,163,000	7,684,000		1,251,000	292,000		202,000		3,164,000	3,164,000		2,570,000		601,000	155,000	436,000	623,000	149,000		236,000	205,000	202,000	862,000	923,000			84,000	157,000		95,000	854,000	808,000	394,000	173,000	1,149,000	637,000			113,000	127,000		19,000	401,000	723,000	6,009,000	397,000	347,000	3,333,000	5,324,000
Post-Modification Recorded Investment			202,000		114,000	325,000	2,178,000	7,132,000	4,685,000	704,000	13,139,000	7,023,000		1,251,000	292,000		202,000		3,164,000	3,164,000		2,570,000		601,000	155,000	436,000	623,000	149,000		236,000	205,000	202,000	862,000	923,000			84,000	157,000		95,000	854,000	808,000	394,000	68,000	1,149,000	401,000			89,000	103,000		19,000	325,000	723,000	5,933,000	397,000	232,000	3,333,000	4,899,000
Charge-offs and Specific Reserves			168,000		0	76,000	0	76,000	695,000	588,000	3,045,000	1,247,000		673,000	96,000		168,000		496,000	496,000		1,425,000		0	0	119,000	169,000	40,000		0	56,000	200,000	235,000	232,000			23,000	50,000		0	0	0	0	105,000	0	236,000			24,000	24,000		0	76,000	0	76,000	0	115,000	0	425,000
Redefaulted loans	0	0
Period past due of recorded redefaulted loans (in days)	90 days
Troubled Debt Restructuring Activity [Roll Forward]
Beginning balance							21,256,000				28,418,000		1,251,000			0		3,164,000			2,570,000		1,224,000						862,000						0	84,000			2,004,000								0	127,000			4,055,000									0
Additions							2,178,000				13,163,000
Charge-offs							0				-3,127,000
Principal payments, net							-883,000				-8,008,000
Removals							0				-565,000
Transfer to other real estate owned							0				-206,000
Transfer from/to performing							8,458,000				1,098,000
Transfer from/to nonperforming							-1,098,000				-8,458,000
Ending balance	$15,341,000	$15,341,000			$29,911,000		$29,911,000		$22,315,000		$22,315,000		$1,251,000			$0		$3,164,000			$2,570,000		$1,224,000						$862,000						$0	$84,000			$2,004,000								$0	$127,000			$4,055,000									$0

Loans_Details_5

Loans (Details 5) (USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	$3,464
Extended Maturity, Delay in Payments and Reduction of Interest Rate	205
Extended Maturity and Reduction of Interest Rate	2,318
Extended Maturity and Delay in Payments and Reduction of Amount	3,164
Extended Maturity	3,398
Delay in Payments or Reduction of Interest Rate	2,792
Total	15,341
Commercial loans
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	42
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	1,209
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	1,251
Commercial loans collateralized by assignment of lease payments
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	0
Healthcare
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	3,164
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	3,164
Industrial
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	2,570
Delay in Payments or Reduction of Interest Rate	0
Total	2,570
Multifamily
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	187
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	601
Delay in Payments or Reduction of Interest Rate	436
Total	1,224
Retail
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	256
Extended Maturity, Delay in Payments and Reduction of Interest Rate	205
Extended Maturity and Reduction of Interest Rate	401
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	862
Office
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	0
Other
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	84
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	84
Residential real estate
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	1,386
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	618
Total	2,004
Construction real estate
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	0
Indirect vehicle
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	127
Total	127
Home equity lines
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	1,509
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	708
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	227
Delay in Payments or Reduction of Interest Rate	1,611
Total	4,055
Other consumer
Activity in the allowance for loan losses, balance in allowance for loan losses and recorded investment in loans by portfolio segment and based on impairment method
Extended Maturity and Amortization and Reduction of Interest Rate	0
Extended Maturity, Delay in Payments and Reduction of Interest Rate	0
Extended Maturity and Reduction of Interest Rate	0
Extended Maturity and Delay in Payments and Reduction of Amount	0
Extended Maturity	0
Delay in Payments or Reduction of Interest Rate	0
Total	$0

Loans_Details_6

Loans (Details 6) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Allowance for credit losses [Roll Forward]
Beginning Balance					$124,204,000
Transfer to (from) allowance for unfunded credit commitments	0				-500,000		-1,132,000
Allowance for unfunded credit commitments, ending balance	1,694,000		3,744,000		1,694,000		3,744,000
Allowance for credit losses, ending balance	119,725,000		124,926,000		119,725,000		124,926,000
Ending Balance	118,031,000				118,031,000
Ending allowance balance attributable to loans:
Acquired and accounted for under ASC 310-30	2,857,000		2,546,000		2,857,000		2,546,000
Loans:
Individually evaluated for impairment	123,623,000		102,769,000		123,623,000		102,769,000
Collectively evaluated for impairment	5,171,109,000		5,003,052,000		5,171,109,000		5,003,052,000
Acquired and accounted for under ASC 310-30	292,000,000		519,024,000		292,000,000		519,024,000
Unfunded Commitments
Allowance for unfunded credit commitments, beginning balance	1,812,000		7,084,000		4,075,000		9,177,000
Transfer to (from) allowance for unfunded credit commitments	0				-500,000		-1,132,000
Allowance for unfunded commitments, Provision	-118,000		-3,340,000		-1,881,000		-4,301,000
Unfunded commitments collectively evaluated for impairment	1,037,000		2,018,000		1,037,000		2,018,000
Individually evaluated for impairment for unfunded commitments	657,000		1,726,000		657,000		1,726,000
Allowance for unfunded credit commitments, ending balance	1,694,000		3,744,000		1,694,000		3,744,000
Allowance for credit losses
Allowance for loan losses and unfunded commitments charge offs	5,155,000		5,588,000		17,068,000		23,681,000
Allowance for loan losses and unfunded commitments recoveries	2,687,000		14,674,000		11,318,000		22,532,000
Allowance for loan losses and unfunded commitments provision	-3,304,000		-13,000,000		-2,804,000		-9,900,000
Allowance for credit losses, beginning balance	125,497,000		128,840,000		128,279,000		135,975,000
Allowance for credit losses, ending balance	119,725,000		124,926,000		119,725,000		124,926,000
Allowance for credit losses, individually evaluated for impairment	16,849,000		13,026,000		16,849,000		13,026,000
Allowance for credit losses, collectively evaluated for impairment	100,019,000		109,354,000		100,019,000		109,354,000
Total loans	5,586,732,000		5,624,845,000		5,586,732,000		5,624,845,000		5,766,930,000
Commercial loans
Allowance for credit losses [Roll Forward]
Beginning Balance	27,277,000		20,789,000		24,943,000		21,106,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	1,686,000		75,000		3,030,000		2,065,000
Provision	-45,000		1,181,000		2,404,000		430,000
Ending Balance	26,125,000		22,201,000		26,125,000		22,201,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	4,389,000		2,570,000		4,389,000		2,570,000
Collectively evaluated for impairment	20,871,000		19,345,000		20,871,000		19,345,000
Acquired and accounted for under ASC 310-30	865,000	[1]	286,000		865,000	[1]	286,000
Loans:
Individually evaluated for impairment	19,836,000		21,537,000		19,836,000		21,537,000
Collectively evaluated for impairment	1,134,376,000		1,033,534,000		1,134,376,000		1,033,534,000
Acquired and accounted for under ASC 310-30	35,649,000	[1]	78,275,000	[1]	35,649,000	[1]	78,275,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	579,000		306,000		1,808,000		2,730,000
Total loans	1,189,861,000		1,133,346,000		1,189,861,000		1,133,346,000
Commercial loans collateralized by assignment of lease payments
Allowance for credit losses [Roll Forward]
Beginning Balance	8,529,000		7,490,000		7,755,000		7,561,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	0				0		1,720,000
Provision	721,000		-149,000		364,000		1,151,000
Ending Balance	9,250,000		7,452,000		9,250,000		7,452,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	285,000		180,000		285,000		180,000
Collectively evaluated for impairment	8,965,000		7,272,000		8,965,000		7,272,000
Acquired and accounted for under ASC 310-30		[1]				[1]
Loans:
Individually evaluated for impairment	2,330,000		1,168,000		2,330,000		1,168,000
Collectively evaluated for impairment	1,466,484,000		1,218,193,000		1,466,484,000		1,218,193,000
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	0		111,000		1,131,000		460,000
Total loans	1,468,814,000		1,219,361,000		1,468,814,000		1,219,361,000
Commercial real estate
Allowance for credit losses [Roll Forward]
Beginning Balance	60,014,000		68,713,000		61,056,000		68,695,000
Transfer to (from) allowance for unfunded credit commitments	0				0
Charge-offs	1,236,000		2,994,000		5,131,000		8,412,000
Provision	-3,983,000		-12,253,000		-5,517,000		-10,040,000
Ending Balance	55,761,000		66,359,000		55,761,000		66,359,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	7,464,000		7,567,000		7,464,000		7,567,000
Collectively evaluated for impairment	46,412,000		56,851,000		46,412,000		56,851,000
Acquired and accounted for under ASC 310-30	1,885,000	[1]	1,941,000	[1]	1,885,000	[1]	1,941,000	[1]
Loans:
Individually evaluated for impairment	60,600,000		56,037,000		60,600,000		56,037,000
Collectively evaluated for impairment	1,577,768,000		1,714,224,000		1,577,768,000		1,714,224,000
Acquired and accounted for under ASC 310-30	159,799,000	[1]	269,348,000	[1]	159,799,000	[1]	269,348,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments	0				0
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	966,000		12,893,000		5,353,000		16,116,000
Total loans	1,798,167,000		2,039,609,000		1,798,167,000		2,039,609,000
Allowance for loan losses and unfunded commitments acquired with deteriorated credit quality	2,900,000				2,900,000				4,500,000
Residential real estate
Allowance for credit losses [Roll Forward]
Beginning Balance	8,121,000		3,592,000		6,941,000		3,935,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	713,000		474,000		2,074,000		1,876,000
Provision	347,000		738,000		2,475,000		1,575,000
Ending Balance	7,803,000		3,864,000		7,803,000		3,864,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	3,033,000		401,000		3,033,000		401,000
Collectively evaluated for impairment	4,663,000		3,144,000		4,663,000		3,144,000
Acquired and accounted for under ASC 310-30	107,000	[1]	319,000	[1]	107,000	[1]	319,000	[1]
Loans:
Individually evaluated for impairment	15,851,000		11,127,000		15,851,000		11,127,000
Collectively evaluated for impairment	291,699,000		293,787,000		291,699,000		293,787,000
Acquired and accounted for under ASC 310-30	5,982,000	[1]	7,116,000	[1]	5,982,000	[1]	7,116,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	48,000		8,000		461,000		230,000
Total loans	313,532,000		312,030,000		313,532,000		312,030,000
Construction real estate
Allowance for credit losses [Roll Forward]
Beginning Balance	8,695,000		10,586,000		11,222,000		15,639,000
Transfer to (from) allowance for unfunded credit commitments	0				500,000		1,132,000
Charge-offs	26,000		71,000		855,000		3,951,000
Provision	-735,000		-393,000		-3,340,000		-3,404,000
Ending Balance	8,354,000		10,874,000		8,354,000		10,874,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	240,000		582,000		240,000		582,000
Collectively evaluated for impairment	8,114,000		10,292,000		8,114,000		10,292,000
Acquired and accounted for under ASC 310-30		[1]				[1]
Loans:
Individually evaluated for impairment	1,622,000		2,372,000		1,622,000		2,372,000
Collectively evaluated for impairment	134,524,000		147,500,000		134,524,000		147,500,000
Acquired and accounted for under ASC 310-30	61,446,000	[1]	125,515,000	[1]	61,446,000	[1]	125,515,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments	0				500,000		1,132,000
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	420,000		752,000		827,000		1,458,000
Total loans	197,592,000		275,387,000		197,592,000		275,387,000
Indirect vehicle
Allowance for credit losses [Roll Forward]
Beginning Balance	1,537,000		1,941,000		1,324,000		1,834,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	572,000		433,000		1,930,000		1,636,000
Provision	293,000		288,000		1,125,000		987,000
Ending Balance	1,630,000		2,020,000		1,630,000		2,020,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment			0				0
Collectively evaluated for impairment	1,630,000		2,020,000		1,630,000		2,020,000
Acquired and accounted for under ASC 310-30		[1]				[1]
Loans:
Individually evaluated for impairment	106,000				106,000
Collectively evaluated for impairment	257,634,000		206,973,000		257,634,000		206,973,000
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	372,000		224,000		1,111,000		835,000
Total loans	257,740,000		206,973,000		257,740,000		206,973,000
Home equity lines
Allowance for credit losses [Roll Forward]
Beginning Balance	8,206,000		7,617,000		9,401,000		7,333,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	437,000		1,209,000		2,547,000		3,157,000
Provision	-152,000		370,000		549,000		2,482,000
Ending Balance	7,845,000		7,081,000		7,845,000		7,081,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment	781,000		0		781,000		0
Collectively evaluated for impairment	7,064,000		7,081,000		7,064,000		7,081,000
Acquired and accounted for under ASC 310-30		[1]				[1]
Loans:
Individually evaluated for impairment	23,278,000		10,280,000		23,278,000		10,280,000
Collectively evaluated for impairment	251,206,000		304,438,000		251,206,000		304,438,000
Acquired and accounted for under ASC 310-30	110,000	[1]	568,000	[1]	110,000	[1]	568,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	228,000		303,000		442,000		423,000
Total loans	274,594,000		315,286,000		274,594,000		315,286,000
Other consumer
Allowance for credit losses [Roll Forward]
Beginning Balance	1,306,000		1,028,000		1,562,000		695,000
Transfer to (from) allowance for unfunded credit commitments
Charge-offs	485,000		332,000		1,501,000		864,000
Provision	368,000		558,000		1,017,000		1,220,000
Allowance for unfunded credit commitments, ending balance			3,744,000				3,744,000
Ending Balance	1,263,000		1,331,000		1,263,000		1,331,000
Ending allowance balance attributable to loans:
Individually evaluated for impairment			0				0
Collectively evaluated for impairment	1,263,000		1,331,000		1,263,000		1,331,000
Acquired and accounted for under ASC 310-30		[1]				[1]
Loans:
Individually evaluated for impairment	0		248,000		0		248,000
Collectively evaluated for impairment	57,418,000		84,403,000		57,418,000		84,403,000
Acquired and accounted for under ASC 310-30	29,014,000	[1]	38,202,000	[1]	29,014,000	[1]	38,202,000	[1]
Unfunded Commitments
Transfer to (from) allowance for unfunded credit commitments
Allowance for unfunded credit commitments, ending balance			3,744,000				3,744,000
Allowance for credit losses
Financing receivable, allowance for credit losses, recovery	74,000		77,000		185,000		280,000
Total loans	86,432,000		122,853,000		86,432,000		122,853,000
Purchased loans
Allowance for credit losses [Roll Forward]
Provision	-1,500,000				-2,500,000
Allowance for credit losses
Provision and charge-offs related to the number of pools	15
Allowance for loan losses and unfunded commitments write offs net of recoveries	-677,000				-830,000
Total loans	$219,100,000				$219,100,000
[1]	Loans acquired in FDIC-assisted transactions and accounted for under ASC Subtopic 310-30 “Receivables — Loans and Debt Securities Acquired with Deteriorated Credit Quality.”

Loans_Details_7

Loans (Details 7) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Changes in the accretable yield for purchased credit-impaired loans
Balance at beginning of period	$6,360	$9,411	$5,685	$18,703
Accretion	-2,427	-3,406	-2,859	-12,812
Other	0	403	1,107	517
Balance at end of period	$3,933	$6,408	$3,933	$6,408

Loans_Details_8

Loans (Details 8) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	$273,497,000		$449,850,000
Estimated receivable amount from the FDIC under the loss-share agreement	10,049,000
Non covered loans	18,503,000
Outstanding balances on purchased loans from the FDIC	305,000,000		515,700,000
Carrying amount on loans purchased from the FDIC	292,000,000		471,600,000
Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	130,589,000
Estimated receivable amount from the FDIC under the loss-share agreement	36,000	[1]
Non covered loans	4,446,000
Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	142,908,000
Estimated receivable amount from the FDIC under the loss-share agreement	10,013,000	[1]
Non covered loans	14,057,000
Commercial related
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	16,868,000
Non covered loans	14,797,000
Commercial related | Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Reimbursable Amount Covered Other Real Estate Owned	1,000,000
Covered loans	11,130,000	[2]
Non covered loans	4,357,000	[3]
Commercial related | Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	5,738,000	[2]
Non covered loans	10,440,000	[3]
Commercial loans
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	3,984,000
Commercial loans | Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	457,000
Commercial loans | Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	3,527,000
Commercial real estate
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	159,799,000
Commercial real estate | Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	62,576,000
Commercial real estate | Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	97,223,000
Construction real estate
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	61,446,000
Construction real estate | Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	53,444,000
Construction real estate | Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	8,002,000
Other
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	31,400,000
Non covered loans	3,706,000
Other | Purchased Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	2,982,000
Non covered loans	89,000
Other | Purchased Non-Credit Impaired Loans Receivable
Purchased credit-impaired loans and non-credit-impaired loans
Covered loans	28,418,000
Non covered loans	$3,617,000
[1]	Estimated reimbursable amounts from the FDIC under the loss-share agreement exclude $1.0 million in reimbursable amounts related to covered other real estate owned.
[2]	Covered commercial related loans include commercial, commercial real estate and construction real estate loans acquired in connection with the Heritage and Benchmark FDIC-assisted transactions.
[3]	Non covered commercial related loans include commercial, commercial real estate and construction real estate for InBank.

Goodwill_and_Intangibles_Detai

Goodwill and Intangibles (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, impairment loss			$0	$0
Carrying amount of goodwill	423,369,000		423,369,000		423,369,000
Weighted average amortization period (in years)			4
Changes in the carrying amount of core deposit and client relationship intangibles
Balance at beginning of period			29,512,000
Amortization expense	-1,513,000	-1,251,000	-4,595,000	-3,759,000
Balance at end of period	24,917,000		24,917,000
Gross carrying amount	61,429,000		61,429,000
Accumulated amortization	-36,512,000		-36,512,000
Net book value	24,917,000		24,917,000
Estimated future amortization expense
2013	1,489,000		1,489,000
2014	4,748,000		4,748,000
2015	4,030,000		4,030,000
2016	3,418,000		3,418,000
2017	3,071,000		3,071,000
Thereafter	8,161,000		8,161,000
Total estimated future amortization expense	$24,917,000		$24,917,000

Deposits_Details

Deposits (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Deposits, by Type [Abstract]
Demand deposit accounts, noninterest bearing	$2,269,367,000	$2,164,547,000
NOW and money market accounts	2,680,127,000	2,747,273,000
Savings accounts	843,671,000	811,333,000
Certificates of deposit, $100,000 or more	838,606,000	1,020,033,000
Other certificates of deposit	666,915,000	799,511,000
Total	7,298,686,000	7,542,697,000
Brokered deposits	$238,500,000	$294,200,000

ShortTerm_Borrowings_Details

Short-Term Borrowings (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013
			Customer repurchase agreements	Customer repurchase agreements	Federal Home Loan Bank advances	Federal Home Loan Bank advances	Line of credit	Libor [Member]
								Line of credit
Short-term borrowings
Weighted Average Cost	0.22%	0.42%	0.22%	0.23%	0.00%	3.58%
Amount	$240,600,000	$220,602,000	$240,600,000	$208,242,000	$0	$12,360,000
Fixed interest rate Federal Home Loan Bank advances		12,400,000
Unsecured Line of Credit							$35,000,000
Description of interest rate basis							one month LIBOR
Debt Instrument, Basis Spread on Variable Rate								2.00%

Longterm_Borrowings_Details

Long-term Borrowings (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Long-term borrowings
Federal Home Loan Bank advances	$4,300,000	$4,300,000
Effective interest rates on Federal Home Loan Bank advances, low end of range (as a percent)	3.23%
Effective interest rates on Federal Home Loan Bank advances, high end of range (as a percent)	5.87%
Loans pledged as collateral for long-term Federal Home Loan Bank advances	7,300,000	28,400,000
Investment securities pledged as collateral for long-term Federal Home Loan Bank advances	29,200,000	32,100,000
Principal payments due on long-term borrowings
Long-term Debt	62,428,000	116,050,000
Notes payable to banks
Long-term borrowings
Minimum interest rates (as a percent)	2.50%
Maximum interest rates (as a percent)	12.00%
Equipment pledged as collateral	25,900,000	29,700,000
Principal payments due on long-term borrowings
Long-term Debt	17,700,000	21,100,000
Structured repurchase agreement
Long-term borrowings
Term of structured repurchase agreement (in years)	10 years
Fixed interest rate, if option not exercised (as a percent)	4.75%
Principal payments due on long-term borrowings
Long-term Debt	40,000,000
Subordinated debt facility
Principal payments due on long-term borrowings
Long-term Debt	$50,000,000
Description of interest rate basis	3-month LIBOR
Interest rate, basis spread (as a percent)	1.70%
Minimum
Long-term borrowings
Percentage of collateral pledge of first mortgage loans as per agreement	133.00%
Percentage of collateral pledge of home equity loans as per agreement	250.00%

Junior_Subordinated_Notes_Issu2

Junior Subordinated Notes Issued to Capital Trusts (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
In Thousands, unless otherwise specified			Junior Subordinated Notes	Coal City Capital Trust I	MB Financial Capital Trust II	MB Financial Capital Trust III	MB Financial Capital Trust IV	MB Financial Capital Trust V	MB Financial Capital Trust VI	FOBB Statutory Trust III
			Maximum	Junior Subordinated Notes	Junior Subordinated Notes	Junior Subordinated Notes	Junior Subordinated Notes	Junior Subordinated Notes	Junior Subordinated Notes	Junior Subordinated Notes
Outstanding junior subordinated notes
Principal balance	$152,065	$152,065		$25,774	$36,083	$10,310	$20,619	$30,928	$23,196	$5,155
Debt Instrument, Basis Spread on Variable Rate				1.80%	1.40%	1.50%	1.52%	1.30%	1.30%	2.80%
Description of annual interest rate basis				3-mo LIBOR	3-mo LIBOR	3-mo LIBOR	3-mo LIBOR	3-mo LIBOR	3-mo LIBOR	3-mo LIBOR
Period for deferment of payment of interest on notes (in years)			5 years

Junior_Subordinated_Notes_Issu3

Junior Subordinated Notes Issued to Capital Trusts (Details 2) (Trust preferred securities issued by each trust, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Coal City Capital Trust I
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.80%
Description of annual interest rate basis	3-mo LIBOR
Face Value	$25,000
MB Financial Capital Trust II
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.40%
Description of annual interest rate basis	3-mo LIBOR
Face Value	35,000
MB Financial Capital Trust III
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.50%
Description of annual interest rate basis	3-mo LIBOR
Face Value	10,000
MB Financial Capital Trust IV
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.52%
Description of annual interest rate basis	3-mo LIBOR
Face Value	20,000
MB Financial Capital Trust V
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.30%
Description of annual interest rate basis	3-mo LIBOR
Face Value	30,000
MB Financial Capital Trust VI
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	1.30%
Description of annual interest rate basis	3-mo LIBOR
Face Value	22,500
FOBB Statutory Trust III
Trust preferred securities issued by each trust
Debt Instrument, Basis Spread on Variable Rate	2.80%
Description of annual interest rate basis	3-mo LIBOR
Face Value	$5,000

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Commitments [Abstract]
Maximum maturity period for letters of credit (in years)	5 years
Increase (decrease) in maximum potential amount of future payments under letters of credit		$6,700,000
Dollar amount of letters of credit outstanding	73,400,000	73,400,000	66,700,000
Letters of credit issued or renewed		52,600,000
Capital expenditure commitments outstanding		1,400,000
Home equity lines
Commitments and contingencies
Dollar amount of line of credit outstanding	216,992,000	216,992,000	239,771,000
Other commitments
Commitments and contingencies
Dollar amount of line of credit outstanding	1,139,255,000	1,139,255,000	911,166,000
Standby
Commitments and contingencies
Dollar amount of line of credit outstanding	70,720,000	70,720,000	66,247,000
Commercial
Commitments and contingencies
Dollar amount of line of credit outstanding	$2,705,000	$2,705,000	$465,000

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 2) (States and political subdivisions, State of Illinois)	9 Months Ended
	Sep. 30, 2013
States and political subdivisions | State of Illinois
Concentrations of credit risk
Percentage of investments issued by states and political subdivisions that were within the state of Illinois	27.00%

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Financial assets and financial liabilities measured at fair value on a recurring basis
Loans held for sale	$1,120		$7,492
Derivative financial instruments, assets	3,550		236
Derivative financial instrument, liabilities	15,522		28,830
Recurring basis | Total Fair Value
Financial assets and financial liabilities measured at fair value on a recurring basis
Loans held for sale	1,120		7,492
Assets held in trust for deferred compensation	10,077		7,746
Derivative financial instruments, assets	19,112		29,096
Other liabilities	9,892		7,746
Derivative financial instrument, liabilities	19,060		29,055
Recurring basis | Total Fair Value | U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	52,527		41,315
Recurring basis | Total Fair Value | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	19,312		725,019
Recurring basis | Total Fair Value | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	691,276		939,202
Recurring basis | Total Fair Value | Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	53,446		54,126
Recurring basis | Total Fair Value | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	263,021		96,674
Recurring basis | Total Fair Value | Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	10,541		11,835
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	10,541		11,835
Loans held for sale	0		0
Assets held in trust for deferred compensation	10,077		7,746
Derivative financial instruments, assets	0		0
Other liabilities	9,892	[1]	7,746	[1]
Derivative financial instrument, liabilities	0		0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	10,541		11,835
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	1,073,688		1,850,265
Loans held for sale	1,120		7,492
Derivative financial instruments, assets	19,112		29,096
Derivative financial instrument, liabilities	19,060		29,055
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	52,527		41,315
Recurring basis | Significant Other Observable Inputs (Level 2) | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	19,312		725,019
Recurring basis | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	690,546		938,354
Recurring basis | Significant Other Observable Inputs (Level 2) | Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	53,446		54,126
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	257,857		91,451
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	5,894		6,071
Loans held for sale	0		0
Derivative financial instruments, assets	0		0
Derivative financial instrument, liabilities	0		0
Recurring basis | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	730		848
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Securities available for sale	$5,164		$5,223
[1]	Liabilities associated with assets held in trust for deferred compensation

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Nonrecurring basis

Nonrecurring basis

Residential mortgage-backed securities

Residential mortgage-backed securities

Corporate bonds

Corporate bonds

Minimum

Maximum

Minimum

Maximum

Residential mortgage-backed securities

Residential mortgage-backed securities

Assets measured at fair value on a nonrecurring basis

Constant prepayment rates (as a percent)

1.00%

3.00%

Credit assumption (as a percent)

20.00%

Appraisal adjustment impaired loans (as a percent)

5.00%

10.00%

Appraisal adjustment foreclosed assets (as a percent)

5.00%

10.00%

Securities available for sale

$5,894

$6,071

$730

$848

$5,164

$5,223

Financial assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)

Balance at the beginning of the period

6,071

6,992

Other comprehensive income

-59

89

Principal payments

-118

-846

Impairment Charge

0

-117

Balance at the end of the period

$5,894

$5,894

$6,118

Fair value assumption, allowance for impaired real estate loans percentage

85.00%

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (Nonrecurring basis, USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Total Fair Value
Financial Assets:
Impaired loans	$84,500	$62,258
Foreclosed assets	57,009	60,228
Non-financial long-lived assets		2,314
Significant Unobservable Inputs (Level 3)
Financial Assets:
Impaired loans	84,500	62,258
Foreclosed assets	57,009	60,228
Non-financial long-lived assets		$2,314

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details 4) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value Disclosures [Abstract]
Maximum maturity period of short-term borrowings where carrying value approximates fair value (in days)	90 days
Minimum maturity period of short-term borrowings where fair value is based on discounted value of conctractual cash flows (in days)	90 days
Financial Assets:
Cash and due from banks	$215,017	$176,010
Interest bearing deposits with banks	41,700	111,533
Securities available for sale, at fair value	1,090,123	1,868,171
Investment securities held to maturity	1,193,544	493,421
Investment securities held to maturity	1,212,748	535,681
Non-marketable securities - FHLB and FRB stock	50,870	55,385
Loans held for sale	1,120	7,492
Loans, net	5,468,701	5,642,726
Derivative financial instruments	3,550	236
Financial Liabilities:
Non-interest bearing deposits	2,269,367	2,164,547
Interest bearing deposits	5,029,319	5,378,150
Short-term borrowings	240,600	220,602
Long-term borrowings	62,428	116,050
Junior subordinated notes issued to capital trusts	152,065	152,065
Derivative financial instruments	15,522	28,830
Carrying Amount
Financial Assets:
Cash and due from banks	215,017	176,010
Interest bearing deposits with banks	41,700	111,533
Securities available for sale, at fair value	1,090,123
Securities available for sale		1,868,171
Investment securities held to maturity	1,193,544
Investment securities held to maturity		493,421
Non-marketable securities - FHLB and FRB stock	50,870	55,385
Loans held for sale	1,120	7,492
Loans, net	5,468,701
Loans, net		5,642,726
Accrued interest receivable	35,938	36,040
Derivative financial instruments	19,112	29,096
Financial Liabilities:
Non-interest bearing deposits	2,269,367	2,164,547
Interest bearing deposits	5,029,319	5,378,150
Short-term borrowings	240,600	220,602
Long-term borrowings	62,428
Long-term borrowings		116,050
Junior subordinated notes issued to capital trusts	152,065	152,065
Accrued interest payable	1,908	2,828
Derivative financial instruments	19,060	29,055
Total Fair Value
Financial Assets:
Cash and due from banks	215,017	176,010
Interest bearing deposits with banks	41,700	111,533
Securities available for sale	1,090,123	1,868,171
Investment securities held to maturity	1,212,748	535,681
Non-marketable securities - FHLB and FRB stock	50,870	55,385
Loans held for sale	1,120	7,492
Loans, net	5,470,567	5,659,598
Accrued interest receivable	35,938	36,040
Derivative financial instruments	19,112	29,096
Financial Liabilities:
Non-interest bearing deposits	2,269,367	2,164,547
Interest bearing deposits	5,039,175	5,399,709
Short-term borrowings	240,595	220,683
Long-term borrowings	67,425	117,809
Junior subordinated notes issued to capital trusts	105,967	104,009
Accrued interest payable	1,908	2,828
Derivative financial instruments	19,060	29,055
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets:
Cash and due from banks	215,017	176,010
Interest bearing deposits with banks	41,700	111,533
Securities available for sale	10,541	11,835
Investment securities held to maturity	0	0
Non-marketable securities - FHLB and FRB stock	0	0
Loans held for sale	0	0
Loans, net	0	0
Accrued interest receivable	35,938	36,040
Derivative financial instruments	0	0
Financial Liabilities:
Non-interest bearing deposits	2,269,367	2,164,547
Interest bearing deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Junior subordinated notes issued to capital trusts	0	0
Accrued interest payable	1,908	2,828
Derivative financial instruments	0	0
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial Assets:
Cash and due from banks	0	0
Interest bearing deposits with banks	0	0
Securities available for sale	1,073,688	1,850,265
Investment securities held to maturity	1,212,748	535,681
Non-marketable securities - FHLB and FRB stock	0	0
Loans held for sale	1,120	7,492
Loans, net	0	0
Accrued interest receivable	0	0
Derivative financial instruments	19,112	29,096
Financial Liabilities:
Non-interest bearing deposits	0	0
Interest bearing deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Junior subordinated notes issued to capital trusts	0	0
Accrued interest payable	0	0
Derivative financial instruments	19,060	29,055
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial Assets:
Cash and due from banks	0	0
Interest bearing deposits with banks	0	0
Securities available for sale	5,894	6,071
Investment securities held to maturity	0	0
Non-marketable securities - FHLB and FRB stock	50,870	55,385
Loans held for sale	0	0
Loans, net	5,470,567	5,659,598
Accrued interest receivable	0	0
Derivative financial instruments	0	0
Financial Liabilities:
Non-interest bearing deposits	0	0
Interest bearing deposits	5,039,175	5,399,709
Short-term borrowings	240,595	220,683
Long-term borrowings	67,425	117,809
Junior subordinated notes issued to capital trusts	105,967	104,009
Accrued interest payable	0	0
Derivative financial instruments	$0	$0

Stock_Incentive_Plans_Details

Stock Incentive Plans (Details) (USD $)

3 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Jun. 30, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2011

Dec. 31, 2010

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Omnibus Incentive Plan (the "Omnibus Plan")

Omnibus Incentive Plan (the "Omnibus Plan")

Stock options

Stock options

Stock options

Restricted stock and restricted stock units

Restricted stock

Performance-based restricted stock units

Performance-based restricted stock units

Market-based restricted stock

Market-based restricted stock

Salary Stock

Minimum

Minimum

Maximum

Maximum

Director

Director

Restricted stock and restricted stock units

Performance-based restricted stock units

Restricted stock and restricted stock units

Performance-based restricted stock units

Impact of the share-based payment plans in the financial statements

Total cost of share-based payment plans during the period

$1,388,000

$1,080,000

$3,860,000

$3,581,000

Amount of related income tax benefit recognized in income

548,000

430,000

1,530,000

1,431,000

Stock-based compensation

Number of additional authorized shares

2,300,000

Number of common shares authorized for issuance

8,300,000

Numerator of shares granted beyond threshold limit

2

Denominator of shares granted beyond threshold limit

1

Number of shares available for future grants

1,617,262

Continuous service period for vesting of option awards (in years)

4 years

Contractual terms of option awards (in years)

10 years

Minimum vesting period (in years)

5 years

1 year

2 years

4 years

Maximum percentage of fees with an option to be received in equity-based incentive awards

70.00%

100.00%

Period of restriction for sale of underlying shares (in months)

6 months

Number of shares issued

56,752

65,333

92,717

66,193

876

Share-Based Compensation Arrangement By Share Based Payment Award, Percentage Of Shares Earned To Number Of Units Issued

0.00%

175.00%

Performance based restricted units performance period (in years)

3 years

Share based compensation restricted stock units multiplier (in percent)

100.00%

Number of consecutive trading days over which a specified closing price of the entity's stock is maintained

10 days

10 days

Minimum closing price of the entity's stock (in dollars per share)

$27

$25.80

Period of restriction for sale of shares of Salary Stock (in years)

2 years

Weighted average issuance price of Salary Stock (in dollars per share)

$22.39

Unrecognized compensation cost

14,200,000

Expected weighted-average period for recognition of unrecognized compensation expense (in years)

2 years 10 months 9 days

Options outstanding activity

Options outstanding at the beginning of the period (in shares)

2,739,753

Granted (in shares)

211,501

Exercised (in shares)

-330,832

Expired or cancelled (in shares)

-113,290

Forfeited (in shares)

-17,857

Options outstanding at the end of the period (in shares)

2,489,275

Options exercisable at end of the period (in shares)

1,809,183

Weighted Average Exercise Price

Options outstanding at the beginning of the period (in dollars per share)

$27.34

Granted (in dollars per share)

$27.03

Exercised (in dollars per share)

$25.51

Expired or cancelled (in dollars per share)

$30.91

Forfeited (in dollars per share)

$20.18

Options outstanding at the end of the period (in dollars per share)

$27.44

Options exercisable at end of the period (in dollars per share)

$29.72

Weighted Average Remaining Contractual Term (In Years)

Options outstanding at the end of the period

4 years 11 months 9 days

Options exercisable at end of the period

3 years 8 months 1 day

Aggregate Intrinsic Value

Options outstanding at the end of the period

9,407,000

Options exercisable at end of the period

4,764,000

Fair value assumptions

Risk free interest rate (as a percent)

1.96%

Expected volatility of Company's stock (as a percent)

25.60%

Expected dividend yield (as a percent)

1.74%

Expected life of options (in years)

5 years 7 months 6 days

Weighted average fair value per option of options granted during the year (in dollars per share)

$5.97

Total intrinsic value of options exercised

$929,000

$203,000

Changes in restricted shares

Nonvested shares of restricted stock and nonvested restricted stock units at the beginning of the period

634,211

Granted (in shares)

270,983

Vested (in shares)

-201,178

Forfeited (in shares)

-13,983

Nonvested shares of restricted stock and nonvested restricted stock units at the end of the period

690,033

Weighted Average Grant Date Fair Value, restricted shares

Shares Outstanding at the beginning of the period (in dollars per share)

$18.82

Granted (in dollars per share)

$26.91

Vested (in dollars per share)

$16.79

Forfeited (in dollars per share)

$20.52

Nonvested shares of restricted stock and nonvested restricted stock units at the end of the period (in dollars per share)

$22.55

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (USD $)	3 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012
Derivative [Line Items]
Net amount receivable under interest rate swap				$24,000
Net amount payable under interest rate swap							30,000
Interest rate swap credit risk exposure	17,900,000			17,900,000
Asset Derivatives, Notional Amount	675,473,000			675,473,000			562,735,000
Asset Derivatives, Estimated Fair Value	19,112,000			19,112,000			29,096,000
Liability Derivatives, Notional Amount	673,927,000			673,927,000			559,402,000
Liability Derivatives, Estimated Fair Value	-19,060,000			-19,060,000			-29,055,000
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	-22,000		29,000	-48,000		106,000
Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	675,473,000			675,473,000			562,735,000
Asset Derivatives, Estimated Fair Value	19,112,000			19,112,000			29,096,000
Liability Derivatives, Notional Amount	673,679,000			673,679,000			555,695,000
Liability Derivatives, Estimated Fair Value	-19,034,000			-19,034,000			-28,961,000
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	-21,000		29,000	-57,000		142,000
Commercial loan interest rate swaps
Derivative [Line Items]
Liability Derivatives, Notional Amount	248,000			248,000
Interest rate swap contracts | Derivative instruments designated as hedges of fair value
Derivative [Line Items]
Liability Derivatives, Notional Amount	248,000	[1]		248,000	[1]		3,707,000	[1]
Liability Derivatives, Estimated Fair Value	-26,000	[1]		-26,000	[1]		-94,000	[1]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	-1,000		0	9,000		-36,000
Interest rate swap contracts | Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	570,472,000	[2]		570,472,000	[2]		460,956,000	[2]
Asset Derivatives, Estimated Fair Value	17,813,000	[2]		17,813,000	[2]		27,740,000	[2]
Liability Derivatives, Notional Amount	571,445,000	[2]		571,445,000	[2]		462,012,000	[2]
Liability Derivatives, Estimated Fair Value	-17,875,000	[2]		-17,875,000	[2]		-27,832,000	[2]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	7,000		6,000	30,000		19,000
Interest rate options contracts | Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	84,095,000	[2]		84,095,000	[2]		70,346,000	[2]
Asset Derivatives, Estimated Fair Value	307,000	[2]		307,000	[2]		157,000	[2]
Liability Derivatives, Notional Amount	84,095,000	[2]		84,095,000	[2]		70,346,000	[2]
Liability Derivatives, Estimated Fair Value	-307,000	[2]		-307,000	[2]		-157,000	[2]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	0		0	0		0
Foreign exchange contracts | Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	16,112,000	[2]		16,112,000	[2]		20,033,000	[2]
Asset Derivatives, Estimated Fair Value	912,000	[2]		912,000	[2]		1,062,000	[2]
Liability Derivatives, Notional Amount	15,536,000	[2]		15,536,000	[2]		19,337,000	[2]
Liability Derivatives, Estimated Fair Value	-818,000	[2]		-818,000	[2]		-961,000	[2]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	-12,000		14,000	-7,000		44,000
Mortgage banking derivatives | Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	4,794,000	[2]		4,794,000	[2]		11,400,000	[2]
Asset Derivatives, Estimated Fair Value	80,000	[2]		80,000	[2]		137,000	[2]
Liability Derivatives, Notional Amount	2,603,000	[2]		2,603,000	[2]		4,000,000	[2]
Liability Derivatives, Estimated Fair Value	-34,000	[2]		-34,000	[2]		-11,000	[2]
Derivative Instruments, Gain (Loss) Recognized in Income, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives	($16,000)		$9,000	($80,000)		$79,000
[1]	Hedged fixed-rate commercial real estate loans
[2]	These portfolio swaps are not designated as hedging instruments under ASC Topic 815.

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivative [Line Items]
Financial Assets, Gross Amount Recognized	$3,550	$236
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	3,550	236
Financial Liabilities, Gross Amount Recognized	15,522	28,830
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	15,522	28,830
Repurchase Agreements, Financial Assets, Gross Amount Recognized	0	0
Repurchase Agreements, Financial Assets, Gross Amount Offset	0	0
Repurchase Agreements, Financial Assets, Net Amount Recognized	0	0
Repurchase Agreements, Financial Liabilities, Gross Amount Recognized	240,600	208,242
Repurchase Agreements, Financial Liabilities, Gross Amount Offset	0	0
Repurchase Agreements, Financial Liabilities, Net Amount Recognized	240,600	208,242
Total Financial Assets, Gross Amount Recognized	3,550	236
Total Financial Assets, Gross Amount Offset	0	0
Total Financial Assets, Net Amount Recognized	3,550	236
Total Financial Liabilities, Gross Amount Recognized	256,122	237,072
Total Financial Liabilities, Gross Amount Offset	0	0
Total Financial Liabilities, Net Amount Recognized	256,122	237,072
Interest rate swaps, caps and floors
Derivative [Line Items]
Financial Assets, Gross Amount Recognized	3,483	192
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	3,483	192
Financial Liabilities, Gross Amount Recognized	14,724	27,890
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	14,724	27,890
Foreign currency forward contracts
Derivative [Line Items]
Financial Assets, Gross Amount Recognized	67	43
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	67	43
Financial Liabilities, Gross Amount Recognized	764	929
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	764	929
Mortgage banking derivatives
Derivative [Line Items]
Financial Assets, Gross Amount Recognized	0	1
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	0	1
Financial Liabilities, Gross Amount Recognized	34	11
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	$34	$11

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 3) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Derivative [Line Items]
Financial Assets, Net Amount Recognized	$3,550	$236
Financial Assets, Financial Instruments	-2,562	-230
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	988	6
Financial Liabilities, Net Amount Recognized	15,522	28,830
Financial Liabilities, Financial Instruments	-2,562	-230
Financial Liabilities, Collateral	-12,915	-28,545
Financial Liabilities, Net Amount	45	55
Repurchase Agreements, Financial Assets, Net Amount Recognized	0	0
Repurchase Agreements, Financial Assets, Financial Instruments	0	0
Repurchase Agreements, Financial Assets, Collateral	0	0
Repurchase Agreements, Financial Assets, Net Amount	0	0
Repurchase Agreements, Financial Liabilities, Net Amount Recognized	240,600	208,242
Repurchase Agreements, Financial Liabilities, Financial Instruments	0	0
Repurchase Agreements, Financial Liabilities, Financial Instruments	-240,600	-208,242
Repurchase Agreements, Financial Liabilities, Collateral	0	0
Total Financial Assets, Net Amount Recognized	3,550	236
Total Financial Assets, Financial Instruments	-2,562	-230
Total Financial Assets, Collateral	0	0
Total Financial Assets, Net Amount	988	6
Total Financial Liabilities, Net Amount Recognized	256,122	237,072
Total Financial Liabilities, Financial Instruments	-2,562	-230
Total Financial Liabilities, Collateral	-253,515	-236,787
Total Financial Liabilities, Net Amount	45	55
Counterparty A
Derivative [Line Items]
Financial Assets, Net Amount Recognized	440	68
Financial Assets, Financial Instruments	-440	-68
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	0	0
Financial Liabilities, Net Amount Recognized	12,976	25,497
Financial Liabilities, Financial Instruments	-440	-68
Financial Liabilities, Collateral	-12,536	-25,429
Financial Liabilities, Net Amount	0	0
Counterparty B
Derivative [Line Items]
Financial Assets, Net Amount Recognized	1,090	84
Financial Assets, Financial Instruments	-551	-84
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	539	0
Financial Liabilities, Net Amount Recognized	551	633
Financial Liabilities, Financial Instruments	-551	-84
Financial Liabilities, Collateral	0	-549
Financial Liabilities, Net Amount	0	0
Counterparty C
Derivative [Line Items]
Financial Assets, Net Amount Recognized	1,570	36
Financial Assets, Financial Instruments	-1,570	-36
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	0	0
Financial Liabilities, Net Amount Recognized	1,949	2,305
Financial Liabilities, Financial Instruments	-1,570	-36
Financial Liabilities, Collateral	-379	-2,269
Financial Liabilities, Net Amount	0	0
Other counterparties
Derivative [Line Items]
Financial Assets, Net Amount Recognized	450	48
Financial Assets, Financial Instruments	-1	-42
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	449	6
Financial Liabilities, Net Amount Recognized	46	395
Financial Liabilities, Financial Instruments	-1	-42
Financial Liabilities, Collateral	0	-298
Financial Liabilities, Net Amount	$45	$55

Common_and_Preferred_Stock_Det

Common and Preferred Stock (Details) (USD $)	0 Months Ended		1 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	2-May-12	Mar. 14, 2012	Sep. 30, 2009	Sep. 30, 2013	Dec. 31, 2008	Sep. 30, 2009	Sep. 30, 2013	Sep. 17, 2009	Dec. 31, 2008
				Series A Preferred Stock	Series A Preferred Stock	Common Stock	Common Stock	Common Stock	Common Stock
Common and preferred stock
Preferred Stock, Shares Issued					196,000
Share Price					$1,000
Series A Preferred Stock, cumulative dividends rate for the first five years (as a percent)				5.00%
Series A Preferred Stock, cumulative dividends rate after five years (as a percent)				9.00%
Warrants, term (in years)							10 years
Warrants to purchase the Company's common stock, initially authorized (in shares)								1,012,048
Warrants to purchase the Company's common stock, as adjusted (in shares)								506,024
Warrants, exercise price (in dollars per share)									29.05
Common stock issued (in shares)						12,578,125
Gross proceeds from public offering of common stock						$201.30
Proceeds from public offering of common stock, net of underwriting discounts, commissions and offering expenses						190.9
Aggregate gross proceeds from "Qualified Equity Offerings"			196		196
Percentage of reduction in number of common shares to be purchased under the warrant								50.00%
Payments for repurchase of preferred stock and preference stock		196
Payments for repurchase of warrants	$1.50