MB Financial 10-Q 7 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 06, 2017
Document and Entity Information
Entity Registrant Name	MB FINANCIAL INC /MD
Entity Central Index Key	1,139,812
Document Type	10-Q
Document Period End Date	Sep. 30, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock; shares outstanding		83,894,031
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks	$ 361,080	$ 364,783
Interest earning deposits with banks	82,636	98,686
Total cash and cash equivalents	443,716	463,469
Investment securities:
Securities available for sale, at fair value	1,497,543	1,696,195
Securities held to maturity, at amortized cost ($1,031,746 fair value at September 30, 2017 and $1,093,740 at December 31, 2016)	994,238	1,069,750
Non-marketable securities - FHLB and FRB stock	152,345	143,276
Total investment securities	2,644,126	2,909,221
Loans held for sale	722,754	716,883
Loans:
Total loans, excluding purchased credit-impaired loans	13,753,459	12,605,726
Purchased credit-impaired loans	131,919	163,077
Total loans	13,885,378	12,768,803
Less: Allowance for loan and lease losses	159,128	139,366
Net loans	13,726,250	12,629,437
Lease investments, net	371,541	311,327
Premises and equipment, net	286,482	293,910
Cash surrender value of life insurance	204,855	200,945
Goodwill	999,925	1,001,038
Other intangibles	56,745	62,959
Mortgage servicing rights, at fair value	261,446	238,011
Other real estate owned, net	13,020	26,279
Other real estate owned related to FDIC-assisted transactions	4,817	5,006
Other assets	380,858	443,832
Total assets	20,116,535	19,302,317
Deposits:
Non-interest bearing	6,101,159	6,408,169
Interest bearing	8,313,985	7,702,279
Total deposits	14,415,144	14,110,448
Short-term borrowings	1,865,415	1,569,288
Long-term borrowings	405,715	311,790
Junior subordinated notes issued to capital trusts	211,289	210,668
Accrued expenses and other liabilities	526,880	520,914
Total liabilities	17,424,443	16,723,108
STOCKHOLDERS’ EQUITY
Preferred stock, ($0.01 par value, authorized 10,000,000 shares at September 30, 2017 and December 31, 2016; Series A, 8% perpetual non-cumulative, 4,000,000 shares issued and outstanding at September 30, 2017 and December 31, 2016, $25 liquidation value; Series B, 8% cumulative voting convertible, no shares issued and outstanding at September 30, 2017 and 125 shares issued and outstanding at December 31, 2016, $1,000 liquidation value)	115,280	115,572
Common stock, ($0.01 par value; authorized 120,000,000 shares at September 30, 2017 and December 31, 2016; issued 85,765,314 shares at September 30, 2017 and 85,630,748 shares at December 31, 2016)	858	856
Additional paid-in capital	1,685,971	1,678,826
Retained earnings	940,948	838,892
Accumulated other comprehensive income	9,772	5,190
Less: 1,878,217 and 1,905,479 shares of treasury common stock, at cost, at September 30, 2017 and December 31, 2016, respectively	(60,737)	(60,384)
Controlling interest stockholders’ equity	2,692,092	2,578,952
Non-controlling interest	0	257
Total stockholders’ equity	2,692,092	2,579,209
Total liabilities and stockholders’ equity	$ 20,116,535	$ 19,302,317

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Securities held to maturity, at amortized cost, fair value	$ 1,031,746	$ 1,093,740
Preferred stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	120,000,000	120,000,000
Common stock, issued shares (in shares)	85,765,314	85,630,748
Treasury stock, shares (in shares)	1,878,217	1,905,479
Series A Preferred Stock
Preferred stock, dividend rate (percent)	8.00%	8.00%
Preferred stock, shares issued (in shares)	4,000,000	4,000,000
Preferred stock, shares outstanding (in shares)	4,000,000	4,000,000
Preferred stock, liquidation preference per share (in dollars per share)	$ 25	$ 25
Series B Preferred Stock
Preferred stock, dividend rate (percent)	8.00%	8.00%
Preferred stock, shares issued (in shares)	0	125
Preferred stock, shares outstanding (in shares)	0	125
Preferred stock, liquidation preference per share (in dollars per share)	$ 1,000	$ 1,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Loans:
Taxable	$ 155,440		$ 118,675		$ 432,603		$ 333,829
Nontaxable	2,632		2,846		8,303		8,173
Investment securities:
Taxable	8,440		8,844		26,279		26,209
Nontaxable	9,731		10,382		29,541		31,802
Other interest earning accounts and Federal funds sold	327		164		754		430
Total interest income	176,570		140,911		497,480		400,443
Interest expense:
Deposits	10,865		6,681		27,133		18,255
Short-term borrowings	5,148		1,092		11,440		2,723
Long-term borrowings and junior subordinated notes	3,610		2,367		9,923		6,788
Total interest expense	19,623		10,140		48,496		27,766
Net interest income	156,947		130,771		448,984		372,677
Provision for credit losses	4,517		6,549		17,950		16,941
Net interest income after provision for credit losses	152,430		124,222		431,034		355,736
Non-interest income:
Mortgage banking revenue	27,575		49,095		84,853		116,192
Lease financing revenue, net	23,148		18,864		62,967		53,618
Commercial deposit and treasury management fees	14,508		12,957		43,696		36,383
Trust and asset management fees	8,702		8,244		25,720		24,430
Card fees	4,585		4,161		13,564		11,731
Capital markets and international banking fees	4,870		3,313		11,709		9,311
Consumer and other deposit service fees	3,424		3,559		10,072		9,745
Brokerage fees	1,004		1,294		3,379		3,767
Loan service fees	2,114		1,792		6,120		5,505
Increase in cash surrender value of life insurance	1,321		1,055		3,910		2,759
Net gain on investment securities	83		0		451		269
Net (loss) gain on disposal of other assets	(180)		5		(307)		(45)
Other operating income	4,110		4,048		11,420		8,415
Total non-interest income	95,264		108,387		277,554		282,080
Non-interest expenses:
Salaries and employee benefits expense	105,815		111,478		309,932		292,073
Occupancy and equipment expense	15,382		14,766		45,710		41,441
Computer services and telecommunication expense	10,062		12,836		29,287		31,668
Advertising and marketing expense	2,558		3,084		8,964		8,926
Professional and legal expense	2,109		4,460		7,250		10,370
Other intangibles amortization expense	2,038		1,674		6,214		4,917
Branch exit and facilities impairment charges	2,773		(2,908)		8,680		(2,709)
Net loss (gain) recognized on other real estate owned and other related expenses	(86)		(721)		1,448		(809)
Other operating expenses	21,643		25,716		66,033		68,214
Total non-interest expenses	162,294	[1]	170,385	[1]	483,518	[2]	454,091	[2]
Income before income taxes	85,400		62,224		225,070		183,725
Income tax expense	24,557		17,805		65,224		56,780
Net income	60,843		44,419		159,846		126,945
Dividends on preferred shares	2,002		2,004		6,007		6,004
Net income available to common stockholders	$ 58,841		$ 42,415		$ 153,839		$ 120,941
Common share data:
Basic earnings per common share (in dollars per share)	$ 0.70		$ 0.55		$ 1.84		$ 1.62
Diluted earnings per common share (in dollars per share)	$ 0.69		$ 0.54		$ 1.81		$ 1.60
Weighted average common shares outstanding for basic earnings per common share (in shares)	83,891,175		77,506,885		83,799,694		74,780,943
Diluted weighted average common shares outstanding for diluted earnings per common share (in shares)	84,779,797		78,683,170		84,775,952		75,727,580
[1]	Includes merger related and repositioning expenses of $1.6 million and $11.4 million in the Banking Segment for the three months ended September 30, 2017 and 2016, respectively.
[2]	Includes merger related and repositioning expenses of $9.0 million and $17.2 million in the Banking Segment for the nine months ended September 30, 2017 and 2016, respectively.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 60,843	$ 44,419	$ 159,846	$ 126,945
Unrealized holding (gains) losses on investment securities, net of reclassification adjustments	(890)	(7,679)	9,143	15,603
Reclassification adjustment for amortization of unrealized gains on investment securities transferred to held to maturity from available for sale	(266)	(554)	(1,089)	(2,081)
Reclassification adjustments for gains included in net income	(83)	0	(451)	(269)
Other comprehensive (loss) income, before tax	(1,239)	(8,233)	7,603	13,253
Income tax expense (benefit) related to items of other comprehensive income (loss)	491	3,265	(3,021)	(5,267)
Other comprehensive (loss) income, net of tax	(748)	(4,968)	4,582	7,986
Comprehensive income	$ 60,095	$ 39,451	$ 164,428	$ 134,931

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income, Net of Tax	Treasury Stock	Non-controlling Interest
Beginning balance at Dec. 31, 2015	$ 2,087,284	$ 115,280	$ 756	$ 1,280,870	$ 731,812	$ 15,777	$ (58,504)	$ 1,293
Increase (Decrease) in Stockholders' Equity
Net income	127,084				126,945			139
Other comprehensive income, net of tax	7,986					7,986
Issuance of preferred and common stock due to business combination	385,099	1,227	97	383,775
Cash dividends declared on preferred shares	(6,004)				(6,004)
Cash dividends declared on common shares	(42,984)				(42,984)
Restricted common stock activity, net of tax	(1,512)		1	(2,263)			750
Stock option activity, net of tax	116		1	272			(157)
Repurchase of common shares in connection with employee benefit plans and held in trust for deferred compensation plan	(3,792)			381			(4,173)
Stock-based compensation expense	12,573			12,573
Purchase of additional investment in subsidiary from minority owners	(2,336)			(1,267)				(1,069)
Distributions to non-controlling interest	(106)							(106)
Ending balance at Sep. 30, 2016	2,563,408	116,507	855	1,674,341	809,769	23,763	(62,084)	257
Beginning balance at Dec. 31, 2016	2,579,209	115,572	856	1,678,826	838,892	5,190	(60,384)	257
Increase (Decrease) in Stockholders' Equity
Net income	159,846				159,846
Other comprehensive income, net of tax	4,582					4,582
Conversion of preferred stock to common stock		(292)		292
Cash dividends declared on preferred shares	(6,007)				(6,007)
Cash dividends declared on common shares	(51,783)				(51,783)
Restricted common stock activity, net of tax	(3,280)			(6,829)			3,549
Stock option activity, net of tax	332		2	330
Repurchase of common shares in connection with employee benefit plans and held in trust for deferred compensation plan	(3,297)			605			(3,902)
Stock-based compensation expense	13,317			13,317
Purchase of additional investment in subsidiary from minority owners	(827)			(570)				(257)
Ending balance at Sep. 30, 2017	$ 2,692,092	$ 115,280	$ 858	$ 1,685,971	$ 940,948	$ 9,772	$ (60,737)	$ 0

CONSOLIDATED STATEMENTS OF CHA7

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.61	$ 0.55

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows From Operating Activities
Net income	$ 159,846	$ 126,945
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation of premises and equipment and leased equipment	69,859	55,259
Branch exit and facilities impairment charges	8,680	(2,709)
Compensation expense for share-based payment plans	13,317	12,573
Net gain on sales of premises and equipment and leased equipment	(794)	(255)
Amortization of other intangibles	6,214	4,917
Provision for credit losses	17,950	16,941
Deferred income tax expense	37,574	26,208
Amortization of premiums and discounts on investment securities, net	30,124	34,968
Accretion of discounts on loans, net	(21,760)	(25,426)
Net gain on investment securities	(451)	(269)
Proceeds from sale of loans held for sale	3,665,709	4,601,291
Origination of loans held for sale	(3,629,230)	(4,694,890)
Net gain on sale of loans held for sale	(10,073)	(41,518)
Change in fair value of mortgage servicing rights	20,601	59,894
Net loss (gain) on other real estate owned	1,294	(1,823)
Net loss on other real estate owned related to FDIC-assisted transactions	103	448
Increase in cash surrender value of life insurance	(3,910)	(2,759)
Increase in other assets, net	(25,122)	(162,260)
(Decrease) increase in other liabilities, net	(49,043)	22,618
Net cash provided by operating activities	290,888	30,153
Cash Flows From Investing Activities
Proceeds from sales of investment securities available for sale	2,271	19,023
Proceeds from maturities and calls of investment securities available for sale	249,264	212,283
Purchases of investment securities available for sale	(66,402)	(19,905)
Proceeds from maturities and calls of investment securities held to maturity	105,065	115,040
Purchases of investment securities held to maturity	(36,877)	(12,690)
Purchases of non-marketable securities - FHLB and FRB stock	(135,479)	(15,999)
Redemption of non-marketable securities - FHLB and FRB stock	126,410	23
Net increase in loans	(1,100,271)	(780,864)
Purchases of mortgage servicing rights	(839)	(3,423)
Purchases of premises and equipment and leased equipment	(130,313)	(125,372)
Proceeds from sales of premises and equipment and leased equipment	20,860	5,194
Capital improvements on other real estate owned	0	(96)
Proceeds from sale of other real estate owned	18,432	8,081
Proceeds from sale of other real estate owned related to FDIC-assisted transactions	3,141	7,105
Net cash paid in business acquisition	0	(9,010)
Purchase of additional investment in subsidiary from minority owners	(827)	(2,336)
Net proceeds from FDIC related covered assets	(583)	(3,182)
Net cash used in investing activities	(946,148)	(606,128)
Cash Flows From Financing Activities
Net increase in deposits	304,696	384,628
Proceeds from short-term borrowings - FHLB advances	3,125,000	2,200,000
Principal paid on short-term borrowings - FHLB advances	(3,150,000)	(1,925,000)
Net increase in short-term borrowings	171,127	17,277
Proceeds from long-term borrowings	348,235	182,247
Principal paid on long-term borrowings	(104,310)	(136,877)
Treasury stock transactions, net	(3,238)	(3,792)
Stock options exercised	1,715	1,062
Dividends paid on preferred stock	(6,007)	(6,004)
Dividends paid on common stock	(51,711)	(42,748)
Net cash provided by financing activities	635,507	670,793
Net (decrease) increase in cash and cash equivalents	(19,753)	94,818
Cash and cash equivalents:
Beginning of period	463,469	381,441
End of period	443,716	476,259
Cash payments for:
Interest paid to depositors and on other borrowed funds	47,104	26,952
Income tax (refunds) payments, net	(4,762)	4,576
Supplemental Schedule of Noncash Investing Activities:
Investment securities available for sale sold not settled	0	(9,741)
Investment securities held to maturity purchased not settled	2,433	440
Loans transferred to other real estate owned	6,467	3,566
Loans transferred to other real estate owned related to FDIC-assisted transactions	2,721	1,145
Loans transferred to repossessed assets	1,410	2,796
Operating leases rewritten as direct finance leases included as loans	1,484	642
Long-term borrowings transferred to short-term borrowings	150,000	150,000
Noncash assets acquired:
Investment securities available for sale	0	505,564
Non-marketable securities - FHLB and FRB stock	0	16,000
Loans	1,846	1,952,826
Premises and equipment	0	39,061
Cash surrender value of life insurance	0	59,917
Goodwill	(1,113)	268,729
Core deposit intangible	0	25,500
Other real estate owned	0	4,148
Other assets	(733)	27,615
Total noncash assets acquired	0	2,899,360
Liabilities assumed:
Deposits	0	2,389,423
Short-term borrowings	0	48,305
Long-term borrowings	0	16,000
Junior subordinated notes issued to capital trusts	0	28,075
Other liabilities	0	23,477
Total liabilities assumed	$ 0	$ 2,505,280

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	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 condition, results of operations and cash flows for the interim periods have been made. The results of operations for the nine months ended September 30, 2017 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 Annual Report on Form 10-K for the year ended December 31, 2016 . 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 Gu

New Authoritative Accounting Guidance	9 Months Ended
	Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
New Authoritative Accounting Guidance	New Authoritative Accounting Guidance ASC Topic 805 "Business Combinations." New authoritative accounting guidance under ASC Topic 805 "Business Combinations" amends prior guidance to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 606 "Revenue from Contracts with Customers." New authoritative accounting guidance under ASC Topic 606, "Revenue from Contracts with Customers" amended prior guidance to require an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and to provide clarification on identifying performance obligations and licensing implementation guidance. The new authoritative guidance was initially effective for reporting periods after January 1, 2017 but was deferred to January 1, 2018. The Company's revenue is comprised of interest income on financial assets, which is excluded from the scope of this new guidance, and non-interest income. The Company expects this new guidance will require it to change how certain recurring revenue streams are recognized within trust and asset management fees, card fees and lease financing revenue but does not expect these changes to have a significant impact on its statements of operations or financial condition. The Company continues to evaluate the impact of this guidance on other components of non-interest income. The Company expects to adopt this new guidance on January 1, 2018 with a cumulative effect adjustment to opening retained earnings, if such adjustment is deemed to be significant. ASC Topic 825 "Financial Instruments." New authoritative accounting guidance under ASC Topic 825 "Financial Instruments" amended prior guidance to require equity investments (except those accounted for under the equity method of accounting) to be measured at fair value with changes in fair value recognized in net income. An entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. The new guidance simplifies the impairment assessment of equity investments without readily determinable fair values, requires public entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from changes in the instrument-specific credit risk when the entity has selected the fair value option for financial instruments and requires separate presentation of financial assets and liabilities by measurement category and form of financial asset. The new authoritative guidance will be effective for reporting periods after January 1, 2018 and is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 405 "Liabilities-Extinguishment of Liabilities." New authoritative accounting guidance under ASC Topic 405, "Liabilities-Extinguishment of Liabilities" amended prior guidance to clarify that liabilities related to the sale of prepaid store-value products within the scope of this guidance are financial liabilities and that breakage for those liabilities are to be accounted for consistent with the breakage guidance in ASC Topic 606 "Revenue from Contracts with Customers." The new authoritative guidance will be effective for reporting periods after January 1, 2018. The Company is evaluating the new guidance but does not expect it to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 842 "Leases." New authoritative accounting guidance under ASC Topic 842 "Leases" amended prior guidance to require lessees to recognize the assets and liabilities arising from all leases on the balance sheet. The new authoritative guidance defines a lease as a contract, or part of a contract, that conveys the right to control the use of identified property, plant, or equipment (an identified asset) for a period of time in exchange for consideration. In addition, the qualifications for a sale and leaseback transaction have been amended. The new authoritative guidance also requires qualitative and quantitative disclosures by lessees and lessors to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is evaluating the new guidance and its impact on the Company's statements of operations and financial condition. The Company expects an increase in assets and liabilities as a result of recording additional lease contracts where the Company is lessee. ASC Topic 815 "Derivatives and Hedging." New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" amended prior guidance to clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. An entity has an option to apply the amendments in this new authoritative guidance on either a prospective basis or a modified retrospective basis. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" also amended prior guidance to clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. An entity is required to consider whether (1) the payoff is adjusted based on changes in an index, (2) the payoff is indexed to an underlying other than interest rates or credit risk, (3) the debt involves a substantial premium or discount, and (4) the call (put) option is contingently exercisable. An entity should apply this new authoritative guidance on a modified retrospective basis to existing debt instruments as of the beginning of the fiscal year for which the amendments are effective. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" amended prior guidance to better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The new authoritative guidance expands and refines hedge accounting for both nonfinancial and financial risk components. The new authoritative guidance will be effective for reporting periods after January 1, 2019 with early adoption permitted. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 323 "Investment - Equity Method and Joint Ventures." New authoritative accounting guidance under ASC Topic 323 "Investment - Equity Method and Joint Ventures" amended prior guidance to eliminate the requirement to retroactively adopt the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. The new authoritative guidance required that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have an impact on the Company's statements of operations or financial condition. ASC Topic 718 "Compensation - Stock Compensation." New authoritative accounting guidance under ASC Topic 718 "Compensation - Stock Compensation" amended prior guidance in several aspects, including the income tax consequences, classification of awards as either equity or liability, and classification on the statement of cash flows. The new authoritative guidance allows for all excess tax benefits and tax deficiencies to be recognized as income tax benefit or expense in the income statement. The tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity also should recognize excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. For the statement of cash flows, excess tax benefits should be classified along with other income tax cash flows as an operating activity, and cash paid by an employer when directly withholding shares for tax withholding purposes should be classified as a financing activity. The new authoritative guidance also allows an entity to make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. In addition, the threshold to qualify for equity classification permits withholding up to the maximum statutory tax rates in the applicable jurisdictions. The Company early adopted the new guidance in the third quarter of 2016. The Company has also elected to account for forfeitures when they occur. New authoritative accounting guidance under ASC Topic 718 "Compensation - Stock Compensation" amends prior guidance by clarifying which changes to terms or conditions of a share-based payment award requires an entity to apply modification accounting. An entity should account for the effects of a modification unless the fair value, vesting conditions and classification of the modified award are the same as the original award. The new authoritative guidance will be effective for reporting periods after January 1, 2018 with early adoption permitted. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 326 "Financial Instruments - Credit Losses." New authoritative accounting guidance under ASC Topic 326 " Financial Instruments - Credit Losses " amended the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information for credit loss estimates. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The new authoritative guidance also requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected (net of the allowance for credit losses). In addition, the credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses rather than a write-down. The new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is evaluating the new guidance and expects it to have an impact on the Company's statements of operations and financial condition, the significance of which is not yet known. Due to the significant differences in the new authoritative guidance from the existing GAAP, the implementation of this guidance may result in material changes in our accounting for credit losses on the financial instruments. As part of the Company's evaluation process, it has established a steering committee and working group, including individuals from various functional areas, to assess processes, portfolio segmentation, system requirements and needed resources. The Company is also considering third-party consultants to assist in the evaluation process. ASC Topic 230 "Statement of Cash Flows." New authoritative accounting guidance under ASC Topic 230 "Statement of Cash Flows" addresses eight specific cash flow classification issues with the objective of reducing the existing diversity in practice. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 230 "Statement of Cash Flows" amends prior guidance to require an entity to include amounts generally described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 740 "Income Taxes." New authoritative accounting guidance under ASC Topic 740 "Income Taxes" amends prior guidance to require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 350 "Intangibles-Goodwill and Other." New authoritative accounting guidance under ASC Topic 350 "Intangibles-Goodwill and Other" amends prior guidance to eliminate Step 2 from the goodwill impairment test and require an entity to perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is evaluating the new guidance and its impact on the Company's statements of operations and financial condition. ASC Topic 610 "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets." New authoritative accounting guidance under ASC Topic 610 "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets" amends prior guidance to clarify the scope of Subtopic 610-20 by defining in substance nonfinancial assets and to add guidance for partial sales of nonfinancial assets. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs." New authoritative accounting guidance under ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs" amends prior guidance by shortening the amortization period for certain callable debt securities held at a premium requiring the premium to be amortized to the earliest call date. The new authoritative guidance will be effective for reporting periods after January 1, 2019 with early adoption permitted. The Company is evaluating the new guidance and its impact on the Company's statements of operations and financial condition.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [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, 2017 2016 2017 2016 Distributed earnings allocated to common stock $ 17,823 $ 16,114 $ 51,783 $ 42,984 Undistributed earnings 43,020 28,305 108,063 83,961 Net income 60,843 44,419 159,846 126,945 Less: preferred stock dividends 2,002 2,004 6,007 6,004 Net income available to common stockholders for basic earnings per common share 58,841 42,415 153,839 120,941 Plus: preferred stock dividends on convertible preferred stock 2 4 7 4 Less: earnings allocated to participating securities 1 2 3 6 Earnings allocated to common stockholders for diluted earnings per common share $ 58,842 $ 42,417 $ 153,843 $ 120,939 Weighted average shares outstanding for basic earnings per common share 83,891,175 77,506,885 83,799,694 74,780,943 Dilutive effect of: Stock options 502,794 491,238 564,541 378,420 Restricted shares and units 379,684 672,480 404,850 564,028 Convertible preferred stock 6,144 12,567 6,867 4,189 Total dilutive effect of equity awards and convertible preferred stock 888,622 1,176,285 976,258 946,637 Weighted average shares outstanding for diluted earnings per common share 84,779,797 78,683,170 84,775,952 75,727,580 Basic earnings per common share $ 0.70 $ 0.55 $ 1.84 $ 1.62 Diluted earnings per common share 0.69 0.54 1.81 1.60

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Business Combinations	Business Combinations American Chartered Bancorp, Inc. On August 24, 2016, American Chartered Bancorp, Inc. ("American Chartered"), an Illinois corporation, was merged (the "American Chartered merger") with and into the Company, pursuant to the Agreement and Plan of Merger, dated as of November 20, 2015 (the "Merger Agreement"), by and between the Company and American Chartered. This transaction continues to solidify the Company's market position in Chicago. At the effective time of the merger (the "American Chartered Effective Time"), (i) each share of the common stock, no par value, of American Chartered ("American Chartered Common Stock") that was issued and outstanding immediately prior to the American Chartered Effective Time, (ii) each share of American Chartered’s 8% Cumulative Voting Convertible Preferred Stock, Series D ("American Chartered Series D Preferred Stock"), that was issued and outstanding immediately prior to the American Chartered Effective Time whose holder elected pursuant to American Chartered’s charter to receive the same consideration in the American Chartered merger as holders of American Chartered Common Stock, based on the number of shares of American Chartered Common Stock into which such share of American Chartered Series D Preferred Stock would otherwise then be convertible, and (iii) each share of American Chartered Non-Voting Perpetual Preferred Stock, Series F, that was issued and outstanding immediately prior to the American Chartered Effective Time, was converted into the right to receive, subject to the election and proration procedures set forth in the Merger Agreement: (1) cash in the amount of $9.30 (the "Cash Consideration") or (2) 0.2732 shares of the Company's common stock, with cash paid in lieu of fractional Company shares determined by multiplying the fractional Company share amount by $39.01 (the average closing sale price of the Company's common stock for the five full trading days ending on August 23, 2016) (the "Stock Consideration"). The holders of such shares of American Chartered stock also could elect to receive a combination of the Cash Consideration and the Stock Consideration for their shares. Each share of American Chartered Series D Preferred Stock whose holder did not elect to receive the same consideration in the American Chartered merger as holders of American Chartered Common Stock, based on the number of shares of American Chartered Common Stock into which such share of American Chartered Series D Preferred Stock would otherwise then be convertible, was converted into the right to receive one share of the Company's 8% cumulative voting convertible preferred stock, Series B. Consideration paid was $487.4 million , including $382.8 million in common stock ( 9.7 million shares), $102.3 million in cash and $2.3 million in preferred stock and stock-based awards assumed. The $102.3 million in cash consideration includes payments for the value of the net option shares of the American Chartered stock options pursuant to the Merger Agreement. This 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, the assets acquired, liabilities assumed and consideration paid are recorded at their estimated fair values. 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. As the consideration paid for American Chartered exceeded the net assets acquired, goodwill of $274.9 million was recorded on the acquisition and allocated to the banking segment. Goodwill recorded in the transaction, which reflects the increased Chicago market share and related synergies expected from the combined operations, is not tax deductible. During the first quarter of 2017, the fair value estimates of loans increased by $1.8 million compared to previously reported balances, which decreased the deferred tax asset by $733 thousand and goodwill by $1.1 million . The amounts recognized for the business combination in the financial statements have been determined to be final as of March 31, 2017. Estimated fair values of the assets acquired and liabilities assumed in the American Chartered transaction, as of the closing date of the transaction were as follows (in thousands): August 24, 2016 ASSETS Cash and cash equivalents $ 93,307 Investment securities available for sale 505,564 Non-marketable securities - FRB and FHLB Stock 16,000 Loans 1,942,548 Premises and equipment 39,048 Cash surrender value of life insurance 59,917 Goodwill 274,885 Other intangibles 25,452 Other real estate owned 3,960 Other assets 31,408 Total assets $ 2,992,089 LIABILITIES Deposits $ 2,389,327 Short-term borrowings 48,305 Long-term borrowings 16,000 Junior subordinated notes issued to capital trusts 28,075 Accrued expenses and other liabilities 22,966 Total liabilities $ 2,504,673 Total identifiable net assets $ 487,416 Consideration: Market value of common stock at $39.28 per share at August 24, 2016 (9,744,636 shares of common stock issued) $ 382,769 Series B preferred stock at $2,337.97 per share at August 24, 2016 (525 shares of preferred stock issued) (1) 1,227 Stock-based compensation attributed to pre-business combination service 1,103 Cash paid 102,317 Total fair value of consideration, excluding Series B preferred stock $ 487,416 (1) Per share fair value amount determined as if the shares of Series B preferred stock were converted into shares of common stock. 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 and lease 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 for in accordance with ASC Topic 310-20 "Nonrefundable Fees and Other Costs" as these loans do not have evidence of credit deterioration since origination. • Non-impaired loans (typically performing substandard loans) are accounted for in accordance with ASC Topic 310-30 if 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 Topic 310-30 as they display significant credit deterioration since origination. For pass rated loans (non-purchased credit-impaired loans), the difference between the estimated fair value of the loans and the principal outstanding is accreted over the remaining life of the loans. The accretable discount for the non-purchased credit-impaired loans was $20.7 million as of the date of the acquisition. In accordance with ASC Topic 310-30, for both purchased non-impaired loans (performing substandard loans) and purchased credit-impaired loans, the loans are pooled by loan type and 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 pools when there is a reasonable expectation about the amount and timing of such cash flows. The non-accretable and accretable discount for the purchased credit-impaired loans was $18.4 million and $5.3 million , respectively, as of the date of the acquisition. The following table presents the acquired loans as of the acquisition date (in thousands): Purchased Purchased Non-Credit-Impaired Fair value $ 62,104 $ 1,880,444 Gross contractual amounts receivable 93,490 2,149,868 Best estimate of contractual cash flows not expected to be collected (1) 22,293 114,154 Best estimate of contractual cash flows expected to be collected 71,197 2,035,714 (1) Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer defaults. The Company incurred costs of $2.0 million directly related to the consummation of the merger for the year ended December 31, 2016, which was recorded in professional and legal fees on the statement of operations. The data processing systems were converted in September 2016. The following table provides the unaudited pro forma information for the results of operations for the three and nine months ended September 30, 2016 , as if the acquisition had occurred on January 1, 2016. The pro forma results combine the historical results of American Chartered into the Company's consolidated statement of operations including the impact of certain acquisition accounting adjustments including loan discount accretion, investment securities discount accretion, intangible assets amortization, deposit premium accretion and borrowing discount amortization. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2016. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, provision for credit losses, expense efficiencies or asset dispositions. The merger related expenses that have been recognized are included in net income in the table below. Three Months Ended Nine Months Ended September 30, September 30, 2016 2016 (in thousands) Total revenues (net interest income plus non-interest income) $ 258,611 $ 735,408 Net income 50,029 149,111 Revenues and earnings of the acquired company since the acquisition date have not been disclosed as it is not practicable as American Chartered was merged into the Company and separate financial information is not readily available.

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities Amortized cost and fair value of investment securities were as follows as of the dates indicated (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2017 Available for Sale U.S. Government sponsored agencies and enterprises $ 23,077 $ 69 $ — $ 23,146 States and political subdivisions 366,187 20,009 (367 ) 385,829 Residential mortgage-backed securities 878,167 4,773 (7,680 ) 875,260 Commercial mortgage-backed securities 86,411 1,097 (291 ) 87,217 Corporate bonds 114,581 450 (17 ) 115,014 Equity securities 11,177 — (100 ) 11,077 Total Available for Sale 1,479,600 26,398 (8,455 ) 1,497,543 Held to Maturity States and political subdivisions 888,576 35,952 (476 ) 924,052 Residential mortgage-backed securities 105,662 2,032 — 107,694 Total Held to Maturity 994,238 37,984 (476 ) 1,031,746 Total $ 2,473,838 $ 64,382 $ (8,931 ) $ 2,529,289 December 31, 2016 Available for Sale U.S. Government sponsored agencies and enterprises $ 23,267 $ 148 $ — $ 23,415 States and political subdivisions 376,541 15,669 (845 ) 391,365 Residential mortgage-backed securities 988,744 5,741 (10,801 ) 983,684 Commercial mortgage-backed securities 91,949 1,221 (162 ) 93,008 Corporate bonds 193,164 1,426 (695 ) 193,895 Equity securities 11,000 — (172 ) 10,828 Total Available for Sale 1,684,665 24,205 (12,675 ) 1,696,195 Held to Maturity States and political subdivisions 910,608 21,609 (3,039 ) 929,178 Residential mortgage-backed securities 159,142 5,420 — 164,562 Total Held to Maturity 1,069,750 27,029 (3,039 ) 1,093,740 Total $ 2,754,415 $ 51,234 $ (15,714 ) $ 2,789,935 The Company has no direct exposure to the State of Illinois in its investment securities portfolio, but approximately 20% of the state and political subdivisions portfolio consisted of securities issued by municipalities located in Illinois as of September 30, 2017 . Approximately 95% of the state and political subdivisions securities were general obligation issues, and 27% were insured or had another form of credit enhancement as of September 30, 2017 . Unrealized losses on investment securities by length of time in a continuous unrealized loss position and the fair value of the related securities at September 30, 2017 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 $ 1,364 $ (4 ) $ 19,044 $ (363 ) $ 20,408 $ (367 ) Residential mortgage-backed securities 308,732 (4,229 ) 222,269 (3,451 ) 531,001 (7,680 ) Commercial mortgage-backed securities 9,602 (188 ) 11,445 (103 ) 21,047 (291 ) Corporate bonds — — 9,978 (17 ) 9,978 (17 ) Equity securities 11,077 (100 ) — — 11,077 (100 ) Total Available for Sale 330,775 (4,521 ) 262,736 (3,934 ) 593,511 (8,455 ) Held to Maturity States and political subdivisions 38,118 (432 ) 2,329 (44 ) 40,447 (476 ) Total $ 368,893 $ (4,953 ) $ 265,065 $ (3,978 ) $ 633,958 $ (8,931 ) Unrealized losses on investment securities by length of time in a continuous unrealized loss position and the fair value of the related securities at December 31, 2016 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 $ 42,806 $ (845 ) $ — $ — $ 42,806 $ (845 ) Residential mortgage-backed securities 623,732 (10,084 ) 54,990 (717 ) 678,722 (10,801 ) Commercial mortgage-backed securities 7,062 (9 ) 11,612 (153 ) 18,674 (162 ) Corporate bonds 21,028 (204 ) 20,088 (491 ) 41,116 (695 ) Equity securities 10,828 (172 ) — — 10,828 (172 ) Total Available for Sale 705,456 (11,314 ) 86,690 (1,361 ) 792,146 (12,675 ) Held to Maturity States and political subdivisions 243,568 (2,999 ) 2,988 (40 ) 246,556 (3,039 ) Total $ 949,024 $ (14,313 ) $ 89,678 $ (1,401 ) $ 1,038,702 $ (15,714 ) The total number of security positions in the investment portfolio in an unrealized loss position at September 30, 2017 was 397 compared to 615 at December 31, 2016 . This decrease in total number of security positions in a continuous unrealized loss position from December 31, 2016 to September 30, 2017 was mainly attributable to the mortgage-backed securities in the investment securities portfolio. 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 the Company is more likely than not to sell the security before recovery of its cost basis. As of September 30, 2017 , 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 securities approach their maturity date or repricing date or if market yields for such investments decline. Accordingly, as of September 30, 2017 , 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 securities portfolio would decline substantially if interest rates increase materially. Net gains recognized on investment securities available for sale were as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Realized gains $ 83 $ 457 $ 323 Realized losses — — (6 ) (54 ) Net gains $ 83 $ — $ 451 $ 269 The amortized cost and fair value of investment securities as of September 30, 2017 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 $ 145,205 $ 145,902 Due after one year through five years 106,869 111,113 Due after five years through ten years 57,764 59,755 Due after ten years 194,007 207,219 Equity securities 11,177 11,077 Residential and commercial mortgage-backed securities 964,578 962,477 1,479,600 1,497,543 Held to maturity: Due in one year or less 41,530 41,588 Due after one year through five years 152,848 159,474 Due after five years through ten years 204,683 215,747 Due after ten years 489,515 507,243 Residential mortgage-backed securities 105,662 107,694 994,238 1,031,746 Total $ 2,473,838 $ 2,529,289 Investment securities with a carrying amount of $833.4 million at September 30, 2017 and $1.0 billion at December 31, 2016 were pledged as collateral on public deposits and for other purposes as required or permitted by law, while only $691.3 million and $756.5 million were required to be pledged at September 30, 2017 and December 31, 2016 , respectively.

Loans

Loans	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Loans	Loans Loans consist of the following at (in thousands): September 30, December 31, Commercial loans $ 4,793,838 $ 4,346,506 Commercial loans collateralized by assignment of lease payments 2,074,215 2,002,976 Commercial real estate 4,094,706 3,788,016 Residential real estate 1,433,595 1,060,828 Construction real estate 395,794 518,562 Indirect vehicle 655,213 541,680 Home equity 228,726 266,377 Other consumer loans 77,372 80,781 Total loans, excluding purchased credit-impaired loans 13,753,459 12,605,726 Purchased credit-impaired loans 131,919 163,077 Total loans $ 13,885,378 $ 12,768,803 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. Except for commercial loans collateralized by assignment of lease payments, asset-based loans, residential real estate loans and indirect vehicle loans, credit risk tends to be geographically concentrated in that a majority of the loan customers are located in Illinois. 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. This policy is reviewed and approved by the Enterprise Risk Committee of the Company's Board of Directors on an annual basis. Commercial Loans. Commercial credit is extended primarily to emerging middle market and 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 cash flow of the borrower and secondarily on the underlying collateral provided by the borrower. The cash flows of borrowers, however, may not perform 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. Asset-based loans, also included in commercial loans, are made to businesses with the primary source of repayment derived from payments on the related assets securing the loan. Collateral for these loans may include accounts receivable, inventory and equipment, and is monitored regularly to ensure ongoing sufficiency of collateral coverage and quality. The primary risk for these loans is a significant decline in collateral values due to general market conditions. Loan terms that mitigate these risks include typical industry amortization schedules, percentage of collateral advances, maintenance of cash collateral accounts and regular asset monitoring. Because of the national scope of our asset-based lending, the risk of these loans is also diversified by geography. Commercial Loans Collateralized by Assignment of Lease Payments ("Lease Loans"). The Company makes lease loans to lessors where the underlying leases are with 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. Whether or not companies fall into this category, each lease loan is considered on its individual merit based on the financial wherewithal of the lessee using financial information available at the time of underwriting. In addition, leases that transfer substantially all of the benefits and risk related to the equipment ownership are classified as direct finance leases and are included in lease loans. 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 property income based loans and the repayment of these loans is largely dependent on the successful operation of the property, which also serves as collateral for the loan. 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 monitored 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, these loans 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 vehicle loans (motorcycle, marine, recreational and powersports vehicles). Each loan type is underwritten based upon several factors including debt to income, type of collateral and loan to collateral value, credit history and the Company's relationship with the borrower. Indirect loan and credit card underwriting involves the use of risk-based pricing in the underwriting process. Purchased credit-impaired loans. Purchased credit-impaired loans are accounted for under ASC Topic 310-30, which include purchased credit-impaired loans acquired through business combinations, FDIC-assisted transactions and re-purchase transactions with the Government National Mortgage Association ("GNMA"). The loans re-purchased from GNMA were originally sold by the Company with servicing retained and subsequently became delinquent. These loans are also insured by the Federal Housing Administration (commonly referred to as "FHA") or the U.S. Department of Veterans Affairs (commonly referred to as "VA") where the Company would be able to recover the principal balance of these loans. All re-purchases from GNMA are at the Company's discretion. A collateral pledge agreement exists whereby at all times, the Company must keep on hand, free of all other pledges, liens, and encumbrances, loans with unpaid principal balances aggregating no less than 129% for qualifying first mortgage loans, 231% for home equity loans, 183% for qualifying commercial real estate loans and 108% for loans held for sale, of the outstanding advances from the Federal Home Loan Bank. As of September 30, 2017 and December 31, 2016 , the Company had $5.6 billion and $5.5 billion , respectively, of loans pledged as collateral for long-term Federal Home Loan Bank advances and third party letters of credit, while only $4.2 billion and $3.2 billion were required to be pledged at September 30, 2017 and December 31, 2016 , respectively. The following table presents the contractual aging of the recorded investment in past due loans by class of loans as of September 30, 2017 and December 31, 2016 (in thousands): Current 30-59 Days 60-89 Days Loans Past Due Total Total September 30, 2017 Commercial $ 4,782,808 $ 5,438 $ 351 $ 5,241 $ 11,030 $ 4,793,838 Commercial collateralized by assignment of lease payments 2,059,556 10,488 3,810 361 14,659 2,074,215 Commercial real estate: Healthcare 698,919 — — — — 698,919 Industrial 856,630 — — 755 755 857,385 Multifamily 608,254 959 — 569 1,528 609,782 Retail 508,048 1,021 — 258 1,279 509,327 Office 447,671 2,131 — 1,634 3,765 451,436 Other 964,855 1,896 87 1,019 3,002 967,857 Residential real estate 1,422,321 575 4,299 6,400 11,274 1,433,595 Construction real estate 395,226 568 — — 568 395,794 Indirect vehicle 649,884 3,938 992 399 5,329 655,213 Home equity 222,804 1,743 753 3,426 5,922 228,726 Other consumer 77,109 89 79 95 263 77,372 Total loans, excluding purchased credit-impaired loans 13,694,085 28,846 10,371 20,157 59,374 13,753,459 Purchased credit-impaired loans 72,900 4,438 6,602 47,979 59,019 131,919 Total loans $ 13,766,985 $ 33,284 $ 16,973 $ 68,136 $ 118,393 $ 13,885,378 Non-performing loan aging $ 27,148 $ 1,179 $ 2,244 $ 20,044 $ 23,467 $ 50,615 December 31, 2016 Commercial $ 4,337,348 $ 2,515 $ 156 $ 6,487 $ 9,158 $ 4,346,506 Commercial collateralized by assignment of lease payments 1,989,934 9,229 1,869 1,944 13,042 2,002,976 Commercial real estate: Healthcare 582,450 — — — — 582,450 Industrial 825,715 3,045 3,293 1,340 7,678 833,393 Multifamily 547,107 458 53 379 890 547,997 Retail 506,789 568 — — 568 507,357 Office 405,992 350 475 6,381 7,206 413,198 Other 899,950 2,385 1,155 131 3,671 903,621 Residential real estate 1,041,189 8,248 3,409 7,982 19,639 1,060,828 Construction real estate 518,171 — 391 — 391 518,562 Indirect vehicle 537,221 2,836 1,062 561 4,459 541,680 Home equity 261,765 1,219 815 2,578 4,612 266,377 Other consumer 80,443 152 120 66 338 80,781 Total loans, excluding purchased credit-impaired loans 12,534,074 31,005 12,798 27,849 71,652 12,605,726 Purchased credit-impaired loans 86,169 6,546 6,600 63,762 76,908 163,077 Total loans $ 12,620,243 $ 37,551 $ 19,398 $ 91,611 $ 148,560 $ 12,768,803 Non-performing loan aging $ 28,364 $ 2,308 $ 978 $ 27,702 $ 30,988 $ 59,352 The following table presents the recorded investment in non-accrual loans and loans past due ninety days or more and still accruing by class of loans, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 December 31, 2016 Loans past due Loans past due Non-accrual 90 days or more and still accruing Non-accrual 90 days or more and still accruing Commercial $ 7,079 $ — $ 11,222 $ 1,406 Commercial collateralized by assignment of lease payments 1,054 360 1,364 1,197 Commercial real estate: Healthcare — — — — Industrial 2,215 — 276 1,064 Multifamily 1,110 — 2,662 — Office 2,973 — 896 6,381 Retail 382 — 384 — Other 1,058 15 83 21 Residential real estate 18,811 185 16,538 235 Construction real estate — — — — Indirect vehicle 2,440 34 2,355 10 Home equity 12,803 — 13,187 — Other consumer 1 95 7 64 Total $ 49,926 $ 689 $ 48,974 $ 10,378 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. Loans rated but not adversely classified are deemed to be Pass. Risk ratings are updated any time the situation warrants and at least annually. Loans not rated are included in groups of homogeneous loans with similar risk and loss characteristics and are not included in the table below. The following tables present the risk category of loans by class of loans based on the most recent analysis performed, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): Pass Special Substandard Doubtful Total September 30, 2017 Commercial $ 4,556,245 $ 160,905 $ 76,688 $ — $ 4,793,838 Commercial collateralized by assignment of lease payments 2,053,456 12,405 8,354 — 2,074,215 Commercial real estate: Healthcare 659,945 2,675 36,299 — 698,919 Industrial 830,106 15,401 11,878 — 857,385 Multifamily 601,515 151 8,116 — 609,782 Retail 505,004 1,566 2,757 — 509,327 Office 442,550 3,782 5,104 — 451,436 Other 893,589 46,688 27,580 — 967,857 Construction real estate 395,267 527 — — 395,794 Total $ 10,937,677 $ 244,100 $ 176,776 $ — $ 11,358,553 December 31, 2016 Commercial $ 4,127,397 $ 113,838 $ 105,271 $ — $ 4,346,506 Commercial collateralized by assignment of lease payments 1,981,689 16,010 5,277 — 2,002,976 Commercial real estate: Healthcare 545,663 32,251 4,536 — 582,450 Industrial 814,668 17,962 763 — 833,393 Multifamily 544,071 312 3,614 — 547,997 Retail 498,458 8,350 549 — 507,357 Office 404,811 5,299 3,088 — 413,198 Other 820,229 44,629 38,763 — 903,621 Construction real estate 518,562 — — — 518,562 Total $ 10,255,548 $ 238,651 $ 161,861 $ — $ 10,656,060 Approximately $15.9 million and $17.3 million of the substandard loans were non-performing as of September 30, 2017 and December 31, 2016 , 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, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): Performing Non-performing Total September 30, 2017 Residential real estate $ 1,414,599 $ 18,996 $ 1,433,595 Indirect vehicle 652,739 2,474 655,213 Home equity 215,923 12,803 228,726 Other consumer 77,276 96 77,372 Total $ 2,360,537 $ 34,369 $ 2,394,906 December 31, 2016 Residential real estate $ 1,044,055 $ 16,773 $ 1,060,828 Indirect vehicle 539,315 2,365 541,680 Home equity 253,190 13,187 266,377 Other consumer 80,710 71 80,781 Total $ 1,917,270 $ 32,396 $ 1,949,666 The recorded investment in residential mortgage loans secured by residential real estate properties (including purchased credit-impaired loans) for which foreclosure proceedings are in process totaled $46.1 million and $29.1 million at September 30, 2017 and December 31, 2016 , respectively. The following tables present loans individually evaluated for impairment by class of loans, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 Three Months Ended Nine Months Ended Unpaid Recorded Partial Allowance for Average Interest Average Interest With no related allowance recorded: Commercial $ 2,997 $ 2,997 $ — $ — $ 2,470 $ 22 $ 4,064 $ 59 Commercial collateralized by assignment of lease payments 16 1 15 — 1 — 403 — Commercial real estate: Healthcare — — — — — — — — Industrial 1,238 1,238 — — 1,350 — 1,684 8 Multifamily — — — — — — 1,686 29 Retail — — — — — — 1,088 27 Office 1,860 1,856 4 — 1,903 6 1,715 12 Other 3,542 3,542 — — 3,552 57 1,197 57 Residential real estate 750 718 32 — — — — — Construction real estate — — — — — — — — Indirect vehicle 572 349 223 — 621 10 396 20 Home equity 108 108 — — 26 — 476 — Other consumer — — — — — — — — With an allowance recorded: Commercial 7,645 7,645 — 1,012 8,406 29 8,481 202 Commercial collateralized by assignment of lease payments 920 920 — 585 500 14 168 14 Commercial real estate: Healthcare — — — — — — — — Industrial 3,254 3,243 11 432 3,293 34 2,213 66 Multifamily 569 569 — 234 565 — 379 — Retail — — — — — — 1,799 28 Office 961 960 1 34 214 4 72 4 Other 591 591 — 155 115 — 39 — Residential real estate 20,876 18,652 2,224 2,169 18,655 16 17,126 21 Construction real estate — — — — — — — — Indirect vehicle — — — — — — — — Home equity 29,648 27,360 2,288 2,562 27,421 12 27,820 39 Other consumer — — — — — — — — Total $ 75,547 $ 70,749 $ 4,798 $ 7,183 $ 69,092 $ 204 $ 70,806 $ 586 December 31, 2016 Year Ended Unpaid Recorded Partial Allowance for Average Interest With no related allowance recorded: Commercial $ 9,056 $ 9,056 $ — $ — $ 5,944 $ — Commercial collateralized by assignment of lease payments 1,129 747 382 — 1,045 34 Commercial real estate: Healthcare — — — — — — Industrial — — — — 402 — Multifamily 1,922 1,922 — — 2,348 — Retail 2,670 929 1,741 — 2,165 — Office — — — — 256 — Other — — — — 60 — Residential real estate — — — — — — Construction real estate — — — — — — Indirect vehicle 223 122 101 — 252 — Home equity — — — — 143 — Other consumer — — — — — — With an allowance recorded: Commercial 14,403 14,403 — 2,889 22,737 — Commercial collateralized by assignment of lease payments — — — — 2,397 18 Commercial real estate: Healthcare — — — — — — Industrial — — — — — — Multifamily — — — — — — Retail 3,592 3,592 — 354 6,827 — Office — — — — 745 — Other — — — — 235 — Residential real estate 16,257 14,353 1,904 2,163 13,412 — Construction real estate — — — — — — Indirect vehicle — — — — — — Home equity 31,104 28,790 2,314 2,930 28,677 — Other consumer — — — — — — Total $ 80,356 $ 73,914 $ 6,442 $ 8,336 $ 87,645 $ 52 Impaired loans included accruing restructured loans of $32.9 million and $32.7 million that have been modified and are performing in accordance with those modified terms as of September 30, 2017 and December 31, 2016 , respectively. In addition, impaired loans included $24.4 million and $27.1 million of non-performing restructured loans as of September 30, 2017 and December 31, 2016 , 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. 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 and lease losses 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 were restructured during the three months ended September 30, 2017 (dollars in thousands): September 30, 2017 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial real estate Industrial 1 $ 387 $ 387 $ — Retail 2 337 337 — Other 2 3,555 3,555 — Home equity 1 19 19 1 Total 6 $ 4,298 $ 4,298 $ 1 Non-Performing: Residential real estate 11 $ 2,775 $ 2,775 $ 739 Indirect vehicle 20 153 153 105 Home equity 1 15 15 1 Total 32 $ 2,943 $ 2,943 $ 845 The following table presents loans that were restructured during the nine months ended September 30, 2017 (dollars in thousands): September 30, 2017 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial 5 $ 2,491 $ 2,491 $ 373 Commercial real estate Industrial 3 3,174 3,174 — Retail 2 337 337 — Office 1 549 549 — Other 3 3,703 3,703 — Residential real estate 6 902 902 135 Home equity 4 97 97 7 Total 24 $ 11,253 $ 11,253 $ 515 Non-Performing: Commercial 2 $ 676 $ 676 $ — Commercial real estate: Multifamily 3 290 290 — Retail 1 906 906 — Residential real estate 28 5,155 5,155 1,182 Indirect vehicle 31 250 250 134 Home equity 4 608 608 58 Total 69 $ 7,885 $ 7,885 $ 1,374 The following table presents loans that were restructured during the three months ended September 30, 2016 (dollars in thousands): September 30, 2016 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Residential real estate 2 $ 101 $ 101 $ 18 Home equity 2 102 102 12 Total 4 $ 203 $ 203 $ 30 Non-Performing: Commercial 3 $ 5,874 $ 5,874 $ 1,490 Residential real estate 4 484 484 85 Indirect vehicle 7 34 34 17 Home equity 5 489 489 72 Total 19 $ 6,881 $ 6,881 $ 1,664 The following table presents loans that were restructured during the nine months ended September 30, 2016 (dollars in thousands): September 30, 2016 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial 1 $ 1,870 $ 1,870 $ 412 Residential real estate 2 101 101 18 Home equity 4 511 511 12 Total 7 $ 2,482 $ 2,482 $ 442 Non-Performing: Commercial 7 $ 14,481 $ 14,481 $ 4,990 Residential real estate 6 639 639 85 Indirect vehicle 25 183 183 60 Home equity 28 3,600 3,600 138 Total 66 $ 18,903 $ 18,903 $ 5,273 Of the troubled debt restructurings entered into during the past twelve months, none subsequently defaulted during the nine months ended September 30, 2017 . 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 table presents the troubled debt restructurings activity during the nine months ended September 30, 2017 (in thousands): Performing Non-performing Beginning balance $ 32,687 $ 27,068 Additions 11,253 7,885 Charge-offs — (520 ) Principal payments, net (1,001 ) (4,601 ) Removals (11,546 ) (3,429 ) Transfer to other real estate owned — (590 ) Transfers in 2,056 599 Transfers out (599 ) (2,056 ) Ending balance $ 32,850 $ 24,356 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 during the nine months ended September 30, 2017 (in thousands): September 30, 2017 Extended Maturity, Delay in Amortization Extended Payments and/or and Reduction Maturity and/or Reduction of of Interest Rate Amortization Interest Rate Total Commercial $ — $ 3,167 $ — $ 3,167 Commercial collateralized by assignment of lease payments — — — — Commercial real estate: Healthcare — — — — Industrial — 3,174 — 3,174 Multifamily — 290 — 290 Retail — 906 337 1,243 Office — 549 — 549 Other — 3,703 — 3,703 Residential real estate 3,885 1,589 583 6,057 Construction real estate — — — — Indirect vehicle — — 250 250 Home equity — 35 670 705 Other consumer — — — — Total $ 3,885 $ 13,413 $ 1,840 $ 19,138 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, 2017 and 2016 (in thousands): Commercial Commercial collateralized by assignment of lease payments Commercial real estate Residential real estate Construction real estate Indirect vehicle Home equity Other consumer Unfunded commitments Total September 30, 2017 Allowance for credit losses: Three Months Ended Beginning balance $ 43,783 $ 12,765 $ 63,247 $ 8,249 $ 15,263 $ 3,963 $ 4,750 $ 2,013 $ 2,264 $ 156,297 Charge-offs 235 188 31 541 — 1,097 439 299 — 2,830 Recoveries 719 — 1,432 38 502 498 149 82 — 3,420 Provision 1,715 240 935 94 (707 ) 1,317 422 489 12 4,517 Ending balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Nine Months Ended Beginning balance $ 44,661 $ 12,238 $ 51,807 $ 5,971 $ 14,758 $ 3,421 $ 4,689 $ 1,821 $ 2,476 $ 141,842 Charge-offs 1,103 188 1,378 901 — 3,438 873 1,243 — 9,124 Recoveries 3,568 712 2,312 624 661 1,715 724 420 — 10,736 Provision (1,144 ) 55 12,842 2,146 (361 ) 2,983 342 1,287 (200 ) 17,950 Ending balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Ending allowance balance attributable to loans: Individually evaluated for impairment $ 1,012 $ 585 $ 855 $ 2,169 $ — $ — $ 2,562 $ — $ 1,220 $ 8,403 Collectively evaluated for impairment 44,879 12,232 63,868 5,671 15,023 4,681 2,320 2,285 1,056 152,015 Acquired and accounted for under ASC 310-30 (1) 91 — 860 — 35 — — — — 986 Total ending allowance balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Loans: Individually evaluated for impairment $ 10,642 $ 921 $ 11,999 $ 19,370 $ — $ 349 $ 27,468 $ — $ — $ 70,749 Collectively evaluated for impairment 4,783,196 2,073,294 4,082,707 1,414,225 395,794 654,864 201,258 77,372 — 13,682,710 Acquired and accounted for under ASC 310-30 (1) 13,677 — 32,063 68,071 5,183 — 11,200 1,725 — 131,919 Total ending loans balance $ 4,807,515 $ 2,074,215 $ 4,126,769 $ 1,501,666 $ 400,977 $ 655,213 $ 239,926 $ 79,097 $ — $ 13,885,378 Commercial Commercial collateralized by assignment of lease payments Commercial real estate Residential real estate Construction real estate Indirect vehicle Home equity Other consumer Unfunded commitments Total September 30, 2016 Allowance for credit losses: Three Months Ended Beginning balance $ 50,297 $ 10,549 $ 46,040 $ 4,800 $ 14,230 $ 3,100 $ 4,199 $ 2,399 $ 2,719 $ 138,333 Charge-offs 1,341 367 529 290 7 838 376 409 — 4,157 Recoveries 665 3 324 45 50 436 65 86 — 1,674 Provision (3,894 ) 2,944 1,239 1,575 2,033 598 2,309 (407 ) 152 6,549 Ending balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Nine Months Ended Beginning balance $ 39,316 $ 10,434 $ 45,475 $ 5,734 $ 15,113 $ 2,418 $ 7,374 $ 2,276 $ 3,368 $ 131,508 Charge-offs 2,126 3,288 2,601 1,134 151 2,420 1,233 1,216 — 14,169 Recoveries 1,997 520 2,761 151 94 1,400 576 620 — 8,119 Provision 6,540 5,463 1,439 1,379 1,250 1,898 (520 ) (11 ) (497 ) 16,941 Ending balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Ending allowance balance attributable to loans: Individually evaluated for impairment $ 5,401 $ 3,933 $ 363 $ 2,394 $ — $ — $ 3,252 $ — $ 737 $ 16,080 Collectively evaluated for impairment 40,161 9,196 46,235 3,736 16,249 3,296 2,945 1,669 2,134 125,621 Acquired and accounted for under ASC 310-30 (1) 165 — 476 — 57 — — — — 698 Total ending allowance balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Loans: Individually evaluated for impairment $ 19,284 $ 8,054 $ 6,530 $ 13,268 $ — $ 125 $ 27,276 $ — $ — $ 74,537 Collectively evaluated for impairment 4,366,528 1,865,326 3,788,271 985,559 451,023 522,146 248,012 77,956 — 12,304,821 Acquired and accounted for under ASC 310-30 (1) 22,913 — 41,286 66,698 14,131 — 13,886 2,424 — 161,338 Total ending loans balance $ 4,408,725 $ 1,873,380 $ 3,836,087 $ 1,065,525 $ 465,154 $ 522,271 $ 289,174 $ 80,380 $ — $ 12,540,696 (1) Loans acquired in business combinations 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 and lease 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 for in accordance with ASC Topic 310-20 "Nonrefundable Fees and Other Costs" as these loans do not have evidence of credit deterioration since origination. • Non-impaired loans (typically performing substandard loans) are accounted for in accordance with ASC Topic 310-30 if 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 Topic 310-30 as they display significant credit deterioration since origination. For pass rated loans (non-purchased credit-impaired loans), the difference between the estimated fair value of the loans and the principal outstanding is accreted over the remaining life of the loans. In accordance with ASC 310-30, for both purchased non-impaired loans and purchased credit-impaired loans, the loans are pooled by loan type and 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 pools when there is a reasonable expectation about the amount and timing of such cash flows. Substantially all of the loans acquired in FDIC-assisted transactions 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 nine months ended September 30, 2017 , there was a provision for credit losses of $243 thousand and net charge-offs of $123 thousand in relation to purchased credit-impaired loans. There was $986 thousand and $866 thousand in allowance for loan and lease losses related to these purchased credit-impaired loans at September 30, 2017 and December 31, 2016 , respectively. The provision for credit losses and accompanying charge-offs are included in the table above. Changes in the accretable yield for loans acquired and accounted for under ASC 310-30 were as follows for the three and nine months ended September 30, 2017 and 2016 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Balance at beginning of period $ 12,686 $ 13,160 $ 16,050 $ 12,596 Purchases — 805 43 805 Accretion (4,315 ) (2,564 ) (9,334 ) (7,193 ) Other (1) 3,453 2,523 5,065 7,716 Balance at end of period $ 11,824 $ 13,924 $ 11,824 $ 13,924 (1) Primarily includes discount transfers from non-accretable discount to accretable discount due to better than expected performance of loan pools acquired and accounted for under ASC 310-30. In our FDIC-assisted transactions, the fair value of purchased credit-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, we 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. For other loans acquired through business combinations, the fair value of purchased credit-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. The carrying amount of loans acquired through a business combination by loan pool type are as follows (in thousands): September 30, 2017 Purchased Purchased Non-Credit-Impaired Total Covered loans (1) : Consumer related $ 15,658 $ — $ 15,658 Non-covered loans: Commercial loans 13,677 353,489 367,166 Commercial loans collateralized by assignment of lease payments — 50,629 50,629 Commercial real estate 32,063 873,179 905,242 Construction real estate 5,183 7,418 12,601 Consumer related 5,277 291,376 296,653 Total non-covered loans 56,200 1,576,091 1,632,291 Total acquired $ 71,858 $ 1,576,091 $ 1,647,949 (1) Covered loans refer to loans covered under loss-sharing agreements with the FDIC. In addition to loans acquired through a business combination noted in the table above, consumer related purchased credit-impaired loans includes loans repurchased from GNMA of $60.1 million as of September 30, 2017 . Effective April 1, 2014, the losses on commercial related loans (commercial, commercial real estate and construction real estate) acquired in connection with the Heritage Community Bank ("Heritage") FDIC-assisted transaction ceased being covered under the loss-share agreement for t

Goodwill and Intangibles

Goodwill and Intangibles	9 Months Ended
	Sep. 30, 2017
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, including core deposit and client relationship intangibles, consists of goodwill. 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 units with the fair value of the reporting units. The Company's annual assessment date is as of December 31. Goodwill is tested for impairment at the reporting unit level. The Company has three reporting units: Banking, Leasing and Mortgage Banking. No impairment losses were recognized during the nine months ended September 30, 2017 or 2016 . The carrying amount of goodwill was $999.9 million and $1.0 billion at September 30, 2017 and December 31, 2016 , respectively. The following table presents the changes in the carrying amount of goodwill for the nine months ended September 30, 2017 (in thousands): Banking Leasing Mortgage Banking Total Balance at beginning of period $ 960,398 $ 40,640 $ — $ 1,001,038 Goodwill from business combinations (1) (1,113 ) — — (1,113 ) Balance at end of period $ 959,285 $ 40,640 $ — $ 999,925 (1) Due to the adjustments recognized for the American Chartered merger during the first quarter of 2017. The Company has other intangible assets consisting of core deposit and client relationship intangibles that had a remaining weighted average amortization period of approximately 13 years as of September 30, 2017 . The following table presents the changes during the nine months ended September 30, 2017 in the carrying amount of core deposit and client relationship intangibles, and the gross carrying amount, accumulated amortization, and net book value as of September 30, 2017 (in thousands): September 30, 2017 Balance at beginning of period $ 62,959 Amortization expense (6,214 ) Balance at end of period $ 56,745 Gross carrying amount $ 112,820 Accumulated amortization (56,075 ) Net book value $ 56,745 The following presents the estimated future amortization expense of other intangible assets (in thousands): Year ending December 31, Amount 2017 $ 1,979 2018 7,451 2019 5,674 2020 5,022 2021 4,790 Thereafter 31,829 $ 56,745

Deposits

Deposits	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Deposits	Deposits The composition of deposits was as follows as of September 30, 2017 and December 31, 2016 (in thousands): September 30, December 31, 2017 2016 Demand deposit accounts, non-interest bearing $ 6,101,159 $ 6,408,169 NOW, money market and interest bearing deposits 4,842,097 4,543,004 Savings accounts 1,088,194 1,135,992 Certificates of deposit, $250,000 or more 1,430,706 1,144,121 Other certificates of deposit 952,988 879,162 Total $ 14,415,144 $ 14,110,448 Certificates of deposit of $250,000 or more included $997.7 million and $795.0 million of brokered deposits at September 30, 2017 and December 31, 2016 , respectively. Brokered deposits typically consist of smaller individual time certificates that have the same liquidity characteristics and yields consistent with time certificates of $250,000 or more.

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Short-Term Borrowings	Short-Term Borrowings Short-term borrowings were as follows as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 Weighted Average Interest Rate Amount Weighted Average Interest Rate Amount Customer repurchase agreements 0.26 % $ 222,915 0.22 % $ 237,538 Federal Home Loan Bank advances 1.22 1,400,000 0.63 1,275,000 Federal funds purchased 1.35 242,500 0.80 46,750 Line of credit — — 2.52 10,000 Total 1.12 % $ 1,865,415 0.59 % $ 1,569,288 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 pledges mortgage-backed securities as collateral for the repurchase agreements and may be required to provide additional collateral based on the fair value of those securities. The Company had Federal Home Loan Bank fixed rate advances with a maturity date less than one year of $1.4 billion at September 30, 2017 and $1.3 billion at December 31, 2016 . At September 30, 2017 , the interest rate on the advances outstanding on that date had rates ranging from 0.85% to 1.30% with maturities from October 2017 to June 2018 . The Company has loans pledged as collateral on this FHLB advance. See Note 6. Loans of the notes to the consolidated financial statements. On December 18, 2015, the Company entered into a $35.0 million unsecured line of credit at the holding company level with a correspondent bank. Interest is payable at a rate of one month LIBOR + 1.75% . No borrowings under the line of credit were outstanding as of September 30, 2017 , and $10.0 million were outstanding as of December 31, 2016 . The line of credit is scheduled to mature on June 30, 2018.

Long-Term Borrowings

Long-Term Borrowings	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Long-Term Borrowings	Long-Term Borrowings Long-term borrowings were as follows as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 Weighted Average Interest Rate Amount Weighted Average Interest Rate Amount Federal Home Loan Bank advances 1.47 % $ 306,367 0.85 % $ 230,865 Notes payable 4.06 88,348 4.18 66,925 Term note 2.98 11,000 2.52 14,000 Total 2.08 % $ 405,715 1.64 % $ 311,790 The Company had Federal Home Loan Bank ("FHLB") advances with remaining contractual maturities greater than one year of $306.4 million at September 30, 2017 and $230.9 million at December 31, 2016 . As of September 30, 2017 , the advances had fixed terms with effective interest rates, net of discounts, ranging from 1.35% to 5.87% and maturities ranging from December 2018 to April 2035 . The Company has loans pledged as collateral on these FHLB advances. See Note 6. Loans of the notes to the consolidated financial statements. The Company had notes payable to banks totaling $73.6 million and $66.9 million at September 30, 2017 and December 31, 2016 , respectively, which as of September 30, 2017 , were accruing interest at rates ranging from 2.25% to 7.40% , with a weighted average rate of 4.28% . Lease investments includes equipment with an amortized cost of $88.3 million and $79.6 million at September 30, 2017 and December 31, 2016 , respectively, that is pledged as collateral on these notes. At September 30, 2017 , the Company also had $14.8 million in other secured borrowings (included in the notes payable above) with a weighted average rate of 2.97% . On August 24, 2016, the Company assumed a $16.0 million unsecured term loan at the holding company level with a correspondent bank through the American Chartered merger. Interest is payable at a rate of one month LIBOR + 1.75% and the loan matures on June 30, 2020. Principal payments of $1.0 million are due quarterly until maturity. As of September 30, 2017 , $11.0 million of principal was outstanding.

Junior Subordinated Notes Issue

Junior Subordinated Notes Issued to Capital Trusts	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
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 2 regulatory capital. Prior to the completion of the American Chartered merger, the trust preferred securities qualified, and were 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, 2017 (in thousands): Coal City Capital Trust I MB Financial Capital Trust II MB Financial Capital Trust III MB Financial 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 Capital Trust V MB Financial Capital Trust VI FOBB Statutory Trust III (2) TAYC Capital Trust II (3) Junior Subordinated Notes: Principal balance $ 30,928 $ 23,196 $ 5,155 $ 41,238 Annual interest rate 3-mo LIBOR + 1.30% 3-mo LIBOR + 1.30% 3-mo LIBOR + 2.80% 3-mo LIBOR + 2.68% Stated maturity date December 15, 2037 October 30, 2037 January 23, 2034 June 17, 2034 Call date December 15, 2012 October 30, 2012 January 23, 2009 June 17, 2009 Trust Preferred Securities: Face Value $ 30,000 $ 22,500 $ 5,000 $ 40,000 Annual distribution rate 3-mo LIBOR + 1.30% 3-mo LIBOR + 1.30% 3-mo LIBOR + 2.80% 3-mo LIBOR + 2.68% Issuance date September 2007 October 2007 December 2003 June 2004 Distribution dates (1) Quarterly Quarterly Quarterly Quarterly American Chartered Statutory Trust I (4) American Chartered Statutory Trust II (4) Junior Subordinated Notes: Principal balance $ 20,619 $ 10,310 Annual interest rate 3-mo LIBOR + 3.60% 3-mo LIBOR + 2.75% Stated maturity date December 18, 2031 October 7, 2034 Call date December 18, 2006 October 7, 2009 Trust Preferred Securities: Face Value $ 20,000 $ 10,000 Annual distribution rate 3-mo LIBOR + 3.60% 3-mo LIBOR + 2.75% Issuance date November 2001 August 2004 Distribution dates (1) 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 in 2006, and the junior subordinated notes issued by FOBB to FOBB Statutory Trust III were assumed by the Company upon completion of the acquisition. (3) TAYC Capital Trust II was established by Taylor Capital Group, Inc. (“Taylor Capital”) prior to the Company's acquisition of Taylor Capital in 2014, and the junior subordinated notes issued by Taylor Capital to TAYC Capital Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with TAYC Capital Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.5 million at September 30, 2017 . (4) American Chartered Statutory Trust I and American Chartered Statutory Trust II were established by American Chartered prior to the Company's acquisition of American Chartered in August 2016, and the junior subordinated notes issued by American Chartered to American Chartered Statutory Trust I and American Chartered Statutory Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with American Chartered Statutory Trust I and American Chartered Statutory Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.1 million at September 30, 2017 . 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. 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, constitute 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 common or preferred stock and generally may not repurchase its common or preferred stock.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
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, 2017 and December 31, 2016 , the following financial instruments were outstanding, the contractual amounts of which represent off-balance sheet credit risk (in thousands): Contractual Amount September 30, 2017 December 31, 2016 Commitments to extend credit: Home equity lines $ 207,444 $ 235,279 Other commitments 3,914,154 3,679,259 Letters of credit: Standby 183,396 185,386 Commercial 4,133 1,766 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, 2017 , the maximum remaining term for any standby letters of credit was September 30, 2030 . 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, 2017 , 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 $377 thousand to $187.5 million from $187.2 million at December 31, 2016 . Of the $187.5 million in commitments outstanding at September 30, 2017 , approximately $28.4 million of the letters of credit have been issued or renewed since December 31, 2016 . Letters of credit issued on behalf of bank customers may be done on either a secured or unsecured basis. If a letter credit is secured, the collateral can take various forms including bank accounts, investments, fixed assets, inventory, accounts receivable or real estate. 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, 2017 , the Company had approximately $6.0 million in capital expenditure commitments outstanding which relate to various projects to renovate the corporate office space and branches. Concentrations of credit risk: As of September 30, 2017 , approximately 20% 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, 2017 . Our commitments to extend credit are primarily related to commercial credits. Standby letters of credit are granted primarily to commercial borrowers. Our asset-based loans are made to borrowers located throughout the United States. Lease banking provides banking services to lessors located throughout the United States. Our leasing subsidiaries originate leases to companies located throughout the United States. In addition, our mortgage segment and indirect vehicle lenders originate loans to borrowers located throughout 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, 2017
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. Mortgage loans originated and held for sale in the secondary market are carried at fair value. The fair value of loans held for sale is determined using quoted secondary market prices and classified as Level 2. Loans. The Company has elected to record certain mortgage loans at fair value. The fair value of these loans is determined using quoted secondary market prices and classified as Level 2. Mortgage Servicing Rights. The Company has elected to record its mortgage servicing rights at fair value. Mortgage servicing rights do not trade in an active market with readily observable prices. Accordingly, the Company determines the fair value of mortgage servicing rights by estimating the fair value of the future cash flows associated with the mortgage loans being serviced. Key economic assumptions used in measuring the fair value of mortgage servicing rights include, but are not limited to, prepayment speeds, discount rates, delinquencies and cost to service. The assumptions used in the model are validated on a regular basis. The fair value is validated on a quarterly basis with an independent third party. Any material discrepancies between the internal model and the third party validation are investigated and resolved by an internal committee. Due to the nature of the valuation inputs, mortgage servicing rights are classified in Level 3 of the fair value hierarchy. 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. The Company also obtains dealer quotations for these derivatives for comparative purposes to assess the reasonableness of the model valuations. In addition, the Company uses forward commitments to buy to-be-announced mortgage securities for which we do not intend to take delivery of the security and will enter into an offsetting position before physical delivery to lessen the price volatility of the mortgage servicing rights asset. Dealer quotations are used for these derivatives and are classified as Level 1. The Company also offers 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. For certain interest rate lock commitments, the Company uses an external valuation model that relies on internally developed inputs to estimate the fair value of its interest rate lock commitments which is based on unobservable inputs that reflect management’s assumptions and specific information about each borrower transaction and is classified in Level 3 of the hierarchy. The following table summarizes financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Financial assets Securities available for sale: U.S Government sponsored agencies and enterprises $ 23,146 $ — $ 23,146 $ — States and political subdivisions 385,829 — 385,456 373 Residential mortgage-backed securities 875,260 — 875,195 65 Commercial mortgage-backed securities 87,217 — 87,217 — Corporate bonds 115,014 — 115,014 — Equity securities 11,077 11,077 — — Loans held for sale 722,754 — 722,754 — Loans 14,481 — 14,481 — Mortgage servicing rights 261,446 — — 261,446 Assets held in trust for deferred compensation 20,103 20,103 — — Derivative financial instruments 36,018 2,366 31,713 1,939 Financial liabilities Other liabilities (1) 20,103 20,103 — — Derivative financial instruments 39,915 1,583 38,332 — December 31, 2016 Financial assets Securities available for sale: U.S. Government sponsored agencies and enterprises $ 23,415 $ — $ 23,415 $ — States and political subdivisions 391,365 — 390,992 373 Residential mortgage-backed securities 983,684 — 983,513 171 Commercial mortgage-backed securities 93,008 — 93,008 — Corporate bonds 193,895 — 193,895 — Equity securities 10,828 10,828 — — Loans held for sale 716,883 — 716,883 — Loans 16,273 — 16,273 — Mortgage servicing rights 238,011 — — 238,011 Assets held in trust for deferred compensation 18,723 18,723 — — Derivative financial instruments 44,586 7,687 33,739 3,160 Financial liabilities Other liabilities (1) 18,723 18,723 — — Derivative financial instruments 63,885 2,046 61,839 — (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 September 30, 2017 Valuation Technique Unobservable Input Range (in thousands) States and political subdivisions $ 373 Discounted cash flows Credit assumption 45% - 50% Loss Residential mortgage-backed securities 65 Discounted cash flows Constant pre-payment rates (CPR) 1% - 3% Mortgage servicing rights 261,446 Discounted cash flows CPR 6.80% - 8.42% Discount rate 9.53 - 11.05 Maturity (months) 323 - 358 Delinquencies 2.16 - 4.82 Costs to service $ 67 - $ 227 Additive delinquent costs to service $ 175 - $ 1,000 Derivative financial instruments (mortgage 1,939 Sales cash flows Expected closing ratio 70% - 95% interest rate lock commitments) Expected delivery price 98.41 bps - 108.57 bps The significant unobservable inputs used in the fair value measurement of the Company’s mortgage servicing rights include prepayment speeds, discount rates, maturities, delinquencies and cost to service. Significant increases in prepayment speeds, discount rates, delinquencies or cost to service would result in a significantly lower fair value measurement. Conversely, significant decreases in prepayment speeds, discount rates, delinquencies or costs to service would result in a significantly higher fair value measurement. With the exception of changes in delinquencies, which can change the cost to service, the unobservable inputs move independently of each other. Key economic assumptions used in the measuring of the fair value of the mortgage servicing rights and the sensitivity of the fair value to immediate adverse changes in those assumptions at September 30, 2017 are presented in the following table. This table does not take into account the derivatives used to economically hedge the mortgage servicing rights. (dollars in thousands, except for weighted average cost to service) September 30, 2017 Weighted average CPR 7.58 % Impact on fair value of 10% adverse change $ 9,030 Impact on fair value of 20% adverse change 18,615 Weighted average discount rate 9.81 % Impact on fair value of 10% adverse change $ 11,673 Impact on fair value of 20% adverse change 24,415 Weighted average delinquency rate 4.57 % Impact on fair value of 10% adverse change $ 1,567 Impact on fair value of 20% adverse change 3,499 Weighted average costs to service $ 90.45 Impact on fair value of 10% adverse change 4,919 Impact on fair value of 20% adverse change 9,838 The Company did not have any transfers between Level 1 and Level 2 of the fair value hierarchy during the nine months ended September 30, 2017 . 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, 2017 2016 2017 2016 2017 2016 (in thousands) Investment Securities Mortgage Servicing Rights Derivatives Balance, beginning of period $ 544 $ 773 $ 238,011 $ 168,162 $ 3,160 $ 3,822 Purchases — — 839 3,423 — — Originations — — 43,197 43,039 — — Included in earnings — — (20,601 ) (59,894 ) (1,221 ) 8,739 Principal payments (106 ) (151 ) — — — — Sales — — — — — — Balance, ending of period $ 438 $ 622 $ 261,446 $ 154,730 $ 1,939 $ 12,561 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 ( 100% at September 30, 2017 ), 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 and lease 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, 2017 and December 31, 2016 are included in the table below (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Financial assets: Impaired loans $ 53,842 $ — $ — $ 53,842 Non-financial assets: Foreclosed assets 18,334 — — 18,334 December 31, 2016 Financial assets: Impaired loans $ 54,576 $ — $ — $ 54,576 Non-financial assets: Foreclosed assets 31,607 — — 31,607 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, 2017 Technique Input Range (in thousands) Impaired loans $ 53,842 Appraisal of collateral Appraisal adjustments 5% - 10% Foreclosed assets 18,334 Appraisal of collateral Appraisal adjustments 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 earning 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 : 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): September 30, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets: Cash and due from banks $ 361,080 $ 361,080 $ 361,080 $ — $ — Interest earning deposits with banks 82,636 82,636 82,636 — — Investment securities available for sale 1,497,543 1,497,543 11,077 1,486,028 438 Investment securities held to maturity 994,238 1,031,746 — 1,031,746 — Non-marketable securities - FHLB and FRB stock 152,345 152,345 — — 152,345 Loans held for sale 722,754 722,754 — 722,754 — Loans, net 13,726,250 13,928,427 — 14,481 13,913,946 Accrued interest receivable 61,962 61,962 61,962 — — Derivative financial instruments 36,018 36,018 2,366 31,713 1,939 Financial Liabilities: Non-interest bearing deposits $ 6,101,159 $ 6,101,159 $ 6,101,159 $ — $ — Interest bearing deposits 8,313,985 8,310,123 — — 8,310,123 Short-term borrowings 1,865,415 1,865,796 — — 1,865,796 Long-term borrowings 405,715 411,218 — — 411,218 Junior subordinated notes issued to capital trusts 211,289 177,843 — — 177,843 Accrued interest payable 5,680 5,680 5,680 — — Derivative financial instruments 39,915 39,915 1,583 38,332 — December 31, 2016 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets: Cash and due from banks $ 364,783 $ 364,783 $ 364,783 $ — $ — Interest earning deposits with banks 98,686 98,686 98,686 — — Investment securities available for sale 1,696,195 1,696,195 10,828 1,684,823 544 Investment securities held to maturity 1,069,750 1,093,740 — 1,093,740 — Non-marketable securities - FHLB and FRB stock 143,276 143,276 — — 143,276 Loans held for sale 716,883 716,883 — 716,883 — Loans, net 12,629,437 12,747,107 — 16,273 12,730,834 Accrued interest receivable 59,024 59,024 59,024 — — Derivative financial instruments 44,586 44,586 7,687 33,739 3,160 Financial Liabilities: Non-interest bearing deposits $ 6,408,169 $ 6,408,169 $ 6,408,169 $ — $ — Interest bearing deposits 7,702,279 7,698,839 — — 7,698,839 Short-term borrowings 1,569,288 1,569,314 — — 1,569,314 Long-term borrowings 311,790 317,028 — — 317,028 Junior subordinated notes issued to capital trusts 210,668 157,098 — — 157,098 Accrued interest payable 4,288 4,288 4,288 — — Derivative financial instruments 63,885 63,885 2,046 61,839 —

Stock Incentive Plans

Stock Incentive Plans	9 Months Ended
	Sep. 30, 2017
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, 2017 2016 2017 2016 Total compensation expense for share-based payment plans during the period $ 4,393 $ 4,238 $ 13,317 $ 12,573 Amount of related income tax benefit recognized in income (1) 2,175 3,394 8,513 6,649 (1) Includes tax benefits recorded for the vesting of restricted shares and exercise of options. The Company adopted the Omnibus Incentive Plan (the “Omnibus Plan”) in 1997. On May 28, 2014, the Company’s stockholders approved the third amendment and restatement of the Omnibus Plan to add 3,100,000 authorized shares for a total of 11,400,000 shares of common stock authorized to be utilized in connection with awards under the Omnibus Plan to directors, officers, and employees of the Company or any of its subsidiaries. The number of shares authorized increased by 2,400,000 to 13,800,000 upon completion of the Taylor Capital merger. 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. No more than 10% of the total number of authorized shares may be issued with respect to awards granted after May 28, 2014, other than stock appreciation rights, stock options and performance-based awards, which at the date of grant are scheduled to fully vest prior to three years from the date of grant (although such awards may provide scheduled vesting earlier with respect to some of such shares and for acceleration of vesting as provided in the Omnibus Plan). As of September 30, 2017 , there were 2,924,386 shares available for future grants. Annual equity-based incentive awards are generally granted to selected officers and employees in the first quarter of the 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 changes in stock options for the nine months ended September 30, 2017 : Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In Years) Aggregate Intrinsic Value (in thousands) Options outstanding as of December 31, 2016 1,940,405 $ 27.45 5.31 Granted 163,818 45.53 Exercised (327,970 ) 28.03 Expired — — Forfeited or cancelled (15,093 ) 31.95 Options outstanding as of September 30, 2017 1,761,160 $ 28.99 5.40 $ 28,356 Options exercisable as of September 30, 2017 1,167,465 $ 26.60 3.97 $ 21,522 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, 2017 : September 30, 2017 Risk-free interest rate 2.18 % Expected volatility of Company’s stock 22.71 % Expected dividend yield 1.68 % Expected life of options 5.8 years Weighted average fair value per option of options granted during the year $ 9.40 The total intrinsic value of options exercised during the nine months ended September 30, 2017 and 2016 was $5.2 million and $3.6 million , respectively. The following is a summary of changes in restricted shares and units for the nine months ended September 30, 2017 : Number of Shares and Units Weighted Average Grant Date Fair Value Shares and units outstanding at December 31, 2016 998,807 $ 31.20 Granted 379,962 45.77 Vested (379,375 ) 30.63 Forfeited or cancelled (21,506 ) 35.10 Shares and units outstanding at September 30, 2017 977,888 36.99 The total intrinsic value of restricted shares that vested during the nine months ended September 30, 2017 and 2016 was $17.4 million and $15.7 million , respectively. The Company awarded 65,476 , 80,780 and 71,560 market-based restricted stock units in 2017, 2016 and 2015, 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 Company awarded 48,569 market-based restricted stock units in 2014 that vested in 2017. Recipients earned shares totaling approximately 121% of the number of units issued, based on the Company’s total shareholder 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 awarded. As of September 30, 2017 , there was $26.1 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, 2017 , the weighted-average period over which the unrecognized compensation expense is expected to be recognized was approximately two years.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2017
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 its qualifying 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 statement of operations. 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, 2017 and December 31, 2016 was approximately $1 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, 2017 , the Company’s credit exposure relating to interest rate swaps was approximately $11.3 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 hedging 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 $70 thousand at September 30, 2017 . 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. Interest rate swaps, swaptions and treasury futures are used in order to lessen the price volatility of the mortgage servicing rights asset. The Company also uses forward commitments to buy to-be-announced ("TBA") mortgage securities for which the Company does not intend to take delivery of the security and will enter into an offsetting position before physical delivery to lessen the price volatility of the mortgage servicing rights asset. These derivatives are recorded at their fair value on the consolidated balance sheets in other assets with changes in fair value recorded on the consolidated statements of operations in mortgage banking revenue in non-interest income. The Company’s derivative financial instruments are summarized below as of September 30, 2017 and December 31, 2016 (in thousands): Asset Derivatives Liability Derivatives September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 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) $ — $ — $ — $ — $ 70 $ (1 ) $ 107 $ (4 ) Stand-alone derivative instruments: (2) Interest rate swap contracts 1,554,709 24,609 1,310,057 25,471 1,554,709 (24,609 ) 1,310,057 (25,471 ) Interest rate options contracts 337,999 1,698 217,546 881 337,999 (1,698 ) 217,546 (881 ) Foreign exchange contracts 35,672 2,157 40,641 4,429 34,837 (1,997 ) 40,505 (4,265 ) Spot foreign exchange contracts 342 3 1,691 12 223 — 660 (5 ) Mortgage related derivatives: Interest rate swap contracts 413,000 3,246 383,000 2,946 1,223,000 (10,027 ) 1,458,000 (31,212 ) Treasury futures contracts 42,500 74 15,500 41 45,000 (216 ) — — TBA mortgage securities — — — — 140,000 (1,105 ) 55,000 (132 ) Forward loan sale commitments 759,500 2,292 585,000 7,646 133,500 (262 ) 386,000 (1,915 ) Interest rate lock commitments 555,375 1,939 543,901 3,160 — — — — Total stand-alone derivative instruments 3,699,097 36,018 3,097,336 44,586 3,469,268 (39,914 ) 3,467,768 (63,881 ) Total $ 3,699,097 $ 36,018 $ 3,097,336 $ 44,586 $ 3,469,338 $ (39,915 ) $ 3,467,875 $ (63,885 ) (1) Derivative instruments designated to hedge fixed-rate commercial real estate loans. (2) These portfolio swaps are not designated as hedging instruments under ASC Topic 815. Amounts included in other operating 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, 2017 2016 2017 2016 Derivative instruments designated as hedges of fair value: Interest rate swap contracts $ — $ 3 $ 2 $ 3 Stand-alone derivative instruments: Interest rate swap contracts 3,276 5,296 6,749 5,260 Interest rate options contracts — (36 ) — — Foreign exchange contracts (70 ) 1,362 190 1,362 Spot foreign exchange contracts 629 6 2,036 6 Mortgage related derivatives (11,625 ) (8,118 ) (22,067 ) 31,653 Total stand-alone derivative instruments (7,790 ) (1,490 ) (13,092 ) 38,281 Total $ (7,790 ) $ (1,487 ) $ (13,090 ) $ 38,284 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, 2017 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 swap contracts, caps and floors $ 7,583 $ — $ 7,583 $ 18,821 $ — $ 18,821 Foreign exchange contracts 748 — 748 1,636 — 1,636 Mortgage related derivatives 5,612 — 5,612 11,610 — 11,610 Total derivatives 13,943 — 13,943 32,067 — 32,067 Repurchase agreements — — — 222,915 — 222,915 Total $ 13,943 $ — $ 13,943 $ 254,982 $ — $ 254,982 Financial Assets Financial Liabilities Net Amount Recognized Financial Instruments Collateral Net Amount Net Amount Recognized Financial Instruments Collateral Net Amount Derivatives: Counterparty A $ 4,941 $ (4,941 ) $ — $ — $ 12,399 $ (4,941 ) $ (7,458 ) $ — Counterparty B 2,276 (2,276 ) — — 9,044 (2,276 ) (6,768 ) — Counterparty C 243 (243 ) — — 2,434 (243 ) (2,191 ) — Other counterparties 6,483 (4,268 ) — 2,215 8,190 (4,268 ) (3,922 ) — Total derivatives 13,943 (11,728 ) — 2,215 32,067 (11,728 ) (20,339 ) — Repurchase agreements — — — — 222,915 — (222,915 ) — Total $ 13,943 $ (11,728 ) $ — $ 2,215 $ 254,982 $ (11,728 ) $ (243,254 ) $ — Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2016 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 swap contracts, caps and floors $ 7,885 $ — $ 7,885 $ 18,564 $ — $ 18,564 Foreign exchange contracts 4,315 — 4,315 1,674 — 1,674 Mortgage related derivatives 10,633 — 10,633 33,259 — 33,259 Total derivatives 22,833 — 22,833 53,497 — 53,497 Repurchase agreements — — — 237,538 — 237,538 Total $ 22,833 $ — $ 22,833 $ 291,035 $ — $ 291,035 Financial Assets Financial Liabilities Net Amount Recognized Financial Instruments Collateral Net Amount Net Amount Recognized Financial Instruments Collateral Net Amount Derivatives: Counterparty A $ 2,697 $ (2,697 ) $ — $ — $ 18,768 $ (2,697 ) $ (16,071 ) $ — Counterparty B 4,683 (4,683 ) — — 12,881 (4,683 ) (8,198 ) — Counterparty C 64 (64 ) — — 4,919 (64 ) (4,855 ) — Other counterparties 15,389 (10,938 ) — 4,451 16,929 (10,938 ) (5,980 ) 11 Total derivatives 22,833 (18,382 ) — 4,451 53,497 (18,382 ) (35,104 ) 11 Repurchase agreements — — — — 237,538 — (237,538 ) — Total $ 22,833 $ (18,382 ) $ — $ 4,451 $ 291,035 $ (18,382 ) $ (272,642 ) $ 11

Operating Segments

Operating Segments	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Operating Segments	Operating Segments The Company's operations consist of three reportable operating segments: Banking, Leasing and Mortgage Banking. The Company offers different products and services through its three segments. The accounting policies of the segments are generally the same as those of the consolidated company. The Banking Segment generates its revenues primarily from its lending, deposit gathering and fee business activities. The profitability of this segment's operations depends primarily on its net interest income after provision for credit losses, which is the difference between interest earned on interest earning assets and interest paid on interest bearing liabilities less provision for credit losses. The provision for credit losses is dependent on changes in the Banking Segment's loan portfolio and management’s assessment of the collectability of the loan portfolio as well as prevailing economic and market conditions. The Banking Segment is also subject to an extensive system of laws and regulations that are intended primarily for the protection of depositors and other customers, federal deposit insurance funds and the banking system as a whole. These laws and regulations govern such areas as capital, permissible activities, allowance for loan and lease losses, loans and investments, and rates of interest that can be charged on loans. The Leasing Segment generates its revenues through lease originations and related services. The Leasing Segment invests directly in equipment that the Company leases (referred to as direct finance, leveraged or operating leases) to "Fortune 1000," middle-market companies and healthcare providers located throughout the United States. The lease portfolio is made up of various kinds of equipment, generally technology related, such as computer systems, satellite equipment, medical equipment and general manufacturing, industrial, construction and transportation equipment. The Leasing Segment also specializes in selling third party equipment maintenance contracts to large companies. The Mortgage Banking Segment originates residential mortgage loans for sale to investors and for the Company's portfolio through its retail and third party originator channels. This segment also services residential mortgage loans for various investors and for loans owned by the Company. The Mortgage Banking Segment is subject to an extensive system of laws and regulations that are intended primarily for the protection of customers. Net interest income for the Leasing and Mortgage Banking segments include adjustments based on the Company's internal funds transfer pricing model. Non-interest income for the Leasing Segment includes income on loans originated for the sole purpose of funding equipment purchases related to leases at the Company's lease subsidiaries. The following tables present summary financial information for the reportable segments (in thousands): Banking Leasing Mortgage Banking Consolidated Three months ended September 30, 2017 Net interest income $ 142,888 $ 2,686 $ 11,373 $ 156,947 Provision for credit losses 3,637 399 481 4,517 Non-interest income 45,091 22,597 27,576 95,264 Non-interest expense (1) 112,977 14,535 34,782 162,294 Income tax expense 18,781 4,307 1,469 24,557 Net income $ 52,584 $ 6,042 $ 2,217 $ 60,843 Total assets $ 16,406,714 $ 1,307,459 $ 2,402,362 $ 20,116,535 Three months ended September 30, 2016 Net interest income $ 119,685 $ 2,168 $ 8,918 $ 130,771 Provision for credit losses 4,394 1,964 191 6,549 Non-interest income 40,533 18,759 49,095 108,387 Non-interest expense (1) 117,211 12,604 40,570 170,385 Income tax expense 8,420 2,484 6,901 17,805 Net income $ 30,193 $ 3,875 $ 10,351 $ 44,419 Total assets $ 16,453,379 $ 1,126,847 $ 1,761,656 $ 19,341,882 (1) Includes merger related and repositioning expenses of $1.6 million and $11.4 million in the Banking Segment for the three months ended September 30, 2017 and 2016 , respectively. Banking Leasing Mortgage Banking Consolidated Nine months ended September 30, 2017 Net interest income $ 410,319 $ 7,300 $ 31,365 $ 448,984 Provision for credit losses 16,054 674 1,222 17,950 Non-interest income 130,460 62,240 84,854 277,554 Non-interest expense (1) 337,185 41,815 104,518 483,518 Income tax expense 50,103 10,951 4,170 65,224 Net income $ 137,437 $ 16,100 $ 6,309 $ 159,846 Total assets $ 16,406,714 $ 1,307,459 $ 2,402,362 $ 20,116,535 Nine months ended September 30, 2016 Net interest income $ 341,445 $ 7,002 $ 24,230 $ 372,677 Provision for credit losses 14,390 2,045 506 16,941 Non-interest income 112,221 53,670 116,189 282,080 Non-interest expense (1) 307,733 35,916 110,442 454,091 Income tax expense 36,120 8,872 11,788 56,780 Net income $ 95,423 $ 13,839 $ 17,683 $ 126,945 Total assets $ 16,453,379 $ 1,126,847 $ 1,761,656 $ 19,341,882 (1) Includes merger related and repositioning expenses of $9.0 million and $17.2 million in the Banking Segment for the nine months ended September 30, 2017 and 2016 , respectively.

Preferred Stock

Preferred Stock	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Preferred Stock	Preferred Stock On August 18, 2014, in connection with the Taylor Capital merger, the Company issued one share of its Perpetual Non-Cumulative Preferred Stock, Series A (“Company Series A Preferred Stock”), in exchange for each of the 4,000,000 outstanding shares of Taylor Capital’s Perpetual Non-Cumulative Preferred Stock, Series A. Holders of the Company Series A Preferred Stock are entitled to receive, when as and if declared by the Company’s board of directors, non-cumulative cash dividends on the liquidation preference amount, which is $25 per share, at a rate of 8.00% per annum, payable quarterly. The Company Series A Preferred Stock is callable in February 2018. The Company Series A Preferred Stock is included in Tier 1 capital for regulatory capital purposes. On August 24, 2016, in connection with the American Chartered merger, the Company issued one share of its Cumulative Voting Convertible Preferred Stock, Series B ("Company Series B Preferred Stock"), in exchange for each of the 525 shares of American Chartered's Series D Preferred Stock outstanding immediately prior to the merger whose holders did not elect to receive the same consideration in the Merger as holders of American Chartered Common Stock, based on the number of shares of American Chartered Common Stock into which each such share of American Chartered Series D Preferred Stock would otherwise then be convertible. Holders of the Company Series B Preferred Stock were entitled to receive cumulative cash dividends on the liquidation preference amount, which was $1,000 per share, at a rate of 8.00% per annum, had the right to vote on all matters upon which holders of the Company's common stock were entitled to vote and had the right to convert each share into shares of the Company's common stock at any time. The Company Series B Preferred stock had a mandatory conversion date of September 20, 2017. The Company Series B Preferred Stock was included in Tier 2 capital for regulatory capital purposes. During the fourth quarter of 2016, 400 shares of the Company Series B Preferred stock were voluntarily converted by the holders of such shares into shares of the Company's common stock. On September 20, 2017, the remaining 125 shares of the Company Series B Preferred stock were converted into shares of the Company's common stock pursuant to the mandatory conversion provision referred to above.

New Authoritative Accounting 26

New Authoritative Accounting Guidance (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
New Authoritative Accounting Guidance	ASC Topic 805 "Business Combinations." New authoritative accounting guidance under ASC Topic 805 "Business Combinations" amends prior guidance to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 606 "Revenue from Contracts with Customers." New authoritative accounting guidance under ASC Topic 606, "Revenue from Contracts with Customers" amended prior guidance to require an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and to provide clarification on identifying performance obligations and licensing implementation guidance. The new authoritative guidance was initially effective for reporting periods after January 1, 2017 but was deferred to January 1, 2018. The Company's revenue is comprised of interest income on financial assets, which is excluded from the scope of this new guidance, and non-interest income. The Company expects this new guidance will require it to change how certain recurring revenue streams are recognized within trust and asset management fees, card fees and lease financing revenue but does not expect these changes to have a significant impact on its statements of operations or financial condition. The Company continues to evaluate the impact of this guidance on other components of non-interest income. The Company expects to adopt this new guidance on January 1, 2018 with a cumulative effect adjustment to opening retained earnings, if such adjustment is deemed to be significant. ASC Topic 825 "Financial Instruments." New authoritative accounting guidance under ASC Topic 825 "Financial Instruments" amended prior guidance to require equity investments (except those accounted for under the equity method of accounting) to be measured at fair value with changes in fair value recognized in net income. An entity may choose to measure equity investments that do not have readily determinable fair values at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or similar investment of the same issuer. The new guidance simplifies the impairment assessment of equity investments without readily determinable fair values, requires public entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes, requires an entity to present separately in other comprehensive income the portion of the total change in the fair value of a liability resulting from changes in the instrument-specific credit risk when the entity has selected the fair value option for financial instruments and requires separate presentation of financial assets and liabilities by measurement category and form of financial asset. The new authoritative guidance will be effective for reporting periods after January 1, 2018 and is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 405 "Liabilities-Extinguishment of Liabilities." New authoritative accounting guidance under ASC Topic 405, "Liabilities-Extinguishment of Liabilities" amended prior guidance to clarify that liabilities related to the sale of prepaid store-value products within the scope of this guidance are financial liabilities and that breakage for those liabilities are to be accounted for consistent with the breakage guidance in ASC Topic 606 "Revenue from Contracts with Customers." The new authoritative guidance will be effective for reporting periods after January 1, 2018. The Company is evaluating the new guidance but does not expect it to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 842 "Leases." New authoritative accounting guidance under ASC Topic 842 "Leases" amended prior guidance to require lessees to recognize the assets and liabilities arising from all leases on the balance sheet. The new authoritative guidance defines a lease as a contract, or part of a contract, that conveys the right to control the use of identified property, plant, or equipment (an identified asset) for a period of time in exchange for consideration. In addition, the qualifications for a sale and leaseback transaction have been amended. The new authoritative guidance also requires qualitative and quantitative disclosures by lessees and lessors to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. In transition, lessees and lessors are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The new authoritative guidance will be effective for reporting periods after January 1, 2019. The Company is evaluating the new guidance and its impact on the Company's statements of operations and financial condition. The Company expects an increase in assets and liabilities as a result of recording additional lease contracts where the Company is lessee. ASC Topic 815 "Derivatives and Hedging." New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" amended prior guidance to clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria continue to be met. An entity has an option to apply the amendments in this new authoritative guidance on either a prospective basis or a modified retrospective basis. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" also amended prior guidance to clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. An entity is required to consider whether (1) the payoff is adjusted based on changes in an index, (2) the payoff is indexed to an underlying other than interest rates or credit risk, (3) the debt involves a substantial premium or discount, and (4) the call (put) option is contingently exercisable. An entity should apply this new authoritative guidance on a modified retrospective basis to existing debt instruments as of the beginning of the fiscal year for which the amendments are effective. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 815 "Derivatives and Hedging" amended prior guidance to better align an entity's risk management activities and financial reporting for hedging relationships through changes to both the designation and measurement guidance for qualifying hedging relationships and the presentation of hedge results. The new authoritative guidance expands and refines hedge accounting for both nonfinancial and financial risk components. The new authoritative guidance will be effective for reporting periods after January 1, 2019 with early adoption permitted. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 323 "Investment - Equity Method and Joint Ventures." New authoritative accounting guidance under ASC Topic 323 "Investment - Equity Method and Joint Ventures" amended prior guidance to eliminate the requirement to retroactively adopt the equity method of accounting as a result of an increase in the level of ownership interest or degree of influence. The new authoritative guidance required that the equity method investor add the cost of acquiring the additional interest in the investee to the current basis of the investor’s previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting. The Company adopted this new authoritative guidance on January 1, 2017, and it did not have an impact on the Company's statements of operations or financial condition. ASC Topic 718 "Compensation - Stock Compensation." New authoritative accounting guidance under ASC Topic 718 "Compensation - Stock Compensation" amended prior guidance in several aspects, including the income tax consequences, classification of awards as either equity or liability, and classification on the statement of cash flows. The new authoritative guidance allows for all excess tax benefits and tax deficiencies to be recognized as income tax benefit or expense in the income statement. The tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity also should recognize excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. For the statement of cash flows, excess tax benefits should be classified along with other income tax cash flows as an operating activity, and cash paid by an employer when directly withholding shares for tax withholding purposes should be classified as a financing activity. The new authoritative guidance also allows an entity to make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. In addition, the threshold to qualify for equity classification permits withholding up to the maximum statutory tax rates in the applicable jurisdictions. The Company early adopted the new guidance in the third quarter of 2016. The Company has also elected to account for forfeitures when they occur. New authoritative accounting guidance under ASC Topic 718 "Compensation - Stock Compensation" amends prior guidance by clarifying which changes to terms or conditions of a share-based payment award requires an entity to apply modification accounting. An entity should account for the effects of a modification unless the fair value, vesting conditions and classification of the modified award are the same as the original award. The new authoritative guidance will be effective for reporting periods after January 1, 2018 with early adoption permitted. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 326 "Financial Instruments - Credit Losses." New authoritative accounting guidance under ASC Topic 326 " Financial Instruments - Credit Losses " amended the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information for credit loss estimates. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. The new authoritative guidance also requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected (net of the allowance for credit losses). In addition, the credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses rather than a write-down. The new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is evaluating the new guidance and expects it to have an impact on the Company's statements of operations and financial condition, the significance of which is not yet known. Due to the significant differences in the new authoritative guidance from the existing GAAP, the implementation of this guidance may result in material changes in our accounting for credit losses on the financial instruments. As part of the Company's evaluation process, it has established a steering committee and working group, including individuals from various functional areas, to assess processes, portfolio segmentation, system requirements and needed resources. The Company is also considering third-party consultants to assist in the evaluation process. ASC Topic 230 "Statement of Cash Flows." New authoritative accounting guidance under ASC Topic 230 "Statement of Cash Flows" addresses eight specific cash flow classification issues with the objective of reducing the existing diversity in practice. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. New authoritative accounting guidance under ASC Topic 230 "Statement of Cash Flows" amends prior guidance to require an entity to include amounts generally described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 740 "Income Taxes." New authoritative accounting guidance under ASC Topic 740 "Income Taxes" amends prior guidance to require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 350 "Intangibles-Goodwill and Other." New authoritative accounting guidance under ASC Topic 350 "Intangibles-Goodwill and Other" amends prior guidance to eliminate Step 2 from the goodwill impairment test and require an entity to perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. The new authoritative guidance will be effective for reporting periods after January 1, 2020. The Company is evaluating the new guidance and its impact on the Company's statements of operations and financial condition. ASC Topic 610 "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets." New authoritative accounting guidance under ASC Topic 610 "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets" amends prior guidance to clarify the scope of Subtopic 610-20 by defining in substance nonfinancial assets and to add guidance for partial sales of nonfinancial assets. The new authoritative guidance will be effective for reporting periods after January 1, 2018. This new authoritative guidance is not expected to have a significant impact on the Company's statements of operations or financial condition. ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs." New authoritative accounting guidance under ASC Topic 310 "Receivables - Nonrefundable Fees and Other Costs" amends prior guidance by shortening the amortization period for certain callable debt securities held at a premium requiring the premium to be amortized to the earliest call date. The new authoritative guidance will be effective for reporting periods after January 1, 2019 with early adoption permitted. The Company is evaluating the new guidance and its 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, 2017
Earnings Per Share [Abstract]
Reconciliation of the Number of Shares Used in the Calculation of Basic and Diluted Earnings Per Common 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, 2017 2016 2017 2016 Distributed earnings allocated to common stock $ 17,823 $ 16,114 $ 51,783 $ 42,984 Undistributed earnings 43,020 28,305 108,063 83,961 Net income 60,843 44,419 159,846 126,945 Less: preferred stock dividends 2,002 2,004 6,007 6,004 Net income available to common stockholders for basic earnings per common share 58,841 42,415 153,839 120,941 Plus: preferred stock dividends on convertible preferred stock 2 4 7 4 Less: earnings allocated to participating securities 1 2 3 6 Earnings allocated to common stockholders for diluted earnings per common share $ 58,842 $ 42,417 $ 153,843 $ 120,939 Weighted average shares outstanding for basic earnings per common share 83,891,175 77,506,885 83,799,694 74,780,943 Dilutive effect of: Stock options 502,794 491,238 564,541 378,420 Restricted shares and units 379,684 672,480 404,850 564,028 Convertible preferred stock 6,144 12,567 6,867 4,189 Total dilutive effect of equity awards and convertible preferred stock 888,622 1,176,285 976,258 946,637 Weighted average shares outstanding for diluted earnings per common share 84,779,797 78,683,170 84,775,952 75,727,580 Basic earnings per common share $ 0.70 $ 0.55 $ 1.84 $ 1.62 Diluted earnings per common share 0.69 0.54 1.81 1.60

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Schedule of Estimated Fair Values of Assets Acquired and Liabilities Assumed	Estimated fair values of the assets acquired and liabilities assumed in the American Chartered transaction, as of the closing date of the transaction were as follows (in thousands): August 24, 2016 ASSETS Cash and cash equivalents $ 93,307 Investment securities available for sale 505,564 Non-marketable securities - FRB and FHLB Stock 16,000 Loans 1,942,548 Premises and equipment 39,048 Cash surrender value of life insurance 59,917 Goodwill 274,885 Other intangibles 25,452 Other real estate owned 3,960 Other assets 31,408 Total assets $ 2,992,089 LIABILITIES Deposits $ 2,389,327 Short-term borrowings 48,305 Long-term borrowings 16,000 Junior subordinated notes issued to capital trusts 28,075 Accrued expenses and other liabilities 22,966 Total liabilities $ 2,504,673 Total identifiable net assets $ 487,416 Consideration: Market value of common stock at $39.28 per share at August 24, 2016 (9,744,636 shares of common stock issued) $ 382,769 Series B preferred stock at $2,337.97 per share at August 24, 2016 (525 shares of preferred stock issued) (1) 1,227 Stock-based compensation attributed to pre-business combination service 1,103 Cash paid 102,317 Total fair value of consideration, excluding Series B preferred stock $ 487,416 (1) Per share fair value amount determined as if the shares of Series B preferred stock were converted into shares of common stock.
Schedule of Acquired Loans	The following table presents the acquired loans as of the acquisition date (in thousands): Purchased Purchased Non-Credit-Impaired Fair value $ 62,104 $ 1,880,444 Gross contractual amounts receivable 93,490 2,149,868 Best estimate of contractual cash flows not expected to be collected (1) 22,293 114,154 Best estimate of contractual cash flows expected to be collected 71,197 2,035,714 (1) Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer defaults.
Summary of Pro Forma Information	The following table provides the unaudited pro forma information for the results of operations for the three and nine months ended September 30, 2016 , as if the acquisition had occurred on January 1, 2016. The pro forma results combine the historical results of American Chartered into the Company's consolidated statement of operations including the impact of certain acquisition accounting adjustments including loan discount accretion, investment securities discount accretion, intangible assets amortization, deposit premium accretion and borrowing discount amortization. The pro forma results have been prepared for comparative purposes only and are not necessarily indicative of the results that would have been obtained had the acquisition actually occurred on January 1, 2016. No assumptions have been applied to the pro forma results of operations regarding possible revenue enhancements, provision for credit losses, expense efficiencies or asset dispositions. The merger related expenses that have been recognized are included in net income in the table below. Three Months Ended Nine Months Ended September 30, September 30, 2016 2016 (in thousands) Total revenues (net interest income plus non-interest income) $ 258,611 $ 735,408 Net income 50,029 149,111

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of Amortized Cost and Fair Value of Investment Securities	Amortized cost and fair value of investment securities were as follows as of the dates indicated (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2017 Available for Sale U.S. Government sponsored agencies and enterprises $ 23,077 $ 69 $ — $ 23,146 States and political subdivisions 366,187 20,009 (367 ) 385,829 Residential mortgage-backed securities 878,167 4,773 (7,680 ) 875,260 Commercial mortgage-backed securities 86,411 1,097 (291 ) 87,217 Corporate bonds 114,581 450 (17 ) 115,014 Equity securities 11,177 — (100 ) 11,077 Total Available for Sale 1,479,600 26,398 (8,455 ) 1,497,543 Held to Maturity States and political subdivisions 888,576 35,952 (476 ) 924,052 Residential mortgage-backed securities 105,662 2,032 — 107,694 Total Held to Maturity 994,238 37,984 (476 ) 1,031,746 Total $ 2,473,838 $ 64,382 $ (8,931 ) $ 2,529,289 December 31, 2016 Available for Sale U.S. Government sponsored agencies and enterprises $ 23,267 $ 148 $ — $ 23,415 States and political subdivisions 376,541 15,669 (845 ) 391,365 Residential mortgage-backed securities 988,744 5,741 (10,801 ) 983,684 Commercial mortgage-backed securities 91,949 1,221 (162 ) 93,008 Corporate bonds 193,164 1,426 (695 ) 193,895 Equity securities 11,000 — (172 ) 10,828 Total Available for Sale 1,684,665 24,205 (12,675 ) 1,696,195 Held to Maturity States and political subdivisions 910,608 21,609 (3,039 ) 929,178 Residential mortgage-backed securities 159,142 5,420 — 164,562 Total Held to Maturity 1,069,750 27,029 (3,039 ) 1,093,740 Total $ 2,754,415 $ 51,234 $ (15,714 ) $ 2,789,935
Unrealized Losses on Investment Securities and the Fair Value of the Related Securities	Unrealized losses on investment securities by length of time in a continuous unrealized loss position and the fair value of the related securities at September 30, 2017 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 $ 1,364 $ (4 ) $ 19,044 $ (363 ) $ 20,408 $ (367 ) Residential mortgage-backed securities 308,732 (4,229 ) 222,269 (3,451 ) 531,001 (7,680 ) Commercial mortgage-backed securities 9,602 (188 ) 11,445 (103 ) 21,047 (291 ) Corporate bonds — — 9,978 (17 ) 9,978 (17 ) Equity securities 11,077 (100 ) — — 11,077 (100 ) Total Available for Sale 330,775 (4,521 ) 262,736 (3,934 ) 593,511 (8,455 ) Held to Maturity States and political subdivisions 38,118 (432 ) 2,329 (44 ) 40,447 (476 ) Total $ 368,893 $ (4,953 ) $ 265,065 $ (3,978 ) $ 633,958 $ (8,931 ) Unrealized losses on investment securities by length of time in a continuous unrealized loss position and the fair value of the related securities at December 31, 2016 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 $ 42,806 $ (845 ) $ — $ — $ 42,806 $ (845 ) Residential mortgage-backed securities 623,732 (10,084 ) 54,990 (717 ) 678,722 (10,801 ) Commercial mortgage-backed securities 7,062 (9 ) 11,612 (153 ) 18,674 (162 ) Corporate bonds 21,028 (204 ) 20,088 (491 ) 41,116 (695 ) Equity securities 10,828 (172 ) — — 10,828 (172 ) Total Available for Sale 705,456 (11,314 ) 86,690 (1,361 ) 792,146 (12,675 ) Held to Maturity States and political subdivisions 243,568 (2,999 ) 2,988 (40 ) 246,556 (3,039 ) Total $ 949,024 $ (14,313 ) $ 89,678 $ (1,401 ) $ 1,038,702 $ (15,714 )
Summary of Net Gains (Losses) on Investment Securities Available for Sale	Net gains recognized on investment securities available for sale were as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Realized gains $ 83 $ 457 $ 323 Realized losses — — (6 ) (54 ) Net gains $ 83 $ — $ 451 $ 269
Amortized Cost and Fair Value of Investment Securities by Contractual Maturity	The amortized cost and fair value of investment securities as of September 30, 2017 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 $ 145,205 $ 145,902 Due after one year through five years 106,869 111,113 Due after five years through ten years 57,764 59,755 Due after ten years 194,007 207,219 Equity securities 11,177 11,077 Residential and commercial mortgage-backed securities 964,578 962,477 1,479,600 1,497,543 Held to maturity: Due in one year or less 41,530 41,588 Due after one year through five years 152,848 159,474 Due after five years through ten years 204,683 215,747 Due after ten years 489,515 507,243 Residential mortgage-backed securities 105,662 107,694 994,238 1,031,746 Total $ 2,473,838 $ 2,529,289

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Schedule of Composition of Loans	Loans consist of the following at (in thousands): September 30, December 31, Commercial loans $ 4,793,838 $ 4,346,506 Commercial loans collateralized by assignment of lease payments 2,074,215 2,002,976 Commercial real estate 4,094,706 3,788,016 Residential real estate 1,433,595 1,060,828 Construction real estate 395,794 518,562 Indirect vehicle 655,213 541,680 Home equity 228,726 266,377 Other consumer loans 77,372 80,781 Total loans, excluding purchased credit-impaired loans 13,753,459 12,605,726 Purchased credit-impaired loans 131,919 163,077 Total loans $ 13,885,378 $ 12,768,803
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, 2017 and December 31, 2016 (in thousands): Current 30-59 Days 60-89 Days Loans Past Due Total Total September 30, 2017 Commercial $ 4,782,808 $ 5,438 $ 351 $ 5,241 $ 11,030 $ 4,793,838 Commercial collateralized by assignment of lease payments 2,059,556 10,488 3,810 361 14,659 2,074,215 Commercial real estate: Healthcare 698,919 — — — — 698,919 Industrial 856,630 — — 755 755 857,385 Multifamily 608,254 959 — 569 1,528 609,782 Retail 508,048 1,021 — 258 1,279 509,327 Office 447,671 2,131 — 1,634 3,765 451,436 Other 964,855 1,896 87 1,019 3,002 967,857 Residential real estate 1,422,321 575 4,299 6,400 11,274 1,433,595 Construction real estate 395,226 568 — — 568 395,794 Indirect vehicle 649,884 3,938 992 399 5,329 655,213 Home equity 222,804 1,743 753 3,426 5,922 228,726 Other consumer 77,109 89 79 95 263 77,372 Total loans, excluding purchased credit-impaired loans 13,694,085 28,846 10,371 20,157 59,374 13,753,459 Purchased credit-impaired loans 72,900 4,438 6,602 47,979 59,019 131,919 Total loans $ 13,766,985 $ 33,284 $ 16,973 $ 68,136 $ 118,393 $ 13,885,378 Non-performing loan aging $ 27,148 $ 1,179 $ 2,244 $ 20,044 $ 23,467 $ 50,615 December 31, 2016 Commercial $ 4,337,348 $ 2,515 $ 156 $ 6,487 $ 9,158 $ 4,346,506 Commercial collateralized by assignment of lease payments 1,989,934 9,229 1,869 1,944 13,042 2,002,976 Commercial real estate: Healthcare 582,450 — — — — 582,450 Industrial 825,715 3,045 3,293 1,340 7,678 833,393 Multifamily 547,107 458 53 379 890 547,997 Retail 506,789 568 — — 568 507,357 Office 405,992 350 475 6,381 7,206 413,198 Other 899,950 2,385 1,155 131 3,671 903,621 Residential real estate 1,041,189 8,248 3,409 7,982 19,639 1,060,828 Construction real estate 518,171 — 391 — 391 518,562 Indirect vehicle 537,221 2,836 1,062 561 4,459 541,680 Home equity 261,765 1,219 815 2,578 4,612 266,377 Other consumer 80,443 152 120 66 338 80,781 Total loans, excluding purchased credit-impaired loans 12,534,074 31,005 12,798 27,849 71,652 12,605,726 Purchased credit-impaired loans 86,169 6,546 6,600 63,762 76,908 163,077 Total loans $ 12,620,243 $ 37,551 $ 19,398 $ 91,611 $ 148,560 $ 12,768,803 Non-performing loan aging $ 28,364 $ 2,308 $ 978 $ 27,702 $ 30,988 $ 59,352
Recorded Investment in Non-accrual Loans and Loans Past Due Ninety Days or More and Still Accruing by Class of Loans	The following table presents the recorded investment in non-accrual loans and loans past due ninety days or more and still accruing by class of loans, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 December 31, 2016 Loans past due Loans past due Non-accrual 90 days or more and still accruing Non-accrual 90 days or more and still accruing Commercial $ 7,079 $ — $ 11,222 $ 1,406 Commercial collateralized by assignment of lease payments 1,054 360 1,364 1,197 Commercial real estate: Healthcare — — — — Industrial 2,215 — 276 1,064 Multifamily 1,110 — 2,662 — Office 2,973 — 896 6,381 Retail 382 — 384 — Other 1,058 15 83 21 Residential real estate 18,811 185 16,538 235 Construction real estate — — — — Indirect vehicle 2,440 34 2,355 10 Home equity 12,803 — 13,187 — Other consumer 1 95 7 64 Total $ 49,926 $ 689 $ 48,974 $ 10,378
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, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): Pass Special Substandard Doubtful Total September 30, 2017 Commercial $ 4,556,245 $ 160,905 $ 76,688 $ — $ 4,793,838 Commercial collateralized by assignment of lease payments 2,053,456 12,405 8,354 — 2,074,215 Commercial real estate: Healthcare 659,945 2,675 36,299 — 698,919 Industrial 830,106 15,401 11,878 — 857,385 Multifamily 601,515 151 8,116 — 609,782 Retail 505,004 1,566 2,757 — 509,327 Office 442,550 3,782 5,104 — 451,436 Other 893,589 46,688 27,580 — 967,857 Construction real estate 395,267 527 — — 395,794 Total $ 10,937,677 $ 244,100 $ 176,776 $ — $ 11,358,553 December 31, 2016 Commercial $ 4,127,397 $ 113,838 $ 105,271 $ — $ 4,346,506 Commercial collateralized by assignment of lease payments 1,981,689 16,010 5,277 — 2,002,976 Commercial real estate: Healthcare 545,663 32,251 4,536 — 582,450 Industrial 814,668 17,962 763 — 833,393 Multifamily 544,071 312 3,614 — 547,997 Retail 498,458 8,350 549 — 507,357 Office 404,811 5,299 3,088 — 413,198 Other 820,229 44,629 38,763 — 903,621 Construction real estate 518,562 — — — 518,562 Total $ 10,255,548 $ 238,651 $ 161,861 $ — $ 10,656,060
Recorded Investment in Loan Classes Based on Payment Activity	The following table presents the recorded investment in those loan classes based on payment activity, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): Performing Non-performing Total September 30, 2017 Residential real estate $ 1,414,599 $ 18,996 $ 1,433,595 Indirect vehicle 652,739 2,474 655,213 Home equity 215,923 12,803 228,726 Other consumer 77,276 96 77,372 Total $ 2,360,537 $ 34,369 $ 2,394,906 December 31, 2016 Residential real estate $ 1,044,055 $ 16,773 $ 1,060,828 Indirect vehicle 539,315 2,365 541,680 Home equity 253,190 13,187 266,377 Other consumer 80,710 71 80,781 Total $ 1,917,270 $ 32,396 $ 1,949,666
Loans Individually Evaluated for Impairment by Class of Loans	The following tables present loans individually evaluated for impairment by class of loans, excluding purchased credit-impaired loans, as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 Three Months Ended Nine Months Ended Unpaid Recorded Partial Allowance for Average Interest Average Interest With no related allowance recorded: Commercial $ 2,997 $ 2,997 $ — $ — $ 2,470 $ 22 $ 4,064 $ 59 Commercial collateralized by assignment of lease payments 16 1 15 — 1 — 403 — Commercial real estate: Healthcare — — — — — — — — Industrial 1,238 1,238 — — 1,350 — 1,684 8 Multifamily — — — — — — 1,686 29 Retail — — — — — — 1,088 27 Office 1,860 1,856 4 — 1,903 6 1,715 12 Other 3,542 3,542 — — 3,552 57 1,197 57 Residential real estate 750 718 32 — — — — — Construction real estate — — — — — — — — Indirect vehicle 572 349 223 — 621 10 396 20 Home equity 108 108 — — 26 — 476 — Other consumer — — — — — — — — With an allowance recorded: Commercial 7,645 7,645 — 1,012 8,406 29 8,481 202 Commercial collateralized by assignment of lease payments 920 920 — 585 500 14 168 14 Commercial real estate: Healthcare — — — — — — — — Industrial 3,254 3,243 11 432 3,293 34 2,213 66 Multifamily 569 569 — 234 565 — 379 — Retail — — — — — — 1,799 28 Office 961 960 1 34 214 4 72 4 Other 591 591 — 155 115 — 39 — Residential real estate 20,876 18,652 2,224 2,169 18,655 16 17,126 21 Construction real estate — — — — — — — — Indirect vehicle — — — — — — — — Home equity 29,648 27,360 2,288 2,562 27,421 12 27,820 39 Other consumer — — — — — — — — Total $ 75,547 $ 70,749 $ 4,798 $ 7,183 $ 69,092 $ 204 $ 70,806 $ 586 December 31, 2016 Year Ended Unpaid Recorded Partial Allowance for Average Interest With no related allowance recorded: Commercial $ 9,056 $ 9,056 $ — $ — $ 5,944 $ — Commercial collateralized by assignment of lease payments 1,129 747 382 — 1,045 34 Commercial real estate: Healthcare — — — — — — Industrial — — — — 402 — Multifamily 1,922 1,922 — — 2,348 — Retail 2,670 929 1,741 — 2,165 — Office — — — — 256 — Other — — — — 60 — Residential real estate — — — — — — Construction real estate — — — — — — Indirect vehicle 223 122 101 — 252 — Home equity — — — — 143 — Other consumer — — — — — — With an allowance recorded: Commercial 14,403 14,403 — 2,889 22,737 — Commercial collateralized by assignment of lease payments — — — — 2,397 18 Commercial real estate: Healthcare — — — — — — Industrial — — — — — — Multifamily — — — — — — Retail 3,592 3,592 — 354 6,827 — Office — — — — 745 — Other — — — — 235 — Residential real estate 16,257 14,353 1,904 2,163 13,412 — Construction real estate — — — — — — Indirect vehicle — — — — — — Home equity 31,104 28,790 2,314 2,930 28,677 — Other consumer — — — — — — Total $ 80,356 $ 73,914 $ 6,442 $ 8,336 $ 87,645 $ 52
Schedule of Loans That Have Been Restructured	The following table presents loans that were restructured during the three months ended September 30, 2017 (dollars in thousands): September 30, 2017 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial real estate Industrial 1 $ 387 $ 387 $ — Retail 2 337 337 — Other 2 3,555 3,555 — Home equity 1 19 19 1 Total 6 $ 4,298 $ 4,298 $ 1 Non-Performing: Residential real estate 11 $ 2,775 $ 2,775 $ 739 Indirect vehicle 20 153 153 105 Home equity 1 15 15 1 Total 32 $ 2,943 $ 2,943 $ 845 The following table presents loans that were restructured during the nine months ended September 30, 2017 (dollars in thousands): September 30, 2017 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial 5 $ 2,491 $ 2,491 $ 373 Commercial real estate Industrial 3 3,174 3,174 — Retail 2 337 337 — Office 1 549 549 — Other 3 3,703 3,703 — Residential real estate 6 902 902 135 Home equity 4 97 97 7 Total 24 $ 11,253 $ 11,253 $ 515 Non-Performing: Commercial 2 $ 676 $ 676 $ — Commercial real estate: Multifamily 3 290 290 — Retail 1 906 906 — Residential real estate 28 5,155 5,155 1,182 Indirect vehicle 31 250 250 134 Home equity 4 608 608 58 Total 69 $ 7,885 $ 7,885 $ 1,374 The following table presents loans that were restructured during the three months ended September 30, 2016 (dollars in thousands): September 30, 2016 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Residential real estate 2 $ 101 $ 101 $ 18 Home equity 2 102 102 12 Total 4 $ 203 $ 203 $ 30 Non-Performing: Commercial 3 $ 5,874 $ 5,874 $ 1,490 Residential real estate 4 484 484 85 Indirect vehicle 7 34 34 17 Home equity 5 489 489 72 Total 19 $ 6,881 $ 6,881 $ 1,664 The following table presents loans that were restructured during the nine months ended September 30, 2016 (dollars in thousands): September 30, 2016 Number of Pre-Modification Recorded Post-Modification Recorded Charge-offs and Performing: Commercial 1 $ 1,870 $ 1,870 $ 412 Residential real estate 2 101 101 18 Home equity 4 511 511 12 Total 7 $ 2,482 $ 2,482 $ 442 Non-Performing: Commercial 7 $ 14,481 $ 14,481 $ 4,990 Residential real estate 6 639 639 85 Indirect vehicle 25 183 183 60 Home equity 28 3,600 3,600 138 Total 66 $ 18,903 $ 18,903 $ 5,273
Troubled Debt Restructuring Activity Rollforward	The following table presents the troubled debt restructurings activity during the nine months ended September 30, 2017 (in thousands): Performing Non-performing Beginning balance $ 32,687 $ 27,068 Additions 11,253 7,885 Charge-offs — (520 ) Principal payments, net (1,001 ) (4,601 ) Removals (11,546 ) (3,429 ) Transfer to other real estate owned — (590 ) Transfers in 2,056 599 Transfers out (599 ) (2,056 ) Ending balance $ 32,850 $ 24,356
Type of Financing Receivable Modifications and Restructuring	The following table presents the type of modification for loans that have been restructured during the nine months ended September 30, 2017 (in thousands): September 30, 2017 Extended Maturity, Delay in Amortization Extended Payments and/or and Reduction Maturity and/or Reduction of of Interest Rate Amortization Interest Rate Total Commercial $ — $ 3,167 $ — $ 3,167 Commercial collateralized by assignment of lease payments — — — — Commercial real estate: Healthcare — — — — Industrial — 3,174 — 3,174 Multifamily — 290 — 290 Retail — 906 337 1,243 Office — 549 — 549 Other — 3,703 — 3,703 Residential real estate 3,885 1,589 583 6,057 Construction real estate — — — — Indirect vehicle — — 250 250 Home equity — 35 670 705 Other consumer — — — — Total $ 3,885 $ 13,413 $ 1,840 $ 19,138
Allowance Activity for Credit Losses, Balance in Allowance for Credit Losses and Recorded Investment in Loans by Portfolio Segment	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, 2017 and 2016 (in thousands): Commercial Commercial collateralized by assignment of lease payments Commercial real estate Residential real estate Construction real estate Indirect vehicle Home equity Other consumer Unfunded commitments Total September 30, 2017 Allowance for credit losses: Three Months Ended Beginning balance $ 43,783 $ 12,765 $ 63,247 $ 8,249 $ 15,263 $ 3,963 $ 4,750 $ 2,013 $ 2,264 $ 156,297 Charge-offs 235 188 31 541 — 1,097 439 299 — 2,830 Recoveries 719 — 1,432 38 502 498 149 82 — 3,420 Provision 1,715 240 935 94 (707 ) 1,317 422 489 12 4,517 Ending balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Nine Months Ended Beginning balance $ 44,661 $ 12,238 $ 51,807 $ 5,971 $ 14,758 $ 3,421 $ 4,689 $ 1,821 $ 2,476 $ 141,842 Charge-offs 1,103 188 1,378 901 — 3,438 873 1,243 — 9,124 Recoveries 3,568 712 2,312 624 661 1,715 724 420 — 10,736 Provision (1,144 ) 55 12,842 2,146 (361 ) 2,983 342 1,287 (200 ) 17,950 Ending balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Ending allowance balance attributable to loans: Individually evaluated for impairment $ 1,012 $ 585 $ 855 $ 2,169 $ — $ — $ 2,562 $ — $ 1,220 $ 8,403 Collectively evaluated for impairment 44,879 12,232 63,868 5,671 15,023 4,681 2,320 2,285 1,056 152,015 Acquired and accounted for under ASC 310-30 (1) 91 — 860 — 35 — — — — 986 Total ending allowance balance $ 45,982 $ 12,817 $ 65,583 $ 7,840 $ 15,058 $ 4,681 $ 4,882 $ 2,285 $ 2,276 $ 161,404 Loans: Individually evaluated for impairment $ 10,642 $ 921 $ 11,999 $ 19,370 $ — $ 349 $ 27,468 $ — $ — $ 70,749 Collectively evaluated for impairment 4,783,196 2,073,294 4,082,707 1,414,225 395,794 654,864 201,258 77,372 — 13,682,710 Acquired and accounted for under ASC 310-30 (1) 13,677 — 32,063 68,071 5,183 — 11,200 1,725 — 131,919 Total ending loans balance $ 4,807,515 $ 2,074,215 $ 4,126,769 $ 1,501,666 $ 400,977 $ 655,213 $ 239,926 $ 79,097 $ — $ 13,885,378 Commercial Commercial collateralized by assignment of lease payments Commercial real estate Residential real estate Construction real estate Indirect vehicle Home equity Other consumer Unfunded commitments Total September 30, 2016 Allowance for credit losses: Three Months Ended Beginning balance $ 50,297 $ 10,549 $ 46,040 $ 4,800 $ 14,230 $ 3,100 $ 4,199 $ 2,399 $ 2,719 $ 138,333 Charge-offs 1,341 367 529 290 7 838 376 409 — 4,157 Recoveries 665 3 324 45 50 436 65 86 — 1,674 Provision (3,894 ) 2,944 1,239 1,575 2,033 598 2,309 (407 ) 152 6,549 Ending balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Nine Months Ended Beginning balance $ 39,316 $ 10,434 $ 45,475 $ 5,734 $ 15,113 $ 2,418 $ 7,374 $ 2,276 $ 3,368 $ 131,508 Charge-offs 2,126 3,288 2,601 1,134 151 2,420 1,233 1,216 — 14,169 Recoveries 1,997 520 2,761 151 94 1,400 576 620 — 8,119 Provision 6,540 5,463 1,439 1,379 1,250 1,898 (520 ) (11 ) (497 ) 16,941 Ending balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Ending allowance balance attributable to loans: Individually evaluated for impairment $ 5,401 $ 3,933 $ 363 $ 2,394 $ — $ — $ 3,252 $ — $ 737 $ 16,080 Collectively evaluated for impairment 40,161 9,196 46,235 3,736 16,249 3,296 2,945 1,669 2,134 125,621 Acquired and accounted for under ASC 310-30 (1) 165 — 476 — 57 — — — — 698 Total ending allowance balance $ 45,727 $ 13,129 $ 47,074 $ 6,130 $ 16,306 $ 3,296 $ 6,197 $ 1,669 $ 2,871 $ 142,399 Loans: Individually evaluated for impairment $ 19,284 $ 8,054 $ 6,530 $ 13,268 $ — $ 125 $ 27,276 $ — $ — $ 74,537 Collectively evaluated for impairment 4,366,528 1,865,326 3,788,271 985,559 451,023 522,146 248,012 77,956 — 12,304,821 Acquired and accounted for under ASC 310-30 (1) 22,913 — 41,286 66,698 14,131 — 13,886 2,424 — 161,338 Total ending loans balance $ 4,408,725 $ 1,873,380 $ 3,836,087 $ 1,065,525 $ 465,154 $ 522,271 $ 289,174 $ 80,380 $ — $ 12,540,696 (1) Loans acquired in business combinations 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 and accounted for under ASC 310-30 were as follows for the three and nine months ended September 30, 2017 and 2016 (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 Balance at beginning of period $ 12,686 $ 13,160 $ 16,050 $ 12,596 Purchases — 805 43 805 Accretion (4,315 ) (2,564 ) (9,334 ) (7,193 ) Other (1) 3,453 2,523 5,065 7,716 Balance at end of period $ 11,824 $ 13,924 $ 11,824 $ 13,924 (1) Primarily includes discount transfers from non-accretable discount to accretable discount due to better than expected performance of loan pools acquired and accounted for under ASC 310-30.
Carrying Amount of Loans Acquired Through a Business Combination by Loan Pool Type	The carrying amount of loans acquired through a business combination by loan pool type are as follows (in thousands): September 30, 2017 Purchased Purchased Non-Credit-Impaired Total Covered loans (1) : Consumer related $ 15,658 $ — $ 15,658 Non-covered loans: Commercial loans 13,677 353,489 367,166 Commercial loans collateralized by assignment of lease payments — 50,629 50,629 Commercial real estate 32,063 873,179 905,242 Construction real estate 5,183 7,418 12,601 Consumer related 5,277 291,376 296,653 Total non-covered loans 56,200 1,576,091 1,632,291 Total acquired $ 71,858 $ 1,576,091 $ 1,647,949 (1) Covered loans refer to loans covered under loss-sharing agreements with the FDIC.

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill	The following table presents the changes in the carrying amount of goodwill for the nine months ended September 30, 2017 (in thousands): Banking Leasing Mortgage Banking Total Balance at beginning of period $ 960,398 $ 40,640 $ — $ 1,001,038 Goodwill from business combinations (1) (1,113 ) — — (1,113 ) Balance at end of period $ 959,285 $ 40,640 $ — $ 999,925 (1) Due to the adjustments recognized for the American Chartered merger during the first quarter of 2017.
Changes in the Carrying Amount of Core Deposit and Client Relationship Intangibles	The following table presents the changes during the nine months ended September 30, 2017 in the carrying amount of core deposit and client relationship intangibles, and the gross carrying amount, accumulated amortization, and net book value as of September 30, 2017 (in thousands): September 30, 2017 Balance at beginning of period $ 62,959 Amortization expense (6,214 ) Balance at end of period $ 56,745 Gross carrying amount $ 112,820 Accumulated amortization (56,075 ) Net book value $ 56,745
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 2017 $ 1,979 2018 7,451 2019 5,674 2020 5,022 2021 4,790 Thereafter 31,829 $ 56,745

Deposits (Tables)

Deposits (Tables)	9 Months Ended
	Sep. 30, 2017
Banking and Thrift [Abstract]
Schedule of Composition of Deposits	The composition of deposits was as follows as of September 30, 2017 and December 31, 2016 (in thousands): September 30, December 31, 2017 2016 Demand deposit accounts, non-interest bearing $ 6,101,159 $ 6,408,169 NOW, money market and interest bearing deposits 4,842,097 4,543,004 Savings accounts 1,088,194 1,135,992 Certificates of deposit, $250,000 or more 1,430,706 1,144,121 Other certificates of deposit 952,988 879,162 Total $ 14,415,144 $ 14,110,448

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Summary of Short-Term Borrowings	Short-term borrowings were as follows as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 Weighted Average Interest Rate Amount Weighted Average Interest Rate Amount Customer repurchase agreements 0.26 % $ 222,915 0.22 % $ 237,538 Federal Home Loan Bank advances 1.22 1,400,000 0.63 1,275,000 Federal funds purchased 1.35 242,500 0.80 46,750 Line of credit — — 2.52 10,000 Total 1.12 % $ 1,865,415 0.59 % $ 1,569,288

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Borrowings	Long-term borrowings were as follows as of September 30, 2017 and December 31, 2016 (dollars in thousands): September 30, 2017 December 31, 2016 Weighted Average Interest Rate Amount Weighted Average Interest Rate Amount Federal Home Loan Bank advances 1.47 % $ 306,367 0.85 % $ 230,865 Notes payable 4.06 88,348 4.18 66,925 Term note 2.98 11,000 2.52 14,000 Total 2.08 % $ 405,715 1.64 % $ 311,790

Junior Subordinated Notes Iss35

Junior Subordinated Notes Issued to Capital Trusts (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
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, 2017 (in thousands): Coal City Capital Trust I MB Financial Capital Trust II MB Financial Capital Trust III MB Financial 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 Capital Trust V MB Financial Capital Trust VI FOBB Statutory Trust III (2) TAYC Capital Trust II (3) Junior Subordinated Notes: Principal balance $ 30,928 $ 23,196 $ 5,155 $ 41,238 Annual interest rate 3-mo LIBOR + 1.30% 3-mo LIBOR + 1.30% 3-mo LIBOR + 2.80% 3-mo LIBOR + 2.68% Stated maturity date December 15, 2037 October 30, 2037 January 23, 2034 June 17, 2034 Call date December 15, 2012 October 30, 2012 January 23, 2009 June 17, 2009 Trust Preferred Securities: Face Value $ 30,000 $ 22,500 $ 5,000 $ 40,000 Annual distribution rate 3-mo LIBOR + 1.30% 3-mo LIBOR + 1.30% 3-mo LIBOR + 2.80% 3-mo LIBOR + 2.68% Issuance date September 2007 October 2007 December 2003 June 2004 Distribution dates (1) Quarterly Quarterly Quarterly Quarterly American Chartered Statutory Trust I (4) American Chartered Statutory Trust II (4) Junior Subordinated Notes: Principal balance $ 20,619 $ 10,310 Annual interest rate 3-mo LIBOR + 3.60% 3-mo LIBOR + 2.75% Stated maturity date December 18, 2031 October 7, 2034 Call date December 18, 2006 October 7, 2009 Trust Preferred Securities: Face Value $ 20,000 $ 10,000 Annual distribution rate 3-mo LIBOR + 3.60% 3-mo LIBOR + 2.75% Issuance date November 2001 August 2004 Distribution dates (1) 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 in 2006, and the junior subordinated notes issued by FOBB to FOBB Statutory Trust III were assumed by the Company upon completion of the acquisition. (3) TAYC Capital Trust II was established by Taylor Capital Group, Inc. (“Taylor Capital”) prior to the Company's acquisition of Taylor Capital in 2014, and the junior subordinated notes issued by Taylor Capital to TAYC Capital Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with TAYC Capital Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.5 million at September 30, 2017 . (4) American Chartered Statutory Trust I and American Chartered Statutory Trust II were established by American Chartered prior to the Company's acquisition of American Chartered in August 2016, and the junior subordinated notes issued by American Chartered to American Chartered Statutory Trust I and American Chartered Statutory Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with American Chartered Statutory Trust I and American Chartered Statutory Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.1 million at September 30, 2017 .

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of Outstanding Financial Instruments, Contractual Amounts of Off-Balance Sheet Credit Risk	At September 30, 2017 and December 31, 2016 , the following financial instruments were outstanding, the contractual amounts of which represent off-balance sheet credit risk (in thousands): Contractual Amount September 30, 2017 December 31, 2016 Commitments to extend credit: Home equity lines $ 207,444 $ 235,279 Other commitments 3,914,154 3,679,259 Letters of credit: Standby 183,396 185,386 Commercial 4,133 1,766

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
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, 2017 and December 31, 2016 , segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Financial assets Securities available for sale: U.S Government sponsored agencies and enterprises $ 23,146 $ — $ 23,146 $ — States and political subdivisions 385,829 — 385,456 373 Residential mortgage-backed securities 875,260 — 875,195 65 Commercial mortgage-backed securities 87,217 — 87,217 — Corporate bonds 115,014 — 115,014 — Equity securities 11,077 11,077 — — Loans held for sale 722,754 — 722,754 — Loans 14,481 — 14,481 — Mortgage servicing rights 261,446 — — 261,446 Assets held in trust for deferred compensation 20,103 20,103 — — Derivative financial instruments 36,018 2,366 31,713 1,939 Financial liabilities Other liabilities (1) 20,103 20,103 — — Derivative financial instruments 39,915 1,583 38,332 — December 31, 2016 Financial assets Securities available for sale: U.S. Government sponsored agencies and enterprises $ 23,415 $ — $ 23,415 $ — States and political subdivisions 391,365 — 390,992 373 Residential mortgage-backed securities 983,684 — 983,513 171 Commercial mortgage-backed securities 93,008 — 93,008 — Corporate bonds 193,895 — 193,895 — Equity securities 10,828 10,828 — — Loans held for sale 716,883 — 716,883 — Loans 16,273 — 16,273 — Mortgage servicing rights 238,011 — — 238,011 Assets held in trust for deferred compensation 18,723 18,723 — — Derivative financial instruments 44,586 7,687 33,739 3,160 Financial liabilities Other liabilities (1) 18,723 18,723 — — Derivative financial instruments 63,885 2,046 61,839 — (1) Liabilities associated with assets held in trust for deferred compensation
Summary of Financial Assets Measured at Fair Value on a 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 nonrecurring basis that were categorized within the Level 3 of the fair value hierarchy: Fair Value at Valuation Unobservable September 30, 2017 Technique Input Range (in thousands) Impaired loans $ 53,842 Appraisal of collateral Appraisal adjustments 5% - 10% Foreclosed assets 18,334 Appraisal of collateral Appraisal adjustments 5% - 10% 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 September 30, 2017 Valuation Technique Unobservable Input Range (in thousands) States and political subdivisions $ 373 Discounted cash flows Credit assumption 45% - 50% Loss Residential mortgage-backed securities 65 Discounted cash flows Constant pre-payment rates (CPR) 1% - 3% Mortgage servicing rights 261,446 Discounted cash flows CPR 6.80% - 8.42% Discount rate 9.53 - 11.05 Maturity (months) 323 - 358 Delinquencies 2.16 - 4.82 Costs to service $ 67 - $ 227 Additive delinquent costs to service $ 175 - $ 1,000 Derivative financial instruments (mortgage 1,939 Sales cash flows Expected closing ratio 70% - 95% interest rate lock commitments) Expected delivery price 98.41 bps - 108.57 bps
Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets	Key economic assumptions used in the measuring of the fair value of the mortgage servicing rights and the sensitivity of the fair value to immediate adverse changes in those assumptions at September 30, 2017 are presented in the following table. This table does not take into account the derivatives used to economically hedge the mortgage servicing rights. (dollars in thousands, except for weighted average cost to service) September 30, 2017 Weighted average CPR 7.58 % Impact on fair value of 10% adverse change $ 9,030 Impact on fair value of 20% adverse change 18,615 Weighted average discount rate 9.81 % Impact on fair value of 10% adverse change $ 11,673 Impact on fair value of 20% adverse change 24,415 Weighted average delinquency rate 4.57 % Impact on fair value of 10% adverse change $ 1,567 Impact on fair value of 20% adverse change 3,499 Weighted average costs to service $ 90.45 Impact on fair value of 10% adverse change 4,919 Impact on fair value of 20% adverse change 9,838
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, 2017 2016 2017 2016 2017 2016 (in thousands) Investment Securities Mortgage Servicing Rights Derivatives Balance, beginning of period $ 544 $ 773 $ 238,011 $ 168,162 $ 3,160 $ 3,822 Purchases — — 839 3,423 — — Originations — — 43,197 43,039 — — Included in earnings — — (20,601 ) (59,894 ) (1,221 ) 8,739 Principal payments (106 ) (151 ) — — — — Sales — — — — — — Balance, ending of period $ 438 $ 622 $ 261,446 $ 154,730 $ 1,939 $ 12,561
Assets Measured at Fair Value on a Nonrecurring Basis	Assets measured at fair value on a nonrecurring basis as of September 30, 2017 and December 31, 2016 are included in the table below (in thousands): Total Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2017 Financial assets: Impaired loans $ 53,842 $ — $ — $ 53,842 Non-financial assets: Foreclosed assets 18,334 — — 18,334 December 31, 2016 Financial assets: Impaired loans $ 54,576 $ — $ — $ 54,576 Non-financial assets: Foreclosed assets 31,607 — — 31,607
Estimated Fair Values of Financial Instruments	The estimated fair values of financial instruments are as follows (in thousands): September 30, 2017 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets: Cash and due from banks $ 361,080 $ 361,080 $ 361,080 $ — $ — Interest earning deposits with banks 82,636 82,636 82,636 — — Investment securities available for sale 1,497,543 1,497,543 11,077 1,486,028 438 Investment securities held to maturity 994,238 1,031,746 — 1,031,746 — Non-marketable securities - FHLB and FRB stock 152,345 152,345 — — 152,345 Loans held for sale 722,754 722,754 — 722,754 — Loans, net 13,726,250 13,928,427 — 14,481 13,913,946 Accrued interest receivable 61,962 61,962 61,962 — — Derivative financial instruments 36,018 36,018 2,366 31,713 1,939 Financial Liabilities: Non-interest bearing deposits $ 6,101,159 $ 6,101,159 $ 6,101,159 $ — $ — Interest bearing deposits 8,313,985 8,310,123 — — 8,310,123 Short-term borrowings 1,865,415 1,865,796 — — 1,865,796 Long-term borrowings 405,715 411,218 — — 411,218 Junior subordinated notes issued to capital trusts 211,289 177,843 — — 177,843 Accrued interest payable 5,680 5,680 5,680 — — Derivative financial instruments 39,915 39,915 1,583 38,332 — December 31, 2016 Carrying Amount Estimated Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets: Cash and due from banks $ 364,783 $ 364,783 $ 364,783 $ — $ — Interest earning deposits with banks 98,686 98,686 98,686 — — Investment securities available for sale 1,696,195 1,696,195 10,828 1,684,823 544 Investment securities held to maturity 1,069,750 1,093,740 — 1,093,740 — Non-marketable securities - FHLB and FRB stock 143,276 143,276 — — 143,276 Loans held for sale 716,883 716,883 — 716,883 — Loans, net 12,629,437 12,747,107 — 16,273 12,730,834 Accrued interest receivable 59,024 59,024 59,024 — — Derivative financial instruments 44,586 44,586 7,687 33,739 3,160 Financial Liabilities: Non-interest bearing deposits $ 6,408,169 $ 6,408,169 $ 6,408,169 $ — $ — Interest bearing deposits 7,702,279 7,698,839 — — 7,698,839 Short-term borrowings 1,569,288 1,569,314 — — 1,569,314 Long-term borrowings 311,790 317,028 — — 317,028 Junior subordinated notes issued to capital trusts 210,668 157,098 — — 157,098 Accrued interest payable 4,288 4,288 4,288 — — Derivative financial instruments 63,885 63,885 2,046 61,839 —

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-Based Payment Plans	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, 2017 2016 2017 2016 Total compensation expense for share-based payment plans during the period $ 4,393 $ 4,238 $ 13,317 $ 12,573 Amount of related income tax benefit recognized in income (1) 2,175 3,394 8,513 6,649 (1) Includes tax benefits recorded for the vesting of restricted shares and exercise of options.
Summary of Changes in Stock Options	The following table summarizes changes in stock options for the nine months ended September 30, 2017 : Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (In Years) Aggregate Intrinsic Value (in thousands) Options outstanding as of December 31, 2016 1,940,405 $ 27.45 5.31 Granted 163,818 45.53 Exercised (327,970 ) 28.03 Expired — — Forfeited or cancelled (15,093 ) 31.95 Options outstanding as of September 30, 2017 1,761,160 $ 28.99 5.40 $ 28,356 Options exercisable as of September 30, 2017 1,167,465 $ 26.60 3.97 $ 21,522
Assumptions Used for Options Granted	The following assumptions were used for options granted during the nine months ended September 30, 2017 : September 30, 2017 Risk-free interest rate 2.18 % Expected volatility of Company’s stock 22.71 % Expected dividend yield 1.68 % Expected life of options 5.8 years Weighted average fair value per option of options granted during the year $ 9.40
Summary of Changes in Restricted Shares and Units	The following is a summary of changes in restricted shares and units for the nine months ended September 30, 2017 : Number of Shares and Units Weighted Average Grant Date Fair Value Shares and units outstanding at December 31, 2016 998,807 $ 31.20 Granted 379,962 45.77 Vested (379,375 ) 30.63 Forfeited or cancelled (21,506 ) 35.10 Shares and units outstanding at September 30, 2017 977,888 36.99

Derivative Financial Instrume39

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
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, 2017 and December 31, 2016 (in thousands): Asset Derivatives Liability Derivatives September 30, 2017 December 31, 2016 September 30, 2017 December 31, 2016 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) $ — $ — $ — $ — $ 70 $ (1 ) $ 107 $ (4 ) Stand-alone derivative instruments: (2) Interest rate swap contracts 1,554,709 24,609 1,310,057 25,471 1,554,709 (24,609 ) 1,310,057 (25,471 ) Interest rate options contracts 337,999 1,698 217,546 881 337,999 (1,698 ) 217,546 (881 ) Foreign exchange contracts 35,672 2,157 40,641 4,429 34,837 (1,997 ) 40,505 (4,265 ) Spot foreign exchange contracts 342 3 1,691 12 223 — 660 (5 ) Mortgage related derivatives: Interest rate swap contracts 413,000 3,246 383,000 2,946 1,223,000 (10,027 ) 1,458,000 (31,212 ) Treasury futures contracts 42,500 74 15,500 41 45,000 (216 ) — — TBA mortgage securities — — — — 140,000 (1,105 ) 55,000 (132 ) Forward loan sale commitments 759,500 2,292 585,000 7,646 133,500 (262 ) 386,000 (1,915 ) Interest rate lock commitments 555,375 1,939 543,901 3,160 — — — — Total stand-alone derivative instruments 3,699,097 36,018 3,097,336 44,586 3,469,268 (39,914 ) 3,467,768 (63,881 ) Total $ 3,699,097 $ 36,018 $ 3,097,336 $ 44,586 $ 3,469,338 $ (39,915 ) $ 3,467,875 $ (63,885 ) (1) Derivative instruments designated to hedge fixed-rate commercial real estate loans. (2) These portfolio swaps are not designated as hedging instruments under ASC Topic 815.
Schedule of the Amounts Included in Consolidated Statements of Operations Related to Derivative Financial Instruments	Amounts included in other operating 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, 2017 2016 2017 2016 Derivative instruments designated as hedges of fair value: Interest rate swap contracts $ — $ 3 $ 2 $ 3 Stand-alone derivative instruments: Interest rate swap contracts 3,276 5,296 6,749 5,260 Interest rate options contracts — (36 ) — — Foreign exchange contracts (70 ) 1,362 190 1,362 Spot foreign exchange contracts 629 6 2,036 6 Mortgage related derivatives (11,625 ) (8,118 ) (22,067 ) 31,653 Total stand-alone derivative instruments (7,790 ) (1,490 ) (13,092 ) 38,281 Total $ (7,790 ) $ (1,487 ) $ (13,090 ) $ 38,284
Schedule of Financial Instruments Eligible for Offset In the Consolidated Balance Sheet	Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of September 30, 2017 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 swap contracts, caps and floors $ 7,583 $ — $ 7,583 $ 18,821 $ — $ 18,821 Foreign exchange contracts 748 — 748 1,636 — 1,636 Mortgage related derivatives 5,612 — 5,612 11,610 — 11,610 Total derivatives 13,943 — 13,943 32,067 — 32,067 Repurchase agreements — — — 222,915 — 222,915 Total $ 13,943 $ — $ 13,943 $ 254,982 $ — $ 254,982 Financial Assets Financial Liabilities Net Amount Recognized Financial Instruments Collateral Net Amount Net Amount Recognized Financial Instruments Collateral Net Amount Derivatives: Counterparty A $ 4,941 $ (4,941 ) $ — $ — $ 12,399 $ (4,941 ) $ (7,458 ) $ — Counterparty B 2,276 (2,276 ) — — 9,044 (2,276 ) (6,768 ) — Counterparty C 243 (243 ) — — 2,434 (243 ) (2,191 ) — Other counterparties 6,483 (4,268 ) — 2,215 8,190 (4,268 ) (3,922 ) — Total derivatives 13,943 (11,728 ) — 2,215 32,067 (11,728 ) (20,339 ) — Repurchase agreements — — — — 222,915 — (222,915 ) — Total $ 13,943 $ (11,728 ) $ — $ 2,215 $ 254,982 $ (11,728 ) $ (243,254 ) $ — Information about the Company's financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2016 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 swap contracts, caps and floors $ 7,885 $ — $ 7,885 $ 18,564 $ — $ 18,564 Foreign exchange contracts 4,315 — 4,315 1,674 — 1,674 Mortgage related derivatives 10,633 — 10,633 33,259 — 33,259 Total derivatives 22,833 — 22,833 53,497 — 53,497 Repurchase agreements — — — 237,538 — 237,538 Total $ 22,833 $ — $ 22,833 $ 291,035 $ — $ 291,035 Financial Assets Financial Liabilities Net Amount Recognized Financial Instruments Collateral Net Amount Net Amount Recognized Financial Instruments Collateral Net Amount Derivatives: Counterparty A $ 2,697 $ (2,697 ) $ — $ — $ 18,768 $ (2,697 ) $ (16,071 ) $ — Counterparty B 4,683 (4,683 ) — — 12,881 (4,683 ) (8,198 ) — Counterparty C 64 (64 ) — — 4,919 (64 ) (4,855 ) — Other counterparties 15,389 (10,938 ) — 4,451 16,929 (10,938 ) (5,980 ) 11 Total derivatives 22,833 (18,382 ) — 4,451 53,497 (18,382 ) (35,104 ) 11 Repurchase agreements — — — — 237,538 — (237,538 ) — Total $ 22,833 $ (18,382 ) $ — $ 4,451 $ 291,035 $ (18,382 ) $ (272,642 ) $ 11

Operating Segments (Tables)

Operating Segments (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Summary Financial Information for the Reportable Segments	The following tables present summary financial information for the reportable segments (in thousands): Banking Leasing Mortgage Banking Consolidated Three months ended September 30, 2017 Net interest income $ 142,888 $ 2,686 $ 11,373 $ 156,947 Provision for credit losses 3,637 399 481 4,517 Non-interest income 45,091 22,597 27,576 95,264 Non-interest expense (1) 112,977 14,535 34,782 162,294 Income tax expense 18,781 4,307 1,469 24,557 Net income $ 52,584 $ 6,042 $ 2,217 $ 60,843 Total assets $ 16,406,714 $ 1,307,459 $ 2,402,362 $ 20,116,535 Three months ended September 30, 2016 Net interest income $ 119,685 $ 2,168 $ 8,918 $ 130,771 Provision for credit losses 4,394 1,964 191 6,549 Non-interest income 40,533 18,759 49,095 108,387 Non-interest expense (1) 117,211 12,604 40,570 170,385 Income tax expense 8,420 2,484 6,901 17,805 Net income $ 30,193 $ 3,875 $ 10,351 $ 44,419 Total assets $ 16,453,379 $ 1,126,847 $ 1,761,656 $ 19,341,882 (1) Includes merger related and repositioning expenses of $1.6 million and $11.4 million in the Banking Segment for the three months ended September 30, 2017 and 2016 , respectively. Banking Leasing Mortgage Banking Consolidated Nine months ended September 30, 2017 Net interest income $ 410,319 $ 7,300 $ 31,365 $ 448,984 Provision for credit losses 16,054 674 1,222 17,950 Non-interest income 130,460 62,240 84,854 277,554 Non-interest expense (1) 337,185 41,815 104,518 483,518 Income tax expense 50,103 10,951 4,170 65,224 Net income $ 137,437 $ 16,100 $ 6,309 $ 159,846 Total assets $ 16,406,714 $ 1,307,459 $ 2,402,362 $ 20,116,535 Nine months ended September 30, 2016 Net interest income $ 341,445 $ 7,002 $ 24,230 $ 372,677 Provision for credit losses 14,390 2,045 506 16,941 Non-interest income 112,221 53,670 116,189 282,080 Non-interest expense (1) 307,733 35,916 110,442 454,091 Income tax expense 36,120 8,872 11,788 56,780 Net income $ 95,423 $ 13,839 $ 17,683 $ 126,945 Total assets $ 16,453,379 $ 1,126,847 $ 1,761,656 $ 19,341,882 (1) Includes merger related and repositioning expenses of $9.0 million and $17.2 million in the Banking Segment for the nine months ended September 30, 2017 and 2016 , respectively.

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 60,843	$ 44,419	$ 159,846	$ 126,945
Less: preferred stock dividends	2,002	2,004	6,007	6,004
Net income available to common stockholders	58,841	42,415	153,839	120,941
Plus: preferred stock dividends on convertible preferred stock	2	4	7	4
Earnings allocated to common stockholders for diluted earnings per common share	$ 58,842	$ 42,417	$ 153,843	$ 120,939
Weighted average shares outstanding for basic earnings per common share (in shares)	83,891,175	77,506,885	83,799,694	74,780,943
Dilutive effect of convertible preferred stock (in shares)	6,144	12,567	6,867	4,189
Total dilutive effect of equity awards and convertible preferred stock (in shares)	888,622	1,176,285	976,258	946,637
Weighted average shares outstanding for diluted earnings per common share (in shares)	84,779,797	78,683,170	84,775,952	75,727,580
Basic earnings per common share (in dollars per share)	$ 0.70	$ 0.55	$ 1.84	$ 1.62
Diluted earnings per common share (in dollars per share)	$ 0.69	$ 0.54	$ 1.81	$ 1.60
Stock options
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of stock options and restricted shares/units (in shares)	502,794	491,238	564,541	378,420
Restricted shares and units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dilutive effect of stock options and restricted shares/units (in shares)	379,684	672,480	404,850	564,028
Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Distributed earnings allocated to common stock	$ 17,823	$ 16,114	$ 51,783	$ 42,984
Undistributed earnings	43,020	28,305	108,063	83,961
Net income	60,843	44,419	159,846	126,945
Net income available to common stockholders	$ 58,841	$ 42,415	$ 153,839	$ 120,941
Weighted average shares outstanding for basic earnings per common share (in shares)	83,891,175	77,506,885	83,799,694	74,780,943
Weighted average shares outstanding for diluted earnings per common share (in shares)	84,779,797	78,683,170	84,775,952	75,727,580
Participating Securities
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Less: earnings allocated to participating securities	$ 1	$ 2	$ 3	$ 6

Business Combinations - Additio

Business Combinations - Additional Information (Details) - USD ($)	Aug. 24, 2016	Nov. 20, 2015	Mar. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill				$ 999,925,000		$ 1,001,038,000
Accretable discount on loans				$ 21,760,000	$ 25,426,000
Series B Preferred Stock
Business Acquisition [Line Items]
Preferred stock, dividend rate (percent)				8.00%		8.00%
American Chartered Bancorp, Inc.
Business Acquisition [Line Items]
Total identifiable net assets	$ 487,416,000
Cash paid	102,317,000
Preferred stock and stock-based awards assumed	2,300,000
Goodwill	274,885,000
Increase in fair value estimates			$ 1,800,000
Decrease in deferred tax asset			733,000
Decrease to goodwill			$ 1,100,000
Acquisition costs incurred						$ 2,000,000
American Chartered Bancorp, Inc. | Purchased Credit-Impaired Loans
Business Acquisition [Line Items]
Best estimate of contractual cash flows not expected to be collected	18,400,000
Accretable discount	5,300,000
American Chartered Bancorp, Inc. | Substandard
Business Acquisition [Line Items]
Accretable discount on loans	20,700,000
American Chartered Bancorp, Inc. | Common Stock
Business Acquisition [Line Items]
Market value of common stock and Series B preferred stock	$ 382,800,000
Stock issued (in shares)	9,700,000
American Chartered Bancorp, Inc.
Business Acquisition [Line Items]
Amount called by each warrant or right (in dollars per share)		$ 9.30
Amount paid for each fractional share (in dollars per share)		$ 39.01
American Chartered Bancorp, Inc. | Common Stock
Business Acquisition [Line Items]
Number of securities called by each warrant (in shares)		0.2732
American Chartered Bancorp, Inc. | Series D Preferred Stock
Business Acquisition [Line Items]
Preferred stock, dividend rate (percent)	8.00%	8.00%
American Chartered Bancorp, Inc. | Series B Preferred Stock
Business Acquisition [Line Items]
Preferred stock, dividend rate (percent)	8.00%	8.00%
Number of securities called by each warrant (in shares)	1

Business Combinations - Fair Va

Business Combinations - Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ / shares in Units, $ in Thousands		Aug. 24, 2016	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Goodwill			$ 999,925	$ 1,001,038
American Chartered Bancorp, Inc.
ASSETS
Cash and cash equivalents		$ 93,307
Investment securities available for sale		505,564
Non-marketable securities - FRB and FHLB Stock		16,000
Loans		1,942,548
Premises and equipment		39,048
Cash surrender value of life insurance		59,917
Goodwill		274,885
Other intangibles		25,452
Other real estate owned		3,960
Other assets		31,408
Total assets		2,992,089
LIABILITIES
Deposits		2,389,327
Short-term borrowings		48,305
Long-term borrowings		16,000
Accrued expenses and other liabilities		22,966
Total liabilities		2,504,673
Total identifiable net assets		487,416
Consideration:
Stock-based compensation attributed to pre-business combination service		1,103
Cash paid		102,317
Total fair value of consideration, excluding Series B preferred stock		487,416
American Chartered Bancorp, Inc. | Common Stock
Consideration:
Market value of common stock and Series B preferred stock		$ 382,769
Stock issued (in dollars per share)	[1]	$ 39.28
Stock issued (in shares)	[1]	9,744,636
American Chartered Bancorp, Inc. | Preferred Stock | Series B Preferred Stock
Consideration:
Market value of common stock and Series B preferred stock	[1]	$ 1,227
Stock issued (in dollars per share)	[1]	$ 2,337.97
Stock issued (in shares)	[1]	525
American Chartered Bancorp, Inc. | Junior Subordinated Notes
LIABILITIES
Long-term borrowings		$ 28,075
[1]	Per share fair value amount determined as if the shares of Series B preferred stock were converted into shares of common stock.

Business Combinations - Acquire

Business Combinations - Acquired Loans (Details) - American Chartered Bancorp, Inc. $ in Thousands	Aug. 24, 2016USD ($)
Purchased Credit-Impaired Loans
Business Acquisition [Line Items]
Fair value	$ 62,104
Gross contractual amounts receivable	93,490
Best estimate of contractual cash flows not expected to be collected	22,293	[1]
Best estimate of contractual cash flows expected to be collected	71,197
Purchased Non-Credit-Impaired Loans
Business Acquisition [Line Items]
Fair value	1,880,444
Gross contractual amounts receivable	2,149,868
Best estimate of contractual cash flows not expected to be collected	114,154	[1]
Best estimate of contractual cash flows expected to be collected	$ 2,035,714
[1]	Includes interest payments not expected to be collected due to loan prepayments as well as principal and interest payments not expected to be collected due to customer defaults.

Business Combinations - Pro For

Business Combinations - Pro Forma Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Business Combinations [Abstract]
Total revenues (net interest income plus non-interest income	$ 258,611	$ 735,408
Net income	$ 50,029	$ 149,111

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Fair Value of Investment Securities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Available for Sale
Amortized Cost	$ 1,479,600	$ 1,684,665
Gross Unrealized Gains	26,398	24,205
Gross Unrealized Losses	(8,455)	(12,675)
Fair Value	1,497,543	1,696,195
Held to Maturity
Amortized Cost	994,238	1,069,750
Gross Unrealized Gains	37,984	27,029
Gross Unrealized Losses	(476)	(3,039)
Fair Value	1,031,746	1,093,740
Total Available for Sale and Held to Maturity Investment Securities
Amortized Cost	2,473,838	2,754,415
Gross Unrealized Gains	64,382	51,234
Gross Unrealized Losses	(8,931)	(15,714)
Fair Value	2,529,289	2,789,935
U.S. Government sponsored agencies and enterprises
Available for Sale
Amortized Cost	23,077	23,267
Gross Unrealized Gains	69	148
Gross Unrealized Losses	0	0
Fair Value	23,146	23,415
States and political subdivisions
Available for Sale
Amortized Cost	366,187	376,541
Gross Unrealized Gains	20,009	15,669
Gross Unrealized Losses	(367)	(845)
Fair Value	385,829	391,365
Held to Maturity
Amortized Cost	888,576	910,608
Gross Unrealized Gains	35,952	21,609
Gross Unrealized Losses	(476)	(3,039)
Fair Value	$ 924,052	929,178
Total Available for Sale and Held to Maturity Investment Securities
Percentage of securities consisting general obligation issues	95.00%
Percentage of securities insured	27.00%
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	20.00%
Residential mortgage-backed securities
Available for Sale
Amortized Cost	$ 878,167	988,744
Gross Unrealized Gains	4,773	5,741
Gross Unrealized Losses	(7,680)	(10,801)
Fair Value	875,260	983,684
Held to Maturity
Amortized Cost	105,662	159,142
Gross Unrealized Gains	2,032	5,420
Gross Unrealized Losses	0	0
Fair Value	107,694	164,562
Commercial mortgage-backed securities
Available for Sale
Amortized Cost	86,411	91,949
Gross Unrealized Gains	1,097	1,221
Gross Unrealized Losses	(291)	(162)
Fair Value	87,217	93,008
Corporate bonds
Available for Sale
Amortized Cost	114,581	193,164
Gross Unrealized Gains	450	1,426
Gross Unrealized Losses	(17)	(695)
Fair Value	115,014	193,895
Equity securities
Available for Sale
Amortized Cost	11,177	11,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(100)	(172)
Fair Value	$ 11,077	$ 10,828

Investment Securities - Unreali

Investment Securities - Unrealized Losses on Investment Securities and Fair Value of Related Securities (Details) $ in Thousands	Sep. 30, 2017USD ($)Security_Position	Dec. 31, 2016USD ($)Security_Position
Available for Sale
Less Than 12 Months, Fair Value	$ 330,775	$ 705,456
Less Than 12 Months, Unrealized Losses	(4,521)	(11,314)
12 Months or More, Fair Value	262,736	86,690
12 Months or More, Unrealized Losses	(3,934)	(1,361)
Total Fair Value	593,511	792,146
Total Unrealized Losses	(8,455)	(12,675)
Total
Less Than 12 Months, Fair Value	368,893	949,024
Less Than 12 Months, Unrealized Losses	(4,953)	(14,313)
12 Months or More, Fair Value	265,065	89,678
12 Months or More, Unrealized Losses	(3,978)	(1,401)
Total Fair Value	633,958	1,038,702
Total Unrealized Losses	$ (8,931)	$ (15,714)
Number of security positions in the investment portfolio in an unrealized loss position | Security_Position	397	615
States and political subdivisions
Available for Sale
Less Than 12 Months, Fair Value	$ 1,364	$ 42,806
Less Than 12 Months, Unrealized Losses	(4)	(845)
12 Months or More, Fair Value	19,044	0
12 Months or More, Unrealized Losses	(363)	0
Total Fair Value	20,408	42,806
Total Unrealized Losses	(367)	(845)
Held to Maturity
Less Than 12 Months, Fair Value	38,118	243,568
Less Than 12 Months, Unrealized Losses	(432)	(2,999)
12 Months or More, Fair Value	2,329	2,988
12 Months or More, Unrealized Losses	(44)	(40)
Total Fair Value	40,447	246,556
Total Unrealized Losses	(476)	(3,039)
Residential mortgage-backed securities
Available for Sale
Less Than 12 Months, Fair Value	308,732	623,732
Less Than 12 Months, Unrealized Losses	(4,229)	(10,084)
12 Months or More, Fair Value	222,269	54,990
12 Months or More, Unrealized Losses	(3,451)	(717)
Total Fair Value	531,001	678,722
Total Unrealized Losses	(7,680)	(10,801)
Commercial mortgage-backed securities
Available for Sale
Less Than 12 Months, Fair Value	9,602	7,062
Less Than 12 Months, Unrealized Losses	(188)	(9)
12 Months or More, Fair Value	11,445	11,612
12 Months or More, Unrealized Losses	(103)	(153)
Total Fair Value	21,047	18,674
Total Unrealized Losses	(291)	(162)
Corporate bonds
Available for Sale
Less Than 12 Months, Fair Value	0	21,028
Less Than 12 Months, Unrealized Losses	0	(204)
12 Months or More, Fair Value	9,978	20,088
12 Months or More, Unrealized Losses	(17)	(491)
Total Fair Value	9,978	41,116
Total Unrealized Losses	(17)	(695)
Equity securities
Available for Sale
Less Than 12 Months, Fair Value	11,077	10,828
Less Than 12 Months, Unrealized Losses	(100)	(172)
12 Months or More, Fair Value	0	0
12 Months or More, Unrealized Losses	0	0
Total Fair Value	11,077	10,828
Total Unrealized Losses	$ (100)	$ (172)

Investment Securities - Net Gai

Investment Securities - Net Gains Recognized and Amortized Cost and Fair Value by Contractual Maturity of Investment Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Amortized cost and fair value of investment securities by contractual maturity
Realized gains	$ 83		$ 457	$ 323
Realized losses	0	0	(6)	(54)
Net gains	83	$ 0	451	$ 269
Amortized Cost, Available for sale
Due in one year or less	145,205		145,205
Due after one year through five years	106,869		106,869
Due after five years through ten years	57,764		57,764
Due after ten years	194,007		194,007
Amortized Cost	1,479,600		1,479,600		$ 1,684,665
Fair Value, Available for sale
Due in one year or less	145,902		145,902
Due after one year through five years	111,113		111,113
Due after five years through ten years	59,755		59,755
Due after ten years	207,219		207,219
Fair Value	1,497,543		1,497,543		1,696,195
Amortized Cost, Held to maturity
Due in one year or less	41,530		41,530
Due after one year through five years	152,848		152,848
Due after five years through ten years	204,683		204,683
Due after ten years	489,515		489,515
Investment securities held to maturity	994,238		994,238		1,069,750
Fair value, Held to maturity
Due in one year or less	41,588		41,588
Due after one year through five years	159,474		159,474
Due after five years through ten years	215,747		215,747
Due after ten years	507,243		507,243
Fair Value	1,031,746		1,031,746		1,093,740
Total Available for Sale and Held to Maturity Investment Securities
Amortized Cost	2,473,838		2,473,838		2,754,415
Fair Value	2,529,289		2,529,289		2,789,935
Pledged financial instruments, not separately reported, securities	833,400		833,400		1,000,000
Pledged financial instruments, not separately reported, securities required to be pledged	691,300		691,300		756,500
Equity securities
Amortized Cost, Available for sale
Amortized Cost	11,177		11,177		11,000
Fair Value, Available for sale
Fair Value	11,077		11,077		10,828
Residential and commercial mortgage-backed securities
Amortized Cost, Available for sale
Amortized Cost	964,578		964,578
Fair Value, Available for sale
Fair Value	962,477		962,477
Residential mortgage-backed securities
Amortized Cost, Available for sale
Amortized Cost	878,167		878,167		988,744
Fair Value, Available for sale
Fair Value	875,260		875,260		983,684
Amortized Cost, Held to maturity
Investment securities held to maturity	105,662		105,662		159,142
Fair value, Held to maturity
Fair Value	$ 107,694		$ 107,694		$ 164,562

Loans - Schedule of Composition

Loans - Schedule of Composition of Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Loans
Total loans, excluding purchased credit-impaired loans	$ 13,753,459	$ 12,605,726
Purchased credit-impaired loans	131,919	163,077
Total loans	13,885,378	12,768,803	$ 12,540,696
Commercial Portfolio Segment
Loans
Total loans, excluding purchased credit-impaired loans	4,793,838	4,346,506
Total loans	4,807,515		4,408,725
Commercial Portfolio Segment | Collateralized
Loans
Total loans, excluding purchased credit-impaired loans	2,074,215	2,002,976
Total loans	2,074,215		1,873,380
Commercial Real Estate Portfolio Segment | Commercial real estate
Loans
Total loans, excluding purchased credit-impaired loans	4,094,706	3,788,016
Total loans	4,126,769		3,836,087
Commercial Real Estate Portfolio Segment | Construction real estate
Loans
Total loans, excluding purchased credit-impaired loans	395,794	518,562
Total loans	400,977		465,154
Commercial Real Estate Portfolio Segment | Other
Loans
Total loans, excluding purchased credit-impaired loans	967,857	903,621
Consumer Portfolio Segment | Commercial real estate
Loans
Total loans, excluding purchased credit-impaired loans	1,433,595	1,060,828
Consumer Portfolio Segment | Indirect vehicle
Loans
Total loans, excluding purchased credit-impaired loans	655,213	541,680
Total loans	655,213		522,271
Consumer Portfolio Segment | Home equity
Loans
Total loans, excluding purchased credit-impaired loans	228,726	266,377
Total loans	239,926		289,174
Consumer Portfolio Segment | Other
Loans
Total loans, excluding purchased credit-impaired loans	77,372	$ 80,781
Total loans	$ 79,097		$ 80,380

Loans - Additional Information

Loans - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)category	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Receivables [Abstract]
Number of highest rating categories by rating services company | category			1
Number of highest rating categories to be achieved for classification as investment grade companies | category			4
Percentage of collateral pledge of first mortgage loans as per agreement (minimum)	129.00%		129.00%
Percentage of collateral pledge of home equity loans as per agreement (minimum)	231.00%		231.00%
Percentage of collateral pledge of commercial real estate loans as per agreement (minimum)	183.00%		183.00%
Percentage of collateral pledge of outstanding advances from federal home loan bank as per agreement (minimum)	108.00%		108.00%
Loans pledged as collateral for long-term Federal Home Loan Bank advances	$ 5,600,000		$ 5,600,000		$ 5,500,000
Loans required to be pledged as collateral for long-term Federal Home Loan Bank advances	4,200,000		4,200,000		3,200,000
Real estate | Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for credit losses	935	$ 1,239	12,842	$ 1,439
Purchased Credit-Impaired Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Provision for credit losses			243
Allowance for loan losses and unfunded commitments write offs net of recoveries			123
Allowance for loan losses and unfunded commitments acquired with deteriorated credit quality	$ 986		$ 986		$ 866

Loans - Contractual Aging of Re

Loans - Contractual Aging of Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Contractual aging of the recorded investment in loans
Total loans, excluding covered loans	$ 13,753,459	$ 12,605,726
Total loans	13,885,378	12,768,803	$ 12,540,696
Non-performing loan aging
Contractual aging of the recorded investment in loans
Current	27,148	28,364
Past Due	23,467	30,988
Total loans	50,615	59,352
Non-performing loan aging | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	1,179	2,308
Non-performing loan aging | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	2,244	978
Non-performing loan aging | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	20,044	27,702
Purchased credit-impaired loans
Contractual aging of the recorded investment in loans
Current	72,900	86,169
Past Due	59,019	76,908
Total loans	131,919	163,077
Purchased credit-impaired loans | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	4,438	6,546
Purchased credit-impaired loans | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	6,602	6,600
Purchased credit-impaired loans | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	47,979	63,762
Total loans, excluding purchased credit-impaired loans
Contractual aging of the recorded investment in loans
Current	13,694,085	12,534,074
Past Due	59,374	71,652
Total loans, excluding covered loans	13,753,459	12,605,726
Total loans, excluding purchased credit-impaired loans | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	28,846	31,005
Total loans, excluding purchased credit-impaired loans | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	10,371	12,798
Total loans, excluding purchased credit-impaired loans | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	20,157	27,849
Total loans
Contractual aging of the recorded investment in loans
Current	13,766,985	12,620,243
Past Due	118,393	148,560
Total loans	13,885,378	12,768,803
Total loans | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	33,284	37,551
Total loans | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	16,973	19,398
Total loans | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	68,136	91,611
Commercial Portfolio Segment
Contractual aging of the recorded investment in loans
Current	4,782,808	4,337,348
Past Due	11,030	9,158
Total loans, excluding covered loans	4,793,838	4,346,506
Total loans	4,807,515		4,408,725
Commercial Portfolio Segment | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	5,438	2,515
Commercial Portfolio Segment | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	351	156
Commercial Portfolio Segment | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	5,241	6,487
Commercial Portfolio Segment | Collateralized
Contractual aging of the recorded investment in loans
Current	2,059,556	1,989,934
Past Due	14,659	13,042
Total loans, excluding covered loans	2,074,215	2,002,976
Total loans	2,074,215		1,873,380
Commercial Portfolio Segment | Collateralized | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	10,488	9,229
Commercial Portfolio Segment | Collateralized | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	3,810	1,869
Commercial Portfolio Segment | Collateralized | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	361	1,944
Commercial Real Estate Portfolio Segment | Healthcare
Contractual aging of the recorded investment in loans
Current	698,919	582,450
Past Due	0	0
Total loans, excluding covered loans	698,919	582,450
Commercial Real Estate Portfolio Segment | Healthcare | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	0
Commercial Real Estate Portfolio Segment | Healthcare | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	0
Commercial Real Estate Portfolio Segment | Healthcare | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	0	0
Commercial Real Estate Portfolio Segment | Industrial
Contractual aging of the recorded investment in loans
Current	856,630	825,715
Past Due	755	7,678
Total loans, excluding covered loans	857,385	833,393
Commercial Real Estate Portfolio Segment | Industrial | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	3,045
Commercial Real Estate Portfolio Segment | Industrial | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	3,293
Commercial Real Estate Portfolio Segment | Industrial | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	755	1,340
Commercial Real Estate Portfolio Segment | Multifamily
Contractual aging of the recorded investment in loans
Current	608,254	547,107
Past Due	1,528	890
Total loans, excluding covered loans	609,782	547,997
Commercial Real Estate Portfolio Segment | Multifamily | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	959	458
Commercial Real Estate Portfolio Segment | Multifamily | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	53
Commercial Real Estate Portfolio Segment | Multifamily | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	569	379
Commercial Real Estate Portfolio Segment | Retail
Contractual aging of the recorded investment in loans
Current	508,048	506,789
Past Due	1,279	568
Total loans, excluding covered loans	509,327	507,357
Commercial Real Estate Portfolio Segment | Retail | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	1,021	568
Commercial Real Estate Portfolio Segment | Retail | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	0
Commercial Real Estate Portfolio Segment | Retail | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	258	0
Commercial Real Estate Portfolio Segment | Office
Contractual aging of the recorded investment in loans
Current	447,671	405,992
Past Due	3,765	7,206
Total loans, excluding covered loans	451,436	413,198
Commercial Real Estate Portfolio Segment | Office | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	2,131	350
Commercial Real Estate Portfolio Segment | Office | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	475
Commercial Real Estate Portfolio Segment | Office | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	1,634	6,381
Commercial Real Estate Portfolio Segment | Other
Contractual aging of the recorded investment in loans
Current	964,855	899,950
Past Due	3,002	3,671
Total loans, excluding covered loans	967,857	903,621
Commercial Real Estate Portfolio Segment | Other | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	1,896	2,385
Commercial Real Estate Portfolio Segment | Other | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	87	1,155
Commercial Real Estate Portfolio Segment | Other | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	1,019	131
Commercial Real Estate Portfolio Segment | Construction real estate
Contractual aging of the recorded investment in loans
Current	395,226	518,171
Past Due	568	391
Total loans, excluding covered loans	395,794	518,562
Total loans	400,977		465,154
Commercial Real Estate Portfolio Segment | Construction real estate | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	568	0
Commercial Real Estate Portfolio Segment | Construction real estate | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	0	391
Commercial Real Estate Portfolio Segment | Construction real estate | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	0	0
Consumer Portfolio Segment | Other
Contractual aging of the recorded investment in loans
Current	77,109	80,443
Past Due	263	338
Total loans, excluding covered loans	77,372	80,781
Total loans	79,097		80,380
Consumer Portfolio Segment | Other | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	89	152
Consumer Portfolio Segment | Other | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	79	120
Consumer Portfolio Segment | Other | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	95	66
Consumer Portfolio Segment | Residential real estate
Contractual aging of the recorded investment in loans
Current	1,422,321	1,041,189
Past Due	11,274	19,639
Total loans, excluding covered loans	1,433,595	1,060,828
Total loans	1,501,666		1,065,525
Consumer Portfolio Segment | Residential real estate | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	575	8,248
Consumer Portfolio Segment | Residential real estate | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	4,299	3,409
Consumer Portfolio Segment | Residential real estate | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	6,400	7,982
Consumer Portfolio Segment | Indirect vehicle
Contractual aging of the recorded investment in loans
Current	649,884	537,221
Past Due	5,329	4,459
Total loans, excluding covered loans	655,213	541,680
Total loans	655,213		522,271
Consumer Portfolio Segment | Indirect vehicle | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	3,938	2,836
Consumer Portfolio Segment | Indirect vehicle | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	992	1,062
Consumer Portfolio Segment | Indirect vehicle | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	399	561
Consumer Portfolio Segment | Home equity
Contractual aging of the recorded investment in loans
Current	222,804	261,765
Past Due	5,922	4,612
Total loans, excluding covered loans	228,726	266,377
Total loans	239,926		$ 289,174
Consumer Portfolio Segment | Home equity | 30-59 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	1,743	1,219
Consumer Portfolio Segment | Home equity | 60-89 Days Past Due
Contractual aging of the recorded investment in loans
Past Due	753	815
Consumer Portfolio Segment | Home equity | Loans Past Due 90 Days or More
Contractual aging of the recorded investment in loans
Past Due	$ 3,426	$ 2,578

Loans - Recorded Investment in

Loans - Recorded Investment in Non-Accrual Loans and Loans Past Due (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Contractual aging of the recorded investment in loans
Period past due of recorded investment in loans	90 days
Total loans
Contractual aging of the recorded investment in loans
Non-accrual	$ 49,926	$ 48,974
Loans past due 90 days or more and still accruing	689	10,378
Commercial Portfolio Segment
Contractual aging of the recorded investment in loans
Non-accrual	7,079	11,222
Loans past due 90 days or more and still accruing	0	1,406
Commercial Portfolio Segment | Collateralized
Contractual aging of the recorded investment in loans
Non-accrual	1,054	1,364
Loans past due 90 days or more and still accruing	360	1,197
Commercial Real Estate Portfolio Segment | Healthcare
Contractual aging of the recorded investment in loans
Non-accrual	0	0
Loans past due 90 days or more and still accruing	0	0
Commercial Real Estate Portfolio Segment | Industrial
Contractual aging of the recorded investment in loans
Non-accrual	2,215	276
Loans past due 90 days or more and still accruing	0	1,064
Commercial Real Estate Portfolio Segment | Multifamily
Contractual aging of the recorded investment in loans
Non-accrual	1,110	2,662
Loans past due 90 days or more and still accruing	0	0
Commercial Real Estate Portfolio Segment | Office
Contractual aging of the recorded investment in loans
Non-accrual	2,973	896
Loans past due 90 days or more and still accruing	0	6,381
Commercial Real Estate Portfolio Segment | Retail
Contractual aging of the recorded investment in loans
Non-accrual	382	384
Loans past due 90 days or more and still accruing	0	0
Commercial Real Estate Portfolio Segment | Other
Contractual aging of the recorded investment in loans
Non-accrual	1,058	83
Loans past due 90 days or more and still accruing	15	21
Commercial Real Estate Portfolio Segment | Construction real estate
Contractual aging of the recorded investment in loans
Non-accrual	0	0
Loans past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment | Residential real estate
Contractual aging of the recorded investment in loans
Non-accrual	18,811	16,538
Loans past due 90 days or more and still accruing	185	235
Consumer Portfolio Segment | Indirect vehicle
Contractual aging of the recorded investment in loans
Non-accrual	2,440	2,355
Loans past due 90 days or more and still accruing	34	10
Consumer Portfolio Segment | Home equity
Contractual aging of the recorded investment in loans
Non-accrual	12,803	13,187
Loans past due 90 days or more and still accruing	0	0
Consumer Portfolio Segment | Other
Contractual aging of the recorded investment in loans
Non-accrual	1	7
Loans past due 90 days or more and still accruing	$ 95	$ 64

Loans - Risk Category and Recor

Loans - Risk Category and Recorded Investment of Loans by Class (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans
Commercial related loans, excluding purchased credit-impaired loans	$ 11,358,553	$ 10,656,060
Non-performing substandard and doubtful loans	15,900	17,300
Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	10,937,677	10,255,548
Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	244,100	238,651
Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	176,776	161,861
Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Portfolio Segment
Loans
Commercial related loans, excluding purchased credit-impaired loans	4,793,838	4,346,506
Commercial Portfolio Segment | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	4,556,245	4,127,397
Commercial Portfolio Segment | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	160,905	113,838
Commercial Portfolio Segment | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	76,688	105,271
Commercial Portfolio Segment | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Portfolio Segment | Collateralized
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,074,215	2,002,976
Commercial Portfolio Segment | Collateralized | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,053,456	1,981,689
Commercial Portfolio Segment | Collateralized | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	12,405	16,010
Commercial Portfolio Segment | Collateralized | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	8,354	5,277
Commercial Portfolio Segment | Collateralized | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Multifamily
Loans
Commercial related loans, excluding purchased credit-impaired loans	609,782	547,997
Commercial Real Estate Portfolio Segment | Multifamily | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	601,515	544,071
Commercial Real Estate Portfolio Segment | Multifamily | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	151	312
Commercial Real Estate Portfolio Segment | Multifamily | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	8,116	3,614
Commercial Real Estate Portfolio Segment | Multifamily | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Retail
Loans
Commercial related loans, excluding purchased credit-impaired loans	509,327	507,357
Commercial Real Estate Portfolio Segment | Retail | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	505,004	498,458
Commercial Real Estate Portfolio Segment | Retail | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	1,566	8,350
Commercial Real Estate Portfolio Segment | Retail | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,757	549
Commercial Real Estate Portfolio Segment | Retail | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Office
Loans
Commercial related loans, excluding purchased credit-impaired loans	451,436	413,198
Commercial Real Estate Portfolio Segment | Office | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	442,550	404,811
Commercial Real Estate Portfolio Segment | Office | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	3,782	5,299
Commercial Real Estate Portfolio Segment | Office | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	5,104	3,088
Commercial Real Estate Portfolio Segment | Office | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Construction real estate
Loans
Commercial related loans, excluding purchased credit-impaired loans	395,794	518,562
Commercial Real Estate Portfolio Segment | Construction real estate | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	395,267	518,562
Commercial Real Estate Portfolio Segment | Construction real estate | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	527	0
Commercial Real Estate Portfolio Segment | Construction real estate | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Construction real estate | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Other
Loans
Commercial related loans, excluding purchased credit-impaired loans	967,857	903,621
Commercial Real Estate Portfolio Segment | Other | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	893,589	820,229
Commercial Real Estate Portfolio Segment | Other | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	46,688	44,629
Commercial Real Estate Portfolio Segment | Other | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	27,580	38,763
Commercial Real Estate Portfolio Segment | Other | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Healthcare
Loans
Commercial related loans, excluding purchased credit-impaired loans	698,919	582,450
Commercial Real Estate Portfolio Segment | Healthcare | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	659,945	545,663
Commercial Real Estate Portfolio Segment | Healthcare | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,675	32,251
Commercial Real Estate Portfolio Segment | Healthcare | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	36,299	4,536
Commercial Real Estate Portfolio Segment | Healthcare | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Commercial Real Estate Portfolio Segment | Industrial
Loans
Commercial related loans, excluding purchased credit-impaired loans	857,385	833,393
Commercial Real Estate Portfolio Segment | Industrial | Pass
Loans
Commercial related loans, excluding purchased credit-impaired loans	830,106	814,668
Commercial Real Estate Portfolio Segment | Industrial | Special Mention
Loans
Commercial related loans, excluding purchased credit-impaired loans	15,401	17,962
Commercial Real Estate Portfolio Segment | Industrial | Substandard
Loans
Commercial related loans, excluding purchased credit-impaired loans	11,878	763
Commercial Real Estate Portfolio Segment | Industrial | Doubtful
Loans
Commercial related loans, excluding purchased credit-impaired loans	0	0
Consumer Portfolio Segment
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,394,906	1,949,666
Consumer Portfolio Segment | Performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,360,537	1,917,270
Consumer Portfolio Segment | Non-performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	34,369	32,396
Consumer Portfolio Segment | Residential real estate
Loans
Commercial related loans, excluding purchased credit-impaired loans	1,433,595	1,060,828
Consumer Portfolio Segment | Residential real estate | Performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	1,414,599	1,044,055
Consumer Portfolio Segment | Residential real estate | Non-performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	18,996	16,773
Consumer Portfolio Segment | Indirect vehicle
Loans
Commercial related loans, excluding purchased credit-impaired loans	655,213	541,680
Consumer Portfolio Segment | Indirect vehicle | Performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	652,739	539,315
Consumer Portfolio Segment | Indirect vehicle | Non-performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	2,474	2,365
Consumer Portfolio Segment | Home equity
Loans
Commercial related loans, excluding purchased credit-impaired loans	228,726	266,377
Consumer Portfolio Segment | Home equity | Performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	215,923	253,190
Consumer Portfolio Segment | Home equity | Non-performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	12,803	13,187
Consumer Portfolio Segment | Other
Loans
Commercial related loans, excluding purchased credit-impaired loans	77,372	80,781
Consumer Portfolio Segment | Other | Performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	77,276	80,710
Consumer Portfolio Segment | Other | Non-performing
Loans
Commercial related loans, excluding purchased credit-impaired loans	$ 96	$ 71

Loans - Loans Individually Eval

Loans - Loans Individually Evaluated for Impairment by Class of Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Loans
Amount of mortgage loans in process of foreclosure	$ 46,100	$ 46,100	$ 29,100
Unpaid Principal Balance	75,547	75,547	80,356
Recorded Investment	70,749	70,749	73,914
Partial Charge-offs	4,798	4,798	6,442
Allowance for Loan Losses Allocated	7,183	7,183	8,336
Average Recorded Investment	69,092	70,806	87,645
Interest Income Recognized	204	586	52
Performing
Loans
Restructured loans	32,850	32,850	32,687
Non-performing
Loans
Restructured loans	24,356	24,356	27,068
Impaired financing receivable with no allowance | Commercial Portfolio Segment
Loans
Unpaid Principal Balance	2,997	2,997	9,056
Recorded Investment	2,997	2,997	9,056
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	2,470	4,064	5,944
Interest Income Recognized	22	59	0
Impaired financing receivable with no allowance | Commercial Portfolio Segment | Collateralized
Loans
Unpaid Principal Balance	16	16	1,129
Recorded Investment	1	1	747
Partial Charge-offs	15	15	382
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	1	403	1,045
Interest Income Recognized	0	0	34
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Healthcare
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Industrial
Loans
Unpaid Principal Balance	1,238	1,238	0
Recorded Investment	1,238	1,238	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	1,350	1,684	402
Interest Income Recognized	0	8	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Multifamily
Loans
Unpaid Principal Balance	0	0	1,922
Recorded Investment	0	0	1,922
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	0	1,686	2,348
Interest Income Recognized	0	29	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Retail
Loans
Unpaid Principal Balance	0	0	2,670
Recorded Investment	0	0	929
Partial Charge-offs	0	0	1,741
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	0	1,088	2,165
Interest Income Recognized	0	27	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Office
Loans
Unpaid Principal Balance	1,860	1,860	0
Recorded Investment	1,856	1,856	0
Partial Charge-offs	4	4	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	1,903	1,715	256
Interest Income Recognized	6	12	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Other
Loans
Unpaid Principal Balance	3,542	3,542	0
Recorded Investment	3,542	3,542	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	3,552	1,197	60
Interest Income Recognized	57	57	0
Impaired financing receivable with no allowance | Commercial Real Estate Portfolio Segment | Construction real estate
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Consumer Portfolio Segment | Real estate
Loans
Unpaid Principal Balance	750	750	0
Recorded Investment	718	718	0
Partial Charge-offs	32	32	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Consumer Portfolio Segment | Indirect vehicle
Loans
Unpaid Principal Balance	572	572	223
Recorded Investment	349	349	122
Partial Charge-offs	223	223	101
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	621	396	252
Interest Income Recognized	10	20	0
Impaired financing receivable with no allowance | Consumer Portfolio Segment | Home equity
Loans
Unpaid Principal Balance	108	108	0
Recorded Investment	108	108	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	0
Average Recorded Investment	26	476	143
Interest Income Recognized	0	0	0
Impaired financing receivable with no allowance | Consumer Portfolio Segment | Other consumer
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial Portfolio Segment
Loans
Unpaid Principal Balance	7,645	7,645	14,403
Recorded Investment	7,645	7,645	14,403
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	1,012	1,012	2,889
Average Recorded Investment	8,406	8,481	22,737
Interest Income Recognized	29	202	0
Impaired financing receivable with allowance | Commercial Portfolio Segment | Collateralized
Loans
Unpaid Principal Balance	920	920	0
Recorded Investment	920	920	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	585	585	0
Average Recorded Investment	500	168	2,397
Interest Income Recognized	14	14	18
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Healthcare
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Industrial
Loans
Unpaid Principal Balance	3,254	3,254	0
Recorded Investment	3,243	3,243	0
Partial Charge-offs	11	11	0
Allowance for Loan Losses Allocated	432	432	0
Average Recorded Investment	3,293	2,213	0
Interest Income Recognized	34	66	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Multifamily
Loans
Unpaid Principal Balance	569	569	0
Recorded Investment	569	569	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	234	234	0
Average Recorded Investment	565	379	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Retail
Loans
Unpaid Principal Balance	0	0	3,592
Recorded Investment	0	0	3,592
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	0	0	354
Average Recorded Investment	0	1,799	6,827
Interest Income Recognized	0	28	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Office
Loans
Unpaid Principal Balance	961	961	0
Recorded Investment	960	960	0
Partial Charge-offs	1	1	0
Allowance for Loan Losses Allocated	34	34	0
Average Recorded Investment	214	72	745
Interest Income Recognized	4	4	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Other
Loans
Unpaid Principal Balance	591	591	0
Recorded Investment	591	591	0
Partial Charge-offs	0	0	0
Allowance for Loan Losses Allocated	155	155	0
Average Recorded Investment	115	39	235
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Commercial Real Estate Portfolio Segment | Construction real estate
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Consumer Portfolio Segment | Real estate
Loans
Unpaid Principal Balance	20,876	20,876	16,257
Recorded Investment	18,652	18,652	14,353
Partial Charge-offs	2,224	2,224	1,904
Allowance for Loan Losses Allocated	2,169	2,169	2,163
Average Recorded Investment	18,655	17,126	13,412
Interest Income Recognized	16	21	0
Impaired financing receivable with allowance | Consumer Portfolio Segment | Indirect vehicle
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
Average Recorded Investment	0	0	0
Interest Income Recognized	0	0	0
Impaired financing receivable with allowance | Consumer Portfolio Segment | Home equity
Loans
Unpaid Principal Balance	29,648	29,648	31,104
Recorded Investment	27,360	27,360	28,790
Partial Charge-offs	2,288	2,288	2,314
Allowance for Loan Losses Allocated	2,562	2,562	2,930
Average Recorded Investment	27,421	27,820	28,677
Interest Income Recognized	12	39	0
Impaired financing receivable with allowance | Consumer Portfolio Segment | Other consumer
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
Average Recorded Investment	0	0	0
Interest Income Recognized	$ 0	$ 0	$ 0

Loans - Loans That Have Been Re

Loans - Loans That Have Been Restructured (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)loan	Sep. 30, 2016USD ($)loan	Sep. 30, 2017USD ($)loan	Sep. 30, 2016USD ($)loan
Restructured loans
Redefaulted loans			$ 0
Period past due of redefaulted loans			90 days
Performing
Restructured loans
Number of Loans | loan	6	4	24	7
Pre-Modification Recorded Investment	$ 4,298,000	$ 203,000	$ 11,253,000	$ 2,482,000
Post-Modification Recorded Investment	4,298,000	203,000	11,253,000	2,482,000
Charge-offs and Specific Reserves	$ 1,000	$ 30,000	$ 515,000	$ 442,000
Performing | Commercial Portfolio Segment
Restructured loans
Number of Loans | loan			5	1
Pre-Modification Recorded Investment			$ 2,491,000	$ 1,870,000
Post-Modification Recorded Investment			2,491,000	1,870,000
Charge-offs and Specific Reserves			$ 373,000	$ 412,000
Performing | Commercial Real Estate Portfolio Segment | Office
Restructured loans
Number of Loans | loan			1
Pre-Modification Recorded Investment			$ 549,000
Post-Modification Recorded Investment			549,000
Charge-offs and Specific Reserves			$ 0
Performing | Commercial Real Estate Portfolio Segment | Other
Restructured loans
Number of Loans | loan	2		3
Pre-Modification Recorded Investment	$ 3,555,000		$ 3,703,000
Post-Modification Recorded Investment	3,555,000		3,703,000
Charge-offs and Specific Reserves	$ 0		$ 0
Performing | Commercial Real Estate Portfolio Segment | Industrial
Restructured loans
Number of Loans | loan	1		3
Pre-Modification Recorded Investment	$ 387,000		$ 3,174,000
Post-Modification Recorded Investment	387,000		3,174,000
Charge-offs and Specific Reserves	$ 0		$ 0
Performing | Consumer Portfolio Segment | Real estate
Restructured loans
Number of Loans | loan		2	6	2
Pre-Modification Recorded Investment		$ 101,000	$ 902,000	$ 101,000
Post-Modification Recorded Investment		101,000	902,000	101,000
Charge-offs and Specific Reserves		$ 18,000	$ 135,000	$ 18,000
Performing | Consumer Portfolio Segment | Home equity
Restructured loans
Number of Loans | loan	1	2	4	4
Pre-Modification Recorded Investment	$ 19,000	$ 102,000	$ 97,000	$ 511,000
Post-Modification Recorded Investment	19,000	102,000	97,000	511,000
Charge-offs and Specific Reserves	$ 1,000	$ 12,000	$ 7,000	$ 12,000
Non-performing
Restructured loans
Number of Loans | loan	32	19	69	66
Pre-Modification Recorded Investment	$ 2,943,000	$ 6,881,000	$ 7,885,000	$ 18,903,000
Post-Modification Recorded Investment	2,943,000	6,881,000	7,885,000	18,903,000
Charge-offs and Specific Reserves	$ 845,000	$ 1,664,000	$ 1,374,000	$ 5,273,000
Non-performing | Commercial Portfolio Segment
Restructured loans
Number of Loans | loan		3	2	7
Pre-Modification Recorded Investment		$ 5,874,000	$ 676,000	$ 14,481,000
Post-Modification Recorded Investment		5,874,000	676,000	14,481,000
Charge-offs and Specific Reserves		$ 1,490,000	$ 0	$ 4,990,000
Non-performing | Commercial Real Estate Portfolio Segment | Multifamily
Restructured loans
Number of Loans | loan			3
Pre-Modification Recorded Investment			$ 290,000
Post-Modification Recorded Investment			290,000
Charge-offs and Specific Reserves			$ 0
Non-performing | Commercial Real Estate Portfolio Segment | Retail
Restructured loans
Number of Loans | loan			1
Pre-Modification Recorded Investment			$ 906,000
Post-Modification Recorded Investment			906,000
Charge-offs and Specific Reserves			$ 0
Non-performing | Consumer Portfolio Segment | Real estate
Restructured loans
Number of Loans | loan	11	4	28	6
Pre-Modification Recorded Investment	$ 2,775,000	$ 484,000	$ 5,155,000	$ 639,000
Post-Modification Recorded Investment	2,775,000	484,000	5,155,000	639,000
Charge-offs and Specific Reserves	$ 739,000	$ 85,000	$ 1,182,000	$ 85,000
Non-performing | Consumer Portfolio Segment | Indirect vehicle
Restructured loans
Number of Loans | loan	20	7	31	25
Pre-Modification Recorded Investment	$ 153,000	$ 34,000	$ 250,000	$ 183,000
Post-Modification Recorded Investment	153,000	34,000	250,000	183,000
Charge-offs and Specific Reserves	$ 105,000	$ 17,000	$ 134,000	$ 60,000
Non-performing | Consumer Portfolio Segment | Home equity
Restructured loans
Number of Loans | loan	1	5	4	28
Pre-Modification Recorded Investment	$ 15,000	$ 489,000	$ 608,000	$ 3,600,000
Post-Modification Recorded Investment	15,000	489,000	608,000	3,600,000
Charge-offs and Specific Reserves	$ 1,000	$ 72,000	$ 58,000	$ 138,000
Retail | Performing | Commercial Real Estate Portfolio Segment
Restructured loans
Number of Loans | loan	2		2
Pre-Modification Recorded Investment	$ 337,000		$ 337,000
Post-Modification Recorded Investment	337,000		337,000
Charge-offs and Specific Reserves	$ 0		$ 0

Loans - Troubled Debt Restructu

Loans - Troubled Debt Restructuring Activity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Performing
Financing Receivable, Modifications, Post Modification Recorded Investment [Roll Forward]
Beginning balance	$ 32,687
Additions	11,253
Charge-offs	0
Principal payments, net	(1,001)
Removals	(11,546)
Transfer to other real estate owned	0
Transfers in	2,056
Transfers out	(599)
Ending balance	32,850
Non-performing
Financing Receivable, Modifications, Post Modification Recorded Investment [Roll Forward]
Beginning balance	27,068
Additions	7,885
Charge-offs	(520)
Principal payments, net	(4,601)
Removals	(3,429)
Transfer to other real estate owned	(590)
Transfers in	599
Transfers out	(2,056)
Ending balance	$ 24,356

Loans - Financing Receivable Mo

Loans - Financing Receivable Modifications and Restructuring (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
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
Post-modification recorded investment	$ 19,138
Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	3,885
Extended Maturity and/or Amortization
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
Post-modification recorded investment	13,413
Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	1,840
Commercial Portfolio Segment
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
Post-modification recorded investment	3,167
Commercial Portfolio Segment | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Portfolio Segment | Extended Maturity and/or Amortization
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
Post-modification recorded investment	3,167
Commercial Portfolio Segment | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Portfolio Segment | Collateralized
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
Post-modification recorded investment	0
Commercial Portfolio Segment | Collateralized | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Portfolio Segment | Collateralized | Extended Maturity and/or Amortization
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
Post-modification recorded investment	0
Commercial Portfolio Segment | Collateralized | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	290
Commercial Real Estate Portfolio Segment | Multifamily | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Multifamily | Extended Maturity and/or Amortization
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
Post-modification recorded investment	290
Commercial Real Estate Portfolio Segment | Multifamily | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	1,243
Commercial Real Estate Portfolio Segment | Retail | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Retail | Extended Maturity and/or Amortization
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
Post-modification recorded investment	906
Commercial Real Estate Portfolio Segment | Retail | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	337
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	549
Commercial Real Estate Portfolio Segment | Office | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Office | Extended Maturity and/or Amortization
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
Post-modification recorded investment	549
Commercial Real Estate Portfolio Segment | Office | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	3,703
Commercial Real Estate Portfolio Segment | Other | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Other | Extended Maturity and/or Amortization
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
Post-modification recorded investment	3,703
Commercial Real Estate Portfolio Segment | Other | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Construction real estate | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Construction real estate | Extended Maturity and/or Amortization
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Construction real estate | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Healthcare | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Healthcare | Extended Maturity and/or Amortization
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Healthcare | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | 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
Post-modification recorded investment	3,174
Commercial Real Estate Portfolio Segment | Industrial | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Commercial Real Estate Portfolio Segment | Industrial | Extended Maturity and/or Amortization
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
Post-modification recorded investment	3,174
Commercial Real Estate Portfolio Segment | Industrial | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	0
Consumer Portfolio Segment | 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
Post-modification recorded investment	6,057
Consumer Portfolio Segment | Residential real estate | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	3,885
Consumer Portfolio Segment | Residential real estate | Extended Maturity and/or Amortization
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
Post-modification recorded investment	1,589
Consumer Portfolio Segment | Residential real estate | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	583
Consumer Portfolio Segment | 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
Post-modification recorded investment	250
Consumer Portfolio Segment | Indirect vehicle | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Consumer Portfolio Segment | Indirect vehicle | Extended Maturity and/or Amortization
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
Post-modification recorded investment	0
Consumer Portfolio Segment | Indirect vehicle | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	250
Consumer Portfolio Segment | Home equity
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
Post-modification recorded investment	705
Consumer Portfolio Segment | Home equity | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Consumer Portfolio Segment | Home equity | Extended Maturity and/or Amortization
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
Post-modification recorded investment	35
Consumer Portfolio Segment | Home equity | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	670
Consumer Portfolio Segment | 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
Post-modification recorded investment	0
Consumer Portfolio Segment | Other consumer | Extended Maturity, Amortization and Reduction of Interest Rate
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
Post-modification recorded investment	0
Consumer Portfolio Segment | Other consumer | Extended Maturity and/or Amortization
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
Post-modification recorded investment	0
Consumer Portfolio Segment | Other consumer | Delay in Payments and/or Reduction of Interest Rate
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
Post-modification recorded investment	$ 0

Loans - Allowance for Credit Lo

Loans - Allowance for Credit Losses (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Allowance for credit losses:
Beginning balance				$ 139,366
Ending balance		$ 159,128		159,128
Unfunded Commitments
Allowance for unfunded credit commitments, Beginning balance		2,264	$ 2,719	2,476	$ 3,368
Allowance for unfunded commitments, Charge-Offs		0	0	0	0
Allowance for unfunded commitments, Recoveries		0	0	0	0
Allowance for unfunded commitments, Provision		12	152	(200)	(497)
Allowance for unfunded credit commitments, Ending balance		2,276	2,871	2,276	2,871
Allowance for credit losses
Allowance for credit losses, Beginning balance		156,297	138,333	141,842	131,508
Allowance for loan losses and unfunded commitments charge offs		2,830	4,157	9,124	14,169
Allowance for loan losses and unfunded commitments recoveries		3,420	1,674	10,736	8,119
Allowance for loan losses and unfunded commitments provision		4,517	6,549	17,950	16,941
Allowance for credit losses, Ending balance		161,404	142,399	161,404	142,399
Ending allowance balance attributable to loans:
Individually evaluated for impairment, Unfunded commitments		1,220	737	1,220	737
Individually evaluated for impairment, Total		8,403	16,080	8,403	16,080
Collectively evaluated for impairment, Unfunded commitments		1,056	2,134	1,056	2,134
Collectively evaluated for impairment, Total		152,015	125,621	152,015	125,621
Acquired and accounted for under ASC 310-30	[1]	986	698	986	698
Acquired and accounted for under ASC 310-30, Unfunded commitments	[1]	0	0	0	0
Loans:
Individually evaluated for impairment		70,749	74,537	70,749	74,537
Individually evaluated for impairment, Unfunded commitments		0	0	0	0
Collectively evaluated for impairment		13,682,710	12,304,821	13,682,710	12,304,821
Collectively evaluated for impairment, Unfunded commitments		0	0	0	0
Acquired and accounted for under ASC 310-30	[1]	131,919	161,338	131,919	161,338
Acquired and accounted for under ASC 310-30, Unfunded commitments	[1]	0	0	0	0
Total loans		13,885,378	12,540,696	13,885,378	12,540,696	$ 12,768,803
Total loans, Unfunded commitments		0	0	0	0
Commercial Portfolio Segment
Allowance for credit losses:
Beginning balance		43,783	50,297	44,661	39,316
Charge-offs		235	1,341	1,103	2,126
Recoveries		719	665	3,568	1,997
Provision		1,715	(3,894)	(1,144)	6,540
Ending balance		45,982	45,727	45,982	45,727
Ending allowance balance attributable to loans:
Individually evaluated for impairment		1,012	5,401	1,012	5,401
Collectively evaluated for impairment		44,879	40,161	44,879	40,161
Acquired and accounted for under ASC 310-30	[1]	91	165	91	165
Loans:
Individually evaluated for impairment		10,642	19,284	10,642	19,284
Collectively evaluated for impairment		4,783,196	4,366,528	4,783,196	4,366,528
Acquired and accounted for under ASC 310-30	[1]	13,677	22,913	13,677	22,913
Total loans		4,807,515	4,408,725	4,807,515	4,408,725
Commercial Portfolio Segment | Collateralized
Allowance for credit losses:
Beginning balance		12,765	10,549	12,238	10,434
Charge-offs		188	367	188	3,288
Recoveries		0	3	712	520
Provision		240	2,944	55	5,463
Ending balance		12,817	13,129	12,817	13,129
Ending allowance balance attributable to loans:
Individually evaluated for impairment		585	3,933	585	3,933
Collectively evaluated for impairment		12,232	9,196	12,232	9,196
Acquired and accounted for under ASC 310-30	[1]		0		0
Loans:
Individually evaluated for impairment		921	8,054	921	8,054
Collectively evaluated for impairment		2,073,294	1,865,326	2,073,294	1,865,326
Acquired and accounted for under ASC 310-30	[1]	0	0	0	0
Total loans		2,074,215	1,873,380	2,074,215	1,873,380
Commercial Real Estate Portfolio Segment | Commercial real estate
Allowance for credit losses:
Beginning balance		63,247	46,040	51,807	45,475
Charge-offs		31	529	1,378	2,601
Recoveries		1,432	324	2,312	2,761
Provision		935	1,239	12,842	1,439
Ending balance		65,583	47,074	65,583	47,074
Ending allowance balance attributable to loans:
Individually evaluated for impairment		855	363	855	363
Collectively evaluated for impairment		63,868	46,235	63,868	46,235
Acquired and accounted for under ASC 310-30	[1]	860	476	860	476
Loans:
Individually evaluated for impairment		11,999	6,530	11,999	6,530
Collectively evaluated for impairment		4,082,707	3,788,271	4,082,707	3,788,271
Acquired and accounted for under ASC 310-30	[1]	32,063	41,286	32,063	41,286
Total loans		4,126,769	3,836,087	4,126,769	3,836,087
Commercial Real Estate Portfolio Segment | Construction real estate
Allowance for credit losses:
Beginning balance		15,263	14,230	14,758	15,113
Charge-offs		0	7	0	151
Recoveries		502	50	661	94
Provision		(707)	2,033	(361)	1,250
Ending balance		15,058	16,306	15,058	16,306
Ending allowance balance attributable to loans:
Individually evaluated for impairment			0		0
Collectively evaluated for impairment		15,023	16,249	15,023	16,249
Acquired and accounted for under ASC 310-30	[1]	35	57	35	57
Loans:
Individually evaluated for impairment		0	0	0	0
Collectively evaluated for impairment		395,794	451,023	395,794	451,023
Acquired and accounted for under ASC 310-30	[1]	5,183	14,131	5,183	14,131
Total loans		400,977	465,154	400,977	465,154
Consumer Portfolio Segment | Residential real estate
Allowance for credit losses:
Beginning balance		8,249	4,800	5,971	5,734
Charge-offs		541	290	901	1,134
Recoveries		38	45	624	151
Provision		94	1,575	2,146	1,379
Ending balance		7,840	6,130	7,840	6,130
Ending allowance balance attributable to loans:
Individually evaluated for impairment		2,169	2,394	2,169	2,394
Collectively evaluated for impairment		5,671	3,736	5,671	3,736
Acquired and accounted for under ASC 310-30	[1]		0		0
Loans:
Individually evaluated for impairment		19,370	13,268	19,370	13,268
Collectively evaluated for impairment		1,414,225	985,559	1,414,225	985,559
Acquired and accounted for under ASC 310-30	[1]	68,071	66,698	68,071	66,698
Total loans		1,501,666	1,065,525	1,501,666	1,065,525
Consumer Portfolio Segment | Indirect vehicle
Allowance for credit losses:
Beginning balance		3,963	3,100	3,421	2,418
Charge-offs		1,097	838	3,438	2,420
Recoveries		498	436	1,715	1,400
Provision		1,317	598	2,983	1,898
Ending balance		4,681	3,296	4,681	3,296
Ending allowance balance attributable to loans:
Individually evaluated for impairment			0		0
Collectively evaluated for impairment		4,681	3,296	4,681	3,296
Acquired and accounted for under ASC 310-30	[1]		0		0
Loans:
Individually evaluated for impairment		349	125	349	125
Collectively evaluated for impairment		654,864	522,146	654,864	522,146
Acquired and accounted for under ASC 310-30	[1]	0	0	0	0
Total loans		655,213	522,271	655,213	522,271
Consumer Portfolio Segment | Home equity
Allowance for credit losses:
Beginning balance		4,750	4,199	4,689	7,374
Charge-offs		439	376	873	1,233
Recoveries		149	65	724	576
Provision		422	2,309	342	(520)
Ending balance		4,882	6,197	4,882	6,197
Ending allowance balance attributable to loans:
Individually evaluated for impairment		2,562	3,252	2,562	3,252
Collectively evaluated for impairment		2,320	2,945	2,320	2,945
Acquired and accounted for under ASC 310-30	[1]		0		0
Loans:
Individually evaluated for impairment		27,468	27,276	27,468	27,276
Collectively evaluated for impairment		201,258	248,012	201,258	248,012
Acquired and accounted for under ASC 310-30	[1]	11,200	13,886	11,200	13,886
Total loans		239,926	289,174	239,926	289,174
Consumer Portfolio Segment | Other
Allowance for credit losses:
Beginning balance		2,013	2,399	1,821	2,276
Charge-offs		299	409	1,243	1,216
Recoveries		82	86	420	620
Provision		489	(407)	1,287	(11)
Ending balance		2,285	1,669	2,285	1,669
Ending allowance balance attributable to loans:
Individually evaluated for impairment			0		0
Collectively evaluated for impairment		2,285	1,669	2,285	1,669
Acquired and accounted for under ASC 310-30	[1]		0		0
Loans:
Individually evaluated for impairment		0	0	0	0
Collectively evaluated for impairment		77,372	77,956	77,372	77,956
Acquired and accounted for under ASC 310-30	[1]	1,725	2,424	1,725	2,424
Total loans		$ 79,097	$ 80,380	$ 79,097	$ 80,380
[1]	Loans acquired in business combinations and accounted for under ASC Subtopic 310-30 “Receivables — Loans and Debt Securities Acquired with Deteriorated Credit Quality.”

Loans - Changes in the Accretab

Loans - Changes in the Accretable Yield (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Changes in the accretable yield for purchased credit-impaired loans
Balance at beginning of period		$ 12,686	$ 13,160	$ 16,050	$ 12,596
Purchases		0	805	43	805
Accretion		(4,315)	(2,564)	(9,334)	(7,193)
Other	[1]	3,453	2,523	5,065	7,716
Balance at end of period		$ 11,824	$ 13,924	$ 11,824	$ 13,924
[1]	Primarily includes discount transfers from non-accretable discount to accretable discount due to better than expected performance of loan pools acquired and accounted for under ASC 310-30.

Loans - Carrying Amount of Loan

Loans - Carrying Amount of Loans Acquired (Details) $ in Thousands	Sep. 30, 2017USD ($)
Loans
Non covered loans	$ 1,632,291
Total acquired	1,647,949
Purchased Credit-Impaired Loans
Loans
Non covered loans	56,200
Total acquired	71,858
Purchased Non-Credit-Impaired Loans
Loans
Non covered loans	1,576,091
Total acquired	1,576,091
Other Loans | Purchased Credit-Impaired Loans | Ginnie Mae
Loans
Consumer related purchased credit-impaired loans	60,100
Commercial Loans, Commercial Real Estate Receivable and Construction Loans | Heritage
Loans
Loans not covered under the loss share agreement	1,500
Commercial Loans, Commercial Real Estate Receivable and Construction Loans | Benchmark
Loans
Loans not covered under the loss share agreement	197
Commercial Loans, Commercial Real Estate Receivable and Construction Loans | Broadway and New Century
Loans
Loans not covered under the loss share agreement	4,500
Consumer Portfolio Segment | Consumer related
Loans
Covered loans	15,658	[1]
Non covered loans	296,653
Consumer Portfolio Segment | Consumer related | Purchased Credit-Impaired Loans
Loans
Covered loans	15,658	[1]
Non covered loans	5,277
Consumer Portfolio Segment | Consumer related | Purchased Non-Credit-Impaired Loans
Loans
Covered loans	0	[1]
Non covered loans	291,376
Commercial Portfolio Segment
Loans
Non covered loans	367,166
Commercial Portfolio Segment | Purchased Credit-Impaired Loans
Loans
Non covered loans	13,677
Commercial Portfolio Segment | Purchased Non-Credit-Impaired Loans
Loans
Non covered loans	353,489
Commercial Portfolio Segment | Collateralized
Loans
Non covered loans	50,629
Commercial Portfolio Segment | Collateralized | Purchased Credit-Impaired Loans
Loans
Non covered loans	0
Commercial Portfolio Segment | Collateralized | Purchased Non-Credit-Impaired Loans
Loans
Non covered loans	50,629
Commercial Real Estate Portfolio Segment | Real estate
Loans
Non covered loans	905,242
Commercial Real Estate Portfolio Segment | Real estate | Purchased Credit-Impaired Loans
Loans
Non covered loans	32,063
Commercial Real Estate Portfolio Segment | Real estate | Purchased Non-Credit-Impaired Loans
Loans
Non covered loans	873,179
Commercial Real Estate Portfolio Segment | Construction real estate
Loans
Non covered loans	12,601
Commercial Real Estate Portfolio Segment | Construction real estate | Purchased Credit-Impaired Loans
Loans
Non covered loans	5,183
Commercial Real Estate Portfolio Segment | Construction real estate | Purchased Non-Credit-Impaired Loans
Loans
Non covered loans	$ 7,418
[1]	Covered loans refer to loans covered under loss-sharing agreements with the FDIC.

Goodwill and Intangibles - Addi

Goodwill and Intangibles - Additional Information (Details)	9 Months Ended
	Sep. 30, 2017USD ($)segment	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of operating segments | segment	3
Impairment loss	$ 0	$ 0
Goodwill	$ 999,925,000		$ 1,001,038,000
Weighted average amortization period (in years)	13 years

Goodwill and Intangibles - Chan

Goodwill and Intangibles - Changes In Carrying Amount of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Goodwill [Roll Forward]
Balance at beginning of period	$ 1,001,038
Goodwill from business combinations	(1,113)	[1]
Balance at end of period	999,925
Banking
Goodwill [Roll Forward]
Balance at beginning of period	960,398
Goodwill from business combinations	(1,113)	[1]
Balance at end of period	959,285
Leasing
Goodwill [Roll Forward]
Balance at beginning of period	40,640
Goodwill from business combinations	0	[1]
Balance at end of period	40,640
Mortgage Banking
Goodwill [Roll Forward]
Balance at beginning of period	0
Goodwill from business combinations	0	[1]
Balance at end of period	$ 0
[1]	Due to the adjustments recognized for the American Chartered merger during the first quarter of 2017.

Goodwill and Intangibles - Ch63

Goodwill and Intangibles - Changes in Core Deposit and Client Relationship Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017
Changes in the carrying amount of core deposit and client relationship intangibles
Balance at beginning of period			$ 62,959
Amortization expense	$ (2,038)	$ (1,674)	(6,214)	$ (4,917)
Balance at end of period	56,745		56,745
Gross carrying amount					$ 112,820
Accumulated amortization					(56,075)
Net book value	$ 56,745		$ 62,959		$ 56,745

Goodwill and Intangibles - Esti

Goodwill and Intangibles - Estimated Future Amortization Expense (Details) $ in Thousands	Sep. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 1,979
2,018	7,451
2,019	5,674
2,020	5,022
2,021	4,790
Thereafter	31,829
Total estimated future amortization expense	$ 56,745

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Banking and Thrift [Abstract]
Demand deposit accounts, noninterest bearing	$ 6,101,159	$ 6,408,169
NOW, money market and interest bearing deposits	4,842,097	4,543,004
Savings accounts	1,088,194	1,135,992
Certificates of deposit, $250,000 or more	1,430,706	1,144,121
Other certificates of deposit	952,988	879,162
Total deposits	14,415,144	14,110,448
Brokered deposits	$ 997,700	$ 795,000

Short-Term Borrowings - Schedul

Short-Term Borrowings - Schedule of Short-Term Borrowings (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Short-term borrowings
Weighted Average Interest Rate	1.12%	0.59%
Amount	$ 1,865,415,000	$ 1,569,288,000
Customer repurchase agreements
Short-term borrowings
Weighted Average Interest Rate	0.26%	0.22%
Amount	$ 222,915,000	$ 237,538,000
Federal Home Loan Bank advances
Short-term borrowings
Weighted Average Interest Rate	1.22%	0.63%
Amount	$ 1,400,000,000	$ 1,275,000,000
Federal funds purchased
Short-term borrowings
Weighted Average Interest Rate	1.35%	0.80%
Amount	$ 242,500,000	$ 46,750,000
Line of credit
Short-term borrowings
Weighted Average Interest Rate	0.00%	2.52%
Amount	$ 0	$ 10,000,000

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Details) - USD ($)	Aug. 24, 2016	Dec. 18, 2015	Sep. 30, 2017	Dec. 31, 2016
Short-term borrowings
Fixed interest rate Federal Home Loan Bank advances			$ 1,400,000,000	$ 1,300,000,000
Short-term borrowings			1,865,415,000	1,569,288,000
London Interbank Offered Rate (LIBOR)
Short-term borrowings
Basis spread on variable rate	1.75%
Federal Home Loan Bank advances
Short-term borrowings
Short-term borrowings			1,400,000,000	1,275,000,000
Line of credit
Short-term borrowings
Line of credit facility, maximum borrowing capacity		$ 35,000,000
Short-term borrowings			$ 0	$ 10,000,000
Line of credit | London Interbank Offered Rate (LIBOR)
Short-term borrowings
Basis spread on variable rate		1.75%
Minimum | Federal Home Loan Bank advances
Short-term borrowings
Effective interest rate of amounts due within one year			0.85%
Maximum | Federal Home Loan Bank advances
Short-term borrowings
Effective interest rate of amounts due within one year			1.30%

Long-Term Borrowings (Details)

Long-Term Borrowings (Details) - USD ($) $ in Thousands	Aug. 24, 2016	Sep. 30, 2017	Dec. 31, 2016
Long-term borrowings
Weighted Average Interest Rate		2.08%	1.64%
Amount		$ 405,715	$ 311,790
Federal Home Loan Bank advances		$ 306,400	$ 230,900
London Interbank Offered Rate (LIBOR)
Long-term borrowings
Basis spread on variable rate	1.75%
Federal Home Loan Bank advances
Long-term borrowings
Weighted Average Interest Rate		1.47%	0.85%
Amount		$ 306,367	$ 230,865
Federal Home Loan Bank advances | Minimum
Long-term borrowings
Interest rate		1.35%
Federal Home Loan Bank advances | Maximum
Long-term borrowings
Interest rate		5.87%
Notes payable
Long-term borrowings
Weighted Average Interest Rate		4.06%	4.18%
Amount		$ 88,348	$ 66,925
Unsecured term
Long-term borrowings
Weighted Average Interest Rate		2.98%	2.52%
Amount	$ 16,000	$ 11,000	$ 14,000
Quarterly principal payments	$ 1,000
Notes payable to banks
Long-term borrowings
Weighted Average Interest Rate		4.28%
Amount		$ 73,600	66,900
Equipment pledged as collateral		$ 88,300	$ 79,600
Notes payable to banks | Minimum
Long-term borrowings
Interest rate		2.25%
Notes payable to banks | Maximum
Long-term borrowings
Interest rate		7.40%
Other secured borrowings
Long-term borrowings
Weighted Average Interest Rate		2.97%
Amount		$ 14,800

Junior Subordinated Notes Iss69

Junior Subordinated Notes Issued to Capital Trusts (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Dec. 31, 2016
Junior Subordinated Notes
Principal balance		$ 211,289	$ 210,668
Junior Subordinated Notes | Maximum
Investment Owned, Balance [Abstract]
Period for deferment of payment of interest on notes (in years)		5 years
Coal City Capital Trust I | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.80%
Face Value		$ 25,000
Coal City Capital Trust I | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 25,774
Basis spread on variable rate		1.80%
MB Financial Capital Trust II | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.40%
Face Value		$ 35,000
MB Financial Capital Trust II | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 36,083
Basis spread on variable rate		1.40%
MB Financial Capital Trust III | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.50%
Face Value		$ 10,000
MB Financial Capital Trust III | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 10,310
Basis spread on variable rate		1.50%
MB Financial Capital Trust IV | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.52%
Face Value		$ 20,000
MB Financial Capital Trust IV | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 20,619
Basis spread on variable rate		1.52%
MB Financial Capital Trust V | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.30%
Face Value		$ 30,000
MB Financial Capital Trust V | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 30,928
Basis spread on variable rate		1.30%
MB Financial Capital Trust VI | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate		1.30%
Face Value		$ 22,500
MB Financial Capital Trust VI | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance		$ 23,196
Basis spread on variable rate		1.30%
FOBB Statutory Trust III | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate	[1]	2.80%
Face Value	[1]	$ 5,000
FOBB Statutory Trust III | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance	[1]	$ 5,155
Basis spread on variable rate	[1]	2.80%
TAYC Capital Trust II
Investment Owned, Balance [Abstract]
Purchase accounting adjustments discount		$ 6,500
TAYC Capital Trust II | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate	[2]	2.68%
Face Value	[2]	$ 40,000
TAYC Capital Trust II | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance	[2]	$ 41,238
Basis spread on variable rate	[2]	2.68%
American Chartered Statutory Trust I | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate	[3]	3.60%
Face Value	[3]	$ 20,000
American Chartered Statutory Trust I | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance	[3]	$ 20,619
Basis spread on variable rate	[3]	3.60%
American Chartered Statutory Trust II | Trust Preferred Securities
Junior Subordinated Notes
Basis spread on variable rate	[3]	2.75%
Face Value	[3]	$ 10,000
American Chartered Statutory Trust II | Junior Subordinated Notes
Junior Subordinated Notes
Principal balance	[3]	$ 10,310
Basis spread on variable rate	[3]	2.75%
American Chartered Statutory Trust I and II
Investment Owned, Balance [Abstract]
Purchase accounting adjustments discount		$ 6,100
[1]	FOBB Statutory Trust III was established by First Oak Brook Bancshares, Inc. (“FOBB”) prior to the Company's acquisition of FOBB in 2006, and the junior subordinated notes issued by FOBB to FOBB Statutory Trust III were assumed by the Company upon completion of the acquisition.
[2]	TAYC Capital Trust II was established by Taylor Capital Group, Inc. (“Taylor Capital”) prior to the Company's acquisition of Taylor Capital in 2014, and the junior subordinated notes issued by Taylor Capital to TAYC Capital Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with TAYC Capital Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.5 million at September 30, 2017.
[3]	American Chartered Statutory Trust I and American Chartered Statutory Trust II were established by American Chartered prior to the Company's acquisition of American Chartered in August 2016, and the junior subordinated notes issued by American Chartered to American Chartered Statutory Trust I and American Chartered Statutory Trust II were assumed by the Company upon completion of the acquisition. Principal balance and face value amounts associated with American Chartered Statutory Trust I and American Chartered Statutory Trust II do not include purchase accounting adjustments to such amounts, which in each case resulted in a remaining discount of $6.1 million at September 30, 2017.

Commitments and Contingencies70

Commitments and Contingencies (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
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	$ 377
Dollar amount of letters of credit outstanding	187,500	$ 187,200
Letters of credit issued or renewed	28,400
Capital expenditure commitments outstanding	$ 6,000
State of Illinois | States and political subdivisions
Concentrations of credit risk
Concentration risk	20.00%
Home equity lines
Long-term Purchase Commitment [Line Items]
Dollar amount of line of credit outstanding	$ 207,444	235,279
Other commitments
Long-term Purchase Commitment [Line Items]
Dollar amount of line of credit outstanding	3,914,154	3,679,259
Standby
Long-term Purchase Commitment [Line Items]
Dollar amount of line of credit outstanding	183,396	185,386
Commercial
Long-term Purchase Commitment [Line Items]
Dollar amount of line of credit outstanding	$ 4,133	$ 1,766

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value On A Recurring Basis (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		$ 1,497,543	$ 1,696,195
Loans held for sale		722,754	716,883
Loans		13,753,459	12,605,726
Mortgage servicing rights		261,446	238,011
Derivative financial instruments		13,943	22,833
Derivative financial instruments		32,067	53,497
U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		23,146	23,415
States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		385,829	391,365
Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		875,260	983,684
Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		87,217	93,008
Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		115,014	193,895
Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		11,077	10,828
Recurring basis
Financial assets and financial liabilities measured at fair value on a recurring basis
Loans held for sale		722,754	716,883
Loans		14,481	16,273
Assets held in trust for deferred compensation		20,103	18,723
Other liabilities	[1]	20,103	18,723
Derivative financial instruments		39,915	63,885
Recurring basis | U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		23,146	23,415
Recurring basis | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		385,829	391,365
Recurring basis | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		875,260	983,684
Recurring basis | Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		87,217	93,008
Recurring basis | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		115,014	193,895
Recurring basis | Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		11,077	10,828
Recurring basis | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights		261,446	238,011
Recurring basis | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments		36,018	44,586
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
Investment securities available for sale		11,077	10,828
Loans held for sale		0	0
Loans		0	0
Assets held in trust for deferred compensation		20,103	18,723
Derivative financial instruments		2,366	7,687
Other liabilities	[1]	20,103	18,723
Derivative financial instruments		1,583	2,046
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		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
Investment securities available for sale		11,077	10,828
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights		0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments		2,366	7,687
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		1,486,028	1,684,823
Loans held for sale		722,754	716,883
Loans		14,481	16,273
Assets held in trust for deferred compensation		0	0
Derivative financial instruments		31,713	33,739
Other liabilities	[1]	0	0
Derivative financial instruments		38,332	61,839
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
Investment securities available for sale		23,146	23,415
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
Investment securities available for sale		385,456	390,992
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
Investment securities available for sale		875,195	983,513
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
Investment securities available for sale		87,217	93,008
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		115,014	193,895
Recurring basis | Significant Other Observable Inputs (Level 2) | Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Significant Other Observable Inputs (Level 2) | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights		0	0
Recurring basis | Significant Other Observable Inputs (Level 2) | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments		31,713	33,739
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		438	544
Loans held for sale		0	0
Loans		0	0
Assets held in trust for deferred compensation		0	0
Derivative financial instruments		1,939	3,160
Other liabilities	[1]	0	0
Derivative financial instruments		0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. Government sponsored agencies and enterprises
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		373	373
Recurring basis | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		65	171
Recurring basis | Significant Unobservable Inputs (Level 3) | Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate bonds
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Equity securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale		0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights		261,446	238,011
Recurring basis | Significant Unobservable Inputs (Level 3) | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments		$ 1,939	$ 3,160
[1]	Liabilities associated with assets held in trust for deferred compensation

Fair Value Measurements - Unobs

Fair Value Measurements - Unobservable Inputs Used In Fair Value Measurement (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	$ 1,497,543,000	$ 1,696,195,000
Mortgage servicing rights	261,446,000	238,011,000
Derivative financial instruments	13,943,000	22,833,000
States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	385,829,000	391,365,000
Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	875,260,000	983,684,000
Recurring basis | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	385,829,000	391,365,000
Recurring basis | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	875,260,000	983,684,000
Recurring basis | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights	261,446,000	238,011,000
Recurring basis | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments	36,018,000	44,586,000
Significant Unobservable Inputs (Level 3) | Recurring basis
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	438,000	544,000
Derivative financial instruments	1,939,000	3,160,000
Significant Unobservable Inputs (Level 3) | Recurring basis | States and political subdivisions
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	$ 373,000	373,000
Significant Unobservable Inputs (Level 3) | Recurring basis | States and political subdivisions | Minimum
Financial assets and financial liabilities measured at fair value on a recurring basis
Credit assumption (as a percent)	45.00%
Significant Unobservable Inputs (Level 3) | Recurring basis | States and political subdivisions | Maximum
Financial assets and financial liabilities measured at fair value on a recurring basis
Credit assumption (as a percent)	50.00%
Significant Unobservable Inputs (Level 3) | Recurring basis | Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value on a recurring basis
Investment securities available for sale	$ 65,000	171,000
Significant Unobservable Inputs (Level 3) | Recurring basis | Residential mortgage-backed securities | Minimum
Financial assets and financial liabilities measured at fair value on a recurring basis
Constant prepayment rates (as a percent)	1.00%
Significant Unobservable Inputs (Level 3) | Recurring basis | Residential mortgage-backed securities | Maximum
Financial assets and financial liabilities measured at fair value on a recurring basis
Constant prepayment rates (as a percent)	3.00%
Significant Unobservable Inputs (Level 3) | Recurring basis | Mortgage servicing rights
Financial assets and financial liabilities measured at fair value on a recurring basis
Mortgage servicing rights	$ 261,446,000	238,011,000
Significant Unobservable Inputs (Level 3) | Recurring basis | Mortgage servicing rights | Minimum
Financial assets and financial liabilities measured at fair value on a recurring basis
Constant prepayment rates (as a percent)	6.80%
Discount rate	9.53%
Maturity (months)	323 months
Delinquencies	2.16%
Costs to service	$ 67
Additive delinquent costs to service	$ 175
Significant Unobservable Inputs (Level 3) | Recurring basis | Mortgage servicing rights | Maximum
Financial assets and financial liabilities measured at fair value on a recurring basis
Constant prepayment rates (as a percent)	8.42%
Discount rate	11.05%
Maturity (months)	358 months
Delinquencies	4.82%
Costs to service	$ 227
Additive delinquent costs to service	1,000
Significant Unobservable Inputs (Level 3) | Recurring basis | Derivative financial instruments
Financial assets and financial liabilities measured at fair value on a recurring basis
Derivative financial instruments	$ 1,939,000	$ 3,160,000
Significant Unobservable Inputs (Level 3) | Recurring basis | Derivative financial instruments | Minimum
Financial assets and financial liabilities measured at fair value on a recurring basis
Expected closing ratio	70.00%
Expected delivery price	0.9841%
Significant Unobservable Inputs (Level 3) | Recurring basis | Derivative financial instruments | Maximum
Financial assets and financial liabilities measured at fair value on a recurring basis
Expected closing ratio	95.00%
Expected delivery price	1.0857%

Fair Value Measurements - Assum

Fair Value Measurements - Assumptions Used In Measuring Fair Value of Mortgage Servicing Rights (Details) - Mortgage servicing rights	9 Months Ended
	Sep. 30, 2017USD ($)
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Impact on fair value of 10% adverse change, CPR	$ 9,030,000
Impact on fair value of 20% adverse change, CPR	18,615,000
Impact on fair value of 10% adverse change, discount rate	11,673,000
Impact on fair value of 20% adverse change, discount rate	24,415,000
Impact on fair value of 10% adverse change, delinquency rate	1,567,000
Impact on fair value of 20% adverse change, delinquency rate	3,499,000
Impact on fair value of 10% adverse change, costs to service	4,919,000
Impact on fair value of 20% adverse change, costs to service	$ 9,838,000
Weighted average
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Weighted average CPR	7.58%
Weighted average discount rate	9.81%
Weighted average delinquency rate	4.57%
Weighted average costs to service	$ 90.45

Fair Value Measurements - Level

Fair Value Measurements - Level 3 Financial Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Investment Securities
Financial assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance, beginning of period	$ 544	$ 773
Purchases	0	0
Originations	0	0
Included in earnings	0	0
Principal payments	(106)	(151)
Sales	0	0
Balance, ending of period	438	622
Mortgage Servicing Rights
Financial assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance, beginning of period	238,011	168,162
Purchases	839	3,423
Originations	43,197	43,039
Included in earnings	(20,601)	(59,894)
Principal payments	0	0
Sales	0	0
Balance, ending of period	261,446	154,730
Derivatives
Financial assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Balance, beginning of period	3,160	3,822
Purchases	0	0
Originations	0	0
Included in earnings	(1,221)	8,739
Principal payments	0	0
Sales	0	0
Balance, ending of period	$ 1,939	$ 12,561

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair value assumption, allowance for impaired real estate loans percentage	100.00%
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 contractual cash flows (in days)	90 days

Fair Value Measurements - Asset

Fair Value Measurements - Assets Measured at Fair Value on Nonrecurring Basis (Details) - Nonrecurring basis - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial Assets:
Impaired loans	$ 53,842	$ 54,576
Foreclosed assets	18,334	31,607
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets:
Impaired loans	0	0
Foreclosed assets	0	0
Significant Other Observable Inputs (Level 2)
Financial Assets:
Impaired loans	0	0
Foreclosed assets	0	0
Significant Unobservable Inputs (Level 3)
Financial Assets:
Impaired loans	53,842	54,576
Foreclosed assets	$ 18,334	$ 31,607
Significant Unobservable Inputs (Level 3) | Minimum
Financial Assets:
Appraisal adjustment impaired loans (as a percent)	5.00%
Appraisal adjustment foreclosed assets (as a percent)	5.00%
Significant Unobservable Inputs (Level 3) | Maximum
Financial Assets:
Appraisal adjustment impaired loans (as a percent)	10.00%
Appraisal adjustment foreclosed assets (as a percent)	10.00%

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial Assets:
Cash and due from banks	$ 361,080	$ 364,783
Interest earning deposits with banks	82,636	98,686
Investment securities available for sale	1,497,543	1,696,195
Investment securities held to maturity	1,031,746	1,093,740
Non-marketable securities - FHLB and FRB stock	152,345	143,276
Loans held for sale	722,754	716,883
Derivative financial instruments	13,943	22,833
Financial Liabilities:
Non-interest bearing deposits	6,101,159	6,408,169
Interest bearing deposits	8,313,985	7,702,279
Short-term borrowings	1,865,415	1,569,288
Junior subordinated notes issued to capital trusts	211,289	210,668
Derivative financial instruments	32,067	53,497
Carrying Amount
Financial Assets:
Cash and due from banks	361,080	364,783
Interest earning deposits with banks	82,636	98,686
Investment securities available for sale	1,497,543	1,696,195
Investment securities held to maturity	994,238	1,069,750
Non-marketable securities - FHLB and FRB stock	152,345	143,276
Loans held for sale	722,754	716,883
Loans, net	13,726,250	12,629,437
Accrued interest receivable	61,962	59,024
Derivative financial instruments	36,018	44,586
Financial Liabilities:
Non-interest bearing deposits	6,101,159	6,408,169
Interest bearing deposits	8,313,985	7,702,279
Short-term borrowings	1,865,415	1,569,288
Long-term borrowings	405,715	311,790
Junior subordinated notes issued to capital trusts	211,289	210,668
Accrued interest payable	5,680	4,288
Derivative financial instruments	39,915	63,885
Estimated Fair Value
Financial Assets:
Cash and due from banks	361,080	364,783
Interest earning deposits with banks	82,636	98,686
Investment securities available for sale	1,497,543	1,696,195
Investment securities held to maturity	1,031,746	1,093,740
Non-marketable securities - FHLB and FRB stock	152,345	143,276
Loans held for sale	722,754	716,883
Loans, net	13,928,427	12,747,107
Accrued interest receivable	61,962	59,024
Derivative financial instruments	36,018	44,586
Financial Liabilities:
Non-interest bearing deposits	6,101,159	6,408,169
Interest bearing deposits	8,310,123	7,698,839
Short-term borrowings	1,865,796	1,569,314
Long-term borrowings	411,218	317,028
Junior subordinated notes issued to capital trusts	177,843	157,098
Accrued interest payable	5,680	4,288
Derivative financial instruments	39,915	63,885
Recurring basis
Financial Assets:
Loans held for sale	722,754	716,883
Financial Liabilities:
Derivative financial instruments	39,915	63,885
Recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets:
Cash and due from banks	361,080	364,783
Interest earning deposits with banks	82,636	98,686
Investment securities available for sale	11,077	10,828
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	61,962	59,024
Derivative financial instruments	2,366	7,687
Financial Liabilities:
Non-interest bearing deposits	6,101,159	6,408,169
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	5,680	4,288
Derivative financial instruments	1,583	2,046
Recurring basis | Significant Other Observable Inputs (Level 2)
Financial Assets:
Cash and due from banks	0	0
Interest earning deposits with banks	0	0
Investment securities available for sale	1,486,028	1,684,823
Investment securities held to maturity	1,031,746	1,093,740
Non-marketable securities - FHLB and FRB stock	0	0
Loans held for sale	722,754	716,883
Loans, net	14,481	16,273
Accrued interest receivable	0	0
Derivative financial instruments	31,713	33,739
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	38,332	61,839
Recurring basis | Significant Unobservable Inputs (Level 3)
Financial Assets:
Cash and due from banks	0	0
Interest earning deposits with banks	0	0
Investment securities available for sale	438	544
Investment securities held to maturity	0	0
Non-marketable securities - FHLB and FRB stock	152,345	143,276
Loans held for sale	0	0
Loans, net	13,913,946	12,730,834
Accrued interest receivable	0	0
Derivative financial instruments	1,939	3,160
Financial Liabilities:
Non-interest bearing deposits	0	0
Interest bearing deposits	8,310,123	7,698,839
Short-term borrowings	1,865,796	1,569,314
Long-term borrowings	411,218	317,028
Junior subordinated notes issued to capital trusts	177,843	157,098
Accrued interest payable	0	0
Derivative financial instruments	$ 0	$ 0

Stock Incentive Plans - Impact

Stock Incentive Plans - Impact of Share-Based Payment Plans (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total compensation expense for share-based payment plans during the period		$ 4,393	$ 4,238	$ 13,317	$ 12,573
Amount of related income tax benefit recognized in income (1)	[1]	$ 2,175	$ 3,394	$ 8,513	$ 6,649
[1]	Includes tax benefits recorded for the vesting of restricted shares and exercise of options.

Stock Incentive Plans - Additio

Stock Incentive Plans - Additional Information (Details) - USD ($) $ in Millions	Aug. 18, 2014	May 28, 2014	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock-based compensation
Grants beyond threshold limit count numerator (in shares)			2
Omnibus Incentive Plan
Stock-based compensation
Additional number of share authorized (in shares)		3,100,000
Total number of shares authorized (in shares)		11,400,000
Percentage of shares authorized for issuance		10.00%
Vesting period		3 years
Shares available for future grant (in shares)			2,924,386
Unrecognized compensation cost related to nonvested share-based compensation			$ 26.1
Period for recognition			2 years
Omnibus Incentive Plan | Taylor Capital Group, Inc.
Stock-based compensation
Total number of shares authorized (in shares)	13,800,000
Increase in amount of shares authorized (in shares)	2,400,000
Stock options
Stock-based compensation
Award requisite service period			4 years
Expiration term of options			10 years
Intrinsic value of options exercised			$ 5.2	$ 3.6
Stock options | Director
Stock-based compensation
Vesting period			5 years
Maximum percentage of directors fees with option to be received in equity based incentive awards			70.00%
Period of restriction for sale of shares vested			6 months
Restricted shares
Stock-based compensation
Intrinsic value of restricted shares that vested			$ 17.4	$ 15.7
Restricted shares | Minimum
Stock-based compensation
Vesting period			2 years
Restricted shares | Maximum
Stock-based compensation
Vesting period			4 years
Restricted stock | Director
Stock-based compensation
Vesting period			1 year
Maximum percentage of directors fees with option to be received in equity based incentive awards			100.00%
Performance-based restricted stock units
Stock-based compensation
Vesting period			3 years
Restricted stock issued (in shares)			65,476		80,780	71,560	48,569
Percentage of shares earned to number of units issued			121.00%
Performance based restricted units performance period			3 years
Share based compensation restricted stock units multiplier			100.00%
Performance-based restricted stock units | Minimum
Stock-based compensation
Percentage of shares earned to number of units issued			0.00%
Performance-based restricted stock units | Maximum
Stock-based compensation
Percentage of shares earned to number of units issued			175.00%

Stock Incentive Plans - Summary

Stock Incentive Plans - Summary of Impact of Share-Based Payment Plans (Details) - Stock options - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Number of Options
Outstanding, beginning balance (in shares)	1,940,405
Granted (in shares)	163,818
Exercised (in shares)	(327,970)
Expired (in shares)	0
Forfeited or cancelled (in shares)	(15,093)
Outstanding, ending balance (in shares)	1,761,160	1,940,405
Options exercisable (in shares)	1,167,465
Weighted Average Exercise Price
Outstanding, beginning balance (in dollars per share)	$ 27.45
Granted (in dollars per share)	45.53
Exercised (in dollars per share)	28.03
Expired (in dollars per share)	0
Forfeited or cancelled (in dollars per share)	31.95
Outstanding, ending balance (in dollars per share)	28.99	$ 27.45
Options exercisable (in dollars per share)	$ 26.60
Weighted Average Remaining Contractual Term (In Years)
Outstanding, balance (in years)	5 years 4 months 25 days	5 years 3 months 23 days
Options exercisable (in years)	3 years 11 months 20 days
Aggregate Intrinsic Value (in thousands)
Options outstanding	$ 28,356
Options exercisable	$ 21,522

Stock Incentive Plans - Assumpt

Stock Incentive Plans - Assumptions Used For Options Granted (Details) - Stock options	9 Months Ended
	Sep. 30, 2017$ / shares
Fair value assumptions
Risk-free interest rate	2.18%
Expected volatility of Company’s stock	22.71%
Expected dividend yield	1.68%
Expected life of options	5 years 9 months
Weighted average fair value per option of options granted during the year (in dollars per share)	$ 9.40

Stock Incentive Plans - Changes

Stock Incentive Plans - Changes in Restricted Shares and Units (Details) - Restricted shares	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Number of Shares and Units
Shares and units outstanding, beginning balance (in shares) | shares	998,807
Granted (in shares) | shares	379,962
Vested (in shares) | shares	(379,375)
Forfeited or cancelled (in shares) | shares	(21,506)
Shares and units outstanding, ending balance (in shares) | shares	977,888
Weighted Average Grant Date Fair Value
Shares and units outstanding, beginning balance (in dollars per share) | $ / shares	$ 31.20
Granted (in dollars per share) | $ / shares	45.77
Vested (in dollars per share) | $ / shares	30.63
Forfeited or cancelled (in dollars per share) | $ / shares	35.10
Shares and units outstanding, ending balance (in dollars per share) | $ / shares	$ 36.99

Derivative Financial Instrume83

Derivative Financial Instruments - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Net amount payable under interest rate swap	$ 1	$ 1
Interest rate swap credit risk exposure	11,300
Derivative liability, notional amount	3,469,338	$ 3,467,875
Commercial loan interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative liability, notional amount	$ 70

Derivative Financial Instrume84

Derivative Financial Instruments - Summary of Derivative Financial Instruments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Asset Derivatives, Notional Amount		$ 3,699,097		$ 3,699,097		$ 3,097,336
Asset Derivatives, Estimated Fair Value		36,018		36,018		44,586
Liability Derivatives, Notional Amount		3,469,338		3,469,338		3,467,875
Liability Derivatives, Estimated Fair Value		(39,915)		(39,915)		(63,885)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		(7,790)	$ (1,487)	(13,090)	$ 38,284
Derivative instruments designated as hedges of fair value | Interest rate swap contracts
Derivative [Line Items]
Asset Derivatives, Notional Amount	[1]	0		0		0
Asset Derivatives, Estimated Fair Value	[1]	0		0		0
Liability Derivatives, Notional Amount	[1]	70		70		107
Liability Derivatives, Estimated Fair Value	[1]	(1)		(1)		(4)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		0	3	2	3
Stand-alone derivative instruments
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	3,699,097		3,699,097		3,097,336
Asset Derivatives, Estimated Fair Value	[2]	36,018		36,018		44,586
Liability Derivatives, Notional Amount	[2]	3,469,268		3,469,268		3,467,768
Liability Derivatives, Estimated Fair Value	[2]	(39,914)		(39,914)		(63,881)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		(7,790)	(1,490)	(13,092)	38,281
Stand-alone derivative instruments | Interest rate swap contracts
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	1,554,709		1,554,709		1,310,057
Asset Derivatives, Estimated Fair Value	[2]	24,609		24,609		25,471
Liability Derivatives, Notional Amount	[2]	1,554,709		1,554,709		1,310,057
Liability Derivatives, Estimated Fair Value	[2]	(24,609)		(24,609)		(25,471)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		3,276	5,296	6,749	5,260
Stand-alone derivative instruments | Interest rate swap contracts | Mortgage Banking
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	413,000		413,000		383,000
Asset Derivatives, Estimated Fair Value	[2]	3,246		3,246		2,946
Liability Derivatives, Notional Amount	[2]	1,223,000		1,223,000		1,458,000
Liability Derivatives, Estimated Fair Value	[2]	(10,027)		(10,027)		(31,212)
Stand-alone derivative instruments | Interest rate options contracts
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	337,999		337,999		217,546
Asset Derivatives, Estimated Fair Value	[2]	1,698		1,698		881
Liability Derivatives, Notional Amount	[2]	337,999		337,999		217,546
Liability Derivatives, Estimated Fair Value	[2]	(1,698)		(1,698)		(881)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		0	(36)	0	0
Stand-alone derivative instruments | Foreign exchange contracts
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	35,672		35,672		40,641
Asset Derivatives, Estimated Fair Value	[2]	2,157		2,157		4,429
Liability Derivatives, Notional Amount	[2]	34,837		34,837		40,505
Liability Derivatives, Estimated Fair Value	[2]	(1,997)		(1,997)		(4,265)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		(70)	1,362	190	1,362
Stand-alone derivative instruments | Spot foreign exchange contracts
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	342		342		1,691
Asset Derivatives, Estimated Fair Value	[2]	3		3		12
Liability Derivatives, Notional Amount	[2]	223		223		660
Liability Derivatives, Estimated Fair Value	[2]	0		0		(5)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		629	6	2,036	6
Stand-alone derivative instruments | Treasury futures contracts | Mortgage Banking
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	42,500		42,500		15,500
Asset Derivatives, Estimated Fair Value	[2]	74		74		41
Liability Derivatives, Notional Amount	[2]	45,000		45,000		0
Liability Derivatives, Estimated Fair Value	[2]	(216)		(216)		0
Stand-alone derivative instruments | TBA mortgage securities | Mortgage Banking
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	0		0		0
Asset Derivatives, Estimated Fair Value	[2]	0		0		0
Liability Derivatives, Notional Amount	[2]	140,000		140,000		55,000
Liability Derivatives, Estimated Fair Value	[2]	(1,105)		(1,105)		(132)
Stand-alone derivative instruments | Forward loan sale commitments | Mortgage Banking
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	759,500		759,500		585,000
Asset Derivatives, Estimated Fair Value	[2]	2,292		2,292		7,646
Liability Derivatives, Notional Amount	[2]	133,500		133,500		386,000
Liability Derivatives, Estimated Fair Value	[2]	(262)		(262)		(1,915)
Stand-alone derivative instruments | Interest rate lock commitments | Mortgage Banking
Derivative [Line Items]
Asset Derivatives, Notional Amount	[2]	555,375		555,375		543,901
Asset Derivatives, Estimated Fair Value	[2]	1,939		1,939		3,160
Liability Derivatives, Notional Amount	[2]	0		0		0
Liability Derivatives, Estimated Fair Value	[2]	0		0		$ 0
Stand-alone derivative instruments | Mortgage related derivatives
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net [Abstract]
Amounts of gain or (loss) recognized in income on derivatives		$ (11,625)	$ (8,118)	$ (22,067)	$ 31,653
[1]	Derivative instruments designated to hedge fixed-rate commercial real estate loans.
[2]	These portfolio swaps are not designated as hedging instruments under ASC Topic 815.

Derivative Financial Instrume85

Derivative Financial Instruments - Financial Instruments Eligible for Offset In Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial Assets [Abstract]
Financial Assets, Gross Amount Recognized	$ 13,943	$ 22,833
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	13,943	22,833
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
Total Financial Assets, Gross Amount Recognized	13,943	22,833
Total Financial Assets, Gross Amount Offset	0	0
Total Financial Assets, Net Amount Recognized	13,943	22,833
Financial Assets, Financial Instruments	(11,728)	(18,382)
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	2,215	4,451
Repurchase Agreements, Financial Assets, Financial Instruments	0	0
Repurchase Agreements, Financial Assets, Collateral	0	0
Repurchase Agreements, Financial Assets, Net Amount	0	0
Total Financial Assets, Financial Instruments	(11,728)	(18,382)
Total Financial Assets, Collateral	0	0
Total Financial Assets, Net Amount	2,215	4,451
Financial Liabilities [Abstract]
Financial Liabilities, Gross Amount Recognized	32,067	53,497
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	32,067	53,497
Repurchase Agreements, Financial Liabilities, Gross Amount Recognized	222,915	237,538
Repurchase Agreements, Financial Liabilities, Gross Amount Offset	0	0
Repurchase Agreements, Financial Liabilities, Net Amount Recognized	222,915	237,538
Total Financial Liabilities, Gross Amount Recognized	254,982	291,035
Total Financial Liabilities, Gross Amount Offset	0	0
Total Financial Liabilities, Net Amount Recognized	254,982	291,035
Financial Liabilities, Financial Instruments	(11,728)	(18,382)
Financial Liabilities, Collateral	(20,339)	(35,104)
Financial Liabilities, Net Amount	0	11
Repurchase Agreements, Financial Liabilities, Financial Instruments	0	0
Repurchase Agreements, Financial Liabilities, Collateral	(222,915)	(237,538)
Repurchase Agreements, Financial Liabilities, Net Amount	0	0
Total Financial Liabilities, Financial Instruments	(11,728)	(18,382)
Total Financial Liabilities, Collateral	(243,254)	(272,642)
Total Financial Liabilities, Net Amount	0	11
Counterparty A
Financial Assets [Abstract]
Financial Assets, Net Amount Recognized	4,941	2,697
Financial Assets, Financial Instruments	(4,941)	(2,697)
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	0	0
Financial Liabilities [Abstract]
Financial Liabilities, Net Amount Recognized	12,399	18,768
Financial Liabilities, Financial Instruments	(4,941)	(2,697)
Financial Liabilities, Collateral	(7,458)	(16,071)
Financial Liabilities, Net Amount	0	0
Counterparty B
Financial Assets [Abstract]
Financial Assets, Net Amount Recognized	2,276	4,683
Financial Assets, Financial Instruments	(2,276)	(4,683)
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	0	0
Financial Liabilities [Abstract]
Financial Liabilities, Net Amount Recognized	9,044	12,881
Financial Liabilities, Financial Instruments	(2,276)	(4,683)
Financial Liabilities, Collateral	(6,768)	(8,198)
Financial Liabilities, Net Amount	0	0
Counterparty C
Financial Assets [Abstract]
Financial Assets, Net Amount Recognized	243	64
Financial Assets, Financial Instruments	(243)	(64)
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	0	0
Financial Liabilities [Abstract]
Financial Liabilities, Net Amount Recognized	2,434	4,919
Financial Liabilities, Financial Instruments	(243)	(64)
Financial Liabilities, Collateral	(2,191)	(4,855)
Financial Liabilities, Net Amount	0	0
Other counterparties
Financial Assets [Abstract]
Financial Assets, Net Amount Recognized	6,483	15,389
Financial Assets, Financial Instruments	(4,268)	(10,938)
Financial Assets, Collateral	0	0
Financial Assets, Net Amount	2,215	4,451
Financial Liabilities [Abstract]
Financial Liabilities, Net Amount Recognized	8,190	16,929
Financial Liabilities, Financial Instruments	(4,268)	(10,938)
Financial Liabilities, Collateral	(3,922)	(5,980)
Financial Liabilities, Net Amount	0	11
Interest rate swap contracts, caps and floors
Financial Assets [Abstract]
Financial Assets, Gross Amount Recognized	7,583	7,885
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	7,583	7,885
Financial Liabilities [Abstract]
Financial Liabilities, Gross Amount Recognized	18,821	18,564
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	18,821	18,564
Foreign exchange contracts
Financial Assets [Abstract]
Financial Assets, Gross Amount Recognized	748	4,315
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	748	4,315
Financial Liabilities [Abstract]
Financial Liabilities, Gross Amount Recognized	1,636	1,674
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	1,636	1,674
Mortgage related derivatives
Financial Assets [Abstract]
Financial Assets, Gross Amount Recognized	5,612	10,633
Financial Assets, Gross Amount Offset	0	0
Financial Assets, Net Amount Recognized	5,612	10,633
Financial Liabilities [Abstract]
Financial Liabilities, Gross Amount Recognized	11,610	33,259
Financial Liabilities, Gross Amount Offset	0	0
Financial Liabilities, Net Amount Recognized	$ 11,610	$ 33,259

Operating Segments (Details)

Operating Segments (Details) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017USD ($)		Sep. 30, 2016USD ($)		Sep. 30, 2017USD ($)segment		Sep. 30, 2016USD ($)		Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable operating segments | segment					3
Net interest income	$ 156,947		$ 130,771		$ 448,984		$ 372,677
Provision for credit losses	4,517		6,549		17,950		16,941
Non-interest income	95,264		108,387		277,554		282,080
Non-interest expense	162,294	[1]	170,385	[1]	483,518	[2]	454,091	[2]
Income tax expense	24,557		17,805		65,224		56,780
Net income	60,843		44,419		159,846		126,945
Total assets	20,116,535		19,341,882		20,116,535		19,341,882		$ 19,302,317
Taylor Capital Group, Inc.
Segment Reporting Information [Line Items]
Pretax merger related costs	1,600		11,400		9,000		17,200
Banking
Segment Reporting Information [Line Items]
Net interest income	142,888		119,685		410,319		341,445
Provision for credit losses	3,637		4,394		16,054		14,390
Non-interest income	45,091		40,533		130,460		112,221
Non-interest expense	112,977	[1]	117,211	[1]	337,185	[2]	307,733	[2]
Income tax expense	18,781		8,420		50,103		36,120
Net income	52,584		30,193		137,437		95,423
Total assets	16,406,714		16,453,379		16,406,714		16,453,379
Leasing
Segment Reporting Information [Line Items]
Net interest income	2,686		2,168		7,300		7,002
Provision for credit losses	399		1,964		674		2,045
Non-interest income	22,597		18,759		62,240		53,670
Non-interest expense	14,535	[1]	12,604	[1]	41,815	[2]	35,916	[2]
Income tax expense	4,307		2,484		10,951		8,872
Net income	6,042		3,875		16,100		13,839
Total assets	1,307,459		1,126,847		1,307,459		1,126,847
Mortgage Banking
Segment Reporting Information [Line Items]
Net interest income	11,373		8,918		31,365		24,230
Provision for credit losses	481		191		1,222		506
Non-interest income	27,576		49,095		84,854		116,189
Non-interest expense	34,782	[1]	40,570	[1]	104,518	[2]	110,442	[2]
Income tax expense	1,469		6,901		4,170		11,788
Net income	2,217		10,351		6,309		17,683
Total assets	$ 2,402,362		$ 1,761,656		$ 2,402,362		$ 1,761,656
[1]	Includes merger related and repositioning expenses of $1.6 million and $11.4 million in the Banking Segment for the three months ended September 30, 2017 and 2016, respectively.
[2]	Includes merger related and repositioning expenses of $9.0 million and $17.2 million in the Banking Segment for the nine months ended September 30, 2017 and 2016, respectively.

Preferred Stock (Details)

Preferred Stock (Details)	Sep. 20, 2017shares	Aug. 24, 2016$ / sharesshares	Aug. 18, 2014$ / sharesshares	Dec. 31, 2016$ / sharesshares	Sep. 30, 2017$ / sharesshares	Dec. 31, 2016$ / sharesshares
Series A Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares outstanding (in shares)				4,000,000	4,000,000	4,000,000
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares				$ 25	$ 25	$ 25
Preferred stock, dividend rate (percent)					8.00%	8.00%
Series A Preferred Stock | Taylor Capital Merger
Business Acquisition [Line Items]
Stock conversion			1
Preferred stock, shares outstanding (in shares)			4,000,000
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares			$ 25
Preferred stock, dividend rate (percent)			8.00%
Series B Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares outstanding (in shares)				125	0	125
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares				$ 1,000	$ 1,000	$ 1,000
Preferred stock, dividend rate (percent)					8.00%	8.00%
Series B Preferred Stock | American Chartered Merger
Business Acquisition [Line Items]
Stock conversion		1
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares		$ 1,000
Preferred stock, dividend rate (percent)		8.00%
Conversion of preferred stock to common stock (in shares)	125			400
Series D Preferred Stock | American Chartered Merger
Business Acquisition [Line Items]
Preferred stock, shares outstanding (in shares)		525