Webster Financial (WBS) 10-K 1 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Feb. 17, 2017	Jun. 30, 2016
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	WBS
Entity Registrant Name	WEBSTER FINANCIAL CORPORATION
Entity Central Index Key	801,337
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		92,016,254
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,030,152,489

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Assets:
Cash and due from banks		$ 190,663	$ 199,693
Interest-bearing deposits		29,461	155,907
Securities available-for-sale, at fair value		2,991,091	2,984,631
Securities held-to-maturity (fair value of $4,125,125 and $3,961,534)		4,160,658	3,923,052
Federal Home Loan Bank and Federal Reserve Bank stock		194,646	188,347
Loans held for sale (valued under fair value option $60,260 and $0)		67,577	37,091
Loans and leases	[1],[2]	17,026,588	15,671,735
Allowance for loan and lease losses		(194,320)	(174,990)
Loans and leases, net		16,832,268	15,496,745
Deferred tax assets, net		84,391	101,578
Premises and equipment, net		137,413	129,426
Goodwill		538,373	538,373
Other intangible assets, net		33,674	39,326
Cash surrender value of life insurance policies		517,852	503,093
Accrued interest receivable and other assets		294,462	343,856
Total assets		26,072,529	24,641,118
Liabilities and shareholders' equity:
Non-interest-bearing		4,021,061	3,713,063
Interest-bearing		15,282,796	14,239,715
Total deposits		19,303,857	17,952,778
Securities sold under agreements to repurchase and other borrowings		949,526	1,151,400
Federal Home Loan Bank advances		2,842,908	2,664,139
Long-term debt		225,514	225,260
Accrued expenses and other liabilities		223,712	233,581
Total liabilities		23,545,517	22,227,158
Shareholders’ equity:
Preferred stock, $.01 par value; Authorized - 3,000,000 shares: Series E issued and outstanding (5,060 shares)		122,710	122,710
Common stock, $.01 par value: Authorized - 200,000,000 shares; (Issued 93,651,601 shares)		937	937
Paid-in capital		1,125,937	1,124,325
Retained earnings		1,425,320	1,315,948
Treasury stock, at cost (1,899,502 and 2,090,409 shares)		(70,899)	(71,854)
Accumulated other comprehensive loss, net of tax		(76,993)	(78,106)
Total shareholders' equity		2,527,012	2,413,960
Total liabilities and shareholders' equity		$ 26,072,529	$ 24,641,118
[1]	At December 31, 2016, the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015, respectively.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Security held-to-maturity, fair value	$ 4,125,125	$ 3,961,534
LHFS, at fair value option	$ 60,260	$ 0
Preferred stock, shares authorized	3,000,000	3,000,000
Preferred stock, shares issued	5,060	5,060
Preferred Stock, Shares Outstanding	5,060	5,060
Common stock par value (in usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	93,651,601	93,651,601
Treasury stock, shares	1,899,502	2,090,409

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest Income:
Interest and fees on loans and leases	$ 621,028	$ 552,441	$ 511,612
Taxable interest and dividends on securities	180,346	190,061	189,408
Non-taxable interest on securities	19,090	15,948	17,064
Loans held for sale	1,449	1,590	857
Total interest income	821,913	760,040	718,941
Interest Expense:
Deposits	49,858	46,031	44,162
Securities sold under agreements to repurchase and other borrowings	14,528	16,861	19,388
Federal Home Loan Bank advances	29,033	22,858	16,909
Long-term debt	9,981	9,665	10,041
Total interest expense	103,400	95,415	90,500
Net interest income	718,513	664,625	628,441
Provision for loan and lease losses	56,350	49,300	37,250
Net interest income (loss) after provision for loan and lease losses	662,163	615,325	591,191
Non-interest Income:
Deposit service fees	140,685	135,057	103,431
Loan and lease related fees	30,113	25,594	23,212
Wealth and investment services	28,962	32,486	34,946
Mortgage banking activities	11,103	7,795	4,070
Increse in cash surrender value of life insurance policies	14,759	13,020	13,178
Gain on sale of investment securities, net	414	609	5,499
Impairment loss on securities recognized in earnings	(149)	(110)	(1,145)
Other income	38,591	23,326	18,917
Total non-interest income	264,478	237,777	202,108
Non-interest Expense:
Compensation and benefits	331,726	297,517	270,151
Occupancy	60,294	48,836	47,325
Technology and equipment	79,882	80,813	61,993
Intangible assets amortization	5,652	6,340	2,685
Marketing	19,703	16,053	15,379
Professional and outside services	14,801	11,156	8,296
Deposit insurance	26,006	24,042	22,670
Other expense	85,127	70,584	73,101
Total non-interest expense	623,191	555,341	501,600
Income before income tax expense	303,450	297,761	291,699
Income tax expense	96,323	93,032	91,973
Net income	207,127	204,729	199,726
Preferred stock dividends and other	(8,704)	(9,368)	(11,230)
Earnings applicable to common shareholders	$ 198,423	$ 195,361	$ 188,496
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 2.17	$ 2.15	$ 2.10
Earnings per common share, Diluted (in dollars per share)	$ 2.16	$ 2.13	$ 2.08

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 57,660	$ 51,817	$ 50,603	$ 47,047	$ 51,812	$ 51,370	$ 52,043	$ 49,504	$ 207,127	$ 204,729	$ 199,726
Other comprehensive income (loss), net of tax:
Total available-for-sale and transferred securities									(9,069)	(22,828)	19,038
Total derivative instruments									5,912	2,550	(7,324)
Total defined benefit pension and postretirement benefit plans									4,270	(1,567)	(19,426)
Other comprehensive income (loss), net of tax									1,113	(21,845)	(7,712)
Comprehensive income									$ 208,240	$ 182,884	$ 192,014

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Series A Preferred Stock [Member]	Series E Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series A Preferred Stock [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Treasury Stock, at cost [Member]	Accumulated Other Comprehensive Loss, Net of Tax [Member]
Beginning Balance at Dec. 31, 2013	$ 2,209,348			$ 151,649	$ 934	$ 1,125,584	$ 1,080,648			$ (100,918)	$ (48,549)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	199,726						199,726
Other comprehensive income (loss), net of tax	(7,712)										(7,712)
Dividends and dividend equivalents declared on common stock	(67,690)					57	(67,747)
Dividends on preferred stock $85.00, $85.00, and $21.25 per share on Series A for 2013, 2014, and 2015, respectively and $1,648.89, $1,600.00, and $1,600.00 per share on Series E for 2013, 2014 and 2015, respectively		$ (2,460)	$ (8,096)					$ (2,460)	$ (8,096)
Common stock issued	435				2	433	0			0
Stock-based compensation, net of tax impact	10,113					3,223	180			6,710
Exercise of stock options	2,221					(1,760)				3,981
Shares acquired related to employee share-based compensation plans	(2,326)									(2,326)
Common stock repurchased	(10,741)									(10,741)
Common stock warrants repurchased	(3)					(3)
Ending Balance at Dec. 31, 2014	2,322,815			151,649	936	1,127,534	1,202,251			(103,294)	(56,261)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	204,729						204,729
Other comprehensive income (loss), net of tax	(21,845)										(21,845)
Dividends and dividend equivalents declared on common stock	(81,197)					119	(81,316)
Dividends on preferred stock $85.00, $85.00, and $21.25 per share on Series A for 2013, 2014, and 2015, respectively and $1,648.89, $1,600.00, and $1,600.00 per share on Series E for 2013, 2014 and 2015, respectively		$ (615)	(8,096)					$ (615)	(8,096)
Common stock issued	0				1	(1)
Preferred stock conversion	0			(28,939)		(3,429)				32,368
Stock-based compensation, net of tax impact	12,947					2,906	(1,005)			11,046
Exercise of stock options	3,060					(2,781)				5,841
Shares acquired related to employee share-based compensation plans	(5,251)									(5,251)
Common stock repurchased	(12,564)									(12,564)
Common stock warrants repurchased	(23)					(23)
Ending Balance at Dec. 31, 2015	2,413,960			122,710	937	1,124,325	1,315,948			(71,854)	(78,106)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	207,127						207,127
Other comprehensive income (loss), net of tax	1,113										1,113
Dividends and dividend equivalents declared on common stock	(89,913)					149	(90,062)
Dividends on preferred stock $85.00, $85.00, and $21.25 per share on Series A for 2013, 2014, and 2015, respectively and $1,648.89, $1,600.00, and $1,600.00 per share on Series E for 2013, 2014 and 2015, respectively			$ (8,096)						$ (8,096)
Stock-based compensation, net of tax impact	14,092					2,976	403			10,713
Exercise of stock options	11,762					(1,350)				13,112
Shares acquired related to employee share-based compensation plans	(11,664)									(11,664)
Common stock repurchased	(11,206)									(11,206)
Common stock warrants repurchased	(163)					(163)
Ending Balance at Dec. 31, 2016	$ 2,527,012			$ 122,710	$ 937	$ 1,125,937	$ 1,425,320			$ (70,899)	$ (76,993)

Consolidated Statements of Sha7

Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Dividends on common stock and dividend equivalents declared, per share	$ 0.98	$ 0.89	$ 0.75
Series A Preferred Stock [Member]
Dividends on preferred stock, per share		21.25	85
Series E Preferred Stock [Member]
Dividends on preferred stock, per share	$ 1,600	$ 1,600	$ 1,600

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Operating Activities:
Net income	$ 207,127	$ 204,729		$ 199,726
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	56,350	49,300		37,250
Deferred tax expense (benefit)	17,700	(15,513)		(5,154)
Depreciation and amortization	36,449	34,678		30,585
Amortization of earning assets and funding premium/discount, net	57,331	54,555		50,758
Stock-based compensation	11,438	10,935		10,223
Gain on sale, net of write-down, on foreclosed and repossessed assets	(976)	(311)		(1,297)
Loss (gain) on sale, net of write-down, on premises and equipment	397	(244)		(292)
Impairment loss on securities recognized in earnings	149	110		1,145
Gain on the sale of investment securities, net	(414)	(609)		(5,499)
Increase in cash surrender value of life insurance policies	(14,759)	(13,020)		(13,178)
Gain from life insurance policies	0	(220)		(2,229)
Mortgage banking activities	(11,103)	(7,795)		(4,070)
Proceeds from sale of loans held for sale	438,925	452,590		287,132
Originations of loans held for sale	(452,886)	(449,048)		(296,996)
Net decrease (increase) in derivative contract assets net of liabilities	27,929	(6,489)		(49,158)
Gain on redemption of other assets	(7,331)	0		0
Net decrease (increase) in accrued interest receivable and other assets	50,737	(44,334)	[1]	(2,552)	[1]
Net (decrease) increase in accrued expenses and other liabilities	(18,918)	33,478	[1]	6,601	[1]
Net cash provided by operating activities	398,145	302,792		242,995
Investing Activities:
Net decrease (increase) in interest-bearing deposits	126,446	(23,212)		(109,021)
Purchases of available-for-sale securities	(980,870)	(903,240)		(217,920)
Proceeds from maturities and principal payments of available-for-sale securities	672,965	558,301		416,821
Proceeds from sales of available-for-sale securities	259,283	123,270		98,402
Purchases of held-to-maturity securities	(1,066,156)	(761,033)		(1,113,958)
Proceeds from maturities and principal payments of held-to-maturity securities	795,953	681,124		575,009
Net (purchase) proceeds of Federal Home Loan Bank stock	(6,299)	4,943		(34,412)
Purchases of intercompany debt securities	(381)	458		(115)
Net increase in loans	(1,440,141)	(1,813,811)		(1,269,290)
Proceeds from loans not originated for sale	34,170	33,644		0
Purchase of life insurance policies	0	(50,000)		0
Proceeds from life insurance policies	0	3,912		2,178
Proceeds from the sale of foreclosed properties and repossessed assets	9,205	10,511		8,995
Proceeds from the sale of premises and equipment	1,550	650		3,565
Additions to premises and equipment	(40,731)	(36,115)		(30,039)
Acquisition of business, net cash acquired	0	1,396,414		0
Net cash used for investing activities	(1,635,006)	(774,184)		(1,669,785)
Financing Activities:
Net increase in deposits	1,351,609	853,921		797,244
Contingent consideration	5,000	0		0
Proceeds from Federal Home Loan Bank advances	19,630,000	13,505,000		10,372,226
Repayments of Federal Home Loan Bank advances	(19,451,219)	(13,700,279)		(9,565,192)
Net decrease in securities sold under agreements to repurchase and other borrowings	(201,874)	(99,356)		(80,906)
Issuance of long-term debt	0	0		150,000
Repayment of long-term debt	0	0		(150,000)
Debt issuance costs	0	0		(1,349)
Dividends paid to common shareholders	(89,522)	(80,964)		(67,431)
Dividends paid to preferred shareholders	(8,096)	(8,711)		(10,556)
Exercise of stock options	11,762	3,060		2,221
Excess tax benefits from stock-based compensation	3,204	2,338		1,161
Common stock issued	0	0		435
Common stock repurchased	(11,206)	(12,564)		(10,741)
Shares acquired related to employee share-based compensation plans	(11,664)	(5,251)		(2,326)
Common stock warrants repurchased	(163)	(23)		(3)
Net cash (used for) provided by financing activities	1,227,831	457,171		1,434,783
Net (decrease) increase in cash and due from banks	(9,030)	(14,221)		7,993
Cash and due from banks at beginning of period	199,693	213,914		205,921
Cash and due from banks at end of period	190,663	199,693		213,914
Supplemental disclosure of cash flow information:
Interest paid	102,438	95,428		89,942
Income taxes paid	80,143	106,991		102,973
Noncash investing and financing activities:
Transfer of loans and leases to foreclosed properties and repossessed assets	6,769	8,714		5,532
Transfer of loans from portfolio to loans held for sale	39,383	585		0
Deposits assumed in business acquisition	0	1,446,899		0
Preferred stock conversion	$ 0	$ 28,939		$ 0
[1]	An additional line item, net decrease (increase) in derivative contract assets net of liabilities, was added to the Consolidated Statements of Cash Flows to detail the net change in derivative balances subject to offsetting. The update removed $6.5 million and $49.2 million in net increases in derivative contract assets net of liabilities from the net (increase) in accrued interest receivable and other assets and net increase in accrued expenses and other liabilities line items for the years ended December 31, 2015 and December 31, 2014 respectively.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations Webster Financial Corporation is a bank holding company and financial holding company under the Bank Holding Company Act, incorporated under the laws of Delaware in 1986 and headquartered in Waterbury, Connecticut. At December 31, 2016 , Webster Financial Corporation's principal asset is all of the outstanding capital stock of Webster Bank. Webster delivers financial services to individuals, families, and businesses primarily within its regional footprint from New York to Massachusetts. Webster provides business and consumer banking, mortgage lending, financial planning, trust, and investment services through banking offices, ATMs, mobile banking and its internet website (www.websterbank.com or www.wbst.com). Webster also offers equipment financing, commercial real estate lending, and asset-based lending primarily across the Northeast. On a nationwide basis, through its HSA Bank division, Webster Bank offers and administers health savings accounts, flexible spending accounts, health reimbursement accounts, and commuter benefits. Basis of Presentation The Consolidated Financial Statements and the accompanying Notes thereto include the accounts of Webster Financial Corporation and all other entities in which it has a controlling financial interest. Intercompany accounts and transactions have been eliminated in consolidation. Webster's accounting and financial reporting policies conform, in all material respects, to GAAP and to general practices within the financial services industry. Assets that the Company holds or manages in a fiduciary or agency capacity for customers, typically referred to as assets under administration or assets under management are not included in the accompanying Consolidated Balance Sheets since those assets are not Webster's, and the Company is not the primary beneficiary. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on net income, comprehensive income, total assets, total liabilities, total shareholders' equity, net cash provided by operating activities, and net cash used for investing activities. Correction of Immaterial Errors Related to Prior Periods Cash Collateral Associated with Derivative Instruments. During the three months ended March 31, 2016, the Company identified an error relating to the accounting for cash collateral associated with derivative instruments. Based on requirements of ASC Topic 305, " Cash and Cash Equivalents ," the Company determined the cash collateral was incorrectly classified as cash and due from banks. In accordance with the requirements of ASC Topic 815, " Derivatives and Hedging, " the variation margin of cash collateral, pertaining to derivatives reported on a net basis, subject to a legally enforceable master netting arrangement, with the same counterparty, are offset against the net derivative position on the Company's Consolidated Balance Sheets. The cash collateral, relating to the initial margin, is included within accrued interest receivable and other assets on the Company's Consolidated Balance Sheets. The Company reviewed the impact of this error on the prior periods in accordance with Securities and Exchange Commission Staff Accounting Bulletin No. 99, Materiality , and ASC Topic 250, " Accounting Changes and Error Corrections, " and determined that the error was immaterial to previously reported amounts contained in the Company's annual and quarterly reports. HSA Bank segment fee accruals and certain expenses. During the three months ended June 30, 2016, the Company identified immaterial errors, impacting the quarter ended March 31, 2015 through the quarter ended March 31, 2016, relating to the reporting of certain fee accruals and certain expenses within the Company's HSA Bank segment. The Company determined that such fee and expense accruals were not accurately reported. As a result, deposit service fees were overstated and technology and equipment expense was understated. The Company reviewed the impact of the errors on prior periods in accordance with Securities and Exchange Commission Staff Accounting Bulletin No. 99, Materiality and ASC Topic 250, " Accounting Changes and Error Corrections," and determined that the errors, individually and in the aggregate, were immaterial to all prior periods impacted. While the errors were immaterial, the Company has elected to correct the previously reported amounts. The errors had no effect on individual customer's accounts. The effects of correcting the immaterial errors in the Consolidated Balance Sheets, Consolidated Statements of Income and Consolidated Statements of Cash Flows are summarized in the following tables: December 31, 2015 (In thousands) As Reported As Revised Consolidated Balance Sheets Cash and due from banks $ 251,258 $ 199,693 Accrued interest receivable and other assets (1) 328,993 343,856 Accrued expenses and other liabilities 267,576 233,581 Retained earnings 1,317,559 1,315,948 (1) The amount recorded as revised includes the impact of a $1.1 million reclassification of debt issuance cost from accrued interest receivable and other assets into long-term debt. The reclassification was made in accordance with the Company's adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, and is not considered part of the error correction. Year ended December 31, 2015 (In thousands, except per share data) As Reported As Revised Consolidated Statements of Income Deposit service fees $ 136,578 $ 135,057 Other income 23,573 23,326 Technology and equipment 80,026 80,813 Income tax expense 93,976 93,032 Net income 206,340 204,729 Earnings per common share: Basic $ 2.17 $ 2.15 Diluted 2.15 2.13 HSA Segment: Net income $ 39,173 $ 37,443 December 31, 2015 December 31, 2014 (In thousands) As Reported As Revised As Reported As Revised Consolidated Statements of Cash Flows Net (increase) in accrued interest receivable and other assets (1) $ (49,899 ) $ (44,334 ) $ (24,502 ) $ (2,552 ) Net increase in accrued expenses and other liabilities (1) 35,336 33,478 9,213 6,601 (1) An additional line item, net decrease (increase) in derivative contract assets net of liabilities, was added to the Consolidated Statements of Cash Flows to detail the net change in derivative balances subject to offsetting. The update removed $6.5 million and $49.2 million in net increases in derivative contract assets net of liabilities from the net (increase) in accrued interest receivable and other assets and net increase in accrued expenses and other liabilities line items for the years ended December 31, 2015 and December 31, 2014 respectively. Variable Interest Entities A VIE is an entity that has either a total equity investment that is insufficient to finance its activities without additional subordinated financial support or whose equity investors lack the ability to control the entity’s activities or lack the ability to receive expected benefits or absorb obligations in a manner that’s consistent with their investment in the entity. The Company evaluates each VIE to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE. The Company will consolidate the VIE if it has: • the power to direct the activities of the VIE that most significantly affect the VIE's economic performance; and • an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. See Note 3: Variable Interest Entities for further information. Use of Estimates The preparation of financial statements in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the financial statements as well as income and expense during the period. The allowance for loan and lease losses, the fair value measurements for valuation of investments and other financial instruments, evaluation of investments for OTTI, valuation of goodwill and other intangible assets, and assessing the realizability of deferred tax assets and the measurement of uncertain tax position, as well as the status of contingencies, are particularly subject to change. Actual results could differ from those estimates. Cash Equivalents Cash equivalents have a maturity of three months or less. Cash and due from banks. Cash equivalents, including cash on hand, certain cash due from banks, and deposits at the FRB of Boston, are referenced as cash and due from banks in the accompanying Consolidated Balance Sheets and Consolidated Statements of Cash Flows. Interest-bearing deposits. Cash equivalents, primarily representing deposits at the FRB of Boston in excess of reserve requirements, and federal funds sold, which essentially represent uncollateralized loans to other financial institutions, are referenced as interest-bearing deposits in the accompanying Consolidated Balance Sheets and Consolidated Statements of Cash Flows. The Company regularly evaluates the credit risk associated with those financial institutions to assess that Webster is not exposed to any significant credit risk on cash equivalents. Investment Securities Investment securities are classified as available-for-sale or held-to-maturity at the time of purchase. Any subsequent change to classification is reviewed for compliance with corporate objectives and accounting policy. Debt securities classified as held-to-maturity are those which Webster has the ability and intent to hold to maturity. Securities classified as held-to-maturity are recorded at amortized cost net of unamortized premiums and discounts. Discount accretion income and premium amortization expense are recognized as interest income according to a constant yield methodology, with consideration given to prepayment assumptions on mortgage backed securities. Securities classified as available-for-sale are recorded at fair value with unrealized gains and losses recorded as a component of OCI/OCL. Securities transferred from available-for-sale to held-to-maturity are recorded at fair value at the time of transfer, and the respective gain or loss is recorded as a separate component of OCI/OCL and amortized as an adjustment to interest income over the remaining life of the security. All securities classified as available-for-sale or held-to-maturity that are in an unrealized loss position are evaluated for OTTI on a quarterly basis. The evaluation considers several qualitative factors, including the period of time the security has been in a loss position, and the amount of the unrealized loss. If the Company intends to sell the security or it is more than likely the Company will be required to sell the security prior to recovery of its amortized cost basis, the security is written down to fair value, and the loss is recognized in non-interest income in the accompanying Consolidated Statements of Income. If the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery of its amortized cost basis, only the credit component of the unrealized loss is recorded as an impairment charge to a debt security and recognized as a loss. The remaining loss component would be recorded to AOCL in the accompanying Consolidated Balance Sheets. The entire amount of an unrealized loss position of an equity security that is considered OTTI is recorded as an impairment loss in non-interest income in the accompanying Consolidated Statements of Income. The specific identification method is used to determine realized gains and losses on sales of securities. See Note 2: Investment Securities for further information. Federal Home Loan Bank and Federal Reserve Bank Stock Webster Bank is a member of the FHLB and the Federal Reserve System, and is required to maintain an investment in capital stock of the FHLB of Boston and FRB of Boston. Based on redemption provisions, the stock of both the FHLB and the FRB has no quoted market value and is carried at cost. Membership stock is not reviewed for impairment unless economic circumstances warrant special review. Loans Held for Sale Effective January 1, 2016, on a loan by loan election, residential mortgage loans that are classified as held for sale are accounted for under either the fair value option method of accounting or the lower of cost or fair value method of accounting with the election being made at the time the asset is first recognized. The Company has elected the fair value option to mitigate accounting mismatches between held for sale derivative commitments and loan valuations. Prior to January 1, 2016, residential mortgage loans that were classified as held for sale were accounted for at the lower of cost or fair value method of accounting and were valued on an individual asset basis. Loans not originated for sale but subsequently transferred to held for sale continue to be valued at the lower of cost or fair value method of accounting and are valued on an individual asset basis. Any cost amount in excess of fair value is recorded as a valuation allowance and recognized as a reduction of other income in the Consolidated Statements of Income. Gains or losses on the sale of loans held for sale are recorded as non-interest income. Cash flows from sale of loans made by the Company that were acquired specifically for resale are presented as operating cash flows. All other cash flows from sale of loans are presented as investing cash flows. See Note 5: Transfers of Financial Assets for further information. Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is generally considered to have been surrendered when: (i) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership; (ii) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company; and (iii) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. The Company sells financial assets in the normal course of business, the majority of which are residential mortgage loan sales primarily to government-sponsored enterprises through established programs, commercial loan sales through participation agreements, and other individual or portfolio loan and securities sales. In accordance with accounting guidance for asset transfers, the Company considers any ongoing involvement with transferred assets in determining whether the assets can be derecognized from the balance sheet. With the exception of servicing and certain performance-based guarantees, the Company’s continuing involvement with financial assets sold is minimal and generally limited to market customary representation and warranty clauses covering certain characteristics of the mortgage loans sold and the Company's origination process. The gain or loss on sale depends on the previous carrying amount of the transferred financial assets, the consideration received, and any liabilities incurred in exchange for the transferred assets. When the Company sells financial assets, it may retain servicing rights and/or other interests in the financial assets. Servicing assets and any other interests held by the Company are recorded at fair value upon transfer, and thereafter are carried at the lower of cost or fair value. See Note 5: Transfers of Financial Assets for further information. Loans and Leases Loans and leases are stated at the principal amount outstanding, net of amounts charged off, unamortized premiums and discounts, and deferred loan and lease fees/costs which are recognized as yield adjustments using the interest method. These yield adjustments are amortized over the contractual life of the related loans and leases adjusted for prepayments when applicable. Interest on loans and leases is credited to interest income as earned based on the interest rate applied to principal amounts outstanding. Cash flows from loans and leases are presented as investing cash flows. Loans and leases are placed on non-accrual status when collection of principal and interest in accordance with contractual terms is doubtful, generally when principal or interest payments become 90 days delinquent, unless the loan or lease is well secured and in process of collection, or sooner if management concludes circumstances indicate that the borrower may be unable to meet contractual principal or interest payments. Residential real estate loans, excluding loans fully insured against loss and in the process of collection, and consumer loans are placed on non-accrual status at 90 days past due, or at the date when the Company is notified that the borrower is discharged in bankruptcy. A charge-off is recorded at 180 days if the loan balance exceeds the fair value of the collateral less costs to sell. Residential loans that are more than 90 days past due, fully insured against loss, and in the process of collection, remain accruing and are reported as 90 days or more past due and accruing. Commercial, commercial real estate loans, and equipment finance loans or leases are subject to a detailed review when 90 days past due to determine accrual status, or when payment is uncertain and a specific consideration is made to put a loan or lease on non-accrual status. When loans and leases are placed on non-accrual status, the accrual of interest is discontinued, and any unpaid accrued interest is reversed and charged against interest income. If ultimate repayment of a non-accrual loan or lease is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment is not expected on commercial, commercial real estate, and equipment finance loans and leases, any payment received on a non-accrual loan or lease is applied to principal until the unpaid balance has been fully recovered. Any excess is then credited to interest income when received. If the Company determines, through a current valuation analysis, that principal can be repaid on residential real estate and consumer loans, interest payments may be taken into income as received on a cash basis. Except for loans discharged under Chapter 7 of the U.S. bankruptcy code, loans are removed from non-accrual status when they become current as to principal and interest or demonstrate a period of performance under contractual terms and, in the opinion of management, are fully collectible as to principal and interest. Pursuant to regulatory guidance, a Chapter 7 discharged bankruptcy loan is removed from non-accrual status when the bank expects full repayment of the remaining pre-discharged contractual principal and interest, the loan is a closed-end amortizing loan, it is fully collateralized, and post-discharge the loan had at least six consecutive months of current payments. See Note 4: Loans and Leases for further information. Allowance for Loan and Lease Losses The ALLL is a reserve established through a provision for loan and lease losses charged to expense and represents management’s best estimate of probable losses that may be incurred within the existing loan and lease portfolio as of the balance sheet date. The level of the allowance reflects management’s view of trends in losses, current portfolio quality, and present economic, political, and regulatory conditions. Portions of the allowance may be allocated for specific loans and leases; however, the entire allowance is available for any loan or lease that is charged off. A charge-off is recorded on a case-by-case basis when all or a portion of the loan or lease is deemed to be uncollectible. Back-testing is performed to compare original estimated losses and actual observed losses, resulting in ongoing refinements. While management utilizes its best judgment based on the information available at the time, the ultimate adequacy of the allowance is dependent upon a variety of factors that are beyond the Company’s control, which include the performance of the Company’s portfolio, economic conditions, interest rate sensitivity, and the view of the regulatory authorities regarding loan classifications. The ALLL consists of the following three elements: (i) specific valuation allowances established for probable losses on impaired loans and leases; (ii) quantitative valuation allowances calculated using loss experience for like loans and leases with similar characteristics and trends, adjusted, as necessary, to reflect the impact of current conditions; and (iii) qualitative factors determined based on general economic conditions and other factors that may be internal or external to the Company. Loans and leases are considered impaired when, based on current information and events, it is probable the Company will be unable to collect all amounts due in accordance with the original contractual terms of the loan agreement, including scheduled principal and interest payments. Impairment is evaluated on a pooled basis for smaller-balance homogeneous residential, consumer loans and small business loans. Commercial, commercial real estate, and equipment financing loans and leases over a specific dollar amount and all TDR are evaluated individually for impairment. A loan identified as a TDR is considered an impaired loan for the entire term of the loan, with few exceptions. If a loan is impaired, a specific valuation allowance may be established, and the loan is reported net, at the present value of estimated future cash flows using the loan’s original interest rate or at the fair value of collateral less cost to sell if repayment is expected from collateral liquidation. Interest payments on non-accruing impaired loans are typically applied to principal unless collectability of the principal amount is reasonably assured, in which case interest is recognized on a cash basis. Impaired loans, or portions thereof, are charged off when deemed uncollectible. Factors considered by management in determining impairment include payment status, collateral value, discharged bankruptcy, and the likelihood of collecting scheduled principal and interest payments. Consumer modified loans are analyzed for re-default probability, which is considered when determining if a specific valuation allowance is to be established. The current or weighted-average (for multiple notes within a commercial borrowing arrangement) interest rate of the loan is used as the discount rate, for determining net present value of the loan evaluated for impairment, when the interest rate floats with a specified index. A change in terms or payments would be included in the impairment calculation. See Note 4: Loans and Leases for further information. Reserve for Unfunded Commitments The reserve for unfunded commitments provides for probable losses inherent with funding the unused portion of legal commitments to lend. The unfunded reserve calculation includes factors that are consistent with the ALLL methodology for funded loans using the loss given default, probability of default, and a draw down factor applied to the underlying borrower risk and facility grades. The reserve for unfunded credit commitments is included within other liabilities in the accompanying Consolidated Balance Sheets, and changes in the reserve are reported as a component of other expense in the accompanying Consolidated Statements of Income. See Note 20: Commitments and Contingencies for further information. Troubled Debt Restructurings A modified loan is considered a TDR when the following two conditions are met: (i) the borrower is experiencing financial difficulties; and (ii) the modification constitutes a concession. The Company considers all aspects of the restructuring in determining whether a concession has been granted, including the debtor's ability to access funds at a market rate. In general, a concession exists when the modified terms of the loan are more attractive to the borrower than standard market terms. Modified terms are dependent upon the financial position and needs of the individual borrower. The most common types of modifications include covenant modifications and forbearance. Loans for which the borrower has been discharged under Chapter 7 bankruptcy are considered collateral dependent TDR, impaired at the date of discharge, and charged down to the fair value of collateral less cost to sell, if management considers that loss potential likely exists. The Company’s policy is to place consumer loan TDR, except those that were performing prior to TDR status, on non-accrual status for a minimum period of six months . Commercial TDR are evaluated on a case-by-case basis for determination of whether or not to place them on non-accrual status. Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of six months . Initially, all TDR are reported as impaired. Generally, TDR are classified as impaired loans and reported as TDR for the remaining life of the loan. Impaired and TDR classification may be removed if the borrower demonstrates compliance with the modified terms for a minimum of six months and through a fiscal year-end and the restructuring agreement specifies a market rate of interest equal to that which would be provided to a borrower with similar credit at the time of restructuring. In the limited circumstance that a loan is removed from TDR classification, it is the Company’s policy to continue to base its measure of loan impairment on the contractual terms specified by the loan agreement. The Company’s loan and lease portfolio includes loans that have been restructured into an A-Note/B-Note structure as a result of evaluating the cash flow of the borrowers to support repayment. Following these restructurings, Webster immediately charged off the balances of the B-Notes. The restructuring agreements specify a market interest rate equal to that which would be provided to a borrower with similar credit at the time of restructuring. See Note 4: Loans and Leases for further information. Foreclosed and Repossessed Assets Real estate acquired through foreclosure or completion of a deed in lieu of foreclosure and other assets acquired through repossession are carried at the lower of cost or market value less estimated selling costs and are included within other assets in the accompanying Consolidated Balance Sheets. Independent appraisals generally are obtained to substantiate fair value and may be subject to adjustment based upon historical experience or specific geographic trends impacting the property. Within 90 days of a loan being foreclosed upon, the excess of loan balance over fair value less cost to sell is charged off against the ALLL. Subsequent write-downs in value, maintenance costs as incurred, and gains or losses upon sale are charged to non-interest expense in the accompanying Consolidated Statements of Income. Premises and Equipment Premises and equipment are carried at cost, less accumulated depreciation. Depreciation of premises and equipment is computed on a straight-line basis over the estimated useful lives of the assets, as follows: Building and Improvements 5 - 40 years Leasehold improvements 5 - 20 years (or term or lease, if shorter) Fixtures and equipment 5 - 10 years Data processing and software 3 - 7 years Repairs and maintenance costs are charged to non-interest expense as incurred. Premises and equipment being actively marketed for sale are reclassified as assets held for disposition. The cost and accumulated depreciation relating to premises and equipment retired or otherwise disposed of are eliminated, and any resulting losses are charged to non-interest expense. See Note 6: Premises and Equipment for further information. Goodwill Goodwill represents the excess purchase price of businesses acquired over the fair value of the identifiable net assets acquired and is assigned to specific reporting units. Goodwill is not subject to amortization but rather is evaluated for impairment annually, or more frequently in interim periods if events occur or circumstances change indicating it would more likely than not result in a reduction of the fair value of a reporting unit below its carrying value. Goodwill is evaluated for impairment by either performing a qualitative evaluation or a two-step quantitative test. The qualitative evaluation is an assessment of factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. The Company utilizes an equally weighted combined income and market approach to arrive at an indicated fair value range for the reporting unit. In Step 1, the fair value of a reporting unit is compared to its carrying amount, including goodwill, to ascertain if a goodwill impairment exists. If the fair value of the reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired, and it is not necessary to continue to Step 2 of the impairment process. Otherwise, Step 2 is performed where the implied fair value of goodwill is compared to the carrying value of goodwill in the reporting unit. If a reporting unit's carrying value exceeds fair value, the difference is charged to non-interest expense. See Note 7: Goodwill and Other Intangible Assets for further information. Other Intangible Assets Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights, or because the asset is capable of being sold or exchanged either separately or in combination with a related contract, asset, or liability. Other intangible assets with finite useful lives are amortized to non-interest expense over their estimated useful lives and are evaluated for impairment whenever events occur or circumstances change indicating the carrying amount of the asset may not be recoverable. Core deposit intangible assets resulting from the health savings account acquisition are amortized on an accelerated basis over their estimated useful lives. Core deposit intangible assets existing prior to the health savings account acquisition continue to be amortized on a straight line basis over their remaining estimated useful lives. Intangible assets relating to customer relationships are amortized on a straight line basis over their estimated useful lives. See Note 7: Goodwill and Other Intangible Assets for further information. Cash Surrender Value of Life Insurance The investment in life insurance represents the cash surrender value of life insurance policies on certain current and former officers of Webster. Increases in the cash surrender value are recorded as non-interest income. Decreases are the result of collection on the policies due to the death of an insured. Death benefit proceeds in excess of cash surrender value are recorded in other non-interest income when realized. Securities Sold Under Agreements to Repurchase These agreements are accounted for as secured financing transactions since Webster maintains effective control over the transferred securities and the transfer meets the other criteria for such accounting. Obligations to repurchase securities sold are reflected as a liability in the accompanying Consolidated Balance Sheets. The securities underlying the agreements are delivered to a custodial account for the benefit of the dealer or bank with whom each transaction is executed. The dealers or banks, which may sell, loan, or otherwise hypothecate such securities to other parties in the normal course of their operations, agree to resell to Webster the same securities at the maturity date of the agreements. The securities underlying the agreements with Bank customers are pledged; however, the customer does not have ability to hypothecate the underlying securities. See Note 10: Borrowings for further information. Share-Based Compensation Webster maintains an equity incentive plan under which non-qualified stock options, incentive stock options, restricted stock, restricted stock units, or stock appreciation rights may be granted to employees and directors. Share awards are issued from available treasury shares. Stock-based compensation cost is recognized over the requisite service period for the awards, based on th

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities A Summary of the amortized cost and fair value of investment securities is presented below: At December 31, 2016 2015 (In thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Available-for-sale: U.S. Treasury Bills $ 734 $ — $ — $ 734 $ 924 $ — $ — $ 924 Agency CMO 419,865 3,344 (3,503 ) 419,706 546,168 5,532 (2,946 ) 548,754 Agency MBS 969,460 4,398 (19,509 ) 954,349 1,075,941 6,459 (17,291 ) 1,065,109 Agency CMBS 587,776 63 (14,567 ) 573,272 215,670 639 (959 ) 215,350 CMBS 473,974 4,093 (702 ) 477,365 574,686 7,485 (2,905 ) 579,266 CLO 425,083 2,826 (519 ) 427,390 431,837 592 (3,270 ) 429,159 Single issuer trust preferred securities 30,381 — (1,748 ) 28,633 42,168 — (4,998 ) 37,170 Corporate debt securities 108,490 1,502 (350 ) 109,642 104,031 2,290 — 106,321 Equities - financial institutions — — — — 3,499 — (921 ) 2,578 Total available-for-sale $ 3,015,763 $ 16,226 $ (40,898 ) $ 2,991,091 $ 2,994,924 $ 22,997 $ (33,290 ) $ 2,984,631 Held-to-maturity: Agency CMO $ 339,455 $ 1,977 $ (3,824 ) $ 337,608 $ 407,494 $ 3,717 $ (2,058 ) $ 409,153 Agency MBS 2,317,449 26,388 (41,768 ) 2,302,069 2,030,176 38,813 (19,908 ) 2,049,081 Agency CMBS 547,726 694 (1,348 ) 547,072 686,086 4,253 (325 ) 690,014 Municipal bonds and notes 655,813 4,389 (25,749 ) 634,453 435,905 12,019 (417 ) 447,507 CMBS 298,538 4,107 (411 ) 302,234 360,018 5,046 (2,704 ) 362,360 Private Label MBS 1,677 12 — 1,689 3,373 46 — 3,419 Total held-to-maturity $ 4,160,658 $ 37,567 $ (73,100 ) $ 4,125,125 $ 3,923,052 $ 63,894 $ (25,412 ) $ 3,961,534 Other-Than-Temporary Impairment The balance of OTTI, included in the amortized cost columns above, is related to certain CLO positions that were previously considered Covered Funds as defined by Section 619 of the Dodd-Frank Act commonly known as the Volcker Rule. The Company has taken measures to bring its CLO positions into conformance with the Volcker Rule. To the extent that changes occur in interest rates, credit movements, and other factors that impact fair value and expected recovery of amortized cost of its investment securities, the Company may be required to recognize OTTI in earnings, in future periods. The following table presents the changes in OTTI: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 3,288 $ 3,696 $ 16,633 Reduction for securities sold or called (194 ) (518 ) (14,082 ) Additions for OTTI not previously recognized 149 110 1,145 Ending balance $ 3,243 $ 3,288 $ 3,696 Fair Value and Unrealized Losses The following tables provide information on fair value and unrealized losses for the individual securities with an unrealized loss, aggregated by investment security type and length of time that the individual securities have been in a continuous unrealized loss position: At December 31, 2016 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 107,853 $ (2,168 ) $ 67,351 $ (1,335 ) 15 $ 175,204 $ (3,503 ) Agency MBS 512,075 (10,503 ) 252,779 (9,006 ) 97 764,854 (19,509 ) Agency CMBS 554,246 (14,567 ) — — 32 554,246 (14,567 ) CMBS 12,427 (24 ) 63,930 (678 ) 12 76,357 (702 ) CLO 49,946 (54 ) 50,237 (465 ) 5 100,183 (519 ) Single issuer trust preferred securities — — 28,633 (1,748 ) 5 28,633 (1,748 ) Corporate debt securities — — 7,384 (350 ) 2 7,384 (350 ) Equities-financial institutions — — — — — — — Total available-for-sale in an unrealized loss position $ 1,236,547 $ (27,316 ) $ 470,314 $ (13,582 ) 168 $ 1,706,861 $ (40,898 ) Held-to-maturity: Agency CMO $ 163,439 $ (3,339 ) $ 17,254 $ (485 ) 16 $ 180,693 $ (3,824 ) Agency MBS 1,394,623 (32,942 ) 273,779 (8,826 ) 150 1,668,402 (41,768 ) Agency CMBS 347,725 (1,348 ) — — 25 347,725 (1,348 ) Municipal bonds and notes 384,795 (25,745 ) 1,192 (4 ) 196 385,987 (25,749 ) CMBS 60,768 (411 ) — — 8 60,768 (411 ) Total held-to-maturity in an unrealized loss position $ 2,351,350 $ (63,785 ) $ 292,225 $ (9,315 ) 395 $ 2,643,575 $ (73,100 ) At December 31, 2015 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 195,369 $ (2,195 ) $ 26,039 $ (751 ) 14 $ 221,408 $ (2,946 ) Agency MBS 481,839 (6,386 ) 351,911 (10,905 ) 84 833,750 (17,291 ) Agency CMBS 124,241 (959 ) — — 7 124,241 (959 ) CMBS 276,330 (2,879 ) 19,382 (26 ) 29 295,712 (2,905 ) CLO 211,515 (2,709 ) 15,708 (561 ) 13 227,223 (3,270 ) Single issuer trust preferred securities 4,087 (128 ) 33,083 (4,870 ) 8 37,170 (4,998 ) Corporate debt securities — — — — — — — Equities-financial institutions 2,578 (921 ) — — 1 2,578 (921 ) Total available-for-sale in an unrealized loss position $ 1,295,959 $ (16,177 ) $ 446,123 $ (17,113 ) 156 $ 1,742,082 $ (33,290 ) Held-to-maturity: Agency CMO $ 143,364 $ (1,304 ) $ 27,928 $ (754 ) 13 $ 171,292 $ (2,058 ) Agency MBS 551,918 (7,089 ) 470,828 (12,819 ) 87 1,022,746 (19,908 ) Agency CMBS 110,864 (325 ) — — 7 110,864 (325 ) Municipal bonds and notes 29,034 (130 ) 13,829 (287 ) 27 42,863 (417 ) CMBS 142,382 (1,983 ) 30,129 (721 ) 18 172,511 (2,704 ) Total held-to-maturity in an unrealized loss position $ 977,562 $ (10,831 ) $ 542,714 $ (14,581 ) 152 $ 1,520,276 $ (25,412 ) Impairment Analysis The following impairment analysis by investment security type, summarizes the basis for evaluating if investment securities within the Company’s available-for-sale and held-to-maturity portfolios have been impacted by OTTI. Unless otherwise noted for an investment security type, management does not intend to sell these investments and has determined, based upon available evidence, that it is more likely than not that the Company will not be required to sell these securities before the recovery of their amortized cost. As such, based on the following impairment analysis, the Company does not consider these securities, in unrealized loss positions, to be other-than-temporarily impaired at December 31, 2016 . Available-for-Sale Securities Agency CMO. There were unrealized losses of $3.5 million on the Company’s investment in Agency CMO at December 31, 2016 , compared to $2.9 million at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency MBS. There were unrealized losses of $19.5 million on the Company’s investment in residential mortgage-backed securities issued by government agencies at December 31, 2016 , compared to $17.3 million at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency CMBS. There were unrealized losses of $14.6 million on the Company's investment in commercial mortgage-backed securities issued by government agencies at December 31, 2016 , compared to $1.0 million at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. CMBS. There were unrealized losses of $702 thousand on the Company’s investment in CMBS at December 31, 2016 , compared to $2.9 million at December 31, 2015 . The portfolio of mainly floating rate CMBS experienced reduced market spreads which resulted in higher market prices and smaller unrealized losses at December 31, 2016 compared to December 31, 2015 . Internal and external metrics are considered when evaluating potential OTTI. Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Contractual cash flows for the bonds continue to perform as expected. CLO. There were unrealized losses of $519 thousand on the Company’s investments in CLO at December 31, 2016 compared to $3.3 million unrealized losses at December 31, 2015 . Unrealized losses decreased due to reduced market spreads for the asset class which resulted in higher security prices since December 31, 2015 . Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Single issuer trust preferred securities. There were unrealized losses of $1.7 million on the Company's investment in single issuer trust preferred securities at December 31, 2016 , compared to $5.0 million at December 31, 2015 . Unrealized losses decreased due to reduced market spreads which resulted in higher security prices since December 31, 2015 . The single issuer portfolio consists of three investments issued by two large capitalization money center financial institutions, which continue to service the debt. A security was transferred to corporate debt securities as detailed below. The Company performs periodic credit reviews of the issuer to assess the likelihood for ultimate recovery of amortized cost. Corporate debt securities. There were $350 thousand unrealized losses on the Company's corporate debt securities at December 31, 2016 , as a result of a mandatory exchange in a security reclassification from single issuer trust preferred securities. The company performs periodic credit reviews of the issuer to assess the likelihood for ultimate recovery of amortized cost. Held-to-Maturity Securities Agency CMO. There were unrealized losses of $3.8 million on the Company’s investment in Agency CMO at December 31, 2016 , compared to $2.1 million at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency MBS. There were unrealized losses of $41.8 million on the Company’s investment in residential mortgage-backed securities issued by government agencies at December 31, 2016 , compared to $19.9 million at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Agency CMBS. There were unrealized losses of $1.3 million on the Company’s investment in commercial mortgage-backed securities issued by government agencies at December 31, 2016 , compared to $325 thousand at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . These investments are issued by a government or government sponsored agency and therefore, are backed by certain government guarantees, either direct or indirect. There has been no change in the credit quality, and the contractual cash flows are performing as expected. Municipal bonds and notes. There were unrealized losses of $25.7 million on the Company’s investment in municipal bonds and notes at December 31, 2016 , compared to $417 thousand at December 31, 2015 . Unrealized losses increased due to higher market rates which resulted in lower security prices since December 31, 2015 . The Company performs periodic credit reviews of the issuers and the securities are currently performing as expected. CMBS. There were unrealized losses of $411 thousand on the Company’s investment in CMBS at December 31, 2016 , compared to $2.7 million unrealized losses at December 31, 2015 . Unrealized losses decreased due to lower market rates on mainly seasoned fixed rate conduit transactions which resulted in higher security prices since December 31, 2015 . Internal and external metrics are considered when evaluating potential OTTI. Internal stress tests are performed on individual bonds to monitor potential losses under stress scenarios. Sales of Available-for Sale Securities The following table provides information on sales of available-for-sale securities: Years ended December 31, (In thousands) 2016 2015 2014 Proceeds from sales $ 259,273 $ 95,101 $ 126,580 Gross realized gains on sales $ 2,891 $ 1,029 $ 7,268 Less: Gross realized losses on sales 2,477 420 1,769 Gain on sale of investment securities, net $ 414 $ 609 $ 5,499 Contractual Maturities The amortized cost and fair value of debt securities by contractual maturity are set forth below: At December 31, 2016 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 75,466 $ 76,383 $ 13,612 $ 13,721 Due after one year through five years 21,781 22,190 17,313 17,611 Due after five through ten years 529,247 532,352 46,835 47,780 Due after ten years 2,389,269 2,360,166 4,082,898 4,046,013 Total debt securities $ 3,015,763 $ 2,991,091 $ 4,160,658 $ 4,125,125 For the maturity schedule above, mortgage-backed securities and CLO, which are not due at a single maturity date, have been categorized based on the maturity date of the underlying collateral. Actual principal cash flows may differ from this maturity date presentation as borrowers have the right to prepay obligations with or without prepayment penalties. At December 31, 2016 , the Company had a carrying value of $1.9 billion in callable securities in its CMBS, CLO, and municipal bond portfolios. The Company considers prepayment risk in the evaluation of its interest rate risk profile. These maturities do not reflect actual duration which are impacted by prepayments. Securities with a carrying value totaling $2.5 billion at December 31, 2016 and $2.6 billion at December 31, 2015 were pledged to secure public funds, trust deposits, repurchase agreements, and for other purposes, as required or permitted by law.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities The Company evaluates each VIE to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE. The Company will consolidate the VIE if it has: • the power to direct the activities of the VIE that most significantly affect the VIE's economic performance; and • an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE. Consolidated Rabbi Trust. The Company established a Rabbi Trust to meet its obligations due under Webster's Deferred Compensation Plan for Directors and Officers and to mitigate the the expense volatility oft he aforementioned plans. The funding of the Rabbi Trust and the discontinuation of Webster's Deferred Compensation Plan for Directors and Officers occurred during 2012. Investments held in the Rabbi Trust primarily consist of mutual funds that invest in equity and fixed income securities. The Company is considered the primary beneficiary of the Rabbi Trust as it has the power to direct the activities of the Rabbi Trust that significantly affect the VIE's economic performance and it has the obligation to absorb losses of the VIE that could potentially be significant to the VIE. The Company consolidates the invested assets of the trust along with the total deferred compensation obligations and includes them in accrued interest receivable and other assets and accrued expenses and other liabilities, respectively, in the accompanying Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income, and changes in the corresponding liability are reflected as compensation and benefits, in the accompanying Consolidated Statements of Income. The cost and fair value associated with the assets and liabilities of this trust are not significant. Refer to Note 16: Fair Value Measurements for additional information. Non-Consolidated Securitized Investments. The Company, through normal investment activities, makes passive investments in securities issued by VIEs for which the Company is not the manager. These securities consist of Agency CMO, Agency MBS, Agency CMBS, CLO, and single issuer trust preferred securities. The Company has not provided financial or other support with respect to these investments other than its original investment. For these investments, the Company determined it is not the primary beneficiary due to the relative size of the Company’s investment in comparison to the principal amount of the structured securities issued by the VIEs, the level of credit subordination which reduces the Company’s obligation to absorb losses or right to receive benefits and the Company’s inability to direct the activities that most significantly impact the economic performance of the VIEs. The Company’s maximum exposure to loss on these investments is limited to the amount of the Company’s investment. Refer to Note 2: Investment Securities for additional information. Tax Credit - Finance Investments. The Company makes equity investments in entities that finance affordable housing and other community development projects and provide a return primarily through the realization of tax benefits. In most instances the investments require the funding of capital commitments in the future. While the Company's investment in an entity may exceed 50% of its outstanding equity interests, the entity is not consolidated as Webster is not involved in its management. For these investments, the Company determined it is not the primary beneficiary due to its inability to direct the activities that most significantly impact the economic performance of the VIEs. At December 31, 2016 and December 31, 2015 , the aggregate carrying value of the Company's tax credit-finance investments were $22.8 million and $25.9 million , respectively. At December 31, 2016 and December 31, 2015 , unfunded commitments, which are recognized as a component of accrued expenses and other liabilities, were $14.0 million and $16.5 million , respectively. Webster Statutory Trust. The Company owns all of the outstanding common stock of Webster Statutory Trust, which is a financial vehicle that has issued, and may issue in the future, trust preferred securities. The trust is a VIE in which the Company is not the primary beneficiary and therefore, is not consolidated. The trust's only assets are junior subordinated debentures issued by the Company, which were acquired by the trust using the proceeds from the issuance of the trust preferred securities and common stock. The junior subordinated debentures are included in long-term debt and the Company’s equity interest in the trust is included in accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets. Interest expense on the junior subordinated debentures is reported as interest expense on long-term debt in the accompanying Consolidated Statements of Income. Other Investments. The Company invests in various alternative investments in which it holds a variable interest. Alternative investments are non-public entities which cannot be redeemed since the Company’s investment is distributed as the underlying investments are liquidated. For these investments, the Company has determined it is not the primary beneficiary due to its inability to direct the activities that most significantly impacts the economic performance of the VIEs. At December 31, 2016 and December 31, 2015 , the aggregate carrying value of the Company's other investments in VIEs were $12.3 million and $12.1 million , respectively, and the total exposure of the Company's other investments in VIEs, including unfunded commitments, were $19.9 million and $19.0 million , respectively.

Loans and Leases

Loans and Leases	12 Months Ended
	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Abstract]
Loans and Leases	Loans and Leases The following table summarizes loans and leases: At December 31, (In thousands) 2016 2015 Residential $ 4,254,682 $ 4,061,001 Consumer 2,684,500 2,702,560 Commercial 4,940,931 4,315,999 Commercial Real Estate 4,510,846 3,991,649 Equipment Financing 635,629 600,526 Loans and leases (1) (2) $ 17,026,588 $ 15,671,735 (1) Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015 , respectively. (2) At December 31, 2016 , the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston. Loans and Leases Portfolio Aging The following tables summarize the aging of loans and leases: At December 31, 2016 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans and Leases Residential $ 8,631 $ 2,609 $ — $ 47,279 $ 58,519 $ 4,196,163 $ 4,254,682 Consumer: Home equity 8,831 5,782 — 35,926 50,539 2,359,354 2,409,893 Other consumer 2,233 1,485 — 1,663 5,381 269,226 274,607 Commercial: Commercial non-mortgage 1,382 577 749 38,190 40,898 4,094,727 4,135,625 Asset-based — — — — — 805,306 805,306 Commercial real estate: Commercial real estate 6,357 1,816 — 9,871 18,044 4,117,742 4,135,786 Commercial construction — — — 662 662 374,398 375,060 Equipment financing 903 693 — 225 1,821 633,808 635,629 Total $ 28,337 $ 12,962 $ 749 $ 133,816 $ 175,864 $ 16,850,724 $ 17,026,588 At December 31, 2015 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans and Leases Residential $ 10,365 $ 4,703 $ 2,029 $ 54,201 $ 71,298 $ 3,989,703 $ 4,061,001 Consumer: Home equity 9,061 4,242 — 37,337 50,640 2,402,758 2,453,398 Other consumer 1,390 615 — 560 2,565 246,597 249,162 Commercial: Commercial non-mortgage 768 3,288 22 27,037 31,115 3,531,669 3,562,784 Asset-based — — — — — 753,215 753,215 Commercial real estate: Commercial real estate 1,624 625 — 16,767 19,016 3,673,408 3,692,424 Commercial construction — — — 3,461 3,461 295,764 299,225 Equipment financing 543 59 — 706 1,308 599,218 600,526 Total $ 23,751 $ 13,532 $ 2,051 $ 140,069 $ 179,403 $ 15,492,332 $ 15,671,735 Interest on non-accrual loans and leases that would have been recorded as additional interest income for the years ended December 31, 2016 , 2015 , and 2014 , had the loans and leases been current in accordance with their original terms, totaled $11.0 million , $8.2 million , and $9.3 million , respectively. Allowance for Loan and Lease Losses The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, the ALLL: At or for the Year ended December 31, 2016 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2016 $ 25,876 $ 42,052 $ 59,977 $ 41,598 $ 5,487 $ 174,990 Provision (benefit) charged to expense 230 18,507 28,662 7,930 1,021 56,350 Losses charged off (4,636 ) (20,669 ) (18,360 ) (2,682 ) (565 ) (46,912 ) Recoveries 1,756 5,343 1,626 631 536 9,892 Balance at December 31, 2016 $ 23,226 $ 45,233 $ 71,905 $ 47,477 $ 6,479 $ 194,320 Individually evaluated for impairment $ 8,090 $ 2,903 $ 7,422 $ 169 $ 9 $ 18,593 Collectively evaluated for impairment $ 15,136 $ 42,330 $ 64,483 $ 47,308 $ 6,470 $ 175,727 Loan and lease balances: Individually evaluated for impairment $ 119,424 $ 45,719 $ 53,037 $ 24,755 $ 6,420 $ 249,355 Collectively evaluated for impairment 4,135,258 2,638,781 4,887,894 4,486,091 629,209 16,777,233 Loans and leases $ 4,254,682 $ 2,684,500 $ 4,940,931 $ 4,510,846 $ 635,629 $ 17,026,588 At or for the Year ended December 31, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2015 $ 25,452 $ 43,518 $ 47,068 $ 37,148 $ 6,078 $ 159,264 Provision (benefit) charged to expense 6,057 11,847 21,693 11,381 (1,678 ) 49,300 Losses charged off (6,508 ) (17,679 ) (11,522 ) (7,578 ) (273 ) (43,560 ) Recoveries 875 4,366 2,738 647 1,360 9,986 Balance at December 31, 2015 $ 25,876 $ 42,052 $ 59,977 $ 41,598 $ 5,487 $ 174,990 Individually evaluated for impairment $ 10,364 $ 3,477 $ 5,197 $ 3,163 $ 3 $ 22,204 Collectively evaluated for impairment $ 15,512 $ 38,575 $ 54,780 $ 38,435 $ 5,484 $ 152,786 Loan and lease balances: Individually evaluated for impairment $ 134,448 $ 48,425 $ 56,581 $ 39,295 $ 422 $ 279,171 Collectively evaluated for impairment 3,926,553 2,654,135 4,259,418 3,952,354 600,104 15,392,564 Loans and leases $ 4,061,001 $ 2,702,560 $ 4,315,999 $ 3,991,649 $ 600,526 $ 15,671,735 At or for the Year ended December 31, 2014 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2014 $ 23,027 $ 41,951 $ 46,655 $ 36,754 $ 4,186 $ 152,573 Provision (benefit) charged to expense 7,315 17,224 9,712 2,746 253 37,250 Losses charged off (6,214 ) (20,712 ) (13,668 ) (3,237 ) (595 ) (44,426 ) Recoveries 1,324 5,055 4,369 885 2,234 13,867 Balance at December 31, 2014 $ 25,452 $ 43,518 $ 47,068 $ 37,148 $ 6,078 $ 159,264 Individually evaluated for impairment $ 12,094 $ 4,237 $ 2,710 $ 6,232 $ 28 $ 25,301 Collectively evaluated for impairment $ 13,358 $ 39,281 $ 44,358 $ 30,916 $ 6,050 $ 133,963 Loan and lease balances: Individually evaluated for impairment $ 141,982 $ 50,249 $ 36,176 $ 101,817 $ 632 $ 330,856 Collectively evaluated for impairment 3,367,193 2,499,152 3,713,094 3,452,611 537,119 13,569,169 Loans and leases $ 3,509,175 $ 2,549,401 $ 3,749,270 $ 3,554,428 $ 537,751 $ 13,900,025 Impaired Loans and Leases The following tables summarize impaired loans and leases: At December 31, 2016 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential: 1-4 family $ 131,468 $ 119,424 $ 21,068 $ 98,356 $ 8,090 Consumer: Home equity 52,432 45,719 22,746 22,973 2,903 Commercial: Commercial non-mortgage 57,732 53,037 26,006 27,031 7,422 Commercial real estate: Commercial real estate 24,146 23,568 19,591 3,977 169 Commercial construction 1,188 1,187 1,187 — — Equipment financing 6,398 6,420 6,197 223 9 Total $ 273,364 $ 249,355 $ 96,795 $ 152,560 $ 18,593 At December 31, 2015 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential: 1-4 family $ 148,144 $ 134,448 $ 23,024 $ 111,424 $ 10,364 Consumer: Home equity 56,680 48,425 25,130 23,295 3,477 Commercial: Commercial non-mortgage 67,116 56,581 31,600 24,981 5,197 Commercial real estate: Commercial real estate 36,980 33,333 9,204 24,129 3,160 Commercial construction 7,010 5,962 5,939 23 3 Equipment financing 612 422 328 94 3 Total $ 316,542 $ 279,171 $ 95,225 $ 183,946 $ 22,204 The following table summarizes the average recorded investment and interest income recognized for impaired loans and leases: Years ended December 31, 2016 2015 2014 (In thousands) Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Accrued Cash Basis Interest Income Residential $ 126,936 $ 4,377 $ 1,200 $ 138,215 $ 4,473 $ 1,139 $ 142,198 $ 4,644 $ 1,221 Consumer 47,072 1,361 985 49,337 1,451 1,099 51,171 1,484 1,203 Commercial 54,708 1,540 — 46,379 1,319 — 44,097 2,326 — Commercial real estate: Commercial real estate 28,451 511 — 64,495 1,165 — 93,209 3,429 — Commercial construction 3,574 92 — 6,062 133 — 8,381 269 — Equipment financing 3,421 184 — 527 16 — 421 28 — Total $ 264,162 $ 8,065 $ 2,185 $ 305,015 $ 8,557 $ 2,238 $ 339,477 $ 12,180 $ 2,424 Credit Quality Indicators. To measure credit risk for the commercial, commercial real estate, and equipment financing portfolios, the Company employs a dual grade credit risk grading system for estimating the probability of borrower default and the loss given default. The credit risk grade system assigns a rating to each borrower and to the facility, which together form a CCRP. The credit risk grade system categorizes borrowers by common financial characteristics that measure the credit strength of borrowers and facilities by common structural characteristics. The CCRP has 10 grades, with each grade corresponding to a progressively greater risk of default. Grades 1 through 6 are considered pass ratings, and 7 through 10 are criticized as defined by the regulatory agencies. Risk ratings, assigned to differentiate risk within the portfolio, are reviewed on an ongoing basis and revised to reflect changes in the borrowers’ current financial position and outlook, risk profile, and their related collateral and structural position. Loan officers review updated financial information on at least an annual basis for all pass rated loans to assess the accuracy of the risk grade. Criticized loans undergo more frequent reviews and enhanced monitoring. A "Special Mention" (7) credit has the potential weakness that, if left uncorrected, may result in deterioration of the repayment prospects for the asset. "Substandard" (8) assets have a well defined weakness that jeopardizes the full repayment of the debt. An asset rated "Doubtful" (9) has all of the same weaknesses as a substandard credit with the added characteristic that the weakness makes collection or liquidation in full, given current facts, conditions, and values, improbable. Assets classified as "Loss" (10) in accordance with regulatory guidelines are considered uncollectible and charged off. The following table summarizes commercial, commercial real estate and equipment financing loans and leases segregated by risk rating exposure: Commercial Commercial Real Estate Equipment Financing (In thousands) At December 31, At December 31, At December 31, At December 31, At December 31, At December 31, (1) - (6) Pass $ 4,655,007 $ 4,023,255 $ 4,357,458 $ 3,857,019 $ 618,084 $ 586,445 (7) Special Mention 56,240 70,904 69,023 55,030 1,324 1,628 (8) Substandard 226,603 220,389 84,365 79,289 16,221 12,453 (9) Doubtful 3,081 1,451 — 311 — — Total $ 4,940,931 $ 4,315,999 $ 4,510,846 $ 3,991,649 $ 635,629 $ 600,526 For residential and consumer loans, the Company considers factors such as past due status, updated FICO scores, employment status, home prices, loan to value, geography, loans discharged in bankruptcy, and the status of first lien position loans on second lien position loans as credit quality indicators. On an ongoing basis for portfolio monitoring purposes, the Company estimates the current value of property secured as collateral for both home equity and residential first mortgage lending products. The estimate is based on home price indices compiled by the S&P/Case-Shiller Home Price Indices. The Case-Shiller data indicates trends for Metropolitan Statistical Areas. The trend data is applied to the loan portfolios taking into account the age of the most recent valuation and geographic area. Troubled Debt Restructurings The following table summarizes information for TDRs: At December 31, (Dollars in thousands) 2016 2015 Accrual status $ 147,809 $ 171,784 Non-accrual status 75,719 100,906 Total recorded investment of TDR (1) $ 223,528 $ 272,690 Accruing TDR performing under modified terms more than one year 57.1 % 55.0 % Specific reserves for TDR included in the balance of ALLL $ 14,583 $ 21,405 Additional funds committed to borrowers in TDR status 459 1,133 (1) Total recorded investment of TDRs exclude $0.7 million and $1.1 million at December 31, 2016 and December 31, 2015 , respectively, of accrued interest receivable. For years ended December 31, 2016 , 2015 and 2014 , Webster charged off $18.6 million , $11.8 million , and $13.5 million , respectively, for the portion of TDRs deemed to be uncollectible. The following table provides information on the type of concession for loans and leases modified as TDRs: Years ended December 31, 2016 2015 2014 Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) (Dollars in thousands) Residential: Extended Maturity 17 $ 2,801 27 $ 4,909 27 $ 3,547 Adjusted Interest rates 2 528 3 573 3 448 Combination Rate and Maturity 13 1,537 26 5,315 22 4,220 Other (2) 24 4,090 30 4,366 55 11,791 Consumer: Extended Maturity 11 484 12 1,012 19 944 Adjusted Interest rates — — — — 1 51 Combination Rate and Maturity 15 1,156 12 945 6 411 Other (2) 52 3,131 68 3,646 90 4,931 Commercial: Extended Maturity 12 14,883 3 254 7 422 Adjusted Interest rates — — 1 24 1 25 Combination Rate and Maturity 2 648 7 5,361 22 1,212 Other (2) 13 1,767 20 22,048 6 7,431 Commercial real estate: Extended Maturity 3 4,921 1 315 — — Adjusted Interest rates 1 237 — — — — Combination Rate and Maturity 2 335 1 42 2 11,106 Other (2) 1 509 1 405 — — Equipment Financing Extended Maturity 7 6,642 — — 1 492 Total 175 $ 43,669 212 $ 49,215 262 $ 47,031 (1) Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant. (2) Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, and/or other concessions. The following table provides information on loans and leases modified as TDRs within the previous 12 months and for which there was a payment default during the periods presented: Years ended December 31, 2016 2015 2014 (Dollars in thousands) Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Residential — $ — 1 $ 55 7 $ 1,494 Consumer — — 1 3 2 24 Total — $ — 2 $ 58 9 $ 1,518 The recorded investment of TDRs in commercial, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: At December 31, (In thousands) 2016 2015 (1) - (6) Pass $ 10,210 $ 12,970 (7) Special Mention 7 2,999 (8) Substandard 45,509 72,132 (9) Doubtful 2,738 1,717 Total $ 58,464 $ 89,818

Transfers of Financial Assets

Transfers of Financial Assets	12 Months Ended
	Dec. 31, 2016
Transfers and Servicing [Abstract]
Transfers of Financial Assets	Transfers of Financial Assets Transfers of Financial Assets The Company sells financial assets in the normal course of business, primarily residential mortgage loans sold to government-sponsored enterprises through established programs and securitizations. The gain or loss on residential mortgage loans sold and the fair value adjustment to loans held for sale are included as mortgage banking activities in the accompanying Consolidated Statements of Income. The Company may be required to repurchase a loan in the event of certain breaches of the representations and warranties, or in the event of default of the borrower within 90 days of sale, as provided for in the sale agreements. A reserve for loan repurchases provides for estimated losses pertaining to the potential repurchase of loans associated with the Company's mortgage banking activities. The reserve reflects management’s evaluation of the identity of counterparty, the vintage of the loans sold, the amount of open repurchase requests, specific loss estimates for each open request, the current level of loan losses in similar vintages held in the residential loan portfolio, and estimated recoveries on the underlying collateral. The reserve also reflects management’s expectation of losses from repurchase requests for which the Company has not yet been notified, as the performance of loans sold and the quality of the servicing provided by the acquirer may also impact the reserve. The provision recorded at the time of the loan sale is netted from the gain or loss recorded in mortgage banking activities, while any incremental provision, post loan sale, is recorded in other non-interest expense in the accompanying Consolidated Statements of Income. The following table provides a summary of activity in the reserve for loan repurchases: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 1,192 $ 1,059 $ 2,254 (Benefit) provision charged to expense (303 ) 133 (493 ) Repurchased loans and settlements charged off (99 ) — (702 ) Ending balance $ 790 $ 1,192 $ 1,059 The following table provides information for mortgage banking activities: Years ended December 31, (In thousands) 2016 2015 2014 Residential mortgage loans held for sale: Proceeds from sale $ 438,925 $ 452,590 $ 287,132 Net gain on sale 11,629 7,795 4,070 Fair value option adjustment (526 ) — — Loans sold with servicing rights retained 399,318 416,277 264,292 The Company has retained servicing rights on residential mortgage loans totaling $2.6 billion and $2.5 billion at December 31, 2016 and 2015 , respectively. The following table presents the changes in carrying value for mortgage servicing assets: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 20,698 $ 19,379 $ 20,983 Additions 11,312 8,027 4,581 Amortization (7,554 ) (6,699 ) (6,318 ) Valuation recovery (provision) (1) 10 (9 ) 133 Ending balance $ 24,466 $ 20,698 $ 19,379 (1) The valuation recovery (provision) resulted in a valuation allowance balance of $22 thousand , $32 thousand , and $23 thousand at December 31, 2016, 2015, and 2014, respectively. Loan servicing fees, net of mortgage servicing rights amortization, were $1.1 million , $1.5 million , and $1.5 million , for the years ended December 31, 2016 , 2015 , and 2014 , respectively, and are included as a component of loan related fees in the accompanying Consolidated Statements of Income. See Note 16: Fair Value Measurements for additional fair value information on loans held for sale and mortgage servicing assets. Additionally, loans not originated for sale were sold for cash proceeds of $26.5 million for certain commercial loans, resulting in a gain of $2.1 million , and loans not originated for sale were sold approximately at carrying value, for cash proceeds of $7.6 million for certain residential loans, for the year ended December 31, 2016 . Loans not originated for sale were sold approximately at carrying value for cash proceeds of $729 thousand for certain commercial loans and $32.9 million for certain consumer loans, for the year ended December 31, 2015 .

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment A summary of premises and equipment follows: At December 31, (In thousands) 2016 2015 Land $ 12,595 $ 12,899 Buildings and improvements 90,778 94,686 Leasehold improvements 83,995 79,917 Fixtures and equipment 76,146 73,686 Data processing and software 220,002 195,308 Total premises and equipment 483,516 456,496 Less: Accumulated depreciation and amortization (346,103 ) (327,070 ) Premises and equipment, net $ 137,413 $ 129,426 Depreciation and amortization of premises and equipment was $30.8 million , $28.4 million , and $27.9 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. The following table provides a summary of activity for assets held for disposition: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 637 $ 759 Additions — 144 Write-downs — — Sales — (266 ) Ending balance $ 637 $ 637

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill and other intangible assets by reportable segment consisted of the following: At December 31, 2016 2015 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Community Banking, CDI $ 49,420 $ (49,420 ) $ — $ 49,420 $ (48,277 ) $ 1,143 HSA Bank: CDI 22,000 (6,162 ) 15,838 22,000 (3,269 ) 18,731 Customer relationships 21,000 (3,164 ) 17,836 21,000 (1,548 ) 19,452 Total HSA Bank 43,000 (9,326 ) 33,674 43,000 (4,817 ) 38,183 Total other intangible assets $ 92,420 $ (58,746 ) $ 33,674 $ 92,420 $ (53,094 ) $ 39,326 Goodwill: Community Banking $ 516,560 $ 516,560 $ 516,560 $ 516,560 HSA Bank 21,813 21,813 21,813 21,813 Total goodwill $ 538,373 $ 538,373 $ 538,373 $ 538,373 As of December 31, 2016 , the remaining estimated aggregate future amortization expense for intangible assets is as follows: (In thousands) 2017 $ 4,062 2018 3,847 2019 3,847 2020 3,847 2021 3,847 Thereafter 14,224

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense reflects the following expense (benefit) components: Years ended December 31, (In thousands) 2016 2015 2014 Current: Federal $ 73,194 $ 97,575 $ 90,542 State and local 5,429 10,970 6,585 Total current 78,623 108,545 97,127 Deferred: Federal 12,542 (7,279 ) (3,784 ) State and local 5,158 (8,234 ) (1,370 ) Total deferred 17,700 (15,513 ) (5,154 ) Total federal 85,736 90,296 86,758 Total state and local 10,587 2,736 5,215 Income tax expense $ 96,323 $ 93,032 $ 91,973 The Company's income tax expense reflects the benefits of an operating loss carryforward of $3.0 million in 2015 , and net tax credits of $1.0 million , $2.1 million , and $0.3 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively. The following table reflects a reconciliation of reported income tax expense to the amount that would result from applying the federal statutory rate of 35.0% : Years ended December 31, 2016 2015 2014 (Dollars in thousands) Amount Percent Amount Percent Amount Percent Income tax expense at federal statutory rate $ 106,208 35.0 % $ 104,217 35.0 % $ 102,095 35.0 % Reconciliation to reported income tax expense: State and local income taxes, net of federal benefit 6,882 2.3 7,563 2.5 3,390 1.2 Tax-exempt interest income, net (8,917 ) (2.9 ) (7,117 ) (2.4 ) (7,335 ) (2.5 ) Decrease in valuation allowance applicable to net state deferred tax assets, net of federal effects — — (5,785 ) (1.9 ) — — Increase in cash surrender value of life insurance (5,166 ) (1.7 ) (4,557 ) (1.5 ) (4,612 ) (1.6 ) Other, net (2,684 ) (1.0 ) (1,289 ) (0.5 ) (1,565 ) (0.6 ) Income tax expense and effective tax rate $ 96,323 31.7 % $ 93,032 31.2 % $ 91,973 31.5 % Refundable income taxes totaling $0.7 million and $56.6 million at December 31, 2016 and 2015 , respectively, are reflected in accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets. Early in 2016 Webster received refunds of tax with interest from the carryback of its losses during tax years 2008 and 2009. Later in the year the Internal Revenue Service completed an examination of the Company’s 2010 through 2012 tax years, and Webster received refunds of tax with interest applicable to those years. The following table reflects the significant components of the deferred tax assets, net: At December 31, (In thousands) 2016 2015 Deferred tax assets: Allowance for loan and lease losses $ 77,908 $ 70,937 Net operating loss and credit carry forwards 64,644 68,735 Compensation and employee benefit plans 46,433 52,422 Net losses on derivative instruments 8,624 11,734 Net unrealized loss on securities available for sale 9,898 4,138 Other 17,682 21,663 Gross deferred tax assets 225,189 229,629 Valuation allowance (71,474 ) (74,918 ) Total deferred tax assets, net of valuation allowance $ 153,715 $ 154,711 Deferred tax liabilities: Equipment-financing leases $ 41,910 $ 23,934 Deferred income on repurchase of debt 4,251 6,376 Intangible assets 9,952 9,298 Mortgage servicing assets 7,313 7,127 Other 5,898 6,398 Gross deferred tax liabilities 69,324 53,133 Deferred tax assets, net $ 84,391 $ 101,578 The Company's DTAs decreased by $17.2 million during 2016 , reflecting primarily the $17.7 million deferred tax expense and a $1.7 million benefit allocated directly to shareholders equity. The $71.5 million valuation allowance at December 31, 2016 consisted of $67.8 million attributable to net state deferred tax assets and $3.7 million to capital losses, deductible only to the extent of capital gains for federal tax purposes. The decrease in the valuation allowance includes: (i) a $1.7 million net decrease in the portion applicable to capital losses, including $2.1 million related to the redemption of an equity interest in 2016, characterized as capital for tax purposes; and (ii) a $1.8 million decrease applicable to changes in net state deferred tax assets, which had a full valuation allowance at both the beginning and end of the year. Management believes it is more likely than not that Webster will realize its total deferred tax asset, net of the valuation allowance. Significant positive evidence exists in support of management’s conclusion regarding the realization of Webster's DTAs, including: book-taxable income levels in recent years and projected future years; recoverable taxes paid in 2016 and 2015 ; and projected future reversals of existing taxable temporary differences. There can, however, be no assurance that any specific level of future income will be generated or that the Company’s DTAs will ultimately be realized. Capital losses approximating $12.3 million at December 31, 2016 are scheduled to expire in varying amounts during tax years 2017 and 2018. A valuation allowance has been established for the tax effect of substantially all of these losses, as noted above. State net operating losses approximating $1.2 billion at December 31, 2016 are scheduled to expire in varying amounts during tax years 2021 through 2032, and credits, totaling $1.4 million at December 31, 2016 , have a five-year carryover period, with excess credits subject to expiration annually. A valuation allowance of $56.5 million , net, has been established for those state net operating losses and credits not expected to be utilized, and is included in the valuation allowance attributable to net state deferred tax assets as noted above. A deferred tax liability of $21.4 million has not been recognized for certain thrift bad-debt reserves, established before 1988, that would become taxable upon the occurrence of certain events: distributions by Webster Bank in excess of certain earnings and profits; the redemption of Webster Bank’s stock; or a liquidation. Webster does not expect any of those events to occur. At December 31, 2016 and 2015 the cumulative taxable temporary differences applicable to those reserves approximated $58.0 million . The following table reflects a reconciliation of the beginning and ending balances for UTBs: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 5,094 $ 4,593 $ 3,109 Additions as a result of tax positions taken during the current year 613 865 956 Additions as a result of tax positions taken during prior years — 1,254 1,031 Reductions as a result of tax positions taken during prior years (625 ) (247 ) — Reductions relating to settlements with taxing authorities (693 ) (992 ) — Reductions as a result of lapse of statute of limitations (542 ) (379 ) (503 ) Ending balance $ 3,847 $ 5,094 $ 4,593 At December 31, 2016 , 2015 , and 2014 , there are $2.5 million , $3.3 million , and $3.0 million , respectively, of UTBs that, if recognized, would affect the effective tax rate. Webster recognizes interest and penalties related to UTBs, where applicable, in income tax expense. During the years ended December 31, 2016 , 2015 , and 2014 , Webster recognized interest and penalties resulting in a benefit of $0.2 million , and an expense of $1.1 million , and $0.5 million , respectively. At December 31, 2016 and 2015 , the Company had accrued interest and penalties related to UTBs of $1.7 million and $2.5 million , respectively. Webster has determined it is reasonably possible that its total UTBs could decrease by an amount in the range of $1.0 million to $2.1 million by the end of 2017, primarily as a result of potential settlements with state and local taxing authorities concerning tax-base and apportionment determinations. Webster is currently under, or subject to, examination by various taxing authorities. Federal tax returns for all years subsequent to 2012 remain open to examination. For Webster's principal state tax jurisdictions (Connecticut, Massachusetts, New York and Rhode Island) returns for years subsequent to 2012 are either under, or remain open to, examination.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2016
Banking and Thrift [Abstract]
Deposits	Deposits A summary of deposits by type follows: At December 31, (In thousands) 2016 2015 Non-interest-bearing: Demand $ 4,021,061 $ 3,713,063 Interest-bearing: Checking 2,528,274 2,369,971 Health savings accounts 4,362,503 3,802,313 Money market 2,047,121 1,933,460 Savings 4,320,090 4,047,817 Time deposits 2,024,808 2,086,154 Total interest-bearing 15,282,796 14,239,715 Total deposits $ 19,303,857 $ 17,952,778 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 848,618 $ 910,304 Time deposits, included in above balance, that meet or exceed the FDIC limit 490,721 542,206 Demand deposit overdrafts reclassified as loan balances 1,885 1,356 The scheduled maturities of time deposits are as follows: (In thousands) At December 31, 2016 2017 $ 846,160 2018 409,785 2019 482,977 2020 181,197 2021 104,578 Thereafter 111 Total time deposits $ 2,024,808

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Borrowings	Borrowings Total borrowings of $4.0 billion at December 31, 2016 and December 31, 2015 are described in detail below. The following table summarizes securities sold under agreements to repurchase and other borrowings: At December 31, (In thousands) 2016 2015 Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase: Original maturity of one year or less $ 340,526 0.16 $ 334,400 0.15 Original maturity of greater than one year, non-callable 400,000 3.09 500,000 3.04 Total securities sold under agreements to repurchase 740,526 1.82 834,400 1.93 Fed funds purchased 209,000 0.46 317,000 0.21 Securities sold under agreements to repurchase and other borrowings $ 949,526 1.53 $ 1,151,400 1.47 Repurchase agreements are used as a source of borrowed funds and are collateralized by U.S. Government agency mortgage-backed securities which are delivered to broker/dealers. Repurchase agreements counterparties are limited to primary dealers in government securities and commercial/municipal customers through Webster’s Treasury Unit. Dealer counterparties have the right to pledge, transfer, or hypothecate purchased securities during the term of the transaction. The Company has right of offset with respect to all repurchase agreement assets and liabilities. Total securities sold under agreements to repurchase represents the gross amount for these transactions, as only liabilities are outstanding for the periods presented. The following table provides information for FHLB advances: At December 31, 2016 2015 (Dollars in thousands) Total Outstanding Weighted- Average Contractual Coupon Rate Total Outstanding Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 2,130,500 0.71 % $ 2,025,934 0.55 % After 1 but within 2 years 200,000 1.36 500 5.66 After 2 but within 3 years 128,026 1.73 200,000 1.36 After 3 but within 4 years 175,000 1.77 103,026 1.54 After 4 but within 5 years 200,000 1.81 175,000 1.77 After 5 years 9,370 2.59 159,655 1.60 2,842,896 0.95 2,664,115 0.79 Premiums on advances 12 24 Federal Home Loan Bank advances $ 2,842,908 $ 2,664,139 Aggregate carrying value of assets pledged as collateral $ 5,967,318 $ 5,719,746 Remaining borrowing capacity $ 1,192,758 $ 1,203,057 Webster Bank was in compliance with FHLB collateral requirements for the periods presented. Eligible collateral, primarily certain residential and commercial real estate loans, has been pledged to secure FHLB advances. The following table summarizes long-term debt: At December 31, (Dollars in thousands) 2016 2015 4.375% Senior fixed-rate notes due February 15, 2024 $ 150,000 $ 150,000 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (1) 77,320 77,320 Total notes and subordinated debt 227,320 227,320 Discount on senior fixed-rate notes (845 ) (964 ) Debt issuance cost on senior fixed-rate notes (2) (961 ) (1,096 ) Long-term debt $ 225,514 $ 225,260 (1) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95% , was 3.94% at December 31, 2016 and 3.48% at December 31, 2015 . (2) In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Consolidated Balance Sheets.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Share activity during the year ended December 31, 2016 is as follows: Preferred Stock Series E Common Stock Issued Treasury Stock Held Common Stock Outstanding Balance at January 1, 2016 5,060 93,651,601 2,090,409 91,561,192 Restricted share activity — — (248,603 ) 248,603 Stock options exercised — — (292,304 ) 292,304 Common stock repurchased — — 350,000 (350,000 ) Balance at December 31, 2016 5,060 93,651,601 1,899,502 91,752,099 Common Stock On December 6, 2012, Webster announced that its Board of Directors had authorized a $100 million common stock repurchase program under which shares may be repurchased from time to time in the open market or in privately negotiated transactions, subject to market conditions and other factors. Common stock repurchased during 2016 was acquired at an average cost of $32.02 per common share, which results in a remaining repurchase authority for the common stock repurchase program of $15.5 million at December 31, 2016 . On June 8, 2011, the U.S. Treasury closed an underwritten public offering of 3,282,276 warrants issued in connection with the Company’s participation in the Capital Purchase Program, each representing the right to purchase one share of Webster common stock, $0.01 par value per share. The warrants have an exercise price of $18.28 , and expire on November 21, 2018. Concurrent with the U.S. Treasury's action, the Board of Directors approved the repurchase of a significant number of warrants in a public auction conducted on behalf of the U.S. Treasury. The board approved plan provides for additional repurchases from time-to-time, as permitted by securities laws and other legal requirements. During 2016 the Company purchased 10,317 warrants at an average price of $15.74 per warrant leaving 53,027 warrants outstanding and exercisable at December 31, 2016 . On June 1, 2015, Webster exercised its right, as specified in the Prospectus Supplement, for conversion of all the outstanding shares of 8.50% Series A Non-Cumulative Perpetual Convertible Preferred Stock, par value $0.01 per share, previously known as Series A Preferred Stock, for Webster common stock, issued from treasury stock held. Each share of Series A Preferred Stock received 36.8046 shares of Webster common stock, reflecting an approximate conversion price of $27.17 per share based on the initial issuance price of $1,000 per share of Series A Preferred Stock, and cash in lieu of any fractional share of common stock. Preferred Stock On December 4, 2012, Webster closed on a public offering of 5,060,000 depository shares, each representing 1/1000th ownership interest in a share of Webster's 6.40% Series E Non-Cumulative Perpetual Preferred Stock, par value $0.01 per share, with a liquidation preference of $25,000 per share (equivalent to $25 per depository share)(the "Series E Preferred Stock"). Webster will pay dividends as declared by the Board of Directors or a duly authorized committee of the Board. Dividends are payable at a rate of 6.40% per annum, quarterly in arrears, on the fifteenth day of each March, June, September, and December. Dividends on the Series E Preferred Stock are not cumulative and are not mandatory. If for any reason the Board of Directors or a duly authorized committee of the Board does not declare a dividend on the Series E Preferred Stock for any dividend period, such dividend will not accrue or be payable, and Webster will have no obligation to pay dividends for such dividend period, whether or not dividends are declared for any future dividend periods. The terms of the Series E Preferred Stock prohibit the Company from declaring or paying any cash dividends on its common stock, unless Webster has declared and paid full dividends on the Series E Preferred Stock for the most recently completed dividend period. The Company may redeem the Series E Preferred Stock, at its option in whole or in part, on December 15, 2017, or any dividend payment date thereafter, or in whole but not in part upon a "regulatory capital treatment event" as defined in the Prospectus Supplement, at a redemption price equal to the liquidation preference plus any declared and unpaid dividends, without accumulation of any undeclared dividends. The Series E Preferred Stock does not have any voting rights except with respect to authorizing or increasing the authorized amount of senior stock, certain changes to the terms of the Series E Preferred Stock, or in the case of certain dividend nonpayments.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss, Net of Tax	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Accumulated Other Comprehensive Loss, Net of Tax	Accumulated Other Comprehensive Loss, Net of Tax The following table summarizes the changes in AOCL by component: (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Balance at December 31, 2013 $ (2,617 ) $ (18,206 ) $ (27,726 ) $ (48,549 ) Other comprehensive income (loss) before reclassifications 21,811 (12,506 ) (21,329 ) (12,024 ) Amounts reclassified from accumulated other comprehensive (loss) income (2,773 ) 5,182 1,903 4,312 Net current-period other comprehensive income (loss), net of tax 19,038 (7,324 ) (19,426 ) (7,712 ) Balance at December 31, 2014 16,421 (25,530 ) (47,152 ) (56,261 ) Other comprehensive (loss) income before reclassifications (22,512 ) (3,136 ) (5,500 ) (31,148 ) Amounts reclassified from accumulated other comprehensive (loss) income (316 ) 5,686 3,933 9,303 Net current-period other comprehensive (loss) income, net of tax (22,828 ) 2,550 (1,567 ) (21,845 ) Balance at December 31, 2015 (6,407 ) (22,980 ) (48,719 ) (78,106 ) Other comprehensive (loss) income before reclassifications (8,901 ) 825 (232 ) (8,308 ) Amounts reclassified from accumulated other comprehensive (loss) income (168 ) 5,087 4,502 9,421 Net current-period other comprehensive (loss) income, net of tax (9,069 ) 5,912 4,270 1,113 Balance at December 31, 2016 $ (15,476 ) $ (17,068 ) $ (44,449 ) $ (76,993 ) The following table provides information for the items reclassified from AOCL: Years ended December 31, Accumulated Other Comprehensive Loss Components 2016 2015 2014 Associated Line Item in the Consolidated Statements Of Income (In thousands) Available-for-sale and transferred securities: Unrealized gains on investments $ 414 $ 609 $ 5,499 Gain on sale of investment securities, net Unrealized losses on investments (149 ) (110 ) (1,145 ) Impairment loss recognized in earnings Total before tax 265 499 4,354 Tax expense (97 ) (183 ) (1,581 ) Income tax expense Net of tax $ 168 $ 316 $ 2,773 Derivative instruments: Cash flow hedges $ (8,020 ) $ (8,965 ) $ (8,100 ) Total interest expense Tax benefit 2,933 3,279 2,918 Income tax expense Net of tax $ (5,087 ) $ (5,686 ) $ (5,182 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (7,126 ) $ (6,161 ) $ (2,921 ) (1) Prior service costs (14 ) (73 ) (73 ) (1) Total before tax (7,140 ) (6,234 ) (2,994 ) Tax benefit 2,638 2,301 1,091 Income tax expense Net of tax $ (4,502 ) $ (3,933 ) $ (1,903 ) (1) These accumulated other comprehensive income components are included in the computation of net periodic benefit cost (see Note 17 Retirement Benefit Plans for further details). The following tables summarize the items and related tax effects for each component of OCI/OCL, net of tax: Year ended December 31, 2016 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized loss during the period $ (14,113 ) $ 5,212 $ (8,901 ) Reclassification for net gain included in net income (414 ) 152 (262 ) Net non-credit other-than-temporary impairment 149 (55 ) 94 Amortization of unrealized loss on securities transferred to held-to-maturity — — — Total available-for-sale and transferred securities (14,378 ) 5,309 (9,069 ) Derivative instruments: Net unrealized gain during the period 1,331 (506 ) 825 Reclassification adjustment for net loss included in net income 8,020 (2,933 ) 5,087 Total derivative instruments 9,351 (3,439 ) 5,912 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (368 ) 136 (232 ) Reclassification adjustment for amortization of net loss included in net income 7,126 (2,633 ) 4,493 Reclassification adjustment for prior service cost included in net income 14 (5 ) 9 Total defined benefit pension and postretirement benefit plans 6,772 (2,502 ) 4,270 Other comprehensive income, net of tax $ 1,745 $ (632 ) $ 1,113 Year ended December 31, 2015 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized loss during the period $ (35,701 ) $ 13,166 $ (22,535 ) Reclassification for net gain included in net income (609 ) 223 (386 ) Net non-credit other-than-temporary impairment 110 (40 ) 70 Amortization of unrealized loss on securities transferred to held-to-maturity 37 (14 ) 23 Total available-for-sale and transferred securities (36,163 ) 13,335 (22,828 ) Derivative instruments: Net unrealized loss during the period (4,945 ) 1,809 (3,136 ) Reclassification adjustment for net loss included in net income 8,965 (3,279 ) 5,686 Total derivative instruments 4,020 (1,470 ) 2,550 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (8,719 ) 3,219 (5,500 ) Reclassification adjustment for amortization of net loss included in net income 6,161 (2,274 ) 3,887 Reclassification adjustment for prior service cost included in net income 73 (27 ) 46 Total defined benefit pension and postretirement benefit plans (2,485 ) 918 (1,567 ) Other comprehensive loss, net of tax $ (34,628 ) $ 12,783 $ (21,845 ) Year ended December 31, 2014 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized gain during the period $ 34,242 $ (12,469 ) $ 21,773 Reclassification for net gain included in net income (5,499 ) 1,999 (3,500 ) Net non-credit other-than-temporary impairment 1,145 (418 ) 727 Amortization of unrealized loss on securities transferred to held-to-maturity 60 (22 ) 38 Total available-for-sale and transferred securities 29,948 (10,910 ) 19,038 Derivative instruments: Net unrealized loss during the period (19,589 ) 7,083 (12,506 ) Reclassification adjustment for net loss included in net income 8,100 (2,918 ) 5,182 Total derivative instruments (11,489 ) 4,165 (7,324 ) Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (33,567 ) 12,238 (21,329 ) Reclassification adjustment for amortization of net loss included in net income 2,921 (1,065 ) 1,856 Reclassification adjustment for prior service cost included in net income 73 (26 ) 47 Total defined benefit pension and postretirement benefit plans (30,573 ) 11,147 (19,426 ) Other comprehensive loss, net of tax $ (12,114 ) $ 4,402 $ (7,712 )

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2016
Regulatory Capital Requirements [Abstract]
Regulatory Matters	Regulatory Matters Capital Requirements Webster Financial Corporation is subject to regulatory capital requirements administered by the Federal Reserve System, while Webster Bank is subject to regulatory capital requirements administered by the OCC. Regulatory authorities can initiate certain mandatory actions if Webster Financial Corporation or Webster Bank fail to meet minimum capital requirements, which could have a direct material effect on the Company's financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, both Webster Financial Corporation and Webster Bank must meet specific capital guidelines that involve quantitative measures of assets, liabilities, and certain off-balance sheet items calculated under regulatory accounting practices. These quantitative measures require minimum amounts and ratios to ensure capital adequacy. Under Basel III, total risk-based capital is comprised of three categories: CET1 capital, additional Tier 1 capital, and Tier 2 capital. CET1 capital includes common shareholders' equity, less deductions for goodwill and other intangibles adjusted for certain deferred tax liabilities. Webster's common shareholders' equity, for purposes of CET1 capital, excludes AOCL components as permitted by the opt-out election taken by Webster upon adoption of Basel III. Tier 1 capital is comprised of CET1 capital plus perpetual preferred stock, while Tier 2 capital includes qualifying subordinated debt and qualifying allowance for credit losses, that together equal total capital. The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: Actual Capital Requirements Minimum Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio At December 31, 2016 Webster Financial Corporation CET1 risk-based capital $ 1,932,171 10.5 % $ 826,504 4.5 % $ 1,193,840 6.5 % Total risk-based capital 2,328,808 12.7 1,469,341 8.0 1,836,677 10.0 Tier 1 risk-based capital 2,054,881 11.2 1,102,006 6.0 1,469,341 8.0 Tier 1 leverage capital 2,054,881 8.1 1,010,857 4.0 1,263,571 5.0 Webster Bank CET1 risk-based capital $ 1,945,332 10.6 % $ 825,228 4.5 % $ 1,191,995 6.5 % Total risk-based capital 2,141,939 11.7 1,467,071 8.0 1,833,839 10.0 Tier 1 risk-based capital 1,945,332 10.6 1,100,304 6.0 1,467,071 8.0 Tier 1 leverage capital 1,945,332 7.7 1,010,005 4.0 1,262,507 5.0 At December 31, 2015 Webster Financial Corporation CET1 risk-based capital $ 1,824,106 10.7 % $ 766,848 4.5 % $ 1,107,670 6.5 % Total risk-based capital 2,201,245 12.9 1,363,286 8.0 1,704,107 10.0 Tier 1 risk-based capital 1,966,146 11.5 1,022,464 6.0 1,363,286 8.0 Tier 1 leverage capital 1,966,146 8.2 954,369 4.0 1,192,962 5.0 Webster Bank CET1 risk-based capital $ 1,869,241 11.0 % $ 765,152 4.5 % $ 1,105,220 6.5 % Total risk-based capital 2,046,350 12.0 1,360,271 8.0 1,700,338 10.0 Tier 1 risk-based capital 1,869,241 11.0 1,020,203 6.0 1,360,271 8.0 Tier 1 leverage capital 1,869,241 7.8 953,300 4.0 1,191,626 5.0 Dividend Restrictions Webster Financial Corporation is dependent upon dividends from Webster Bank to provide funds for its cash requirements, including payments of dividends to shareholders. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of Webster Bank to fall below specified minimum levels, or if dividends declared exceed the net income for that year combined with the undistributed net income for the preceding two years. In addition, the OCC has discretion to prohibit any otherwise permitted capital distribution on general safety and soundness grounds. Dividends paid by Webster Bank to Webster Financial Corporation totaled $145 million and $110 million during the years ended December 31, 2016 and 2015 , respectively. Cash Restrictions Webster Bank is required by Federal Reserve System regulations to hold cash reserve balances, on hand or with Federal Reserve Banks. Pursuant to this requirement, the Bank held $58.6 million and $109.4 million at December 31, 2016 and 2015 , respectively.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Common Share	Earnings Per Common Share Reconciliation of the calculation of basic and diluted earnings per common share follows: Years ended December 31, (In thousands, except per share data) 2016 2015 2014 Earnings for basic and diluted earnings per common share: Net income $ 207,127 $ 204,729 $ 199,726 Less: Preferred stock dividends 8,096 8,711 10,556 Net income available to common shareholders 199,031 196,018 189,170 Less: Earnings applicable to participating securities 608 657 674 Earnings applicable to common shareholders $ 198,423 $ 195,361 $ 188,496 Shares: Weighted-average common shares outstanding - basic 91,367 90,968 89,899 Effect of dilutive securities: Stock options and restricted stock 461 524 466 Warrants 28 41 255 Weighted-average common shares outstanding - diluted 91,856 91,533 90,620 Earnings per common share: Basic $ 2.17 $ 2.15 $ 2.10 Diluted 2.16 2.13 2.08 Potential common shares excluded from the effect of dilutive securities because they would have been anti-dilutive, are as follows: Years ended December 31, (In thousands) 2016 2015 2014 Stock options (shares with exercise price greater than market price) 41 213 587 Restricted stock (due to performance conditions on non-participating shares) 125 92 171 Basic weighted-average common shares outstanding includes the effect of conversion of the Series A Preferred Stock which occurred on June 1, 2015. Prior to that, the Series A Preferred Stock was considered to be anti-dilutive. Refer to Note 11: Shareholders' Equity and Note 18: Share-Based Plans for further information relating to potential common shares excluded from the effect of dilutive securities.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments Risk Management Objective of Using Derivatives Webster manages economic risks, including interest rate, liquidity, and credit risk by managing the amount, sources, and duration of its debt funding along with the use of interest rate derivative financial instruments. Webster enters into interest rate derivative financial instruments to manage exposure related to business activities that result in the receipt or payment of both future known and uncertain cash amounts determined by interest rates. Webster’s primary objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish these objectives, Webster uses interest rate swaps and interest rate caps as part of its interest rate risk management strategy. Interest rate swaps and caps designated as cash flow hedges are designed to manage the risk associated with a forecasted event or an uncertain variable-rate cash flow. Forward-settle interest rate swaps protect the Company against adverse fluctuations in interest rates by reducing its exposure to variability in cash flows relating to interest payments on forecasted debt issuances. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. Interest rate caps designated as cash flow hedges involve the receipt of variable amounts from a counterparty if interest rates rise above the strike rate on the contract in exchange for payment of an up-front premium. Derivative instruments designated as cash flow hedges are recorded on the balance sheet at fair value. The effective portion of the change in the fair value of derivatives which are designated as cash flow hedges, and that qualify for hedge accounting, is recorded to AOCL and is reclassified into earnings in the subsequent periods that the hedged forecasted transaction affects earnings. During the periods presented, such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt and forecasted issuances of debt. The ineffective portion of the change in the fair value of the derivatives is recognized directly in earnings. For the twelve months ended December 31, 2016 and 2015 , the Company recorded no ineffectiveness in earnings attributable to the difference in the effective date of the hedge and the effective date of the debt issuance. Webster is also exposed to changes in the fair value of certain of its fixed-rate obligations due to changes in benchmark interest rates. Webster, on occasion, uses interest rate swaps to manage its exposure to changes in fair value on these obligations attributable to changes in the benchmark interest rates. Interest rate swaps designated as fair value hedges involve the receipt of fixed-rate amounts from a counterparty in exchange for Webster making variable-rate payments over the life of the agreements without the exchange of the underlying notional amount. For a qualifying derivative designated as a fair value hedge, the gain or loss on the derivative, as well as the gain or loss on the hedged item, is recognized in interest expense. Webster did not have interest rate derivative financial instruments designated as fair value hedges at December 31, 2016 and December 31, 2015 . As a result, there was no impact to interest expense during the periods presented. Additionally, in order to address certain other risk management matters, the Company utilizes the following derivative instruments that do not qualify for hedge accounting. These derivative instruments are recorded on the balance sheet at fair value, with changes in fair value recognized each period as other non-interest income in the accompanying Consolidated Statements of Income. Interest rate swap and cap contracts are sold to commercial and other customers who wish to modify loan interest rate sensitivity. These contracts are offset with dealer counterparty transactions structured with matching terms. As a result, there is minimal impact on earnings, except for fee income earned in such transactions. RPAs are entered into as financial guarantees of performance on interest rate swap derivatives. The purchased (asset) or sold (liability) guarantee allows the Company to participate-in (for a fee received) or participate-out (for a fee paid) the risk associated with certain derivative positions executed with the borrower by a lead bank. Other derivatives include foreign currency forward contracts related to lending arrangements, a VISA equity swap transaction, and mortgage banking derivatives such as mortgage-backed securities related to residential loan commitments and loans held for sale. Mortgage banking derivatives are utilized by Webster in its efforts to manage risk of loss associated with its mortgage loan commitments and mortgage loans held for sale. Prior to closing and funding certain single-family residential mortgage loans interest rate lock commitments are generally extended to the borrowers. During the period from commitment date to closing date, Webster is subject to the risk that market rates of interest may change. If market rates rise, investors generally will pay less to purchase such loans causing a reduction in the anticipated gain on sale of the loans and possibly resulting in a loss. In an effort to mitigate such risk, forward delivery sales commitments are established under which Webster agrees to deliver whole mortgage loans to various investors or issue mortgage-backed securities. Mandatory forward commitments establish the price to be received upon the sale of the related mortgage loan, thereby mitigating certain interest rate risk. There is, however, still certain execution risk specifically related to Webster’s ability to close and deliver to its investors the mortgage loans it has committed to sell. Fair Value of Derivative Instruments The following table presents the notional amounts and fair values of derivative positions: At December 31, 2016 At December 31, 2015 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives $ 225,000 $ 3,270 $ 100,000 $ 792 $ 200,000 $ 2,507 $ 100,000 $ 1,359 Not designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives 1,943,485 32,226 1,242,937 24,388 989,695 2,255 1,543,479 40,302 Other 10,634 231 14,265 120 8,237 183 4,561 66 Positions not subject to a master netting agreement (2) Interest rate derivatives 1,734,679 38,668 1,451,762 19,001 2,050,460 58,304 482,738 571 RPAs 86,037 139 87,273 166 41,798 153 92,985 245 Mortgage banking derivatives (3) 103,440 3,084 59,895 711 62,514 819 — — Other 1,438 19 181 11 — — 60 9 Total not designated as hedging instruments 3,879,713 74,367 2,856,313 44,397 3,152,704 61,714 2,123,823 41,193 Gross derivative instruments, before netting $ 4,104,713 77,637 $ 2,956,313 45,189 $ 3,352,704 64,221 $ 2,223,823 42,552 Less: Legally enforceable master netting agreements 24,253 24,253 4,945 4,945 Less: Cash collateral posted 11,475 600 — 31,330 Total derivative instruments, after netting $ 41,909 $ 20,336 $ 59,276 $ 6,277 (1) The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information. (2) Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Consolidated Balance Sheets. (3) Notional amounts include mandatory forward commitments of $99.0 million , while notional amounts do not include approved floating rate commitments of $27.8 million , at December 31, 2016 . Changes in Fair Value Changes in the fair value of derivatives not qualifying for hedge accounting treatment are reported as a component of other non-interest income in the accompanying Consolidated Statements of Income as follows: Years ended December 31, (In thousands) 2016 2015 2014 Interest rate derivatives $ 8,668 $ 4,361 $ 4,482 RPA (361 ) (33 ) 51 Mortgage banking derivatives 1,553 801 (522 ) Other (67 ) (63 ) (253 ) Total impact on other non-interest income $ 9,793 $ 5,066 $ 3,758 Amounts for the effective portion of changes in the fair value of derivatives are reclassified to interest expense as interest payments are made on Webster's variable-rate debt. Over the next twelve months, the Company estimates that $1.7 million will be reclassified from AOCL as an increase to interest expense. Webster records gains and losses related to swap terminations as OCI. These balances are subsequently amortized into interest expense over the respective terms of the hedged debt instruments. At December 31, 2016 , the remaining unamortized loss on the termination of cash flow hedges is $21.3 million . Over the next twelve months, the Company estimates that $6.4 million will be reclassified from AOCL as an increase to interest expense. Additional information about cash flow hedge activity impacting AOCL, and the related amounts reclassified to interest expense is provided in Note 12: Accumulated Other Comprehensive Loss, Net of Tax . Information about the valuation methods used to measure fair value is provided in Note 16: Fair Value Measurements . Offsetting Derivatives Webster has entered into transactions with counterparties that are subject to a legally enforceable master netting agreement. Derivatives subject to a legally enforceable master netting agreement are reported on a net basis, net of cash collateral. Net positions are recorded in other assets for a net gain position and in other liabilities for a net loss position in the accompanying Consolidated Balance Sheets. The following table is presented on a gross basis, prior to the application of counterparty netting agreements. Derivative assets and liabilities are shown net of cash collateral: At December 31, 2016 At December 31, 2015 (In thousands) Gross Amount Amount Offset Net Amount (1) (2) Gross Amount Amount Offset Net Amount (1) (2) Derivative instrument assets Hedged Accounting Positions $ 3,270 $ (3,270 ) $ — $ 2,507 $ (2,507 ) $ — Non-Hedged Accounting Positions 32,457 (32,457 ) — 2,438 (2,438 ) — Total $ 35,727 $ (35,727 ) $ — $ 4,945 $ (4,945 ) $ — Derivative instrument liabilities Hedged Accounting Positions $ 792 $ (792 ) $ — $ 1,359 $ (1,359 ) $ — Non-Hedged Accounting Positions 24,508 (24,062 ) 446 40,368 (34,916 ) 5,452 Total $ 25,300 $ (24,854 ) $ 446 $ 41,727 $ (36,275 ) $ 5,452 (1) Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015 , respectively, as presented in the accompanying Consolidated Balance Sheets. (2) Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015 , respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets Counterparty Credit Risk Use of derivative contracts may expose the bank to counterparty credit risk. The Company has ISDA master agreements, including a Credit Support Annex, with all derivative counterparties. The ISDA master agreements provide that on each payment date, all amounts otherwise owing the same currency under the same transaction are netted so that only a single amount is owed in that currency. The ISDA provides, if the parties so elect, for such netting of amounts in the same currency among all transactions identified as being subject to such election that have common payment dates and booking offices. Under the Credit Support Annex, daily net exposure in excess of a negotiated threshold is secured by posted cash collateral. The Company has negotiated a zero threshold with the majority of its approved financial institution counterparties. In accordance with Webster policies, institutional counterparties must be analyzed and approved through the Company’s credit approval process. The Company’s credit exposure on interest rate derivatives with non-dealer counterparties is limited to the net favorable value, including accrued interest, of all such instruments, reduced by the amount of collateral pledged by the counterparties. The Company's credit exposure related to derivatives with dealer counterparties is significantly mitigated with cash collateral equal to, or in excess of, the market value of the instrument updated daily. In accordance with counterparty credit agreements and derivative clearing rules, the Company had approximately $23.8 million in net margin collateral posted with financial counterparties at December 31, 2016 , comprised of $42.5 million in initial margin and $18.7 million in variation margin collateral received from financial counterparties or the derivative clearing organization. Collateral levels for approved financial institution counterparties are monitored daily and adjusted as necessary. In the event of default, should the collateral not be returned, the exposure would be offset by terminating the transaction. The Company regularly evaluates the credit risk of its counterparties, taking into account the likelihood of default, net exposures, and remaining contractual life, among other related factors. The Company's net current credit exposure relating to interest rate derivatives with Webster Bank customers was $38.7 million at December 31, 2016 . In addition, the Company monitors potential future exposure, representing its best estimate of exposure to remaining contractual maturity. The potential future exposure relating to interest rate derivatives with Webster Bank customers totaled $26.4 million at December 31, 2016 . The credit exposures are mitigated as transactions with customers are generally secured by the same collateral of the underlying transactions being hedged.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is best determined using quoted market prices. However, in many instances, quoted market prices are not available. In such instances, fair values are determined using appropriate valuation techniques. Various assumptions and observable inputs must be relied upon in applying these techniques. Accordingly, categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. As such, the fair value estimates may not be realized in an immediate transfer of the respective asset or liability. Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These estimates do not reflect any premium or discount that could result from offering for sale at one time the entire holdings or any part of a particular financial instrument. Fair value estimates are based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These factors are subjective in nature and involve uncertainties and matters of significant judgment and therefore, cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair Value Hierarchy The three levels within the fair value hierarchy are as follows: • Level 1: Valuation is based upon unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. • Level 2: Fair value is calculated using significant inputs other than quoted market prices that are directly or indirectly observable for the asset or liability. The valuation may rely on quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit ratings, etc.), or inputs that are derived principally or corroborated by market data, by correlation, or other means. • Level 3: Inputs for determining the fair value of the respective assets or liabilities are not observable. Level 3 valuations are reliant upon pricing models and techniques that require significant management judgment or estimation. Assets and Liabilities Measured at Fair Value on a Recurring Basis Available-for-Sale Investment Securities. When quoted prices are available in an active market, the Company classifies securities within Level 1 of the valuation hierarchy. Equity securities in financial services and U.S. Treasury Bills are classified within Level 1 of the fair value hierarchy. When quoted market prices are not available, the Company engages an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's assumptions and establishes processes to challenge the pricing service's valuations that appear unusual or out of tolerance with expected results. Available-for-Sale investment securities which include Agency CMO, Agency MBS, Agency CMBS, CMBS, CLO, single-issuer trust preferred securities, and corporate debt securities, are classified within Level 2 of the fair value hierarchy. Derivative Instruments. Foreign exchange contracts are valued based on unadjusted quoted prices in active markets and classified within Level 1 of the fair value hierarchy. Derivative instruments are valued using third-party valuation software, which considers the present value of cash flows discounted using observable forward rate assumptions. The resulting fair values are validated against valuations performed by independent third parties and are classified within Level 2 of the fair value hierarchy. In determining if any fair value adjustment related to credit risk is required, Webster evaluates the credit risk of its counterparties by considering factors such as the likelihood of default by the counterparties, its net exposures, the remaining contractual life, as well as the amount of collateral securing the position. Webster reviews its counterparty exposure on a regular basis, and, when necessary, appropriate business actions are taken to adjust the exposure. When determining fair value, Webster applies the portfolio exception with respect to measuring counterparty credit risk for all of its derivative transactions subject to a master netting arrangement. The change in value of derivative assets and liabilities attributable to credit risk was not significant during the reported periods. Mortgage Banking Derivatives. Forward sales of mortgage loans and mortgage-backed securities are utilized by the Company in its efforts to manage risk of loss associated with its mortgage loan commitments and mortgage loans held for sale. Prior to closing and funding certain single-family residential mortgage loans, an interest rate lock commitment is generally extended to the borrower. During the period from commitment date to closing date, the Company is subject to the risk that market rates of interest may change. If market rates rise, investors generally will pay less to purchase such loans resulting in a reduction in the gain on sale of the loans or, possibly, a loss. In an effort to mitigate such risk, forward delivery sales commitments are established, under which the Company agrees to deliver whole mortgage loans to various investors or issue mortgage-backed securities. The fair value of mortgage banking derivatives is determined based on current market prices for similar assets in the secondary market and, therefore, classified within Level 2 of the fair value hierarchy. Investments Held in Rabbi Trust. Investments held in the Rabbi Trust primarily include mutual funds that invest in equity and fixed income securities. Shares of mutual funds are valued based on net asset value, which represents quoted market prices for the underlying shares held in the mutual funds. Therefore, investments held in the Rabbi Trust are classified within Level 1 of the fair value hierarchy. Webster has elected to measure the investments held in the Rabbi Trust at fair value. The Company consolidates the invested assets of the trust in other assets within the accompanying Consolidated Balance Sheets. Earnings in the Rabbi Trust, including appreciation or depreciation, are reflected as other non-interest income within the accompanying Consolidated Statements of Income. The cost basis of the investments held in the Rabbi Trust is $3.3 million as of December 31, 2016 . Alternative Investments. The Company generally records alternative investments at cost, subject to impairment testing. The alternative investments that are carried at cost are considered to be measured at fair value on a non-recurring basis when there is impairment. There are certain funds in which the ownership percentage is greater than 3% and are, therefore, recorded at fair value on a recurring basis based upon the net asset value of the respective fund. Alternative investments are non-public entities that cannot be redeemed since the Company’s investment is distributed as the underlying investments are liquidated. As such, these investments are classified within Level 3 of the fair value hierarchy. The Company has $7.7 million in unfunded commitments remaining for its alternative investments as of December 31, 2016 . See the Investment Securities Portfolio section of Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations for additional discussion of the Company's alternative investments. Originated Loans Held For Sale. Residential mortgage loans typically are classified as held for sale upon origination based on management's intent to sell such loans. The Company generally records residential mortgage loans held for sale under the fair value option of ASC Topic 825 "Financial Instruments." The fair value of residential mortgage loans held for sale is based on quoted market prices of similar loans sold in conjunction with securitization transactions. Accordingly, such loans are classified within Level 2 of the fair value hierarchy. Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At December 31, 2016 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 734 $ — $ — $ 734 Agency CMO — 419,706 — 419,706 Agency MBS — 954,349 — 954,349 Agency CMBS — 573,272 — 573,272 CMBS — 477,365 — 477,365 CLO — 427,390 — 427,390 Single issuer trust preferred securities — 28,633 — 28,633 Corporate debt securities — 109,642 — 109,642 Equities - financial services — — — — Total available-for-sale investment securities 734 2,990,357 — 2,991,091 Gross derivative instruments, before netting (1) 250 77,387 — 77,637 Investments held in Rabbi Trust 5,119 — — 5,119 Alternative investments — — 5,502 5,502 Originated loans held for sale (2) — 60,260 — 60,260 Contingent consideration — — — — Total financial assets held at fair value $ 6,103 $ 3,128,004 $ 5,502 $ 3,139,609 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 120 $ 45,069 $ — $ 45,189 Contingent liability — — — — Total financial liabilities held at fair value $ 120 $ 45,069 $ — $ 45,189 At December 31, 2015 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 924 $ — $ — $ 924 Agency CMO — 548,754 — 548,754 Agency MBS — 1,065,109 — 1,065,109 Agency CMBS — 215,350 — 215,350 CMBS — 579,266 — 579,266 CLO — 429,159 — 429,159 Single issuer trust preferred securities — 37,170 — 37,170 Corporate debt securities — 106,321 — 106,321 Equities - financial services 2,578 — — 2,578 Total available-for-sale investment securities 3,502 2,981,129 — 2,984,631 Gross derivative instruments, before netting (1) 183 64,038 — 64,221 Investments held in Rabbi Trust 5,372 — — 5,372 Alternative investments — — 3,471 3,471 Originated loans held for sale — — — — Contingent Consideration — — 5,331 5,331 Total financial assets held at fair value $ 9,057 $ 3,045,167 $ 8,802 $ 3,063,026 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 66 $ 42,486 $ — $ 42,552 Contingent liability — — 6,000 6,000 Total financial liabilities held at fair value $ 66 $ 42,486 $ 6,000 $ 48,552 (1) For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 15: Derivative Financial Instruments . (2) Loans held for sale accounted for under the fair value option of ASC Topic 825 "Financial Instruments" at December 31, 2016 . The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies . The following table presents the changes in Level 3 assets and liabilities that are measured at fair value on a recurring basis: Financial Assets (In thousands) Alternative Investments Contingent Consideration Total Contingent Liability Balance at January 1, 2016 $ 3,471 $ 5,331 $ 8,802 $ 6,000 Gain included in net income 349 2,690 3,039 — Purchases/capital funding 1,682 — 1,682 — Receipts — (8,021 ) (8,021 ) — Payments — — — (6,000 ) Balance at December 31, 2016 $ 5,502 $ — $ 5,502 $ — Contingent Consideration. As part of the health savings accounts acquisition, the contingent consideration arrangement entitled the Company to receive a rebate of the purchase price relating to the premium paid, for account attrition during the eighteen-month period beginning on the acquisition date of January 13, 2015. In periods subsequent to the initial valuation the fair value was adjusted for measurable attrition milestones. The contingent consideration was classified within Level 3 of the fair value hierarchy as the valuation is based on a contractual obligation that is reliant upon calculation inputs, and as such could be subject to miscalculation. On November 30, 2016, the funds were received to settle the contingent consideration arrangement. Contingent Liability. As part of the health savings accounts acquisition, the contingent liability arrangement provided for the Company to assume a pre-existing liability as part of the transaction. The fair value of the contingency represented the estimated price to transfer the liability between market participants at the measurement date under current market conditions. The contingent liability was classified within Level 3 of the fair value hierarchy as its valuation was based upon unobservable inputs. On August 18, 2016, the funds were paid to settle the contingent liability arrangement. Assets Measured at Fair Value on a Non-Recurring Basis Certain assets are measured at fair value on a non-recurring basis; that is, the assets are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances, for example, when there is evidence of impairment. The following is a description of valuation methodologies used for assets measured on a non-recurring basis. Transferred Loans Held For Sale. Certain loans are transferred to loans held for sale once a decision has been made to sell such loans. These loans are accounted for at the lower of cost or market and are considered to be recognized at fair value when they are recorded at below cost. This activity is primarily commercial loans with observable inputs and are classified within Level 2. On the occasion should these loans include adjustments for changes in loan characteristics using unobservable inputs, the loans would be classified within Level 3. Collateral Dependent Impaired Loans and Leases. Impaired loans and leases for which repayment is expected to be provided solely by the value of the underlying collateral are considered collateral dependent and are valued based on the estimated fair value of such collateral using customized discounting criteria. As such, collateral dependent impaired loans and leases are classified as Level 3 of the fair value hierarchy. Other Real Estate Owned and Repossessed Assets. The total book value of OREO and repossessed assets was $3.9 million at December 31, 2016 . OREO and repossessed assets are accounted for at the lower of cost or market and are considered to be recognized at fair value when they are recorded at below cost. The fair value of OREO is based on independent appraisals or internal valuation methods, less estimated selling costs. The valuation may consider available pricing guides, auction results, and price opinions. Certain assets require assumptions about factors that are not observable in an active market in the determination of fair value, as such, OREO and repossessed assets are classified within Level 3 of the fair value hierarchy. Mortgage Servicing Assets. Mortgage servicing assets are accounted for at cost, subject to impairment testing. When the carrying cost exceeds fair value, a valuation allowance is established to reduce the carrying cost to fair value with any change included as a component of other non-interest income in the accompanying Consolidated Statements of Income. Fair value is calculated as the present value of estimated future net servicing income and relies on market based assumptions for loan prepayment speeds, servicing costs, discount rates, and other economic factors; as such, the primary risk inherent in valuing mortgage servicing assets is the impact of fluctuating interest rates on the servicing revenue stream. Mortgage servicing assets are classified within Level 3 of the fair value hierarchy. The following table presents the changes in fair value for mortgage servicing assets: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 33,568 $ 28,690 Originations of servicing assets 11,312 8,027 Changes in fair value: Due to payoffs/paydowns (2,447 ) (2,741 ) Due to market changes 9,642 (408 ) Ending balance $ 52,075 $ 33,568 The table below presents the valuation methodology and unobservable inputs for Level 3 assets measured at fair value on a non-recurring basis as of December 31, 2016 : (Dollars in thousands) Asset Fair Value Valuation Methodology Unobservable Inputs Range of Inputs Collateral dependent impaired loans and leases $ 7,374 Real Estate Appraisals Discount for appraisal type 0% - 15 % Discount for costs to sell 8% OREO $ 166 Real Estate Appraisals Discount for appraisal type 0% Discount for costs to sell 8% Mortgage servicing assets $ 52,075 Discounted cash flow Constant prepayment rate 2.8% - 27.7 % Discount rates 1.9% - 3.6 % Fair Value of Financial Instruments The Company is required to disclose the estimated fair value of financial instruments, both assets and liabilities, for which it is practicable to estimate fair value. The following is a description of valuation methodologies used for those assets and liabilities. Cash, Due from Banks, and Interest-bearing Deposits. The carrying amount of cash, due from banks, and interest-bearing deposits is used to approximate fair value, given the short time frame to maturity and, as such, these assets do not present unanticipated credit concerns. Cash, due from banks, and interest-bearing deposits are classified within Level 1 of the fair value hierarchy. Held-to-Maturity Investment Securities. When quoted market prices are not available, the Company employs an independent pricing service that utilizes matrix pricing to calculate fair value. Such fair value measurements consider observable data such as dealer quotes, market spreads, cash flows, yield curves, live trading levels, trade execution data, market consensus prepayments speeds, credit information, and respective terms and conditions for debt instruments. Management maintains procedures to monitor the pricing service's assumptions and establishes processes to challenge the pricing service's valuations that appear unusual or unexpected. Held-to-Maturity investment securities, which include Agency CMO, Agency MBS, Agency CMBS, CMBS, municipal bonds and notes, and private label MBS securities, are classified within Level 2 of the fair value hierarchy. Loans and Leases, net. The estimated fair value of loans and leases held for investment is calculated using a discounted cash flow method, using future prepayments and market interest rates inclusive of an illiquidity premium for comparable loans and leases. The associated cash flows are adjusted for credit and other potential losses. Fair value for impaired loans and leases is estimated using the net present value of the expected cash flows. Loans and leases are classified within Level 3 of the fair value hierarchy. Deposit Liabilities. The fair value of demand deposits, savings accounts, and certain money market deposits is the amount payable on demand at the reporting date. The fair value of fixed-maturity certificates of deposit is estimated using the rates currently offered for deposits of similar remaining maturities. Deposit liabilities are classified within Level 2 of the fair value hierarchy. Securities Sold Under Agreements to Repurchase and Other Borrowings. The carrying value is an estimate of fair value for those securities sold under agreements to repurchase and other borrowings that mature within 90 days. The fair values of all other borrowings are estimated using discounted cash flow analysis based on current market rates adjusted, as appropriate, for associated credit risks. Securities sold under agreements to repurchase and other borrowings are classified within Level 2 of the fair value hierarchy. Federal Home Loan Bank Advances and Long-Term Debt. The fair value of FHLB advances and long-term debt is estimated using a discounted cash flow technique. Discount rates are matched with the time period of the expected cash flow and are adjusted, as appropriate, to reflect credit risk. FHLB advances and long-term debt are classified within Level 2 of the fair value hierarchy. The estimated fair values of selected financial instruments and servicing assets are as follows: At December 31, 2016 2015 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Financial Assets: Level 2 Held-to-maturity investment securities $ 4,160,658 $ 4,125,125 $ 3,923,052 $ 3,961,534 Loans held for sale (1) 7,317 7,444 37,091 37,457 Level 3 Loans and leases, net 16,832,268 16,678,106 15,496,745 15,453,892 Mortgage servicing assets 24,466 52,075 20,698 33,568 Alternative investments 11,034 13,189 12,900 14,294 Financial Liabilities: Level 2 Deposit liabilities, other than time deposits $ 17,279,049 $ 17,279,049 $ 15,866,624 $ 15,866,624 Time deposits 2,024,808 2,024,395 2,086,154 2,095,357 Securities sold under agreements to repurchase and other borrowings 949,526 955,660 1,151,400 1,163,974 FHLB advances (2) 2,842,908 2,825,101 2,664,139 2,647,872 Long-term debt (2) 225,514 225,514 225,260 218,143 (1) Loans held for sale that are accounted for at the lower of cost or market. At December 31, 2016 , the amounts include transferred residential and commercial loans not originated for sale, and at December 31, 2015 , the amounts include transferred commercial loans not originated for sale and residential loans originated for sale prior to the adoption of the fair value option of ASC Topic 825 "Financial Instruments." (2) The following adjustments to the carrying amount are not included for determination of fair value, see Note 10: Borrowings : • FHLB advances - unamortized premiums on advances • Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes

Retirement Benefit Plans

Retirement Benefit Plans	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Retirement Benefit Plans	Retirement Benefit Plans Defined benefit pension and other postretirement benefits Webster Bank offered a defined benefit noncontributory pension plan through December 31, 2007 for eligible employees who met certain minimum service and age requirements. Pension plan benefits are based upon employee earnings during the period of credited service. A SERP was also offered to certain employees who were at the Executive Vice President level or above through December 31, 2007. The SERP provides eligible participants with additional pension benefits. Webster Bank also provides other postretirement healthcare benefits to certain retired employees. The Webster Bank Pension Plan and the SERP were frozen as of December 31, 2007. No additional benefits have been accrued since that time. Employees hired on or after January 1, 2007 receive no qualified or supplemental retirement income under the plans. All other employees accrue no additional qualified or supplemental retirement income after January 1, 2008, and the amount of their qualified and supplemental retirement income will not exceed the amount of benefits determined as of December 31, 2007. During 2016 , the Company made a discretionary $20.0 million contribution to the Webster Bank Pension Plan. Additional contributions to the Webster Bank Pension Plan will be made, as deemed appropriate by management, in conjunction with information provided by the plan’s actuaries. There were $124 thousand and $241 thousand in company contributions to the SERP for the years ended December 31, 2016 and 2015 , respectively. The mortality assumptions used in the pension liability assessment for the year ended December 31, 2016 were the RP-2014 adjusted to 2006 dataset mortality table projected to measurement date with Mercer's mortality improvement scale MMP-2007. The measurement date is December 31 for the Webster Bank Pension Plan, SERP, and other postretirement healthcare benefits. The following table sets forth changes in benefit obligation, changes in plan assets, and the funded status of the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Change in benefit obligation: Beginning balance $ 203,645 $ 210,548 $ 10,518 $ 10,041 $ 3,853 $ 4,133 Service cost 45 45 — — — — Interest cost 8,441 8,008 389 345 125 123 Actuarial loss (gain) 6,108 (8,588 ) 1,023 373 59 (178 ) Benefits paid and administrative expenses (6,731 ) (6,368 ) (124 ) (241 ) (185 ) (225 ) Ending balance 211,508 203,645 11,806 10,518 3,852 3,853 Change in plan assets: Beginning balance 161,369 172,976 — — — — Actual return on plan assets 18,284 (5,239 ) — — — — Employer contributions 20,000 — 124 241 185 225 Benefits paid and administrative expenses (6,731 ) (6,368 ) (124 ) (241 ) (185 ) (225 ) Ending balance 192,922 161,369 — — — — Funded status of the plan at year end $ (18,586 ) $ (42,276 ) $ (11,806 ) $ (10,518 ) $ (3,852 ) $ (3,853 ) The accumulated benefit obligation for the defined benefit pension and other postretirement benefits was $227.2 million and $218.0 million at December 31, 2016 and 2015 , respectively. Amounts recognized in the accompanying Consolidated Balance Sheets consist of the following: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Accrued expenses and other liabilities $ (18,586 ) $ (42,276 ) $ (11,806 ) $ (10,518 ) $ (3,852 ) $ (3,853 ) The Company expects that $6.5 million in net actuarial loss will be recognized as a component of net periodic benefit cost in 2017 . The components of AOCL related to the defined benefit pension and other postretirement benefits at December 31, 2016 and 2015 are summarized below: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 65,857 $ 73,238 $ 3,009 $ 2,412 $ 616 $ 591 Prior service cost — — — — — 14 Total pre-tax amounts included in AOCL 65,857 73,238 3,009 2,412 616 605 Deferred tax benefit 23,727 26,447 1,084 871 222 218 Amounts included in accumulated AOCL, net of tax $ 42,130 $ 46,791 $ 1,925 $ 1,541 $ 394 $ 387 Expected future benefit payments for the defined benefit pension and other postretirement benefits are presented below: (In thousands) Pension Plan SERP Other Benefits 2017 $ 7,786 $ 1,208 $ 404 2018 8,604 1,091 398 2019 8,654 8,104 387 2020 9,072 141 375 2021 9,828 140 358 2022-2026 53,711 683 1,457 The components of the net periodic benefit cost (benefit) for the defined benefit pension and other postretirement benefits were as follows for the years ended December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2014 2016 2015 2014 2016 2015 2014 Service cost $ 45 $ 45 $ 40 $ — $ — $ — $ — $ — $ — Interest cost on benefit obligations 8,441 8,008 8,068 389 345 364 125 123 139 Expected return on plan assets (11,461 ) (11,873 ) (11,495 ) — — — — — — Amortization of prior service cost — — — — — — 14 73 73 Recognized net loss 6,665 5,724 2,781 426 390 135 35 47 5 Net periodic benefit cost (benefit) $ 3,690 $ 1,904 $ (606 ) $ 815 $ 735 $ 499 $ 174 $ 243 $ 217 Changes in funded status related to the defined benefit pension and other postretirement benefits and recognized as a component of OCI in the accompanying Consolidated Statements of Comprehensive Income as follows for the years ended December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2014 2016 2015 2014 2016 2015 2014 Net (gain) loss $ (715 ) $ 8,525 $ 31,951 $ 1,023 $ 372 $ 1,145 $ 60 $ (178 ) $ 470 Amounts reclassified from AOCL (6,665 ) (5,724 ) (2,781 ) (426 ) (390 ) (134 ) (35 ) (47 ) (5 ) Amortization of prior service cost — — — — — — (14 ) (73 ) (73 ) Total (gain) loss recognized in OCI $ (7,380 ) $ 2,801 $ 29,170 $ 597 $ (18 ) $ 1,011 $ 11 $ (298 ) $ 392 Fair Value Measurements The following is a description of the valuation methodologies used for the pension plan assets measured at fair value, including the general classification of such instruments pursuant to the valuation hierarchy: Registered investment companies. Exchange traded funds are quoted at market prices in an exchange and active market, which represent the net asset values of shares held by the plan at year end. Money market funds are shown at cost, which approximates fair value. The exchange traded fund is benchmarked against the Standard & Poor's 500 Index. Common collective trust funds. The net asset value (NAV), as provided by the trustee, is used as the fair value of the investments. The NAV is based on the fair value of the underlying investments held by the fund less its liabilities. Plan transactions (purchases and sales) may occur daily. Were the Plan to initiate a full redemption of the collective trust, the investment adviser reserves the right to temporarily delay withdrawal from the trust in order to ensure that securities liquidations will be carried out in an orderly business manner. The common collective trust funds performance are benchmarked against the Standard and Poor’s 500 Stock Index, the S&P 400 Mid Cap Index, the Russell 2000 Index, the MSCI ACWI ex U.S. Index, and the Barclays Capital U.S. Long Credit Index. Investment contract with insurance company. These investments are valued at fair value by discounting the related cash flows based on current yields of similar instruments with comparable durations considering the credit-worthiness of the issuer. Holdings of insurance company investment contracts are classified as Level 3 investments. A summary of the fair value and hierarchy classification of financial assets of the pension plan is as follows: At December 31, 2016 2015 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Registered investment companies: Exchange traded funds $ 31,526 $ — $ — $ 31,526 $ 28,329 $ — $ — $ 28,329 Cash and cash equivalents 701 — — 701 295 — — 295 Common collective trust funds: Fixed Income funds — 96,429 — 96,429 — 80,783 — 80,783 Equity Funds — 63,285 — 63,285 — 51,028 — 51,028 Insurance company investment contract — — 793 793 — — 934 934 Total $ 32,227 $ 159,714 $ 793 $ 192,734 $ 28,624 $ 131,811 $ 934 $ 161,369 The following table sets forth a summary of changes in the fair value of Level 3 assets of the pension plan: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 934 $ 1,077 Unrealized gains relating to instruments still held at the reporting date (10 ) (28 ) Benefit payments, administrative expenses, and interest income, net (131 ) (115 ) Ending balance $ 793 $ 934 Asset Management The following table presents the target allocation and the pension plan asset allocation for the periods indicated, by asset category: Target Allocation Percentage of Pension Plan assets 2017 2016 2015 Fixed income investments 50 % 51 % 51 % Equity investments 50 49 49 Total 100 % 100 % 100 % The Retirement Plan Committee is a fiduciary under ERISA and is charged with the responsibility for directing and monitoring the investment management of the pension plan. To assist the Retirement Plan Committee in this function, it engages the services of investment managers and advisors who possess the necessary expertise to manage the pension plan assets within the established investment policy guidelines and objectives. The investment policy guidelines and objectives is reviewed at a minimum annually by the Retirement Plan Committee. The primary objective of the pension plan investment strategy is to provide long-term total return through capital appreciation and dividend and interest income. The Plan invests in registered investment companies and bank collective trusts. The volatility, as measured by standard deviation, of the pension plan assets should not exceed that of the Composite Index. The investment policy guidelines allow the pension plan assets to be invested in certain types of cash equivalents, fixed income securities, equity securities, mutual funds, and collective trusts. Investments in mutual funds and collective trust funds are substantially limited to funds with the securities characteristic of their assigned benchmarks. The pension plan investment strategy is designed to maintain a diversified portfolio, with a target average long-term rate of 7.00% , however, there is no certainty that the portfolio will perform to expectations. Asset allocations are monitored monthly, and the portfolio is rebalanced as needed. Weighted-average assumptions used to determine benefit obligations at December 31 are as follows: Pension Plan SERP Other Benefits 2016 2015 2016 2015 2016 2015 Discount rate 4.01 % 4.20 % 3.63 % 3.75 % 3.27 % 3.35 % Rate of compensation increase n/a n/a n/a n/a n/a n/a Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31 are as follows: Pension Plan SERP Other Benefits 2016 2015 2014 2016 2015 2014 2016 2015 2014 Discount rate 4.20 % 3.85 % 4.80 % 3.75 % 3.50 % 4.25 % 3.35 % 3.15 % 3.75 % Expected long-term return on assets 7.00 % 7.00 % 7.25 % n/a n/a n/a n/a n/a n/a Rate of compensation increase n/a n/a n/a n/a n/a n/a n/a n/a n/a Assumed healthcare cost trend n/a n/a n/a n/a n/a n/a 8.25 % 8.00 % 8.00 % The assumed healthcare cost-trend rate is 8.25% for 2016 and 2017, declining 1.0% each year thereafter until 2024 when the rate will be 4.75% . An increase of 1.0% in the assumed healthcare cost-trend rate for 2016 would have increased the net periodic postretirement benefit cost by $6 thousand and increased the accumulated benefit obligation by $205 thousand . A decrease of 1.0% in the assumed healthcare cost trend rate for 2016 would have decreased the net periodic postretirement benefit cost by $6 thousand and decreased the accumulated postretirement benefit obligation by $185 thousand . Multiple-employer plan Webster Bank, for the benefit of former employees of a bank acquired by the Company, is a sponsor of a multiple-employer pension plan that does not segregate the assets or liabilities of its employers participating in the plan. According to the plan administrator, as of July 1, 2016 , the date of the latest actuarial valuation, Webster Bank’s portion of this plan was under-funded by $1.1 million . The following table sets forth contributions and funding status of Webster Bank's portion of this plan: (Dollars in thousands) Contributions by Webster Bank for the year ended December 31, Funded Status of the Plan at December 31, Plan Name Employer Identification Number Plan Number 2016 2015 2014 2016 2015 Pentegra Defined Benefit Plan for Financial Institutions 13-5645888 333 $690 $340 $765 At least 80 percent At least 80 percent Multi-employer accounting is applied to the Fund. As a multiple-employer pension plan, there are no collective bargained contracts affecting its contribution or benefit provisions. Any shortfall amortization basis is being amortized over seven years, as required by the Pension Protection Act. All benefit accruals were frozen as of September 1, 2004. The Company's contributions to this plan did not exceed more than 5% of total contributions in the plan for the years ended December 31, 2016 , 2015 , and 2014 . Webster Bank Retirement Savings Plan Webster Bank provides an employee retirement savings plan governed by section 401(k) of the Internal Revenue Code. Webster Bank matches 100% of the first 2% and 50% of the next 6% of employees’ pre-tax contributions based on annual compensation. If a participant fails to make a pre-tax contribution election within 90 days of his or her date of hire, automatic pre-tax contributions will commence 90 days after his or her date of hire at a rate equal to 3% of compensation. Compensation and benefit expense included $11.1 million , $10.9 million , and $10.6 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively, for employer contributions.

Share-Based Plans

Share-Based Plans	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Plans	Share-Based Plans Stock compensation plans Webster maintains stock compensation plans under which non-qualified stock options, incentive stock options, restricted stock, restricted stock units, or stock appreciation rights may be granted to employees and directors. The Company believes these share awards better align the interests of its employees with those of its shareholders. Stock compensation cost is recognized over the required service vesting period for the awards, based on the grant-date fair value, net of estimated forfeitures, and is included as a component of compensation and benefits reflected in non-interest expense. The Plans have shareholder approval for up to 13.4 million shares of common stock. At December 31, 2016 , there were 3.1 million common shares remaining available for grant, while no stock appreciation rights have been granted. The following table provides a summary of stock compensation expense, and the related income tax benefit, recognized in the accompanying Consolidated Statements of Income: Years ended December 31, (In thousands) 2016 2015 2014 Stock options $ 43 $ 379 $ 1,175 Restricted stock 11,395 10,556 9,048 Total stock compensation expense $ 11,438 $ 10,935 $ 10,223 Income tax benefit $ 4,132 $ 3,903 $ 3,553 At December 31, 2016 there was $12.3 million of unrecognized stock compensation expense for restricted stock, expected to be recognized over a weighted-average period of 1.9 years . The following table provides a summary of the activity under the stock compensation plans for the year ended December 31, 2016 : Unvested Restricted Stock Awards Stock Options Outstanding Time-Based Performance-Based Number of Shares Weighted-Average Grant Date Fair Value Number of Units Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Exercise Price Balance at January 1, 2016 236,145 $ 32.58 2,088 $ 34.45 115,721 $ 34.14 1,527,074 $ 23.92 Granted 248,418 33.52 12,946 32.89 150,392 32.75 — — Exercised options — — — — — — 412,538 28.47 Vested restricted stock awards (1) 216,933 30.21 12,876 33.23 140,531 33.12 — — Forfeited 14,269 32.89 — — 9,398 33.63 41,562 47.92 Balance at December 31, 2016 253,361 $ 32.24 2,158 $ 32.89 116,184 $ 33.62 1,072,974 $ 21.24 (1) Vested for purposes of recording compensation expense. Time-based restricted stock . Time-based restricted stock awards vest over the applicable service period ranging from one to five years. The number of time-based awards that may be granted to an eligible individual in a calendar year is limited to 100,000 shares. Compensation expense is recorded over the vesting period based on fair value, which is measured using the Company's common stock closing price at the date of grant. Performance-based restricted stock . Performance-based restricted stock awards vest after a three year performance period. The awards vest with a share quantity dependent on that performance, in a range from zero to 150% . For the performance-based shares granted in 2016 , 50% vest based upon Webster's ranking for total shareholder return versus Webster's compensation peer group companies and 50% vest based upon Webster's average of return on equity during the three year vesting period. The compensation peer group companies are utilized because they represent the financial institutions that best compare with Webster. The Company records compensation expense over the vesting period, based on a fair value calculated using the Monte-Carlo simulation model, which allows for the incorporation of the performance condition for the 50% of the performance-based shares tied to total shareholder return versus the compensation peer group, and based on a fair value of the market price on the date of grant for the remaining 50% of the performance-based shares tied to Webster's return on equity. Compensation expense is subject to adjustment based on management's assessment of Webster's return on equity performance relative to the target number of shares condition. The total fair value of restricted stock awards vested during the years ended December 31, 2016 , 2015 , and 2014 was $11.6 million , $11.6 million , and $9.4 million , respectively. Stock options . Stock option awards have an exercise price equal to the market price of Webster's stock on the date of grant. Each option grants the holder the right to acquire a share of Webster common stock over a contractual life of up to ten years. There have been no stock options granted since 2013. All awarded options have vested. There were 998,185 non-qualified stock options and 74,789 incentive stock options outstanding at December 31, 2016 . Aggregate intrinsic value represents the total pretax intrinsic value (the difference between Webster's closing stock price on the last trading day of the year and the weighted-average exercise price, multiplied by the number of shares) that would have been received by the option holders had they all exercised their options at that time. At December 31, 2016 , as all awarded options have vested, all of the outstanding options are exercisable, and the aggregate intrinsic value of these options was $35.5 million . The total intrinsic value of options exercised during the years ended December 31, 2016 , 2015 , and 2014 was $6.4 million , $4.3 million , and $1.9 million , respectively. The following table summarizes information for options, all of which are both outstanding and exercisable, at December 31, 2016 : Range of Exercise Prices Number of Shares Weighted-Average Remaining Contractual Life (years) Weighted-Average Exercise Price $ 5.14 - 20.00 317,814 2.2 $ 8.95 $ 20.01 - 30.00 562,040 5.2 23.53 $ 30.01 - 40.00 151,715 1.0 32.03 $ 40.01 - 48.88 41,405 0.4 44.91 1,072,974 3.5 $ 21.24

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting Webster’s operations are organized into four reportable segments that represent its primary businesses - Commercial Banking, Community Banking, HSA Bank, and Private Banking. These four reportable segments reflect how executive management responsibilities are assigned by the chief operating decision maker for each of the primary businesses, the products and services provided, the type of customer served, and reflects how discrete financial information is currently evaluated. The Company’s Treasury unit and consumer liquidating portfolio are included in the Corporate and Reconciling category along with the amounts required to reconcile profitability metrics to GAAP reported amounts. Webster’s reportable segment results are intended to reflect each segment as if it were a stand-alone business. Webster uses an internal profitability reporting system to generate information by operating segment, which is based on a series of management estimates and allocations regarding funds transfer pricing, provision for loan and lease losses, non-interest expense, income taxes, and equity capital. These estimates and allocations, certain of which are subjective in nature, are periodically reviewed and refined. Changes in estimates and allocations that affect the reported results of any operating segment do not affect the consolidated financial position or results of operations of Webster as a whole. The full profitability measurement reports, which are prepared for each operating segment, reflect non-GAAP reporting methodologies. The differences between full profitability and GAAP results are reconciled in the Corporate and Reconciling category. Webster allocates interest income and interest expense to each business, while also transferring the primary interest rate risk exposures to the Corporate and Reconciling category, using a matched maturity funding concept called Funds Transfer Pricing. The allocation process considers the specific interest rate risk and liquidity risk of financial instruments and other assets and liabilities in each line of business. The matched maturity funding concept considers the origination date and the earlier of the maturity date or the repricing date of a financial instrument to assign an FTP rate for loans and deposits originated each day. Loans are assigned an FTP rate for funds used and deposits are assigned an FTP rate for funds provided. This process is executed by the Company’s Financial Planning and Analysis division and is overseen by ALCO. Webster allocates the provision for loan and lease losses to each segment based on management’s estimate of the inherent loss content in each of the specific loan and lease portfolios. Provision expense for certain elements of risk that are not deemed specifically attributable to a reportable segment, such as the provision for the consumer liquidating portfolio, is shown as part of the Corporate and Reconciling category. Webster allocates a majority of non-interest expense to each reportable segment using a full-absorption costing process. Costs, including corporate overhead, are analyzed, pooled by process, and assigned to the appropriate reportable segment. Income tax expense is allocated to each reportable segment based on the consolidated effective income tax rate for the period shown. The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Year ended December 31, 2016 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 276,246 $ 365,151 $ 81,451 $ 11,350 $ (15,685 ) $ 718,513 Provision (benefit) for loan and lease losses 36,594 21,690 — 861 (2,795 ) 56,350 Net interest income (loss) after provision for loan and lease losses 239,652 343,461 81,451 10,489 (12,890 ) 662,163 Non-interest income 47,435 110,157 71,710 9,818 25,358 264,478 Non-interest expense 118,159 364,549 97,152 20,220 23,111 623,191 Income (loss) before income tax expense 168,928 89,069 56,009 87 (10,643 ) 303,450 Income tax expense (benefit) 53,622 28,273 17,779 27 (3,378 ) 96,323 Net income (loss) $ 115,306 $ 60,796 $ 38,230 $ 60 $ (7,265 ) $ 207,127 Year ended December 31, 2015 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 255,845 $ 354,709 $ 73,433 $ 10,240 $ (29,602 ) $ 664,625 Provision (benefit) for loan and lease losses 30,160 19,603 — 386 (849 ) 49,300 Net interest income (loss) after provision for loan and lease losses 225,685 335,106 73,433 9,854 (28,753 ) 615,325 Non-interest income 37,784 108,604 62,475 9,183 19,731 237,777 Non-interest expense 109,718 330,692 81,449 19,781 13,701 555,341 Income (loss) before income tax expense 153,751 113,018 54,459 (744 ) (22,723 ) 297,761 Income tax expense (benefit) 48,037 35,310 17,016 (233 ) (7,098 ) 93,032 Net income (loss) $ 105,714 $ 77,708 $ 37,443 $ (511 ) $ (15,625 ) $ 204,729 Year ended December 31, 2014 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 238,186 $ 354,781 $ 38,822 $ 8,877 $ (12,225 ) $ 628,441 Provision (benefit) for loan and lease losses 13,088 26,345 — 765 (2,948 ) 37,250 Net interest income (loss) after provision for loan and lease losses 225,098 328,436 38,822 8,112 (9,277 ) 591,191 Non-interest income 37,270 103,543 28,553 9,843 22,899 202,108 Non-interest expense 102,374 324,312 40,900 18,691 15,323 501,600 Income (loss) before income tax expense 159,994 107,667 26,475 (736 ) (1,701 ) 291,699 Income tax expense (benefit) 50,446 33,947 8,311 (232 ) (499 ) 91,973 Net income (loss) $ 109,548 $ 73,720 $ 18,164 $ (504 ) $ (1,202 ) $ 199,726 The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: Total Assets (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated At December 31, 2016 $ 8,518,830 $ 8,655,789 $ 83,987 $ 550,615 $ 8,263,308 $ 26,072,529 At December 31, 2015 7,505,513 8,441,950 95,815 493,571 8,104,269 24,641,118

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Lease Commitments Webster is obligated under various non-cancelable operating leases for properties used as banking centers and other office facilities. The leases contain renewal options and escalation clauses which provide for increased rental expense, or for equipment upgrades. Rental expense under the leases was $30.4 million , $21.5 million , and $20.5 million for the years ended December 31, 2016 , 2015 , and 2014 , respectively, and is recorded as a component of occupancy expense in the accompanying Consolidated Statements of Income. Rental income from sub-leases on certain of these properties is netted as a component of occupancy expense, while rental income under various non-cancelable operating leases for properties owned is recorded as a component of other non-interest income in the accompanying Consolidated Statements of Income. Rental income was $0.8 million for the years ended December 31, 2016 , 2015 , and 2014 . The following table summarizes future minimum rental payments and receipts under lease agreements: At December 31, 2016 (In thousands) Rental Payments Rental Receipts 2017 $ 28,713 $ 601 2018 27,046 451 2019 25,644 364 2020 23,900 293 2021 21,860 202 Thereafter 88,211 918 Total future minimum rental payments and receipts $ 215,374 $ 2,829 Credit-Related Financial Instruments The Company offers credit-related financial instruments, in the normal course of business to meet certain financing needs of its customers, that involve off-balance sheet risk. These transactions may include an unused commitment to extend credit, standby letter of credit, or commercial letter of credit. Such transactions involve, to varying degrees, elements of credit risk. The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: At December 31, (In thousands) 2016 2015 Commitments to extend credit $ 5,224,280 $ 4,851,994 Standby letter of credit 128,985 133,294 Commercial letter of credit 46,497 45,742 Total credit-related financial instruments with off-balance sheet risk $ 5,399,762 $ 5,031,030 Commitments to Extend Credit . The Company makes commitments under various terms to lend funds to customers at a future point in time. These commitments include revolving credit arrangements, term loan commitments, and short-term borrowing agreements. Most of these loans have fixed expiration dates or other termination clauses where a fee may be required. Since commitments routinely expire without being funded, or after required availability of collateral occurs, the total commitment amount does not necessarily represent future liquidity requirements. Standby Letter of Credit . A standby letter of credit commits the Company to make payments on behalf of customers if certain specified future events occur. The Company has recourse against the customer for any amount required to be paid to a third party under a standby letter of credit, which is often part of a larger credit agreement under which security is provided. Historically, a large percentage of standby letters of credit expire without being funded. The contractual amount of a standby letter of credit represents the maximum amount of potential future payments the Company could be required to make, and is the Company's maximum credit risk. Commercial Letter of Credit . A commercial letter of credit is issued to facilitate either domestic or foreign trade arrangements for customers. As a general rule, drafts are committed to be drawn when the goods underlying the transaction are in transit. Similar to a standby letter of credit, a commercial letter of credit is often secured by an underlying security agreement including the assets or inventory they relate to. These commitments subject the Company to potential exposure in excess of amounts recorded in the financial statements, and therefore, management maintains a specific reserve for unfunded credit commitments. This reserve is reported as a component of accrued expenses and other liabilities in the accompanying Consolidated Balance Sheets. The following table provides a summary of activity in the reserve for unfunded credit commitments: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 2,119 $ 5,151 $ 4,384 Provision (benefit) 168 (3,032 ) 767 Ending balance $ 2,287 $ 2,119 $ 5,151 The change in the provision is attributable to a benefit recorded in 2015. The benefit was the result of a change in a key assumption used in calculating expected incremental utilization of credit. The updated assumption is based on a more detailed analysis of customer behavior and performance in the months prior to a charge-off, rather than a general overall utilization rate, which should result in a better estimate of potential loss on credit-related financial instruments. Litigation Webster is involved in routine legal proceedings occurring in the ordinary course of business and is subject to loss contingencies related to such litigation and claims arising therefrom. Webster evaluates these contingencies based on information currently available, including advice of counsel and assessment of available insurance coverage. Webster establishes accruals for litigation and claims when a loss contingency is considered probable and the related amount is reasonably estimable. These accruals are periodically reviewed and may be adjusted as circumstances change. Webster also estimates certain loss contingencies for possible litigation and claims, whether or not there is an accrued probable loss. Webster believes it has defenses to all the claims asserted against it in existing litigation matters and intends to defend itself in all matters. Based upon its current knowledge, after consultation with counsel and after taking into consideration its current litigation accruals, Webster believes that at December 31, 2016 any reasonably possible losses, in addition to amounts accrued, are not material to Webster’s consolidated financial condition. However, in light of the uncertainties involved in such actions and proceedings, there is no assurance that the ultimate resolution of these matters will not significantly exceed the amounts currently accrued by Webster or that the Company’s litigation accrual will not need to be adjusted in future periods. Such an outcome could be material to the Company’s operating results in a particular period, depending on, among other factors, the size of the loss or liability imposed and the level of the Company’s income for that period.

Parent Company Information

Parent Company Information	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Information	Parent Company Information Financial information for the Parent Company only is presented in the following tables: Condensed Balance Sheets December 31, (In thousands) 2016 2015 Assets: Cash and due from banks $ 152,947 $ 279,644 Securities available for sale, at fair value — 2,578 Intercompany debt securities 150,000 — Investment in subsidiaries 2,425,398 2,345,457 Alternative investments 4,275 6,795 Other assets 24,659 15,263 Total assets $ 2,757,279 $ 2,649,737 Liabilities and shareholders’ equity: Senior notes $ 148,194 $ 147,940 Junior subordinated debt 77,320 77,320 Accrued interest payable 2,589 2,591 Due to subsidiaries 365 48 Other liabilities 1,799 7,878 Total liabilities 230,267 235,777 Shareholders’ equity 2,527,012 2,413,960 Total liabilities and shareholders’ equity $ 2,757,279 $ 2,649,737 Condensed Statements of Income Years ended December 31, (In thousands) 2016 2015 2014 Operating Income: Dividend income from bank subsidiary $ 145,000 $ 110,000 $ 100,000 Interest on securities and deposits 1,911 546 613 (Loss) gain on sale of investment securities, net (2,410 ) — 1,185 Alternative investments income 176 2,274 804 Other non-interest income 7,485 152 151 Total operating income 152,162 112,972 102,753 Operating Expense: Interest expense on borrowings 9,981 9,665 10,041 Compensation and benefits 11,461 10,965 10,290 Other non-interest expense 6,278 6,005 4,562 Total operating expense 27,720 26,635 24,893 Income before income tax benefit and equity in undistributed earnings of subsidiaries and associated companies 124,442 86,337 77,860 Income tax benefit 3,086 2,929 8,798 Equity in undistributed earnings of subsidiaries and associated companies 79,599 115,463 113,068 Net income $ 207,127 $ 204,729 $ 199,726 Condensed Statements of Comprehensive Income Years ended December 31, (In thousands) 2016 2015 2014 Net income $ 207,127 $ 204,729 $ 199,726 Other comprehensive income (loss), net of tax: Net unrealized gains (losses) on available for sale securities 584 (2,109 ) 725 Net unrealized gains (losses) on derivative instruments 1,223 1,223 (2,932 ) Other comprehensive loss of subsidiaries and associated companies (694 ) (20,959 ) (5,505 ) Other comprehensive income (loss), net of tax 1,113 (21,845 ) (7,712 ) Comprehensive income $ 208,240 $ 182,884 $ 192,014 Condensed Statements of Cash Flows Years ended December 31, (In thousands) 2016 2015 2014 Operating activities: Net income $ 207,127 $ 204,729 $ 199,726 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries and associated companies (79,599 ) (115,463 ) (113,068 ) Stock-based compensation 11,438 10,935 10,223 Gain on redemption of other assets (7,331 ) — — Other, net (3,736 ) 9,066 (10,721 ) Net cash provided by operating activities 127,899 109,267 86,160 Investing activities: Purchases of available for sale securities — — (3,500 ) Proceeds from sale of available for sale securities 1,089 — 3,499 Purchases of intercompany debt securities (150,000 ) — — Net cash used for investing activities (148,911 ) — (1 ) Financing activities: Issuance of long-term debt — — 150,000 Repayment of long-term debt — — (150,000 ) Cash dividends paid to common shareholders (89,522 ) (80,964 ) (67,431 ) Cash dividends paid to preferred shareholders (8,096 ) (8,711 ) (10,556 ) Exercise of stock options 11,762 3,060 2,221 Excess tax benefits from stock-based compensation 3,204 2,338 1,161 Common stock issued — — 435 Common stock repurchased/shares acquired related to employee share-based plans (22,870 ) (17,815 ) (13,067 ) Common stock warrants repurchased (163 ) (23 ) (3 ) Net cash used for financing activities (105,685 ) (102,115 ) (87,240 ) (Decrease) increase in cash and due from banks (126,697 ) 7,152 (1,081 ) Cash and due from banks at beginning of year 279,644 272,492 273,573 Cash and due from banks at end of year $ 152,947 $ 279,644 $ 272,492

Selected Quarterly Consolidated

Selected Quarterly Consolidated Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Consolidated Financial Information (Unaudited)	Selected Quarterly Consolidated Financial Information (Unaudited) 2016 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 202,335 $ 202,431 $ 205,715 $ 211,432 Interest expense 26,183 25,526 25,518 26,173 Net interest income 176,152 176,905 180,197 185,259 Provision for loan and lease losses 15,600 14,000 14,250 12,500 Non-interest income 62,374 65,075 66,412 70,617 Non-interest expense 152,445 152,778 156,097 161,871 Income before income tax expense 70,481 75,202 76,262 81,505 Income tax expense 23,434 24,599 24,445 23,845 Net income $ 47,047 $ 50,603 $ 51,817 $ 57,660 Earnings applicable to common shareholders $ 44,921 $ 48,398 $ 49,634 $ 55,501 Earnings per common share: Basic $ 0.49 $ 0.53 $ 0.54 $ 0.61 Diluted 0.49 0.53 0.54 0.60 2015 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 182,912 $ 186,970 $ 191,998 $ 198,160 Interest expense 23,148 23,459 23,988 24,820 Net interest income 159,764 163,511 168,010 173,340 Provision for loan and lease losses 9,750 12,750 13,000 13,800 Non-interest income 57,561 59,245 61,292 59,679 Non-interest expense 134,087 137,537 139,937 143,780 Income before income tax expense 73,488 72,469 76,365 75,439 Income tax expense 23,984 20,426 24,995 23,627 Net income $ 49,504 $ 52,043 $ 51,370 $ 51,812 Earnings applicable to common shareholders $ 46,719 $ 49,819 $ 49,176 $ 49,646 Earnings per common share: Basic $ 0.52 $ 0.55 $ 0.54 $ 0.54 Diluted 0.51 0.55 0.53 0.54

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements and the accompanying Notes thereto include the accounts of Webster Financial Corporation and all other entities in which it has a controlling financial interest. Intercompany accounts and transactions have been eliminated in consolidation. Webster's accounting and financial reporting policies conform, in all material respects, to GAAP and to general practices within the financial services industry. Assets that the Company holds or manages in a fiduciary or agency capacity for customers, typically referred to as assets under administration or assets under management are not included in the accompanying Consolidated Balance Sheets since those assets are not Webster's, and the Company is not the primary beneficiary. Certain prior period amounts have been reclassified to conform to the current year's presentation. These reclassifications had an immaterial effect on net income, comprehensive income, total assets, total liabilities, total shareholders' equity, net cash provided by operating activities, and net cash used for investing activities.
Variable Interest Entities	Variable Interest Entities A VIE is an entity that has either a total equity investment that is insufficient to finance its activities without additional subordinated financial support or whose equity investors lack the ability to control the entity’s activities or lack the ability to receive expected benefits or absorb obligations in a manner that’s consistent with their investment in the entity. The Company evaluates each VIE to understand the purpose and design of the entity, and its involvement in the ongoing activities of the VIE. The Company will consolidate the VIE if it has: • the power to direct the activities of the VIE that most significantly affect the VIE's economic performance; and • an obligation to absorb losses of the VIE, or the right to receive benefits from the VIE, that could potentially be significant to the VIE.
Use of Estimates	Use of Estimates The preparation of financial statements in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the financial statements as well as income and expense during the period. The allowance for loan and lease losses, the fair value measurements for valuation of investments and other financial instruments, evaluation of investments for OTTI, valuation of goodwill and other intangible assets, and assessing the realizability of deferred tax assets and the measurement of uncertain tax position, as well as the status of contingencies, are particularly subject to change. Actual results could differ from those estimates.
Cash Equivalents	Cash Equivalents Cash equivalents have a maturity of three months or less. Cash and due from banks. Cash equivalents, including cash on hand, certain cash due from banks, and deposits at the FRB of Boston, are referenced as cash and due from banks in the accompanying Consolidated Balance Sheets and Consolidated Statements of Cash Flows. Interest-bearing deposits. Cash equivalents, primarily representing deposits at the FRB of Boston in excess of reserve requirements, and federal funds sold, which essentially represent uncollateralized loans to other financial institutions, are referenced as interest-bearing deposits in the accompanying Consolidated Balance Sheets and Consolidated Statements of Cash Flows. The Company regularly evaluates the credit risk associated with those financial institutions to assess that Webster is not exposed to any significant credit risk on cash equivalents.
Investment Securities	Investment Securities Investment securities are classified as available-for-sale or held-to-maturity at the time of purchase. Any subsequent change to classification is reviewed for compliance with corporate objectives and accounting policy. Debt securities classified as held-to-maturity are those which Webster has the ability and intent to hold to maturity. Securities classified as held-to-maturity are recorded at amortized cost net of unamortized premiums and discounts. Discount accretion income and premium amortization expense are recognized as interest income according to a constant yield methodology, with consideration given to prepayment assumptions on mortgage backed securities. Securities classified as available-for-sale are recorded at fair value with unrealized gains and losses recorded as a component of OCI/OCL. Securities transferred from available-for-sale to held-to-maturity are recorded at fair value at the time of transfer, and the respective gain or loss is recorded as a separate component of OCI/OCL and amortized as an adjustment to interest income over the remaining life of the security. All securities classified as available-for-sale or held-to-maturity that are in an unrealized loss position are evaluated for OTTI on a quarterly basis. The evaluation considers several qualitative factors, including the period of time the security has been in a loss position, and the amount of the unrealized loss. If the Company intends to sell the security or it is more than likely the Company will be required to sell the security prior to recovery of its amortized cost basis, the security is written down to fair value, and the loss is recognized in non-interest income in the accompanying Consolidated Statements of Income. If the Company does not intend to sell the security and it is more likely than not that the Company will not be required to sell the security prior to recovery of its amortized cost basis, only the credit component of the unrealized loss is recorded as an impairment charge to a debt security and recognized as a loss. The remaining loss component would be recorded to AOCL in the accompanying Consolidated Balance Sheets. The entire amount of an unrealized loss position of an equity security that is considered OTTI is recorded as an impairment loss in non-interest income in the accompanying Consolidated Statements of Income. The specific identification method is used to determine realized gains and losses on sales of securities.
Loans Held for Sale	Loans Held for Sale Effective January 1, 2016, on a loan by loan election, residential mortgage loans that are classified as held for sale are accounted for under either the fair value option method of accounting or the lower of cost or fair value method of accounting with the election being made at the time the asset is first recognized. The Company has elected the fair value option to mitigate accounting mismatches between held for sale derivative commitments and loan valuations. Prior to January 1, 2016, residential mortgage loans that were classified as held for sale were accounted for at the lower of cost or fair value method of accounting and were valued on an individual asset basis. Loans not originated for sale but subsequently transferred to held for sale continue to be valued at the lower of cost or fair value method of accounting and are valued on an individual asset basis. Any cost amount in excess of fair value is recorded as a valuation allowance and recognized as a reduction of other income in the Consolidated Statements of Income. Gains or losses on the sale of loans held for sale are recorded as non-interest income. Cash flows from sale of loans made by the Company that were acquired specifically for resale are presented as operating cash flows. All other cash flows from sale of loans are presented as investing cash flows.
Transfers and Servicing of Financial Assets	Transfers and Servicing of Financial Assets Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is generally considered to have been surrendered when: (i) the transferred assets are legally isolated from the Company or its consolidated affiliates, even in bankruptcy or other receivership; (ii) the transferee has the right to pledge or exchange the assets with no conditions that constrain the transferee and provide more than a trivial benefit to the Company; and (iii) the Company does not maintain the obligation or unilateral ability to reclaim or repurchase the assets. The Company sells financial assets in the normal course of business, the majority of which are residential mortgage loan sales primarily to government-sponsored enterprises through established programs, commercial loan sales through participation agreements, and other individual or portfolio loan and securities sales. In accordance with accounting guidance for asset transfers, the Company considers any ongoing involvement with transferred assets in determining whether the assets can be derecognized from the balance sheet. With the exception of servicing and certain performance-based guarantees, the Company’s continuing involvement with financial assets sold is minimal and generally limited to market customary representation and warranty clauses covering certain characteristics of the mortgage loans sold and the Company's origination process. The gain or loss on sale depends on the previous carrying amount of the transferred financial assets, the consideration received, and any liabilities incurred in exchange for the transferred assets. When the Company sells financial assets, it may retain servicing rights and/or other interests in the financial assets. Servicing assets and any other interests held by the Company are recorded at fair value upon transfer, and thereafter are carried at the lower of cost or fair value.
Loans and Leases	Loans and Leases Loans and leases are stated at the principal amount outstanding, net of amounts charged off, unamortized premiums and discounts, and deferred loan and lease fees/costs which are recognized as yield adjustments using the interest method. These yield adjustments are amortized over the contractual life of the related loans and leases adjusted for prepayments when applicable. Interest on loans and leases is credited to interest income as earned based on the interest rate applied to principal amounts outstanding. Cash flows from loans and leases are presented as investing cash flows. Loans and leases are placed on non-accrual status when collection of principal and interest in accordance with contractual terms is doubtful, generally when principal or interest payments become 90 days delinquent, unless the loan or lease is well secured and in process of collection, or sooner if management concludes circumstances indicate that the borrower may be unable to meet contractual principal or interest payments. Residential real estate loans, excluding loans fully insured against loss and in the process of collection, and consumer loans are placed on non-accrual status at 90 days past due, or at the date when the Company is notified that the borrower is discharged in bankruptcy. A charge-off is recorded at 180 days if the loan balance exceeds the fair value of the collateral less costs to sell. Residential loans that are more than 90 days past due, fully insured against loss, and in the process of collection, remain accruing and are reported as 90 days or more past due and accruing. Commercial, commercial real estate loans, and equipment finance loans or leases are subject to a detailed review when 90 days past due to determine accrual status, or when payment is uncertain and a specific consideration is made to put a loan or lease on non-accrual status. When loans and leases are placed on non-accrual status, the accrual of interest is discontinued, and any unpaid accrued interest is reversed and charged against interest income. If ultimate repayment of a non-accrual loan or lease is expected, any payments received are applied in accordance with contractual terms. If ultimate repayment is not expected on commercial, commercial real estate, and equipment finance loans and leases, any payment received on a non-accrual loan or lease is applied to principal until the unpaid balance has been fully recovered. Any excess is then credited to interest income when received. If the Company determines, through a current valuation analysis, that principal can be repaid on residential real estate and consumer loans, interest payments may be taken into income as received on a cash basis. Except for loans discharged under Chapter 7 of the U.S. bankruptcy code, loans are removed from non-accrual status when they become current as to principal and interest or demonstrate a period of performance under contractual terms and, in the opinion of management, are fully collectible as to principal and interest. Pursuant to regulatory guidance, a Chapter 7 discharged bankruptcy loan is removed from non-accrual status when the bank expects full repayment of the remaining pre-discharged contractual principal and interest, the loan is a closed-end amortizing loan, it is fully collateralized, and post-discharge the loan had at least six consecutive months of current payments.
Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments	Allowance for Loan and Lease Losses The ALLL is a reserve established through a provision for loan and lease losses charged to expense and represents management’s best estimate of probable losses that may be incurred within the existing loan and lease portfolio as of the balance sheet date. The level of the allowance reflects management’s view of trends in losses, current portfolio quality, and present economic, political, and regulatory conditions. Portions of the allowance may be allocated for specific loans and leases; however, the entire allowance is available for any loan or lease that is charged off. A charge-off is recorded on a case-by-case basis when all or a portion of the loan or lease is deemed to be uncollectible. Back-testing is performed to compare original estimated losses and actual observed losses, resulting in ongoing refinements. While management utilizes its best judgment based on the information available at the time, the ultimate adequacy of the allowance is dependent upon a variety of factors that are beyond the Company’s control, which include the performance of the Company’s portfolio, economic conditions, interest rate sensitivity, and the view of the regulatory authorities regarding loan classifications. The ALLL consists of the following three elements: (i) specific valuation allowances established for probable losses on impaired loans and leases; (ii) quantitative valuation allowances calculated using loss experience for like loans and leases with similar characteristics and trends, adjusted, as necessary, to reflect the impact of current conditions; and (iii) qualitative factors determined based on general economic conditions and other factors that may be internal or external to the Company. Loans and leases are considered impaired when, based on current information and events, it is probable the Company will be unable to collect all amounts due in accordance with the original contractual terms of the loan agreement, including scheduled principal and interest payments. Impairment is evaluated on a pooled basis for smaller-balance homogeneous residential, consumer loans and small business loans. Commercial, commercial real estate, and equipment financing loans and leases over a specific dollar amount and all TDR are evaluated individually for impairment. A loan identified as a TDR is considered an impaired loan for the entire term of the loan, with few exceptions. If a loan is impaired, a specific valuation allowance may be established, and the loan is reported net, at the present value of estimated future cash flows using the loan’s original interest rate or at the fair value of collateral less cost to sell if repayment is expected from collateral liquidation. Interest payments on non-accruing impaired loans are typically applied to principal unless collectability of the principal amount is reasonably assured, in which case interest is recognized on a cash basis. Impaired loans, or portions thereof, are charged off when deemed uncollectible. Factors considered by management in determining impairment include payment status, collateral value, discharged bankruptcy, and the likelihood of collecting scheduled principal and interest payments. Consumer modified loans are analyzed for re-default probability, which is considered when determining if a specific valuation allowance is to be established. The current or weighted-average (for multiple notes within a commercial borrowing arrangement) interest rate of the loan is used as the discount rate, for determining net present value of the loan evaluated for impairment, when the interest rate floats with a specified index. A change in terms or payments would be included in the impairment calculation. See Note 4: Loans and Leases for further information. Reserve for Unfunded Commitments The reserve for unfunded commitments provides for probable losses inherent with funding the unused portion of legal commitments to lend. The unfunded reserve calculation includes factors that are consistent with the ALLL methodology for funded loans using the loss given default, probability of default, and a draw down factor applied to the underlying borrower risk and facility grades. The reserve for unfunded credit commitments is included within other liabilities in the accompanying Consolidated Balance Sheets, and changes in the reserve are reported as a component of other expense in the accompanying Consolidated Statements of Income.
Troubled Debt Restructurings	Troubled Debt Restructurings A modified loan is considered a TDR when the following two conditions are met: (i) the borrower is experiencing financial difficulties; and (ii) the modification constitutes a concession. The Company considers all aspects of the restructuring in determining whether a concession has been granted, including the debtor's ability to access funds at a market rate. In general, a concession exists when the modified terms of the loan are more attractive to the borrower than standard market terms. Modified terms are dependent upon the financial position and needs of the individual borrower. The most common types of modifications include covenant modifications and forbearance. Loans for which the borrower has been discharged under Chapter 7 bankruptcy are considered collateral dependent TDR, impaired at the date of discharge, and charged down to the fair value of collateral less cost to sell, if management considers that loss potential likely exists. The Company’s policy is to place consumer loan TDR, except those that were performing prior to TDR status, on non-accrual status for a minimum period of six months . Commercial TDR are evaluated on a case-by-case basis for determination of whether or not to place them on non-accrual status. Loans qualify for return to accrual status once they have demonstrated performance with the restructured terms of the loan agreement for a minimum of six months . Initially, all TDR are reported as impaired. Generally, TDR are classified as impaired loans and reported as TDR for the remaining life of the loan. Impaired and TDR classification may be removed if the borrower demonstrates compliance with the modified terms for a minimum of six months and through a fiscal year-end and the restructuring agreement specifies a market rate of interest equal to that which would be provided to a borrower with similar credit at the time of restructuring. In the limited circumstance that a loan is removed from TDR classification, it is the Company’s policy to continue to base its measure of loan impairment on the contractual terms specified by the loan agreement. The Company’s loan and lease portfolio includes loans that have been restructured into an A-Note/B-Note structure as a result of evaluating the cash flow of the borrowers to support repayment. Following these restructurings, Webster immediately charged off the balances of the B-Notes. The restructuring agreements specify a market interest rate equal to that which would be provided to a borrower with similar credit at the time of restructuring.
Foreclosed and Repossessed Assets	Foreclosed and Repossessed Assets Real estate acquired through foreclosure or completion of a deed in lieu of foreclosure and other assets acquired through repossession are carried at the lower of cost or market value less estimated selling costs and are included within other assets in the accompanying Consolidated Balance Sheets. Independent appraisals generally are obtained to substantiate fair value and may be subject to adjustment based upon historical experience or specific geographic trends impacting the property. Within 90 days of a loan being foreclosed upon, the excess of loan balance over fair value less cost to sell is charged off against the ALLL. Subsequent write-downs in value, maintenance costs as incurred, and gains or losses upon sale are charged to non-interest expense in the accompanying Consolidated Statements of Income.
Premises and Equipment	Premises and Equipment Premises and equipment are carried at cost, less accumulated depreciation. Depreciation of premises and equipment is computed on a straight-line basis over the estimated useful lives of the assets, as follows: Building and Improvements 5 - 40 years Leasehold improvements 5 - 20 years (or term or lease, if shorter) Fixtures and equipment 5 - 10 years Data processing and software 3 - 7 years Repairs and maintenance costs are charged to non-interest expense as incurred. Premises and equipment being actively marketed for sale are reclassified as assets held for disposition. The cost and accumulated depreciation relating to premises and equipment retired or otherwise disposed of are eliminated, and any resulting losses are charged to non-interest expense.
Goodwill	Goodwill Goodwill represents the excess purchase price of businesses acquired over the fair value of the identifiable net assets acquired and is assigned to specific reporting units. Goodwill is not subject to amortization but rather is evaluated for impairment annually, or more frequently in interim periods if events occur or circumstances change indicating it would more likely than not result in a reduction of the fair value of a reporting unit below its carrying value. Goodwill is evaluated for impairment by either performing a qualitative evaluation or a two-step quantitative test. The qualitative evaluation is an assessment of factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount, including goodwill. The Company utilizes an equally weighted combined income and market approach to arrive at an indicated fair value range for the reporting unit. In Step 1, the fair value of a reporting unit is compared to its carrying amount, including goodwill, to ascertain if a goodwill impairment exists. If the fair value of the reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired, and it is not necessary to continue to Step 2 of the impairment process. Otherwise, Step 2 is performed where the implied fair value of goodwill is compared to the carrying value of goodwill in the reporting unit. If a reporting unit's carrying value exceeds fair value, the difference is charged to non-interest expense.
Other Intangible Assets	Other Intangible Assets Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights, or because the asset is capable of being sold or exchanged either separately or in combination with a related contract, asset, or liability. Other intangible assets with finite useful lives are amortized to non-interest expense over their estimated useful lives and are evaluated for impairment whenever events occur or circumstances change indicating the carrying amount of the asset may not be recoverable. Core deposit intangible assets resulting from the health savings account acquisition are amortized on an accelerated basis over their estimated useful lives. Core deposit intangible assets existing prior to the health savings account acquisition continue to be amortized on a straight line basis over their remaining estimated useful lives. Intangible assets relating to customer relationships are amortized on a straight line basis over their estimated useful lives.
Cash Surrender Value of Life Insurance	Cash Surrender Value of Life Insurance The investment in life insurance represents the cash surrender value of life insurance policies on certain current and former officers of Webster. Increases in the cash surrender value are recorded as non-interest income. Decreases are the result of collection on the policies due to the death of an insured. Death benefit proceeds in excess of cash surrender value are recorded in other non-interest income when realized.
Securities Sold Under Agreements to Repurchase	Securities Sold Under Agreements to Repurchase These agreements are accounted for as secured financing transactions since Webster maintains effective control over the transferred securities and the transfer meets the other criteria for such accounting. Obligations to repurchase securities sold are reflected as a liability in the accompanying Consolidated Balance Sheets. The securities underlying the agreements are delivered to a custodial account for the benefit of the dealer or bank with whom each transaction is executed. The dealers or banks, which may sell, loan, or otherwise hypothecate such securities to other parties in the normal course of their operations, agree to resell to Webster the same securities at the maturity date of the agreements. The securities underlying the agreements with Bank customers are pledged; however, the customer does not have ability to hypothecate the underlying securities.
Share-based Compensation	Share-Based Compensation Webster maintains an equity incentive plan under which non-qualified stock options, incentive stock options, restricted stock, restricted stock units, or stock appreciation rights may be granted to employees and directors. Share awards are issued from available treasury shares. Stock-based compensation cost is recognized over the requisite service period for the awards, based on the grant-date fair value, net of estimated forfeitures, and is reported as a component of compensation and benefits expense. All awards are subject to a minimum one -year service vesting period. For stock option awards the Black-Scholes Option-Pricing Model is used to measure fair value at the date of grant. For time-based restricted stock and restricted stock unit awards, fair value is measured using the Company's common stock closing price at the date of grant. The Company grants performance-based restricted stock awards that vest after a three year performance period. Awards vest in a range from zero to 150% of the target number of shares under the grant. The Company records compensation expense over the vesting period, based on a fair value. Compensation expense is subject to adjustment based on management's assessment of Webster's return on equity performance relative to the target number of shares condition. Dividends are accrued on the performance-based shares and paid when the performance target is met. See Note 18: Share-Based Plans for further information. Excess tax benefits result when tax return deductions exceed recognized compensation cost determined using the grant-date fair value approach for financial statement purposes. Excess tax benefits are presented as a cash inflow from financing activities and a cash outflow from operating activities.
Income Taxes	Income Taxes Income tax expense, or benefit, is comprised of two components, current and deferred. The current component reflects taxes payable or refundable for a current period based on applicable tax laws, and the deferred component represents the tax effects of temporary differences between amounts recognized for financial accounting and tax purposes. Deferred tax assets and liabilities reflect the tax effects of such differences that are anticipated to result in taxable or deductible amounts in the future, when the temporary differences reverse. DTAs are recognized if it is more likely than not they will be realized, and may be reduced by a valuation allowance if it is more likely than not that all or some portion will not be realized. Tax positions that are uncertain but meet a more likely than not recognition threshold are initially and subsequently measured as the largest amount of tax benefit that has a greater than 50% likelihood of being realized upon settlement with a taxing authority that has full knowledge of all relevant information. The determination of whether or not a tax position meets the more likely than not recognition threshold considers the facts, circumstances, and information available at the reporting date and is subject to management's judgment. Webster recognizes interest expense and penalties on uncertain tax positions as a component of income tax expense and recognizes interest income on refundable income taxes as a component of other non-interest income.
Earnings Per Common Share	Earnings Per Common Share Earnings per common share is computed under the two-class method. Basic earnings per common share is computed by dividing earnings allocated to common shareholders by the weighted-average number of common shares outstanding during the applicable period, excluding outstanding non-participating securities. Certain non-vested restricted stock awards are participating securities as they have non-forfeitable rights to dividends or dividend equivalents. 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 and warrants for common stock using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted-average common shares used in calculating diluted earnings per common share is provided in Note 14: Earnings Per Common Share .
Comprehensive Income	Comprehensive Income Comprehensive income includes all changes in shareholders’ equity during a period, except those resulting from transactions with shareholders. Comprehensive income consists of net income, and the after-tax effect of the following items; changes in net unrealized gain/loss on securities available for sale, changes in net unrealized gain/loss on derivative instruments, and changes in net actuarial gain/loss and prior service cost for defined benefit pension and other postretirement benefit plans. Comprehensive income is reported in the accompanying Consolidated Statements of Shareholders' Equity, Consolidated Statements of Comprehensive Income, and Note 12: Accumulated Other Comprehensive Loss, Net of Tax .
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Derivatives are recognized as assets and liabilities in the accompanying Consolidated Balance Sheets and measured at fair value. For exchange-traded contracts, fair value is based on quoted market prices. For non-exchange traded contracts, fair value is based on dealer quotes, pricing models, discounted cash flow methodologies, or similar techniques for which the determination of fair value may require management judgment or estimation, relating to future rates and credit activities. Interest Rate Swap Agreements. For asset/liability management purposes, the Company uses interest rate swap agreements to hedge various exposures or to modify interest rate characteristics of various balance sheet accounts. Interest rate swaps are contracts in which a series of interest rate flows are exchanged over a prescribed period of time. The notional amount on which the interest payments are based is not exchanged. These swap agreements are derivative instruments and generally convert a portion of the Company’s variable-rate debt to a fixed-rate (cash flow hedge), or convert a portion of its fixed-rate debt to a variable-rate (fair value hedge). Webster uses forward-settle interest rate swaps to protect the Company against adverse fluctuations in interest rates by reducing its exposure to variability in cash flows relating to interest payments on forecasted debt issuances. Forward-settle swaps typically have a future effective date that coincides with the expected debt issuance date. The forward-settle swaps are typically terminated and cash settled upon hedge debt issuance date. The gain or loss on a derivative designated and qualifying as a fair value hedging instrument, as well as the offsetting gain or loss on the hedged item attributable to the risk being hedged, is recognized currently in earnings in the same accounting period. The effective portion of the gain or loss on a derivative designated and qualifying as a cash flow hedging instrument is initially reported as a component of AOCL and subsequently reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. The ineffective portion of the gain or loss on the derivative instrument, if any, is recognized in non-interest income. Interest rate derivative financial instruments receive hedge accounting treatment only if they are qualified and properly designated as hedges and are expected to be, and are, effective in substantially reducing interest rate risk arising from specifically identified assets and liabilities. A hedging instrument is expected at inception to be highly effective at offsetting changes in the hedged transactions attributable to the changes in the hedged risk. The Company expects that the hedging relationship will be highly effective; however, it does not assume there is no ineffectiveness. The Company performs quarterly prospective and retrospective assessments of the hedge effectiveness to ensure the hedging relationship continues to be highly effective and that hedge accounting can continue to be applied. Those derivative financial instruments that do not meet specified hedging criteria are recorded at fair value with changes in fair value recorded in income. Cash flows from derivative financial instruments designated for hedge accounting are classified in the cash flow statement in the same category as the cash flows of the asset or liability being hedged. Derivative Loan Commitments. Mortgage loan commitments related to the origination of mortgages that will be held for sale upon funding are considered derivative instruments. Loan commitments that are derivatives are recognized at fair value on the Consolidated Balance Sheets in other assets and other liabilities with changes in their fair values recorded in non-interest income. Counterparty Credit Risk. The Company's exposures with the majority of its approved financial institution counterparties are cash collateralized. In accordance with Webster policies, institutional counterparties must be fully underwritten and approved through the Company’s credit approval process. The Company’s credit exposure on interest rate swaps is limited to the net favorable value and interest payments of all swaps by each of the counterparties. Credit exposure may be reduced by the amount of collateral pledged by the counterparty. The Company evaluates the credit risk of its counterparties, taking into account such factors as the likelihood of default, its net exposures, and remaining contractual life, among other things, in determining if any adjustments related to credit risk are required.
Offsetting Assets and Liabilities	Offsetting Assets and Liabilities The Company presents derivative receivables and derivative payables with the same counterparty and the related variation margin of cash collateral receivables and payables on a net basis on the Consolidated Balance Sheets when a legally enforceable master netting agreement exists. The cash collateral, relating to the initial margin, is included within accrued interest receivable and other assets in the Consolidated Balance Sheets.
Fair Value Measurements	Fair Value Measurements The Company measures many of its assets and liabilities on a fair value basis, in accordance with ASC Topic 820, " Fair Value Measurement. " Fair value is used on a recurring basis for certain assets and liabilities in which fair value is the primary basis of accounting. Examples of these include derivative instruments, available-for-sale securities and loans held for sale where the Company has elected the fair value option. Additionally, fair value is used on a non-recurring basis to evaluate assets or liabilities for impairment. Examples of these include impaired loans and leases, mortgage servicing assets, long-lived assets, goodwill, and loans not originated for sale but subsequently transferred to held for sale, which are accounted for at the lower of cost or fair value. Further information regarding the Company's policies and methodology used to measure fair value is presented in Note 16: Fair Value Measurements .
Employee Retirement Benefit Plan	Employee Retirement Benefit Plan Webster Bank maintains a noncontributory defined benefit pension plan covering all employees that were participants on or before December 31, 2007. Costs related to this qualified plan, based upon actuarial computations of current and future benefits for eligible employees, are charged to non-interest expense and are funded in accordance with the requirements of the Employee Retirement Income Security Act. An asset is recognized for an overfunded plan and a liability is recognized for an underfunded plan. A supplemental retirement plan is also maintained for select executive level employees that were participants on or before December 31, 2007. Webster Bank also provides postretirement healthcare benefits to certain retired employees. In December 2016, the Company elected to change the approach to estimating service and interest components of net periodic pension cost for the retirement benefit plans. Starting in January 2017, a full yield curve approach will be utilized to measure the benefit obligation. The Company changed to the new estimate method to improve the correlation between projected benefit cash flows and the corresponding yield spot rates and to provide a more precise measurement of service and interest costs. Historically the Company estimated service and interest costs utilizing a single-weighted average discount rate derived from the yield curve used to measure the benefit obligation at the beginning of the period. The new method measures service and interest costs separately using the full yield curve approach applied to each corresponding obligation. Service costs are determined based on duration-specific spot rates applied to the service cost cash flows. The interest cost calculation is determined by applying duration-specific spot rates to the year-by-year projected benefit obligation.
Fee Revenue	Fee Revenue Generally, fee revenue from deposit service charges and loans is recorded when earned, except where ultimate collection is uncertain, in which case revenue is recognized as received. Trust revenue is recorded as earned on individual accounts based upon a percentage of asset value. Fee income on managed institutional accounts is recognized as earned and collected quarterly based on the quarter-end value of assets managed.
Marketing Costs	Marketing Costs Marketing costs are expensed as incurred over the projected benefit period.
Recently Adopted and Issued Accounting Standards Updates	Recently Adopted Accounting Standards Updates Effective January 1, 2016 , the following new accounting guidance was adopted by the Company: • ASU No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40) - Disclosures of Uncertainties about an Entity's Ability to Continue as a Going Concern; • ASU No. 2015-02, Consolidation (Topic 810) - Amendments to the Consolidation Analysis; • ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs; • ASU No. 2015-07, Fair Value Measurement (Topic 820) - Disclosures for investments in Certain Entities That Calculate Net Asset Value per Share (or its Equivalent) (a consensus of the FASB Emerging Issues Task Force); and • ASU No. 2015-16, Business Combinations (Topic 805) - Simplifying the Accounting for Measurement - Period Adjustments. The adoption of these accounting standards did not have a material impact on the Company's financial statements. Accounting Standards Issued but not yet Adopted The following table identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU Description Effective Date and Financial Statement Impact ASU No. 2016-15 - Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The Update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The Update addresses the following eight issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The Company intends to adopt the Update for the first quarter of 2019. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Current GAAP requires an "incurred loss" methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. Both financial institutions and users of their financial statements expressed concern that current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the "probable" threshold. The main objective of this Update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this Update replace 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 to determine credit loss estimates. The Change from an "incurred loss" method to an "expected loss" method represents a fundamental shift from existing GAAP, and may result in material changes to the Company's accounting for credit losses on financial instruments. The Company is evaluating the effect that this ASU will have on its financial statements and related disclosures. The ASU will be effective for the Company as of January 1, 2020. ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) - Improvements to Employee Share Based Payment Accounting. The Update impacts the accounting for employee share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. In addition, the amendments in this Update eliminates the guidance in Topic 718 that was indefinitely deferred shortly after the issuance of FASB Statement No. 123 (revised 2004), Share-Based Payment. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU Description Effective Date and Financial Statement Impact ASU No. 2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments. The Update clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The Update requires the assessment of embedded call (put) options solely in accordance with the four-step decision sequence. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-02, Leases (Topic 842). The Update introduces a lessee model that brings most leases on the balance sheet. The Update also aligns certain of the underlying principles of the new lessor model with those in ASC Topic 606 " Revenue from Contracts with Customers, " the FASB’s new revenue recognition standard (e.g., evaluating how collectability should be considered and determining when profit can be recognized). Furthermore, the Update addresses other concerns including the elimination of the required use of bright-line tests for determining lease classification. Lessors are required to provide additional transparency into the exposure to the changes in value of their residual assets and how they manage that exposure. The Company intends to adopt the Update for the first quarter of 2019. The Company expects the Update will have a significant effect on the Company's financial statements. While the Company is continuing to assess the effect of adoption, management currently believes the most significant changes relate to the recognition of new right of use assets and lease liabilities on the Company's balance sheet for operating leases. ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. Equity investments not accounted for under the equity method or those that do not result in consolidation of the investee are to be measured at fair value with changes in the fair value recognized through net income. Entities are to present separately in other comprehensive income, the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when an election to measure the liability at fair value in accordance with the fair value option for financial instruments has been made. Also, the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet has been eliminated. The Company intends to adopt the Update for the first quarter of 2018. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) A single comprehensive model has been established for an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled, and will supersede nearly all existing revenue recognition guidance, and clarify and converge revenue recognition principles under GAAP and International Financial Reporting Standards. The five steps to recognizing revenue: (i) identify the contracts with the customer; (ii) identify the separate performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the separate performance obligations; and (v) recognize revenue when each performance obligation is satisfied. One of the most significant potential impacts relates to less prescriptive derecognition requirements on the sale of owned real estate properties. An entity may elect either a full retrospective or a modified retrospective application. ASU No. 2015-14 - Revenue from Contracts with Customers (Topic 606), defers the effective date to annual and interim periods beginning after December 15, 2017. During 2016, the FASB issued amendments to this standard (ASC Updates 2016-08, 2016-10, 2016-11 and 2016-20). The Updates provide further clarification to the standard. The Company intends to adopt the Update for the first quarter of 2018. The Company's revenue is comprised of net interest income on financial assets and financial liabilities, and non-interest income. While the Company is continuing to assess the effect of adoption, management currently believes the Update may require the Company to change how certain trust and investment management fees within non-interest income are recognized. Management does not expect those changes to have a significant impact on the Company's financial statements. Management continues to evaluate the Update's impact on other components of non-interest income.

Summary of Significant Accoun32

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Error Corrections and Prior Period Adjustments	The effects of correcting the immaterial errors in the Consolidated Balance Sheets, Consolidated Statements of Income and Consolidated Statements of Cash Flows are summarized in the following tables: December 31, 2015 (In thousands) As Reported As Revised Consolidated Balance Sheets Cash and due from banks $ 251,258 $ 199,693 Accrued interest receivable and other assets (1) 328,993 343,856 Accrued expenses and other liabilities 267,576 233,581 Retained earnings 1,317,559 1,315,948 (1) The amount recorded as revised includes the impact of a $1.1 million reclassification of debt issuance cost from accrued interest receivable and other assets into long-term debt. The reclassification was made in accordance with the Company's adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, and is not considered part of the error correction. Year ended December 31, 2015 (In thousands, except per share data) As Reported As Revised Consolidated Statements of Income Deposit service fees $ 136,578 $ 135,057 Other income 23,573 23,326 Technology and equipment 80,026 80,813 Income tax expense 93,976 93,032 Net income 206,340 204,729 Earnings per common share: Basic $ 2.17 $ 2.15 Diluted 2.15 2.13 HSA Segment: Net income $ 39,173 $ 37,443 December 31, 2015 December 31, 2014 (In thousands) As Reported As Revised As Reported As Revised Consolidated Statements of Cash Flows Net (increase) in accrued interest receivable and other assets (1) $ (49,899 ) $ (44,334 ) $ (24,502 ) $ (2,552 ) Net increase in accrued expenses and other liabilities (1) 35,336 33,478 9,213 6,601 (1) An additional line item, net decrease (increase) in derivative contract assets net of liabilities, was added to the Consolidated Statements of Cash Flows to detail the net change in derivative balances subject to offsetting. The update removed $6.5 million and $49.2 million in net increases in derivative contract assets net of liabilities from the net (increase) in accrued interest receivable and other assets and net increase in accrued expenses and other liabilities line items for the years ended December 31, 2015 and December 31, 2014 respectively.
Property, Plant and Equipment	Premises and equipment are carried at cost, less accumulated depreciation. Depreciation of premises and equipment is computed on a straight-line basis over the estimated useful lives of the assets, as follows: Building and Improvements 5 - 40 years Leasehold improvements 5 - 20 years (or term or lease, if shorter) Fixtures and equipment 5 - 10 years Data processing and software 3 - 7 years A summary of premises and equipment follows: At December 31, (In thousands) 2016 2015 Land $ 12,595 $ 12,899 Buildings and improvements 90,778 94,686 Leasehold improvements 83,995 79,917 Fixtures and equipment 76,146 73,686 Data processing and software 220,002 195,308 Total premises and equipment 483,516 456,496 Less: Accumulated depreciation and amortization (346,103 ) (327,070 ) Premises and equipment, net $ 137,413 $ 129,426
Schedule of Prospective Adoption of New Accounting Pronouncements	The following table identifies ASUs applicable to the Company that have been issued by the FASB but are not yet effective: ASU Description Effective Date and Financial Statement Impact ASU No. 2016-15 - Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The Update addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The Update addresses the following eight issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies; distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. The Company intends to adopt the Update for the first quarter of 2019. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-13 - Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Current GAAP requires an "incurred loss" methodology for recognizing credit losses that delays recognition until it is probable a loss has been incurred. Both financial institutions and users of their financial statements expressed concern that current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the "probable" threshold. The main objective of this Update is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in this Update replace 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 to determine credit loss estimates. The Change from an "incurred loss" method to an "expected loss" method represents a fundamental shift from existing GAAP, and may result in material changes to the Company's accounting for credit losses on financial instruments. The Company is evaluating the effect that this ASU will have on its financial statements and related disclosures. The ASU will be effective for the Company as of January 1, 2020. ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) - Improvements to Employee Share Based Payment Accounting. The Update impacts the accounting for employee share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. In addition, the amendments in this Update eliminates the guidance in Topic 718 that was indefinitely deferred shortly after the issuance of FASB Statement No. 123 (revised 2004), Share-Based Payment. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU Description Effective Date and Financial Statement Impact ASU No. 2016-06, Derivatives and Hedging (Topic 815) - Contingent Put and Call Options in Debt Instruments. The Update clarifies the requirements for assessing whether contingent call (put) options that can accelerate the payment of principal on debt instruments are clearly and closely related to their debt hosts. The Update requires the assessment of embedded call (put) options solely in accordance with the four-step decision sequence. The Company intends to adopt the Update for the first quarter of 2017. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2016-02, Leases (Topic 842). The Update introduces a lessee model that brings most leases on the balance sheet. The Update also aligns certain of the underlying principles of the new lessor model with those in ASC Topic 606 " Revenue from Contracts with Customers, " the FASB’s new revenue recognition standard (e.g., evaluating how collectability should be considered and determining when profit can be recognized). Furthermore, the Update addresses other concerns including the elimination of the required use of bright-line tests for determining lease classification. Lessors are required to provide additional transparency into the exposure to the changes in value of their residual assets and how they manage that exposure. The Company intends to adopt the Update for the first quarter of 2019. The Company expects the Update will have a significant effect on the Company's financial statements. While the Company is continuing to assess the effect of adoption, management currently believes the most significant changes relate to the recognition of new right of use assets and lease liabilities on the Company's balance sheet for operating leases. ASU No. 2016-01, Financial Instruments—Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. Equity investments not accounted for under the equity method or those that do not result in consolidation of the investee are to be measured at fair value with changes in the fair value recognized through net income. Entities are to present separately in other comprehensive income, the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when an election to measure the liability at fair value in accordance with the fair value option for financial instruments has been made. Also, the requirement to disclose the method(s) and significant assumptions used to estimate the fair value for financial instruments measured at amortized cost on the balance sheet has been eliminated. The Company intends to adopt the Update for the first quarter of 2018. Adoption is not anticipated to have a material impact on the Company's financial statements. ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) A single comprehensive model has been established for an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled, and will supersede nearly all existing revenue recognition guidance, and clarify and converge revenue recognition principles under GAAP and International Financial Reporting Standards. The five steps to recognizing revenue: (i) identify the contracts with the customer; (ii) identify the separate performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the separate performance obligations; and (v) recognize revenue when each performance obligation is satisfied. One of the most significant potential impacts relates to less prescriptive derecognition requirements on the sale of owned real estate properties. An entity may elect either a full retrospective or a modified retrospective application. ASU No. 2015-14 - Revenue from Contracts with Customers (Topic 606), defers the effective date to annual and interim periods beginning after December 15, 2017. During 2016, the FASB issued amendments to this standard (ASC Updates 2016-08, 2016-10, 2016-11 and 2016-20). The Updates provide further clarification to the standard. The Company intends to adopt the Update for the first quarter of 2018. The Company's revenue is comprised of net interest income on financial assets and financial liabilities, and non-interest income. While the Company is continuing to assess the effect of adoption, management currently believes the Update may require the Company to change how certain trust and investment management fees within non-interest income are recognized. Management does not expect those changes to have a significant impact on the Company's financial statements. Management continues to evaluate the Update's impact on other components of non-interest income.

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Summary of Investment Securities	A Summary of the amortized cost and fair value of investment securities is presented below: At December 31, 2016 2015 (In thousands) Amortized Cost Unrealized Gains Unrealized Losses Fair Value Amortized Cost Unrealized Gains Unrealized Losses Fair Value Available-for-sale: U.S. Treasury Bills $ 734 $ — $ — $ 734 $ 924 $ — $ — $ 924 Agency CMO 419,865 3,344 (3,503 ) 419,706 546,168 5,532 (2,946 ) 548,754 Agency MBS 969,460 4,398 (19,509 ) 954,349 1,075,941 6,459 (17,291 ) 1,065,109 Agency CMBS 587,776 63 (14,567 ) 573,272 215,670 639 (959 ) 215,350 CMBS 473,974 4,093 (702 ) 477,365 574,686 7,485 (2,905 ) 579,266 CLO 425,083 2,826 (519 ) 427,390 431,837 592 (3,270 ) 429,159 Single issuer trust preferred securities 30,381 — (1,748 ) 28,633 42,168 — (4,998 ) 37,170 Corporate debt securities 108,490 1,502 (350 ) 109,642 104,031 2,290 — 106,321 Equities - financial institutions — — — — 3,499 — (921 ) 2,578 Total available-for-sale $ 3,015,763 $ 16,226 $ (40,898 ) $ 2,991,091 $ 2,994,924 $ 22,997 $ (33,290 ) $ 2,984,631 Held-to-maturity: Agency CMO $ 339,455 $ 1,977 $ (3,824 ) $ 337,608 $ 407,494 $ 3,717 $ (2,058 ) $ 409,153 Agency MBS 2,317,449 26,388 (41,768 ) 2,302,069 2,030,176 38,813 (19,908 ) 2,049,081 Agency CMBS 547,726 694 (1,348 ) 547,072 686,086 4,253 (325 ) 690,014 Municipal bonds and notes 655,813 4,389 (25,749 ) 634,453 435,905 12,019 (417 ) 447,507 CMBS 298,538 4,107 (411 ) 302,234 360,018 5,046 (2,704 ) 362,360 Private Label MBS 1,677 12 — 1,689 3,373 46 — 3,419 Total held-to-maturity $ 4,160,658 $ 37,567 $ (73,100 ) $ 4,125,125 $ 3,923,052 $ 63,894 $ (25,412 ) $ 3,961,534
Other than Temporary Impairment, Credit Losses Recognized in Earnings	The following table presents the changes in OTTI: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 3,288 $ 3,696 $ 16,633 Reduction for securities sold or called (194 ) (518 ) (14,082 ) Additions for OTTI not previously recognized 149 110 1,145 Ending balance $ 3,243 $ 3,288 $ 3,696
Summary of Gross Unrealized Losses not Considered OTTI	The following tables provide information on fair value and unrealized losses for the individual securities with an unrealized loss, aggregated by investment security type and length of time that the individual securities have been in a continuous unrealized loss position: At December 31, 2016 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 107,853 $ (2,168 ) $ 67,351 $ (1,335 ) 15 $ 175,204 $ (3,503 ) Agency MBS 512,075 (10,503 ) 252,779 (9,006 ) 97 764,854 (19,509 ) Agency CMBS 554,246 (14,567 ) — — 32 554,246 (14,567 ) CMBS 12,427 (24 ) 63,930 (678 ) 12 76,357 (702 ) CLO 49,946 (54 ) 50,237 (465 ) 5 100,183 (519 ) Single issuer trust preferred securities — — 28,633 (1,748 ) 5 28,633 (1,748 ) Corporate debt securities — — 7,384 (350 ) 2 7,384 (350 ) Equities-financial institutions — — — — — — — Total available-for-sale in an unrealized loss position $ 1,236,547 $ (27,316 ) $ 470,314 $ (13,582 ) 168 $ 1,706,861 $ (40,898 ) Held-to-maturity: Agency CMO $ 163,439 $ (3,339 ) $ 17,254 $ (485 ) 16 $ 180,693 $ (3,824 ) Agency MBS 1,394,623 (32,942 ) 273,779 (8,826 ) 150 1,668,402 (41,768 ) Agency CMBS 347,725 (1,348 ) — — 25 347,725 (1,348 ) Municipal bonds and notes 384,795 (25,745 ) 1,192 (4 ) 196 385,987 (25,749 ) CMBS 60,768 (411 ) — — 8 60,768 (411 ) Total held-to-maturity in an unrealized loss position $ 2,351,350 $ (63,785 ) $ 292,225 $ (9,315 ) 395 $ 2,643,575 $ (73,100 ) At December 31, 2015 Less Than Twelve Months Twelve Months or Longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses # of Holdings Fair Value Unrealized Losses Available-for-sale: Agency CMO $ 195,369 $ (2,195 ) $ 26,039 $ (751 ) 14 $ 221,408 $ (2,946 ) Agency MBS 481,839 (6,386 ) 351,911 (10,905 ) 84 833,750 (17,291 ) Agency CMBS 124,241 (959 ) — — 7 124,241 (959 ) CMBS 276,330 (2,879 ) 19,382 (26 ) 29 295,712 (2,905 ) CLO 211,515 (2,709 ) 15,708 (561 ) 13 227,223 (3,270 ) Single issuer trust preferred securities 4,087 (128 ) 33,083 (4,870 ) 8 37,170 (4,998 ) Corporate debt securities — — — — — — — Equities-financial institutions 2,578 (921 ) — — 1 2,578 (921 ) Total available-for-sale in an unrealized loss position $ 1,295,959 $ (16,177 ) $ 446,123 $ (17,113 ) 156 $ 1,742,082 $ (33,290 ) Held-to-maturity: Agency CMO $ 143,364 $ (1,304 ) $ 27,928 $ (754 ) 13 $ 171,292 $ (2,058 ) Agency MBS 551,918 (7,089 ) 470,828 (12,819 ) 87 1,022,746 (19,908 ) Agency CMBS 110,864 (325 ) — — 7 110,864 (325 ) Municipal bonds and notes 29,034 (130 ) 13,829 (287 ) 27 42,863 (417 ) CMBS 142,382 (1,983 ) 30,129 (721 ) 18 172,511 (2,704 ) Total held-to-maturity in an unrealized loss position $ 977,562 $ (10,831 ) $ 542,714 $ (14,581 ) 152 $ 1,520,276 $ (25,412 )
Summary of Sale Proceeds of Available for Sale Securities	The following table provides information on sales of available-for-sale securities: Years ended December 31, (In thousands) 2016 2015 2014 Proceeds from sales $ 259,273 $ 95,101 $ 126,580 Gross realized gains on sales $ 2,891 $ 1,029 $ 7,268 Less: Gross realized losses on sales 2,477 420 1,769 Gain on sale of investment securities, net $ 414 $ 609 $ 5,499
Summary of Debt Securities by Contractual Maturity	The amortized cost and fair value of debt securities by contractual maturity are set forth below: At December 31, 2016 Available-for-Sale Held-to-Maturity (In thousands) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 75,466 $ 76,383 $ 13,612 $ 13,721 Due after one year through five years 21,781 22,190 17,313 17,611 Due after five through ten years 529,247 532,352 46,835 47,780 Due after ten years 2,389,269 2,360,166 4,082,898 4,046,013 Total debt securities $ 3,015,763 $ 2,991,091 $ 4,160,658 $ 4,125,125

Loans and Leases (Tables)

Loans and Leases (Tables)	12 Months Ended
	Dec. 31, 2016
Loans and Leases Receivable Disclosure [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	The following table summarizes loans and leases: At December 31, (In thousands) 2016 2015 Residential $ 4,254,682 $ 4,061,001 Consumer 2,684,500 2,702,560 Commercial 4,940,931 4,315,999 Commercial Real Estate 4,510,846 3,991,649 Equipment Financing 635,629 600,526 Loans and leases (1) (2) $ 17,026,588 $ 15,671,735 (1) Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015 , respectively. (2) At December 31, 2016 , the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
Past Due Financing Receivables	The following tables summarize the aging of loans and leases: At December 31, 2016 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans and Leases Residential $ 8,631 $ 2,609 $ — $ 47,279 $ 58,519 $ 4,196,163 $ 4,254,682 Consumer: Home equity 8,831 5,782 — 35,926 50,539 2,359,354 2,409,893 Other consumer 2,233 1,485 — 1,663 5,381 269,226 274,607 Commercial: Commercial non-mortgage 1,382 577 749 38,190 40,898 4,094,727 4,135,625 Asset-based — — — — — 805,306 805,306 Commercial real estate: Commercial real estate 6,357 1,816 — 9,871 18,044 4,117,742 4,135,786 Commercial construction — — — 662 662 374,398 375,060 Equipment financing 903 693 — 225 1,821 633,808 635,629 Total $ 28,337 $ 12,962 $ 749 $ 133,816 $ 175,864 $ 16,850,724 $ 17,026,588 At December 31, 2015 (In thousands) 30-59 Days Past Due and Accruing 60-89 Days 90 or More Days Past Due and Accruing Non-accrual Total Past Due and Non-accrual Current Total Loans and Leases Residential $ 10,365 $ 4,703 $ 2,029 $ 54,201 $ 71,298 $ 3,989,703 $ 4,061,001 Consumer: Home equity 9,061 4,242 — 37,337 50,640 2,402,758 2,453,398 Other consumer 1,390 615 — 560 2,565 246,597 249,162 Commercial: Commercial non-mortgage 768 3,288 22 27,037 31,115 3,531,669 3,562,784 Asset-based — — — — — 753,215 753,215 Commercial real estate: Commercial real estate 1,624 625 — 16,767 19,016 3,673,408 3,692,424 Commercial construction — — — 3,461 3,461 295,764 299,225 Equipment financing 543 59 — 706 1,308 599,218 600,526 Total $ 23,751 $ 13,532 $ 2,051 $ 140,069 $ 179,403 $ 15,492,332 $ 15,671,735
Activity In Allowance For Losses	The following tables summarize the activity in, as well as the loan and lease balances that were evaluated for, the ALLL: At or for the Year ended December 31, 2016 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2016 $ 25,876 $ 42,052 $ 59,977 $ 41,598 $ 5,487 $ 174,990 Provision (benefit) charged to expense 230 18,507 28,662 7,930 1,021 56,350 Losses charged off (4,636 ) (20,669 ) (18,360 ) (2,682 ) (565 ) (46,912 ) Recoveries 1,756 5,343 1,626 631 536 9,892 Balance at December 31, 2016 $ 23,226 $ 45,233 $ 71,905 $ 47,477 $ 6,479 $ 194,320 Individually evaluated for impairment $ 8,090 $ 2,903 $ 7,422 $ 169 $ 9 $ 18,593 Collectively evaluated for impairment $ 15,136 $ 42,330 $ 64,483 $ 47,308 $ 6,470 $ 175,727 Loan and lease balances: Individually evaluated for impairment $ 119,424 $ 45,719 $ 53,037 $ 24,755 $ 6,420 $ 249,355 Collectively evaluated for impairment 4,135,258 2,638,781 4,887,894 4,486,091 629,209 16,777,233 Loans and leases $ 4,254,682 $ 2,684,500 $ 4,940,931 $ 4,510,846 $ 635,629 $ 17,026,588 At or for the Year ended December 31, 2015 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2015 $ 25,452 $ 43,518 $ 47,068 $ 37,148 $ 6,078 $ 159,264 Provision (benefit) charged to expense 6,057 11,847 21,693 11,381 (1,678 ) 49,300 Losses charged off (6,508 ) (17,679 ) (11,522 ) (7,578 ) (273 ) (43,560 ) Recoveries 875 4,366 2,738 647 1,360 9,986 Balance at December 31, 2015 $ 25,876 $ 42,052 $ 59,977 $ 41,598 $ 5,487 $ 174,990 Individually evaluated for impairment $ 10,364 $ 3,477 $ 5,197 $ 3,163 $ 3 $ 22,204 Collectively evaluated for impairment $ 15,512 $ 38,575 $ 54,780 $ 38,435 $ 5,484 $ 152,786 Loan and lease balances: Individually evaluated for impairment $ 134,448 $ 48,425 $ 56,581 $ 39,295 $ 422 $ 279,171 Collectively evaluated for impairment 3,926,553 2,654,135 4,259,418 3,952,354 600,104 15,392,564 Loans and leases $ 4,061,001 $ 2,702,560 $ 4,315,999 $ 3,991,649 $ 600,526 $ 15,671,735 At or for the Year ended December 31, 2014 (In thousands) Residential Consumer Commercial Commercial Real Estate Equipment Financing Total Allowance for loan and lease losses: Balance at January 1, 2014 $ 23,027 $ 41,951 $ 46,655 $ 36,754 $ 4,186 $ 152,573 Provision (benefit) charged to expense 7,315 17,224 9,712 2,746 253 37,250 Losses charged off (6,214 ) (20,712 ) (13,668 ) (3,237 ) (595 ) (44,426 ) Recoveries 1,324 5,055 4,369 885 2,234 13,867 Balance at December 31, 2014 $ 25,452 $ 43,518 $ 47,068 $ 37,148 $ 6,078 $ 159,264 Individually evaluated for impairment $ 12,094 $ 4,237 $ 2,710 $ 6,232 $ 28 $ 25,301 Collectively evaluated for impairment $ 13,358 $ 39,281 $ 44,358 $ 30,916 $ 6,050 $ 133,963 Loan and lease balances: Individually evaluated for impairment $ 141,982 $ 50,249 $ 36,176 $ 101,817 $ 632 $ 330,856 Collectively evaluated for impairment 3,367,193 2,499,152 3,713,094 3,452,611 537,119 13,569,169 Loans and leases $ 3,509,175 $ 2,549,401 $ 3,749,270 $ 3,554,428 $ 537,751 $ 13,900,025
Impaired Loans	The following tables summarize impaired loans and leases: At December 31, 2016 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential: 1-4 family $ 131,468 $ 119,424 $ 21,068 $ 98,356 $ 8,090 Consumer: Home equity 52,432 45,719 22,746 22,973 2,903 Commercial: Commercial non-mortgage 57,732 53,037 26,006 27,031 7,422 Commercial real estate: Commercial real estate 24,146 23,568 19,591 3,977 169 Commercial construction 1,188 1,187 1,187 — — Equipment financing 6,398 6,420 6,197 223 9 Total $ 273,364 $ 249,355 $ 96,795 $ 152,560 $ 18,593 At December 31, 2015 (In thousands) Unpaid Principal Balance Total Recorded Investment Recorded Investment No Allowance Recorded Investment With Allowance Related Valuation Allowance Residential: 1-4 family $ 148,144 $ 134,448 $ 23,024 $ 111,424 $ 10,364 Consumer: Home equity 56,680 48,425 25,130 23,295 3,477 Commercial: Commercial non-mortgage 67,116 56,581 31,600 24,981 5,197 Commercial real estate: Commercial real estate 36,980 33,333 9,204 24,129 3,160 Commercial construction 7,010 5,962 5,939 23 3 Equipment financing 612 422 328 94 3 Total $ 316,542 $ 279,171 $ 95,225 $ 183,946 $ 22,204 The following table summarizes the average recorded investment and interest income recognized for impaired loans and leases: Years ended December 31, 2016 2015 2014 (In thousands) Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Recorded Investment Accrued Interest Income Cash Basis Interest Income Average Accrued Cash Basis Interest Income Residential $ 126,936 $ 4,377 $ 1,200 $ 138,215 $ 4,473 $ 1,139 $ 142,198 $ 4,644 $ 1,221 Consumer 47,072 1,361 985 49,337 1,451 1,099 51,171 1,484 1,203 Commercial 54,708 1,540 — 46,379 1,319 — 44,097 2,326 — Commercial real estate: Commercial real estate 28,451 511 — 64,495 1,165 — 93,209 3,429 — Commercial construction 3,574 92 — 6,062 133 — 8,381 269 — Equipment financing 3,421 184 — 527 16 — 421 28 — Total $ 264,162 $ 8,065 $ 2,185 $ 305,015 $ 8,557 $ 2,238 $ 339,477 $ 12,180 $ 2,424
Financing Receivable Credit Quality Indicators	The following table summarizes commercial, commercial real estate and equipment financing loans and leases segregated by risk rating exposure: Commercial Commercial Real Estate Equipment Financing (In thousands) At December 31, At December 31, At December 31, At December 31, At December 31, At December 31, (1) - (6) Pass $ 4,655,007 $ 4,023,255 $ 4,357,458 $ 3,857,019 $ 618,084 $ 586,445 (7) Special Mention 56,240 70,904 69,023 55,030 1,324 1,628 (8) Substandard 226,603 220,389 84,365 79,289 16,221 12,453 (9) Doubtful 3,081 1,451 — 311 — — Total $ 4,940,931 $ 4,315,999 $ 4,510,846 $ 3,991,649 $ 635,629 $ 600,526
Troubled Debt Restructurings on Financing Receivables	Troubled Debt Restructurings The following table summarizes information for TDRs: At December 31, (Dollars in thousands) 2016 2015 Accrual status $ 147,809 $ 171,784 Non-accrual status 75,719 100,906 Total recorded investment of TDR (1) $ 223,528 $ 272,690 Accruing TDR performing under modified terms more than one year 57.1 % 55.0 % Specific reserves for TDR included in the balance of ALLL $ 14,583 $ 21,405 Additional funds committed to borrowers in TDR status 459 1,133 (1) Total recorded investment of TDRs exclude $0.7 million and $1.1 million at December 31, 2016 and December 31, 2015 , respectively, of accrued interest receivable. For years ended December 31, 2016 , 2015 and 2014 , Webster charged off $18.6 million , $11.8 million , and $13.5 million , respectively, for the portion of TDRs deemed to be uncollectible. The following table provides information on the type of concession for loans and leases modified as TDRs: Years ended December 31, 2016 2015 2014 Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) Number of Loans and Leases Post- Modification Recorded Investment (1) (Dollars in thousands) Residential: Extended Maturity 17 $ 2,801 27 $ 4,909 27 $ 3,547 Adjusted Interest rates 2 528 3 573 3 448 Combination Rate and Maturity 13 1,537 26 5,315 22 4,220 Other (2) 24 4,090 30 4,366 55 11,791 Consumer: Extended Maturity 11 484 12 1,012 19 944 Adjusted Interest rates — — — — 1 51 Combination Rate and Maturity 15 1,156 12 945 6 411 Other (2) 52 3,131 68 3,646 90 4,931 Commercial: Extended Maturity 12 14,883 3 254 7 422 Adjusted Interest rates — — 1 24 1 25 Combination Rate and Maturity 2 648 7 5,361 22 1,212 Other (2) 13 1,767 20 22,048 6 7,431 Commercial real estate: Extended Maturity 3 4,921 1 315 — — Adjusted Interest rates 1 237 — — — — Combination Rate and Maturity 2 335 1 42 2 11,106 Other (2) 1 509 1 405 — — Equipment Financing Extended Maturity 7 6,642 — — 1 492 Total 175 $ 43,669 212 $ 49,215 262 $ 47,031 (1) Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant. (2) Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, and/or other concessions. The following table provides information on loans and leases modified as TDRs within the previous 12 months and for which there was a payment default during the periods presented: Years ended December 31, 2016 2015 2014 (Dollars in thousands) Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Number of Loans and Leases Recorded Investment Residential — $ — 1 $ 55 7 $ 1,494 Consumer — — 1 3 2 24 Total — $ — 2 $ 58 9 $ 1,518 The recorded investment of TDRs in commercial, commercial real estate, and equipment financing segregated by risk rating exposure is as follows: At December 31, (In thousands) 2016 2015 (1) - (6) Pass $ 10,210 $ 12,970 (7) Special Mention 7 2,999 (8) Substandard 45,509 72,132 (9) Doubtful 2,738 1,717 Total $ 58,464 $ 89,818

Transfers of Financial Assets (

Transfers of Financial Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Transfers and Servicing [Abstract]
Schedule of Reserve For Loan Repurchases Table	The following table provides a summary of activity in the reserve for loan repurchases: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 1,192 $ 1,059 $ 2,254 (Benefit) provision charged to expense (303 ) 133 (493 ) Repurchased loans and settlements charged off (99 ) — (702 ) Ending balance $ 790 $ 1,192 $ 1,059
Schedule of Servicing Assets at Fair Value	The following table provides information for mortgage banking activities: Years ended December 31, (In thousands) 2016 2015 2014 Residential mortgage loans held for sale: Proceeds from sale $ 438,925 $ 452,590 $ 287,132 Net gain on sale 11,629 7,795 4,070 Fair value option adjustment (526 ) — — Loans sold with servicing rights retained 399,318 416,277 264,292 The following table presents the changes in fair value for mortgage servicing assets: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 33,568 $ 28,690 Originations of servicing assets 11,312 8,027 Changes in fair value: Due to payoffs/paydowns (2,447 ) (2,741 ) Due to market changes 9,642 (408 ) Ending balance $ 52,075 $ 33,568
Servicing Asset at Amortized Cost	The following table presents the changes in carrying value for mortgage servicing assets: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 20,698 $ 19,379 $ 20,983 Additions 11,312 8,027 4,581 Amortization (7,554 ) (6,699 ) (6,318 ) Valuation recovery (provision) (1) 10 (9 ) 133 Ending balance $ 24,466 $ 20,698 $ 19,379 (1) The valuation recovery (provision) resulted in a valuation allowance balance of $22 thousand , $32 thousand , and $23 thousand at December 31, 2016, 2015, and 2014, respectively.

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Premises and equipment are carried at cost, less accumulated depreciation. Depreciation of premises and equipment is computed on a straight-line basis over the estimated useful lives of the assets, as follows: Building and Improvements 5 - 40 years Leasehold improvements 5 - 20 years (or term or lease, if shorter) Fixtures and equipment 5 - 10 years Data processing and software 3 - 7 years A summary of premises and equipment follows: At December 31, (In thousands) 2016 2015 Land $ 12,595 $ 12,899 Buildings and improvements 90,778 94,686 Leasehold improvements 83,995 79,917 Fixtures and equipment 76,146 73,686 Data processing and software 220,002 195,308 Total premises and equipment 483,516 456,496 Less: Accumulated depreciation and amortization (346,103 ) (327,070 ) Premises and equipment, net $ 137,413 $ 129,426
Disclosure of Long Lived Assets Held-for-sale	The following table provides a summary of activity for assets held for disposition: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 637 $ 759 Additions — 144 Write-downs — — Sales — (266 ) Ending balance $ 637 $ 637

Goodwill and Other Intangible37

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Goodwill and other intangible assets by reportable segment consisted of the following: At December 31, 2016 2015 (In thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Other intangible assets: Community Banking, CDI $ 49,420 $ (49,420 ) $ — $ 49,420 $ (48,277 ) $ 1,143 HSA Bank: CDI 22,000 (6,162 ) 15,838 22,000 (3,269 ) 18,731 Customer relationships 21,000 (3,164 ) 17,836 21,000 (1,548 ) 19,452 Total HSA Bank 43,000 (9,326 ) 33,674 43,000 (4,817 ) 38,183 Total other intangible assets $ 92,420 $ (58,746 ) $ 33,674 $ 92,420 $ (53,094 ) $ 39,326 Goodwill: Community Banking $ 516,560 $ 516,560 $ 516,560 $ 516,560 HSA Bank 21,813 21,813 21,813 21,813 Total goodwill $ 538,373 $ 538,373 $ 538,373 $ 538,373
Schedule Of Expected Amortization Expense, Next Four Years	As of December 31, 2016 , the remaining estimated aggregate future amortization expense for intangible assets is as follows: (In thousands) 2017 $ 4,062 2018 3,847 2019 3,847 2020 3,847 2021 3,847 Thereafter 14,224

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Income tax expense reflects the following expense (benefit) components: Years ended December 31, (In thousands) 2016 2015 2014 Current: Federal $ 73,194 $ 97,575 $ 90,542 State and local 5,429 10,970 6,585 Total current 78,623 108,545 97,127 Deferred: Federal 12,542 (7,279 ) (3,784 ) State and local 5,158 (8,234 ) (1,370 ) Total deferred 17,700 (15,513 ) (5,154 ) Total federal 85,736 90,296 86,758 Total state and local 10,587 2,736 5,215 Income tax expense $ 96,323 $ 93,032 $ 91,973
Schedule of Effective Income Tax Rate Reconciliation	The following table reflects a reconciliation of reported income tax expense to the amount that would result from applying the federal statutory rate of 35.0% : Years ended December 31, 2016 2015 2014 (Dollars in thousands) Amount Percent Amount Percent Amount Percent Income tax expense at federal statutory rate $ 106,208 35.0 % $ 104,217 35.0 % $ 102,095 35.0 % Reconciliation to reported income tax expense: State and local income taxes, net of federal benefit 6,882 2.3 7,563 2.5 3,390 1.2 Tax-exempt interest income, net (8,917 ) (2.9 ) (7,117 ) (2.4 ) (7,335 ) (2.5 ) Decrease in valuation allowance applicable to net state deferred tax assets, net of federal effects — — (5,785 ) (1.9 ) — — Increase in cash surrender value of life insurance (5,166 ) (1.7 ) (4,557 ) (1.5 ) (4,612 ) (1.6 ) Other, net (2,684 ) (1.0 ) (1,289 ) (0.5 ) (1,565 ) (0.6 ) Income tax expense and effective tax rate $ 96,323 31.7 % $ 93,032 31.2 % $ 91,973 31.5 %
Schedule of Deferred Tax Assets and Liabilities	The following table reflects the significant components of the deferred tax assets, net: At December 31, (In thousands) 2016 2015 Deferred tax assets: Allowance for loan and lease losses $ 77,908 $ 70,937 Net operating loss and credit carry forwards 64,644 68,735 Compensation and employee benefit plans 46,433 52,422 Net losses on derivative instruments 8,624 11,734 Net unrealized loss on securities available for sale 9,898 4,138 Other 17,682 21,663 Gross deferred tax assets 225,189 229,629 Valuation allowance (71,474 ) (74,918 ) Total deferred tax assets, net of valuation allowance $ 153,715 $ 154,711 Deferred tax liabilities: Equipment-financing leases $ 41,910 $ 23,934 Deferred income on repurchase of debt 4,251 6,376 Intangible assets 9,952 9,298 Mortgage servicing assets 7,313 7,127 Other 5,898 6,398 Gross deferred tax liabilities 69,324 53,133 Deferred tax assets, net $ 84,391 $ 101,578
Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible	The following table reflects a reconciliation of the beginning and ending balances for UTBs: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 5,094 $ 4,593 $ 3,109 Additions as a result of tax positions taken during the current year 613 865 956 Additions as a result of tax positions taken during prior years — 1,254 1,031 Reductions as a result of tax positions taken during prior years (625 ) (247 ) — Reductions relating to settlements with taxing authorities (693 ) (992 ) — Reductions as a result of lapse of statute of limitations (542 ) (379 ) (503 ) Ending balance $ 3,847 $ 5,094 $ 4,593

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2016
Banking and Thrift [Abstract]
Summary of Deposits	A summary of deposits by type follows: At December 31, (In thousands) 2016 2015 Non-interest-bearing: Demand $ 4,021,061 $ 3,713,063 Interest-bearing: Checking 2,528,274 2,369,971 Health savings accounts 4,362,503 3,802,313 Money market 2,047,121 1,933,460 Savings 4,320,090 4,047,817 Time deposits 2,024,808 2,086,154 Total interest-bearing 15,282,796 14,239,715 Total deposits $ 19,303,857 $ 17,952,778 Time deposits and interest-bearing checking, included in above balances, obtained through brokers $ 848,618 $ 910,304 Time deposits, included in above balance, that meet or exceed the FDIC limit 490,721 542,206 Demand deposit overdrafts reclassified as loan balances 1,885 1,356
Schedule Of Time Deposits Maturities Table	The scheduled maturities of time deposits are as follows: (In thousands) At December 31, 2016 2017 $ 846,160 2018 409,785 2019 482,977 2020 181,197 2021 104,578 Thereafter 111 Total time deposits $ 2,024,808

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2016
Debt Disclosure [Abstract]
Schedule of Repurchase Agreements	The following table summarizes securities sold under agreements to repurchase and other borrowings: At December 31, (In thousands) 2016 2015 Total Outstanding Rate Total Outstanding Rate Securities sold under agreements to repurchase: Original maturity of one year or less $ 340,526 0.16 $ 334,400 0.15 Original maturity of greater than one year, non-callable 400,000 3.09 500,000 3.04 Total securities sold under agreements to repurchase 740,526 1.82 834,400 1.93 Fed funds purchased 209,000 0.46 317,000 0.21 Securities sold under agreements to repurchase and other borrowings $ 949,526 1.53 $ 1,151,400 1.47
Federal Home Loan Bank, Advances	The following table provides information for FHLB advances: At December 31, 2016 2015 (Dollars in thousands) Total Outstanding Weighted- Average Contractual Coupon Rate Total Outstanding Weighted- Average Contractual Coupon Rate Maturing within 1 year $ 2,130,500 0.71 % $ 2,025,934 0.55 % After 1 but within 2 years 200,000 1.36 500 5.66 After 2 but within 3 years 128,026 1.73 200,000 1.36 After 3 but within 4 years 175,000 1.77 103,026 1.54 After 4 but within 5 years 200,000 1.81 175,000 1.77 After 5 years 9,370 2.59 159,655 1.60 2,842,896 0.95 2,664,115 0.79 Premiums on advances 12 24 Federal Home Loan Bank advances $ 2,842,908 $ 2,664,139 Aggregate carrying value of assets pledged as collateral $ 5,967,318 $ 5,719,746 Remaining borrowing capacity $ 1,192,758 $ 1,203,057
Schedule of Long-Term Debt	The following table summarizes long-term debt: At December 31, (Dollars in thousands) 2016 2015 4.375% Senior fixed-rate notes due February 15, 2024 $ 150,000 $ 150,000 Junior subordinated debt Webster Statutory Trust I floating-rate notes due September 17, 2033 (1) 77,320 77,320 Total notes and subordinated debt 227,320 227,320 Discount on senior fixed-rate notes (845 ) (964 ) Debt issuance cost on senior fixed-rate notes (2) (961 ) (1,096 ) Long-term debt $ 225,514 $ 225,260 (1) The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95% , was 3.94% at December 31, 2016 and 3.48% at December 31, 2015 . (2) In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Consolidated Balance Sheets.

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Schedule of Stock by Class	Share activity during the year ended December 31, 2016 is as follows: Preferred Stock Series E Common Stock Issued Treasury Stock Held Common Stock Outstanding Balance at January 1, 2016 5,060 93,651,601 2,090,409 91,561,192 Restricted share activity — — (248,603 ) 248,603 Stock options exercised — — (292,304 ) 292,304 Common stock repurchased — — 350,000 (350,000 ) Balance at December 31, 2016 5,060 93,651,601 1,899,502 91,752,099

Accumulated Other Comprehensi42

Accumulated Other Comprehensive Loss, Net of Tax (Tables)	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Schedule of Other Comprehensive Income (Loss)	The following table summarizes the changes in AOCL by component: (In thousands) Available For Sale and Transferred Securities Derivative Instruments Defined Benefit Pension and Other Postretirement Benefit Plans Total Balance at December 31, 2013 $ (2,617 ) $ (18,206 ) $ (27,726 ) $ (48,549 ) Other comprehensive income (loss) before reclassifications 21,811 (12,506 ) (21,329 ) (12,024 ) Amounts reclassified from accumulated other comprehensive (loss) income (2,773 ) 5,182 1,903 4,312 Net current-period other comprehensive income (loss), net of tax 19,038 (7,324 ) (19,426 ) (7,712 ) Balance at December 31, 2014 16,421 (25,530 ) (47,152 ) (56,261 ) Other comprehensive (loss) income before reclassifications (22,512 ) (3,136 ) (5,500 ) (31,148 ) Amounts reclassified from accumulated other comprehensive (loss) income (316 ) 5,686 3,933 9,303 Net current-period other comprehensive (loss) income, net of tax (22,828 ) 2,550 (1,567 ) (21,845 ) Balance at December 31, 2015 (6,407 ) (22,980 ) (48,719 ) (78,106 ) Other comprehensive (loss) income before reclassifications (8,901 ) 825 (232 ) (8,308 ) Amounts reclassified from accumulated other comprehensive (loss) income (168 ) 5,087 4,502 9,421 Net current-period other comprehensive (loss) income, net of tax (9,069 ) 5,912 4,270 1,113 Balance at December 31, 2016 $ (15,476 ) $ (17,068 ) $ (44,449 ) $ (76,993 )
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table provides information for the items reclassified from AOCL: Years ended December 31, Accumulated Other Comprehensive Loss Components 2016 2015 2014 Associated Line Item in the Consolidated Statements Of Income (In thousands) Available-for-sale and transferred securities: Unrealized gains on investments $ 414 $ 609 $ 5,499 Gain on sale of investment securities, net Unrealized losses on investments (149 ) (110 ) (1,145 ) Impairment loss recognized in earnings Total before tax 265 499 4,354 Tax expense (97 ) (183 ) (1,581 ) Income tax expense Net of tax $ 168 $ 316 $ 2,773 Derivative instruments: Cash flow hedges $ (8,020 ) $ (8,965 ) $ (8,100 ) Total interest expense Tax benefit 2,933 3,279 2,918 Income tax expense Net of tax $ (5,087 ) $ (5,686 ) $ (5,182 ) Defined benefit pension and other postretirement benefit plans: Amortization of net loss $ (7,126 ) $ (6,161 ) $ (2,921 ) (1) Prior service costs (14 ) (73 ) (73 ) (1) Total before tax (7,140 ) (6,234 ) (2,994 ) Tax benefit 2,638 2,301 1,091 Income tax expense Net of tax $ (4,502 ) $ (3,933 ) $ (1,903 ) (1) These accumulated other comprehensive income components are included in the computation of net periodic benefit cost (see Note 17 Retirement Benefit Plans for further details). The following tables summarize the items and related tax effects for each component of OCI/OCL, net of tax: Year ended December 31, 2016 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized loss during the period $ (14,113 ) $ 5,212 $ (8,901 ) Reclassification for net gain included in net income (414 ) 152 (262 ) Net non-credit other-than-temporary impairment 149 (55 ) 94 Amortization of unrealized loss on securities transferred to held-to-maturity — — — Total available-for-sale and transferred securities (14,378 ) 5,309 (9,069 ) Derivative instruments: Net unrealized gain during the period 1,331 (506 ) 825 Reclassification adjustment for net loss included in net income 8,020 (2,933 ) 5,087 Total derivative instruments 9,351 (3,439 ) 5,912 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (368 ) 136 (232 ) Reclassification adjustment for amortization of net loss included in net income 7,126 (2,633 ) 4,493 Reclassification adjustment for prior service cost included in net income 14 (5 ) 9 Total defined benefit pension and postretirement benefit plans 6,772 (2,502 ) 4,270 Other comprehensive income, net of tax $ 1,745 $ (632 ) $ 1,113 Year ended December 31, 2015 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized loss during the period $ (35,701 ) $ 13,166 $ (22,535 ) Reclassification for net gain included in net income (609 ) 223 (386 ) Net non-credit other-than-temporary impairment 110 (40 ) 70 Amortization of unrealized loss on securities transferred to held-to-maturity 37 (14 ) 23 Total available-for-sale and transferred securities (36,163 ) 13,335 (22,828 ) Derivative instruments: Net unrealized loss during the period (4,945 ) 1,809 (3,136 ) Reclassification adjustment for net loss included in net income 8,965 (3,279 ) 5,686 Total derivative instruments 4,020 (1,470 ) 2,550 Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (8,719 ) 3,219 (5,500 ) Reclassification adjustment for amortization of net loss included in net income 6,161 (2,274 ) 3,887 Reclassification adjustment for prior service cost included in net income 73 (27 ) 46 Total defined benefit pension and postretirement benefit plans (2,485 ) 918 (1,567 ) Other comprehensive loss, net of tax $ (34,628 ) $ 12,783 $ (21,845 ) Year ended December 31, 2014 (In thousands) Pre-Tax Amount Tax Benefit (Expense) Net of Tax Amount Available-for-sale and transferred securities: Net unrealized gain during the period $ 34,242 $ (12,469 ) $ 21,773 Reclassification for net gain included in net income (5,499 ) 1,999 (3,500 ) Net non-credit other-than-temporary impairment 1,145 (418 ) 727 Amortization of unrealized loss on securities transferred to held-to-maturity 60 (22 ) 38 Total available-for-sale and transferred securities 29,948 (10,910 ) 19,038 Derivative instruments: Net unrealized loss during the period (19,589 ) 7,083 (12,506 ) Reclassification adjustment for net loss included in net income 8,100 (2,918 ) 5,182 Total derivative instruments (11,489 ) 4,165 (7,324 ) Defined benefit pension and other postretirement benefit plans: Current year actuarial loss (33,567 ) 12,238 (21,329 ) Reclassification adjustment for amortization of net loss included in net income 2,921 (1,065 ) 1,856 Reclassification adjustment for prior service cost included in net income 73 (26 ) 47 Total defined benefit pension and postretirement benefit plans (30,573 ) 11,147 (19,426 ) Other comprehensive loss, net of tax $ (12,114 ) $ 4,402 $ (7,712 )

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2016
Regulatory Capital Requirements [Abstract]
Information On The Capital Ratios	The following table provides information on the capital ratios for Webster Financial Corporation and Webster Bank: Actual Capital Requirements Minimum Well Capitalized (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio At December 31, 2016 Webster Financial Corporation CET1 risk-based capital $ 1,932,171 10.5 % $ 826,504 4.5 % $ 1,193,840 6.5 % Total risk-based capital 2,328,808 12.7 1,469,341 8.0 1,836,677 10.0 Tier 1 risk-based capital 2,054,881 11.2 1,102,006 6.0 1,469,341 8.0 Tier 1 leverage capital 2,054,881 8.1 1,010,857 4.0 1,263,571 5.0 Webster Bank CET1 risk-based capital $ 1,945,332 10.6 % $ 825,228 4.5 % $ 1,191,995 6.5 % Total risk-based capital 2,141,939 11.7 1,467,071 8.0 1,833,839 10.0 Tier 1 risk-based capital 1,945,332 10.6 1,100,304 6.0 1,467,071 8.0 Tier 1 leverage capital 1,945,332 7.7 1,010,005 4.0 1,262,507 5.0 At December 31, 2015 Webster Financial Corporation CET1 risk-based capital $ 1,824,106 10.7 % $ 766,848 4.5 % $ 1,107,670 6.5 % Total risk-based capital 2,201,245 12.9 1,363,286 8.0 1,704,107 10.0 Tier 1 risk-based capital 1,966,146 11.5 1,022,464 6.0 1,363,286 8.0 Tier 1 leverage capital 1,966,146 8.2 954,369 4.0 1,192,962 5.0 Webster Bank CET1 risk-based capital $ 1,869,241 11.0 % $ 765,152 4.5 % $ 1,105,220 6.5 % Total risk-based capital 2,046,350 12.0 1,360,271 8.0 1,700,338 10.0 Tier 1 risk-based capital 1,869,241 11.0 1,020,203 6.0 1,360,271 8.0 Tier 1 leverage capital 1,869,241 7.8 953,300 4.0 1,191,626 5.0

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share Basic And Diluted	Reconciliation of the calculation of basic and diluted earnings per common share follows: Years ended December 31, (In thousands, except per share data) 2016 2015 2014 Earnings for basic and diluted earnings per common share: Net income $ 207,127 $ 204,729 $ 199,726 Less: Preferred stock dividends 8,096 8,711 10,556 Net income available to common shareholders 199,031 196,018 189,170 Less: Earnings applicable to participating securities 608 657 674 Earnings applicable to common shareholders $ 198,423 $ 195,361 $ 188,496 Shares: Weighted-average common shares outstanding - basic 91,367 90,968 89,899 Effect of dilutive securities: Stock options and restricted stock 461 524 466 Warrants 28 41 255 Weighted-average common shares outstanding - diluted 91,856 91,533 90,620 Earnings per common share: Basic $ 2.17 $ 2.15 $ 2.10 Diluted 2.16 2.13 2.08
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potential common shares excluded from the effect of dilutive securities because they would have been anti-dilutive, are as follows: Years ended December 31, (In thousands) 2016 2015 2014 Stock options (shares with exercise price greater than market price) 41 213 587 Restricted stock (due to performance conditions on non-participating shares) 125 92 171

Derivative Financial Instrume45

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value Of Derivative Financial Instruments Designated As Cash Flow Hedges	The following table presents the notional amounts and fair values of derivative positions: At December 31, 2016 At December 31, 2015 Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives (In thousands) Notional Fair Notional Fair Notional Fair Notional Fair Designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives $ 225,000 $ 3,270 $ 100,000 $ 792 $ 200,000 $ 2,507 $ 100,000 $ 1,359 Not designated as hedging instruments: Positions subject to a master netting agreement (1) Interest rate derivatives 1,943,485 32,226 1,242,937 24,388 989,695 2,255 1,543,479 40,302 Other 10,634 231 14,265 120 8,237 183 4,561 66 Positions not subject to a master netting agreement (2) Interest rate derivatives 1,734,679 38,668 1,451,762 19,001 2,050,460 58,304 482,738 571 RPAs 86,037 139 87,273 166 41,798 153 92,985 245 Mortgage banking derivatives (3) 103,440 3,084 59,895 711 62,514 819 — — Other 1,438 19 181 11 — — 60 9 Total not designated as hedging instruments 3,879,713 74,367 2,856,313 44,397 3,152,704 61,714 2,123,823 41,193 Gross derivative instruments, before netting $ 4,104,713 77,637 $ 2,956,313 45,189 $ 3,352,704 64,221 $ 2,223,823 42,552 Less: Legally enforceable master netting agreements 24,253 24,253 4,945 4,945 Less: Cash collateral posted 11,475 600 — 31,330 Total derivative instruments, after netting $ 41,909 $ 20,336 $ 59,276 $ 6,277 (1) The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information. (2) Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Consolidated Balance Sheets. (3) Notional amounts include mandatory forward commitments of $99.0 million , while notional amounts do not include approved floating rate commitments of $27.8 million , at December 31, 2016 .
Interest Rate Swaps And Caps Not Designated For Hedge Accounting	Changes in the fair value of derivatives not qualifying for hedge accounting treatment are reported as a component of other non-interest income in the accompanying Consolidated Statements of Income as follows: Years ended December 31, (In thousands) 2016 2015 2014 Interest rate derivatives $ 8,668 $ 4,361 $ 4,482 RPA (361 ) (33 ) 51 Mortgage banking derivatives 1,553 801 (522 ) Other (67 ) (63 ) (253 ) Total impact on other non-interest income $ 9,793 $ 5,066 $ 3,758
Offsetting Assets and Liabilities	The following table is presented on a gross basis, prior to the application of counterparty netting agreements. Derivative assets and liabilities are shown net of cash collateral: At December 31, 2016 At December 31, 2015 (In thousands) Gross Amount Amount Offset Net Amount (1) (2) Gross Amount Amount Offset Net Amount (1) (2) Derivative instrument assets Hedged Accounting Positions $ 3,270 $ (3,270 ) $ — $ 2,507 $ (2,507 ) $ — Non-Hedged Accounting Positions 32,457 (32,457 ) — 2,438 (2,438 ) — Total $ 35,727 $ (35,727 ) $ — $ 4,945 $ (4,945 ) $ — Derivative instrument liabilities Hedged Accounting Positions $ 792 $ (792 ) $ — $ 1,359 $ (1,359 ) $ — Non-Hedged Accounting Positions 24,508 (24,062 ) 446 40,368 (34,916 ) 5,452 Total $ 25,300 $ (24,854 ) $ 446 $ 41,727 $ (36,275 ) $ 5,452 (1) Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015 , respectively, as presented in the accompanying Consolidated Balance Sheets. (2) Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015 , respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Of Assets And Liabilities Measured On Recurring Basis	Summaries of the fair values of assets and liabilities measured at fair value on a recurring basis are as follows: At December 31, 2016 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 734 $ — $ — $ 734 Agency CMO — 419,706 — 419,706 Agency MBS — 954,349 — 954,349 Agency CMBS — 573,272 — 573,272 CMBS — 477,365 — 477,365 CLO — 427,390 — 427,390 Single issuer trust preferred securities — 28,633 — 28,633 Corporate debt securities — 109,642 — 109,642 Equities - financial services — — — — Total available-for-sale investment securities 734 2,990,357 — 2,991,091 Gross derivative instruments, before netting (1) 250 77,387 — 77,637 Investments held in Rabbi Trust 5,119 — — 5,119 Alternative investments — — 5,502 5,502 Originated loans held for sale (2) — 60,260 — 60,260 Contingent consideration — — — — Total financial assets held at fair value $ 6,103 $ 3,128,004 $ 5,502 $ 3,139,609 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 120 $ 45,069 $ — $ 45,189 Contingent liability — — — — Total financial liabilities held at fair value $ 120 $ 45,069 $ — $ 45,189 At December 31, 2015 (In thousands) Level 1 Level 2 Level 3 Total Financial assets held at fair value: U.S. Treasury Bills $ 924 $ — $ — $ 924 Agency CMO — 548,754 — 548,754 Agency MBS — 1,065,109 — 1,065,109 Agency CMBS — 215,350 — 215,350 CMBS — 579,266 — 579,266 CLO — 429,159 — 429,159 Single issuer trust preferred securities — 37,170 — 37,170 Corporate debt securities — 106,321 — 106,321 Equities - financial services 2,578 — — 2,578 Total available-for-sale investment securities 3,502 2,981,129 — 2,984,631 Gross derivative instruments, before netting (1) 183 64,038 — 64,221 Investments held in Rabbi Trust 5,372 — — 5,372 Alternative investments — — 3,471 3,471 Originated loans held for sale — — — — Contingent Consideration — — 5,331 5,331 Total financial assets held at fair value $ 9,057 $ 3,045,167 $ 8,802 $ 3,063,026 Financial liabilities held at fair value: Gross derivative instruments, before netting (1) $ 66 $ 42,486 $ — $ 42,552 Contingent liability — — 6,000 6,000 Total financial liabilities held at fair value $ 66 $ 42,486 $ 6,000 $ 48,552 (1) For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 15: Derivative Financial Instruments . (2) Loans held for sale accounted for under the fair value option of ASC Topic 825 "Financial Instruments" at December 31, 2016 . The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies .
Schedule Of Quantitative Inputs And Assumptions For Items Categorized In Level 3 Of The Fair Value Hierarchy	The following table presents the changes in Level 3 assets and liabilities that are measured at fair value on a recurring basis: Financial Assets (In thousands) Alternative Investments Contingent Consideration Total Contingent Liability Balance at January 1, 2016 $ 3,471 $ 5,331 $ 8,802 $ 6,000 Gain included in net income 349 2,690 3,039 — Purchases/capital funding 1,682 — 1,682 — Receipts — (8,021 ) (8,021 ) — Payments — — — (6,000 ) Balance at December 31, 2016 $ 5,502 $ — $ 5,502 $ —
Schedule of Servicing Assets at Fair Value	The following table provides information for mortgage banking activities: Years ended December 31, (In thousands) 2016 2015 2014 Residential mortgage loans held for sale: Proceeds from sale $ 438,925 $ 452,590 $ 287,132 Net gain on sale 11,629 7,795 4,070 Fair value option adjustment (526 ) — — Loans sold with servicing rights retained 399,318 416,277 264,292 The following table presents the changes in fair value for mortgage servicing assets: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 33,568 $ 28,690 Originations of servicing assets 11,312 8,027 Changes in fair value: Due to payoffs/paydowns (2,447 ) (2,741 ) Due to market changes 9,642 (408 ) Ending balance $ 52,075 $ 33,568
Schedule Of Valuation Methodology And Unobservable Inputs	The table below presents the valuation methodology and unobservable inputs for Level 3 assets measured at fair value on a non-recurring basis as of December 31, 2016 : (Dollars in thousands) Asset Fair Value Valuation Methodology Unobservable Inputs Range of Inputs Collateral dependent impaired loans and leases $ 7,374 Real Estate Appraisals Discount for appraisal type 0% - 15 % Discount for costs to sell 8% OREO $ 166 Real Estate Appraisals Discount for appraisal type 0% Discount for costs to sell 8% Mortgage servicing assets $ 52,075 Discounted cash flow Constant prepayment rate 2.8% - 27.7 % Discount rates 1.9% - 3.6 %
Summary Of Estimated Fair Values Of Significant Financial Instruments	The estimated fair values of selected financial instruments and servicing assets are as follows: At December 31, 2016 2015 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Financial Assets: Level 2 Held-to-maturity investment securities $ 4,160,658 $ 4,125,125 $ 3,923,052 $ 3,961,534 Loans held for sale (1) 7,317 7,444 37,091 37,457 Level 3 Loans and leases, net 16,832,268 16,678,106 15,496,745 15,453,892 Mortgage servicing assets 24,466 52,075 20,698 33,568 Alternative investments 11,034 13,189 12,900 14,294 Financial Liabilities: Level 2 Deposit liabilities, other than time deposits $ 17,279,049 $ 17,279,049 $ 15,866,624 $ 15,866,624 Time deposits 2,024,808 2,024,395 2,086,154 2,095,357 Securities sold under agreements to repurchase and other borrowings 949,526 955,660 1,151,400 1,163,974 FHLB advances (2) 2,842,908 2,825,101 2,664,139 2,647,872 Long-term debt (2) 225,514 225,514 225,260 218,143 (1) Loans held for sale that are accounted for at the lower of cost or market. At December 31, 2016 , the amounts include transferred residential and commercial loans not originated for sale, and at December 31, 2015 , the amounts include transferred commercial loans not originated for sale and residential loans originated for sale prior to the adoption of the fair value option of ASC Topic 825 "Financial Instruments." (2) The following adjustments to the carrying amount are not included for determination of fair value, see Note 10: Borrowings : • FHLB advances - unamortized premiums on advances • Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes

Retirement Benefit Plans (Table

Retirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract]
Schedule of Defined Benefit Plans Disclosures	The following table sets forth changes in benefit obligation, changes in plan assets, and the funded status of the defined benefit pension and other postretirement benefits at December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Change in benefit obligation: Beginning balance $ 203,645 $ 210,548 $ 10,518 $ 10,041 $ 3,853 $ 4,133 Service cost 45 45 — — — — Interest cost 8,441 8,008 389 345 125 123 Actuarial loss (gain) 6,108 (8,588 ) 1,023 373 59 (178 ) Benefits paid and administrative expenses (6,731 ) (6,368 ) (124 ) (241 ) (185 ) (225 ) Ending balance 211,508 203,645 11,806 10,518 3,852 3,853 Change in plan assets: Beginning balance 161,369 172,976 — — — — Actual return on plan assets 18,284 (5,239 ) — — — — Employer contributions 20,000 — 124 241 185 225 Benefits paid and administrative expenses (6,731 ) (6,368 ) (124 ) (241 ) (185 ) (225 ) Ending balance 192,922 161,369 — — — — Funded status of the plan at year end $ (18,586 ) $ (42,276 ) $ (11,806 ) $ (10,518 ) $ (3,852 ) $ (3,853 )
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the accompanying Consolidated Balance Sheets consist of the following: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Accrued expenses and other liabilities $ (18,586 ) $ (42,276 ) $ (11,806 ) $ (10,518 ) $ (3,852 ) $ (3,853 )
Schedule of Net Periodic Benefit Cost Not yet Recognized	The components of AOCL related to the defined benefit pension and other postretirement benefits at December 31, 2016 and 2015 are summarized below: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2016 2015 2016 2015 Net actuarial loss $ 65,857 $ 73,238 $ 3,009 $ 2,412 $ 616 $ 591 Prior service cost — — — — — 14 Total pre-tax amounts included in AOCL 65,857 73,238 3,009 2,412 616 605 Deferred tax benefit 23,727 26,447 1,084 871 222 218 Amounts included in accumulated AOCL, net of tax $ 42,130 $ 46,791 $ 1,925 $ 1,541 $ 394 $ 387
Schedule of Expected Benefit Payments	Expected future benefit payments for the defined benefit pension and other postretirement benefits are presented below: (In thousands) Pension Plan SERP Other Benefits 2017 $ 7,786 $ 1,208 $ 404 2018 8,604 1,091 398 2019 8,654 8,104 387 2020 9,072 141 375 2021 9,828 140 358 2022-2026 53,711 683 1,457
Summary of Net Periodic Benefit Cost	The components of the net periodic benefit cost (benefit) for the defined benefit pension and other postretirement benefits were as follows for the years ended December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2014 2016 2015 2014 2016 2015 2014 Service cost $ 45 $ 45 $ 40 $ — $ — $ — $ — $ — $ — Interest cost on benefit obligations 8,441 8,008 8,068 389 345 364 125 123 139 Expected return on plan assets (11,461 ) (11,873 ) (11,495 ) — — — — — — Amortization of prior service cost — — — — — — 14 73 73 Recognized net loss 6,665 5,724 2,781 426 390 135 35 47 5 Net periodic benefit cost (benefit) $ 3,690 $ 1,904 $ (606 ) $ 815 $ 735 $ 499 $ 174 $ 243 $ 217
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	Changes in funded status related to the defined benefit pension and other postretirement benefits and recognized as a component of OCI in the accompanying Consolidated Statements of Comprehensive Income as follows for the years ended December 31: Pension Plan SERP Other Benefits (In thousands) 2016 2015 2014 2016 2015 2014 2016 2015 2014 Net (gain) loss $ (715 ) $ 8,525 $ 31,951 $ 1,023 $ 372 $ 1,145 $ 60 $ (178 ) $ 470 Amounts reclassified from AOCL (6,665 ) (5,724 ) (2,781 ) (426 ) (390 ) (134 ) (35 ) (47 ) (5 ) Amortization of prior service cost — — — — — — (14 ) (73 ) (73 ) Total (gain) loss recognized in OCI $ (7,380 ) $ 2,801 $ 29,170 $ 597 $ (18 ) $ 1,011 $ 11 $ (298 ) $ 392
Schedule of Changes in Fair Value of Plan Assets	A summary of the fair value and hierarchy classification of financial assets of the pension plan is as follows: At December 31, 2016 2015 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Registered investment companies: Exchange traded funds $ 31,526 $ — $ — $ 31,526 $ 28,329 $ — $ — $ 28,329 Cash and cash equivalents 701 — — 701 295 — — 295 Common collective trust funds: Fixed Income funds — 96,429 — 96,429 — 80,783 — 80,783 Equity Funds — 63,285 — 63,285 — 51,028 — 51,028 Insurance company investment contract — — 793 793 — — 934 934 Total $ 32,227 $ 159,714 $ 793 $ 192,734 $ 28,624 $ 131,811 $ 934 $ 161,369
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	The following table sets forth a summary of changes in the fair value of Level 3 assets of the pension plan: Years ended December 31, (In thousands) 2016 2015 Beginning balance $ 934 $ 1,077 Unrealized gains relating to instruments still held at the reporting date (10 ) (28 ) Benefit payments, administrative expenses, and interest income, net (131 ) (115 ) Ending balance $ 793 $ 934
Schedule of Allocation of Plan Assets	The following table presents the target allocation and the pension plan asset allocation for the periods indicated, by asset category: Target Allocation Percentage of Pension Plan assets 2017 2016 2015 Fixed income investments 50 % 51 % 51 % Equity investments 50 49 49 Total 100 % 100 % 100 %
Schedule of Assumptions Used	Weighted-average assumptions used to determine benefit obligations at December 31 are as follows: Pension Plan SERP Other Benefits 2016 2015 2016 2015 2016 2015 Discount rate 4.01 % 4.20 % 3.63 % 3.75 % 3.27 % 3.35 % Rate of compensation increase n/a n/a n/a n/a n/a n/a Weighted-average assumptions used to determine net periodic benefit cost for the years ended December 31 are as follows: Pension Plan SERP Other Benefits 2016 2015 2014 2016 2015 2014 2016 2015 2014 Discount rate 4.20 % 3.85 % 4.80 % 3.75 % 3.50 % 4.25 % 3.35 % 3.15 % 3.75 % Expected long-term return on assets 7.00 % 7.00 % 7.25 % n/a n/a n/a n/a n/a n/a Rate of compensation increase n/a n/a n/a n/a n/a n/a n/a n/a n/a Assumed healthcare cost trend n/a n/a n/a n/a n/a n/a 8.25 % 8.00 % 8.00 %
Schedule of Multiemployer Plans	The following table sets forth contributions and funding status of Webster Bank's portion of this plan: (Dollars in thousands) Contributions by Webster Bank for the year ended December 31, Funded Status of the Plan at December 31, Plan Name Employer Identification Number Plan Number 2016 2015 2014 2016 2015 Pentegra Defined Benefit Plan for Financial Institutions 13-5645888 333 $690 $340 $765 At least 80 percent At least 80 percent

Share-Based Plans (Tables)

Share-Based Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Allocation of Stock-based Compensation Expense and Related Tax Benefit	The following table provides a summary of stock compensation expense, and the related income tax benefit, recognized in the accompanying Consolidated Statements of Income: Years ended December 31, (In thousands) 2016 2015 2014 Stock options $ 43 $ 379 $ 1,175 Restricted stock 11,395 10,556 9,048 Total stock compensation expense $ 11,438 $ 10,935 $ 10,223 Income tax benefit $ 4,132 $ 3,903 $ 3,553
Summary of Restricted Stock and Stock Option Activity	The following table provides a summary of the activity under the stock compensation plans for the year ended December 31, 2016 : Unvested Restricted Stock Awards Stock Options Outstanding Time-Based Performance-Based Number of Shares Weighted-Average Grant Date Fair Value Number of Units Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Grant Date Fair Value Number of Shares Weighted-Average Exercise Price Balance at January 1, 2016 236,145 $ 32.58 2,088 $ 34.45 115,721 $ 34.14 1,527,074 $ 23.92 Granted 248,418 33.52 12,946 32.89 150,392 32.75 — — Exercised options — — — — — — 412,538 28.47 Vested restricted stock awards (1) 216,933 30.21 12,876 33.23 140,531 33.12 — — Forfeited 14,269 32.89 — — 9,398 33.63 41,562 47.92 Balance at December 31, 2016 253,361 $ 32.24 2,158 $ 32.89 116,184 $ 33.62 1,072,974 $ 21.24 (1) Vested for purposes of recording compensation expense.
Summary of Options Outstanding and Options Exercisable	The following table summarizes information for options, all of which are both outstanding and exercisable, at December 31, 2016 : Range of Exercise Prices Number of Shares Weighted-Average Remaining Contractual Life (years) Weighted-Average Exercise Price $ 5.14 - 20.00 317,814 2.2 $ 8.95 $ 20.01 - 30.00 562,040 5.2 23.53 $ 30.01 - 40.00 151,715 1.0 32.03 $ 40.01 - 48.88 41,405 0.4 44.91 1,072,974 3.5 $ 21.24

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Reporting [Abstract]
Operating Results And Total Assets Reportable Segments	The following tables present the operating results, including all appropriate allocations, for Webster’s reportable segments and the Corporate and Reconciling category: Year ended December 31, 2016 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 276,246 $ 365,151 $ 81,451 $ 11,350 $ (15,685 ) $ 718,513 Provision (benefit) for loan and lease losses 36,594 21,690 — 861 (2,795 ) 56,350 Net interest income (loss) after provision for loan and lease losses 239,652 343,461 81,451 10,489 (12,890 ) 662,163 Non-interest income 47,435 110,157 71,710 9,818 25,358 264,478 Non-interest expense 118,159 364,549 97,152 20,220 23,111 623,191 Income (loss) before income tax expense 168,928 89,069 56,009 87 (10,643 ) 303,450 Income tax expense (benefit) 53,622 28,273 17,779 27 (3,378 ) 96,323 Net income (loss) $ 115,306 $ 60,796 $ 38,230 $ 60 $ (7,265 ) $ 207,127 Year ended December 31, 2015 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 255,845 $ 354,709 $ 73,433 $ 10,240 $ (29,602 ) $ 664,625 Provision (benefit) for loan and lease losses 30,160 19,603 — 386 (849 ) 49,300 Net interest income (loss) after provision for loan and lease losses 225,685 335,106 73,433 9,854 (28,753 ) 615,325 Non-interest income 37,784 108,604 62,475 9,183 19,731 237,777 Non-interest expense 109,718 330,692 81,449 19,781 13,701 555,341 Income (loss) before income tax expense 153,751 113,018 54,459 (744 ) (22,723 ) 297,761 Income tax expense (benefit) 48,037 35,310 17,016 (233 ) (7,098 ) 93,032 Net income (loss) $ 105,714 $ 77,708 $ 37,443 $ (511 ) $ (15,625 ) $ 204,729 Year ended December 31, 2014 (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated Net interest income (loss) $ 238,186 $ 354,781 $ 38,822 $ 8,877 $ (12,225 ) $ 628,441 Provision (benefit) for loan and lease losses 13,088 26,345 — 765 (2,948 ) 37,250 Net interest income (loss) after provision for loan and lease losses 225,098 328,436 38,822 8,112 (9,277 ) 591,191 Non-interest income 37,270 103,543 28,553 9,843 22,899 202,108 Non-interest expense 102,374 324,312 40,900 18,691 15,323 501,600 Income (loss) before income tax expense 159,994 107,667 26,475 (736 ) (1,701 ) 291,699 Income tax expense (benefit) 50,446 33,947 8,311 (232 ) (499 ) 91,973 Net income (loss) $ 109,548 $ 73,720 $ 18,164 $ (504 ) $ (1,202 ) $ 199,726 The following table presents total assets for Webster's reportable segments and the Corporate and Reconciling category: Total Assets (In thousands) Commercial Community Banking HSA Bank Private Banking Corporate and Consolidated At December 31, 2016 $ 8,518,830 $ 8,655,789 $ 83,987 $ 550,615 $ 8,263,308 $ 26,072,529 At December 31, 2015 7,505,513 8,441,950 95,815 493,571 8,104,269 24,641,118

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments and Receipts for Leases	The following table summarizes future minimum rental payments and receipts under lease agreements: At December 31, 2016 (In thousands) Rental Payments Rental Receipts 2017 $ 28,713 $ 601 2018 27,046 451 2019 25,644 364 2020 23,900 293 2021 21,860 202 Thereafter 88,211 918 Total future minimum rental payments and receipts $ 215,374 $ 2,829
Outstanding Financial Instruments Contract Amounts Represent Credit Risk	The following table summarizes the outstanding amounts of credit-related financial instruments with off-balance sheet risk: At December 31, (In thousands) 2016 2015 Commitments to extend credit $ 5,224,280 $ 4,851,994 Standby letter of credit 128,985 133,294 Commercial letter of credit 46,497 45,742 Total credit-related financial instruments with off-balance sheet risk $ 5,399,762 $ 5,031,030
Reserve For Unfunded Credit Commitments	The following table provides a summary of activity in the reserve for unfunded credit commitments: Years ended December 31, (In thousands) 2016 2015 2014 Beginning balance $ 2,119 $ 5,151 $ 4,384 Provision (benefit) 168 (3,032 ) 767 Ending balance $ 2,287 $ 2,119 $ 5,151

Parent Company Information (Tab

Parent Company Information (Tables)	12 Months Ended
	Dec. 31, 2016
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Parent Company Information Balance Sheet	Condensed Balance Sheets December 31, (In thousands) 2016 2015 Assets: Cash and due from banks $ 152,947 $ 279,644 Securities available for sale, at fair value — 2,578 Intercompany debt securities 150,000 — Investment in subsidiaries 2,425,398 2,345,457 Alternative investments 4,275 6,795 Other assets 24,659 15,263 Total assets $ 2,757,279 $ 2,649,737 Liabilities and shareholders’ equity: Senior notes $ 148,194 $ 147,940 Junior subordinated debt 77,320 77,320 Accrued interest payable 2,589 2,591 Due to subsidiaries 365 48 Other liabilities 1,799 7,878 Total liabilities 230,267 235,777 Shareholders’ equity 2,527,012 2,413,960 Total liabilities and shareholders’ equity $ 2,757,279 $ 2,649,737
Schedule of Parent Company Information Income Statement	Condensed Statements of Income Years ended December 31, (In thousands) 2016 2015 2014 Operating Income: Dividend income from bank subsidiary $ 145,000 $ 110,000 $ 100,000 Interest on securities and deposits 1,911 546 613 (Loss) gain on sale of investment securities, net (2,410 ) — 1,185 Alternative investments income 176 2,274 804 Other non-interest income 7,485 152 151 Total operating income 152,162 112,972 102,753 Operating Expense: Interest expense on borrowings 9,981 9,665 10,041 Compensation and benefits 11,461 10,965 10,290 Other non-interest expense 6,278 6,005 4,562 Total operating expense 27,720 26,635 24,893 Income before income tax benefit and equity in undistributed earnings of subsidiaries and associated companies 124,442 86,337 77,860 Income tax benefit 3,086 2,929 8,798 Equity in undistributed earnings of subsidiaries and associated companies 79,599 115,463 113,068 Net income $ 207,127 $ 204,729 $ 199,726
Schedule of Parent Company Information Comprehensive Income Statement	Condensed Statements of Comprehensive Income Years ended December 31, (In thousands) 2016 2015 2014 Net income $ 207,127 $ 204,729 $ 199,726 Other comprehensive income (loss), net of tax: Net unrealized gains (losses) on available for sale securities 584 (2,109 ) 725 Net unrealized gains (losses) on derivative instruments 1,223 1,223 (2,932 ) Other comprehensive loss of subsidiaries and associated companies (694 ) (20,959 ) (5,505 ) Other comprehensive income (loss), net of tax 1,113 (21,845 ) (7,712 ) Comprehensive income $ 208,240 $ 182,884 $ 192,014
Schedule of Parent Company Information Cash Flow Statement	Condensed Statements of Cash Flows Years ended December 31, (In thousands) 2016 2015 2014 Operating activities: Net income $ 207,127 $ 204,729 $ 199,726 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed earnings of subsidiaries and associated companies (79,599 ) (115,463 ) (113,068 ) Stock-based compensation 11,438 10,935 10,223 Gain on redemption of other assets (7,331 ) — — Other, net (3,736 ) 9,066 (10,721 ) Net cash provided by operating activities 127,899 109,267 86,160 Investing activities: Purchases of available for sale securities — — (3,500 ) Proceeds from sale of available for sale securities 1,089 — 3,499 Purchases of intercompany debt securities (150,000 ) — — Net cash used for investing activities (148,911 ) — (1 ) Financing activities: Issuance of long-term debt — — 150,000 Repayment of long-term debt — — (150,000 ) Cash dividends paid to common shareholders (89,522 ) (80,964 ) (67,431 ) Cash dividends paid to preferred shareholders (8,096 ) (8,711 ) (10,556 ) Exercise of stock options 11,762 3,060 2,221 Excess tax benefits from stock-based compensation 3,204 2,338 1,161 Common stock issued — — 435 Common stock repurchased/shares acquired related to employee share-based plans (22,870 ) (17,815 ) (13,067 ) Common stock warrants repurchased (163 ) (23 ) (3 ) Net cash used for financing activities (105,685 ) (102,115 ) (87,240 ) (Decrease) increase in cash and due from banks (126,697 ) 7,152 (1,081 ) Cash and due from banks at beginning of year 279,644 272,492 273,573 Cash and due from banks at end of year $ 152,947 $ 279,644 $ 272,492

Selected Quarterly Consolidat52

Selected Quarterly Consolidated Financial Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2016
Selected Quarterly Financial Information [Abstract]
Schedule of Quarterly Financial Information	2016 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 202,335 $ 202,431 $ 205,715 $ 211,432 Interest expense 26,183 25,526 25,518 26,173 Net interest income 176,152 176,905 180,197 185,259 Provision for loan and lease losses 15,600 14,000 14,250 12,500 Non-interest income 62,374 65,075 66,412 70,617 Non-interest expense 152,445 152,778 156,097 161,871 Income before income tax expense 70,481 75,202 76,262 81,505 Income tax expense 23,434 24,599 24,445 23,845 Net income $ 47,047 $ 50,603 $ 51,817 $ 57,660 Earnings applicable to common shareholders $ 44,921 $ 48,398 $ 49,634 $ 55,501 Earnings per common share: Basic $ 0.49 $ 0.53 $ 0.54 $ 0.61 Diluted 0.49 0.53 0.54 0.60 2015 (In thousands, except per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest income $ 182,912 $ 186,970 $ 191,998 $ 198,160 Interest expense 23,148 23,459 23,988 24,820 Net interest income 159,764 163,511 168,010 173,340 Provision for loan and lease losses 9,750 12,750 13,000 13,800 Non-interest income 57,561 59,245 61,292 59,679 Non-interest expense 134,087 137,537 139,937 143,780 Income before income tax expense 73,488 72,469 76,365 75,439 Income tax expense 23,984 20,426 24,995 23,627 Net income $ 49,504 $ 52,043 $ 51,370 $ 51,812 Earnings applicable to common shareholders $ 46,719 $ 49,819 $ 49,176 $ 49,646 Earnings per common share: Basic $ 0.52 $ 0.55 $ 0.54 $ 0.54 Diluted 0.51 0.55 0.53 0.54

Summary of Significant Accoun53

Summary of Significant Accounting Policies Schedule of Error Corrections and Prior Period Adjustments (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash and due from banks		$ 190,663				$ 199,693				$ 190,663	$ 199,693		$ 213,914		$ 205,921
Accrued interest receivable and other assets		294,462				343,856				294,462	343,856
Accrued expenses and other liabilities		223,712				233,581				223,712	233,581
Retained earnings		1,425,320				1,315,948				1,425,320	1,315,948
Debt issuance cost	[1]	(961)				(1,096)				(961)	(1,096)
Deposit service fees										140,685	135,057		103,431
Other income										38,591	23,326		18,917
Technology and equipment										79,882	80,813		61,993
Income tax expense		23,845	$ 24,445	$ 24,599	$ 23,434	23,627	$ 24,995	$ 20,426	$ 23,984	96,323	93,032		91,973
Net income		$ 57,660	$ 51,817	$ 50,603	$ 47,047	$ 51,812	$ 51,370	$ 52,043	$ 49,504	$ 207,127	$ 204,729		$ 199,726
Earnings per common share, Basic (in dollars per share)		$ 0.61	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.54	$ 0.55	$ 0.52	$ 2.17	$ 2.15		$ 2.10
Earnings per common share, Diluted (in dollars per share)		$ 0.60	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.53	$ 0.55	$ 0.51	$ 2.16	$ 2.13		$ 2.08
Net (increase) in accrued interest receivable and other assets										$ 50,737	$ (44,334)	[2]	$ (2,552)	[2]
Net increase in accrued expenses and other liabilities										(18,918)	33,478	[2]	6,601	[2]
Net increase in derivative contract assets net of liabilities										$ 27,929	(6,489)		(49,158)
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash and due from banks						$ 251,258					251,258
Accrued interest receivable and other assets	[3]					328,993					328,993
Accrued expenses and other liabilities						267,576					267,576
Retained earnings						1,317,559					1,317,559
Deposit service fees											136,578
Other income											23,573
Technology and equipment											80,026
Income tax expense											93,976
Net income											$ 206,340
Earnings per common share, Basic (in dollars per share)											$ 2.17
Earnings per common share, Diluted (in dollars per share)											$ 2.15
Net (increase) in accrued interest receivable and other assets	[2]										$ (49,899)		(24,502)
Net increase in accrued expenses and other liabilities	[2]										35,336		$ 9,213
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash and due from banks						199,693					199,693
Accrued interest receivable and other assets	[3]					343,856					343,856
Accrued expenses and other liabilities						233,581					233,581
Retained earnings						$ 1,315,948					1,315,948
HSA Bank [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income											37,443
HSA Bank [Member] | Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income											$ 39,173
[1]	In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Consolidated Balance Sheets.
[2]	An additional line item, net decrease (increase) in derivative contract assets net of liabilities, was added to the Consolidated Statements of Cash Flows to detail the net change in derivative balances subject to offsetting. The update removed $6.5 million and $49.2 million in net increases in derivative contract assets net of liabilities from the net (increase) in accrued interest receivable and other assets and net increase in accrued expenses and other liabilities line items for the years ended December 31, 2015 and December 31, 2014 respectively.
[3]	The amount recorded as revised includes the impact of a $1.1 million reclassification of debt issuance cost from accrued interest receivable and other assets into long-term debt. The reclassification was made in accordance with the Company's adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, and is not considered part of the error correction.

Summary of Significant Accoun54

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Narrative) (Loans) (Detail)	12 Months Ended
	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Minimum number of days to be considered past due	90 days
Threshold period past due for write-off of financing receivable (in days)	180 days
Days past due and still accruing (in days)	90 days
Minimum period for troubled debt restructurings placed on non accrual status (in months)	6 months
Minimum performance period for TDR to return to accrual status (in months)	6 months
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Minimum number of days to be considered past due	90 days
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Minimum number of days to be considered past due	90 days
Other Real Estate Owned [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Threshold period past due for write-off of financing receivable (in days)	90 days

Significant Accounting Policies

Significant Accounting Policies (Narrative) (Premises and Equipment) (Detail) (Details)	12 Months Ended
	Dec. 31, 2016
Building and Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Building and Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	20 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years
Data Processing and Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Data Processing and Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years

Summary of Significant Accoun56

Summary of Significant Accounting Policies (Share Based Compensation) (Narrative) (Detail)	12 Months Ended
	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Performance Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	3 years
Award vesting percentage	50.00%
Share-based Compensation Award, Tranche One [Member] | Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	0.00%
Share-based Compensation Award, Tranche One [Member] | Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	150.00%

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities [Abstract]
Amortized Cost	$ 3,015,763	$ 2,994,924
Unrealized Gains	16,226	22,997
Unrealized Losses	(40,898)	(33,290)
Fair Value	2,991,091	2,984,631
Held-to-maturity Securities [Abstract]
Amortized Cost	4,160,658	3,923,052
Unrealized Gains	37,567	63,894
Unrealized Losses	(73,100)	(25,412)
Fair Value	4,125,125	3,961,534
US Treasury Bill Securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	734	924
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	734	924
Agency collateralized mortgage obligations (agency CMO) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	419,865	546,168
Unrealized Gains	3,344	5,532
Unrealized Losses	(3,503)	(2,946)
Fair Value	419,706	548,754
Held-to-maturity Securities [Abstract]
Amortized Cost	339,455	407,494
Unrealized Gains	1,977	3,717
Unrealized Losses	(3,824)	(2,058)
Fair Value	337,608	409,153
Agency mortgage-backed securities (agency MBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	969,460	1,075,941
Unrealized Gains	4,398	6,459
Unrealized Losses	(19,509)	(17,291)
Fair Value	954,349	1,065,109
Held-to-maturity Securities [Abstract]
Amortized Cost	2,317,449	2,030,176
Unrealized Gains	26,388	38,813
Unrealized Losses	(41,768)	(19,908)
Fair Value	2,302,069	2,049,081
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	587,776	215,670
Unrealized Gains	63	639
Unrealized Losses	(14,567)	(959)
Fair Value	573,272	215,350
Held-to-maturity Securities [Abstract]
Amortized Cost	547,726	686,086
Unrealized Gains	694	4,253
Unrealized Losses	(1,348)	(325)
Fair Value	547,072	690,014
Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	473,974	574,686
Unrealized Gains	4,093	7,485
Unrealized Losses	(702)	(2,905)
Fair Value	477,365	579,266
Held-to-maturity Securities [Abstract]
Amortized Cost	298,538	360,018
Unrealized Gains	4,107	5,046
Unrealized Losses	(411)	(2,704)
Fair Value	302,234	362,360
Collateralized loan obligations (CLO) [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	425,083	431,837
Unrealized Gains	2,826	592
Unrealized Losses	(519)	(3,270)
Fair Value	427,390	429,159
Single issuer trust preferred securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	30,381	42,168
Unrealized Gains	0	0
Unrealized Losses	(1,748)	(4,998)
Fair Value	28,633	37,170
Corporate debt securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	108,490	104,031
Unrealized Gains	1,502	2,290
Unrealized Losses	(350)	0
Fair Value	109,642	106,321
Equity securities [Member]
Available-for-sale Securities [Abstract]
Amortized Cost	0	3,499
Unrealized Gains	0	0
Unrealized Losses	0	(921)
Fair Value	0	2,578
Municipal bonds and notes [Member]
Held-to-maturity Securities [Abstract]
Amortized Cost	655,813	435,905
Unrealized Gains	4,389	12,019
Unrealized Losses	(25,749)	(417)
Fair Value	634,453	447,507
Private Label MBS [Member]
Held-to-maturity Securities [Abstract]
Amortized Cost	1,677	3,373
Unrealized Gains	12	46
Unrealized Losses	0	0
Fair Value	$ 1,689	$ 3,419

Investment Securities (Other Th

Investment Securities (Other Than Temporary Impairment Credit Losses Recognized In Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance of OTTI, beginning of period	$ 3,288	$ 3,696	$ 16,633
Reduction for securities sold, called	(194)	(518)	(14,082)
Additions for OTTI not previously recognized	149	110	1,145
Balance of OTTI, end of period	$ 3,243	$ 3,288	$ 3,696

Investment Securities (Summar59

Investment Securities (Summary Of Gross Unrealized Losses Not Considered OTTI) (Detail) $ in Thousands	Dec. 31, 2016USD ($)holding	Dec. 31, 2015USD ($)holding
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	$ 1,236,547	$ 1,295,959
Available for sale, Unrealized Losses - Less Than Twelve Months	(27,316)	(16,177)
Available for sale, Fair Value - Twelve Months or Longer	470,314	446,123
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (13,582)	$ (17,113)
Available for sale, Number of Holdings - Total | holding	168	156
Available for sale, Fair Value - Total	$ 1,706,861	$ 1,742,082
Available for sale, Unrealized Losses - Total	(40,898)	(33,290)
Held-to-maturity, Fair Value - Less Than Twelve Months	2,351,350	977,562
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(63,785)	(10,831)
Held-to-maturity, Fair Value - Twelve Months or Longer	292,225	542,714
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (9,315)	$ (14,581)
Held-to-maturity, Number of Holdings - Total | holding	395	152
Held-to-maturity, Fair Value - Total	$ 2,643,575	$ 1,520,276
Held-to-maturity, Unrealized Losses - Total	(73,100)	(25,412)
Agency collateralized mortgage obligations (agency CMO) [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	107,853	195,369
Available for sale, Unrealized Losses - Less Than Twelve Months	(2,168)	(2,195)
Available for sale, Fair Value - Twelve Months or Longer	67,351	26,039
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (1,335)	$ (751)
Available for sale, Number of Holdings - Total | holding	15	14
Available for sale, Fair Value - Total	$ 175,204	$ 221,408
Available for sale, Unrealized Losses - Total	(3,503)	(2,946)
Held-to-maturity, Fair Value - Less Than Twelve Months	163,439	143,364
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(3,339)	(1,304)
Held-to-maturity, Fair Value - Twelve Months or Longer	17,254	27,928
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (485)	$ (754)
Held-to-maturity, Number of Holdings - Total | holding	16	13
Held-to-maturity, Fair Value - Total	$ 180,693	$ 171,292
Held-to-maturity, Unrealized Losses - Total	(3,824)	(2,058)
Agency mortgage-backed securities (agency MBS) [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	512,075	481,839
Available for sale, Unrealized Losses - Less Than Twelve Months	(10,503)	(6,386)
Available for sale, Fair Value - Twelve Months or Longer	252,779	351,911
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (9,006)	$ (10,905)
Available for sale, Number of Holdings - Total | holding	97	84
Available for sale, Fair Value - Total	$ 764,854	$ 833,750
Available for sale, Unrealized Losses - Total	(19,509)	(17,291)
Held-to-maturity, Fair Value - Less Than Twelve Months	1,394,623	551,918
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(32,942)	(7,089)
Held-to-maturity, Fair Value - Twelve Months or Longer	273,779	470,828
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (8,826)	$ (12,819)
Held-to-maturity, Number of Holdings - Total | holding	150	87
Held-to-maturity, Fair Value - Total	$ 1,668,402	$ 1,022,746
Held-to-maturity, Unrealized Losses - Total	(41,768)	(19,908)
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	554,246	124,241
Available for sale, Unrealized Losses - Less Than Twelve Months	$ (14,567)	$ (959)
Available for sale, Number of Holdings - Total | holding	32	7
Available for sale, Fair Value - Total	$ 554,246	$ 124,241
Available for sale, Unrealized Losses - Total	(14,567)	(959)
Held-to-maturity, Fair Value - Less Than Twelve Months	347,725	110,864
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	$ (1,348)	$ (325)
Held-to-maturity, Number of Holdings - Total | holding	25	7
Held-to-maturity, Fair Value - Total	$ 347,725	$ 110,864
Held-to-maturity, Unrealized Losses - Total	(1,348)	(325)
Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	12,427	276,330
Available for sale, Unrealized Losses - Less Than Twelve Months	(24)	(2,879)
Available for sale, Fair Value - Twelve Months or Longer	63,930	19,382
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (678)	$ (26)
Available for sale, Number of Holdings - Total | holding	12	29
Available for sale, Fair Value - Total	$ 76,357	$ 295,712
Available for sale, Unrealized Losses - Total	(702)	(2,905)
Held-to-maturity, Fair Value - Less Than Twelve Months	60,768	142,382
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	$ (411)	(1,983)
Held-to-maturity, Fair Value - Twelve Months or Longer		30,129
Held-to-maturity, Unrealized Losses, Twelve Months or Longer		$ (721)
Held-to-maturity, Number of Holdings - Total | holding	8	18
Held-to-maturity, Fair Value - Total	$ 60,768	$ 172,511
Held-to-maturity, Unrealized Losses - Total	(411)	(2,704)
Collateralized loan obligations (CLO) [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months	49,946	211,515
Available for sale, Unrealized Losses - Less Than Twelve Months	(54)	(2,709)
Available for sale, Fair Value - Twelve Months or Longer	50,237	15,708
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (465)	$ (561)
Available for sale, Number of Holdings - Total | holding	5	13
Available for sale, Fair Value - Total	$ 100,183	$ 227,223
Available for sale, Unrealized Losses - Total	(519)	(3,270)
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months		4,087
Available for sale, Unrealized Losses - Less Than Twelve Months		(128)
Available for sale, Fair Value - Twelve Months or Longer	28,633	33,083
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (1,748)	$ (4,870)
Available for sale, Number of Holdings - Total | holding	5	8
Available for sale, Fair Value - Total	$ 28,633	$ 37,170
Available for sale, Unrealized Losses - Total	(1,748)	(4,998)
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Available for sale, Fair Value - Twelve Months or Longer	7,384
Available for sale, Unrealized Losses - Twelve Months or Longer	$ (350)
Available for sale, Number of Holdings - Total | holding	2
Available for sale, Fair Value - Total	$ 7,384
Available for sale, Unrealized Losses - Total	(350)	0
Equity Securities [Member]
Schedule of Investments [Line Items]
Available for Sale, Fair Value - Less Than Twelve Months		2,578
Available for sale, Unrealized Losses - Less Than Twelve Months		$ (921)
Available for sale, Number of Holdings - Total | holding		1
Available for sale, Fair Value - Total		$ 2,578
Available for sale, Unrealized Losses - Total		(921)
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity, Fair Value - Less Than Twelve Months	384,795	29,034
Held-to-maturity, Unrealized Losses - Less Than Twelve Months	(25,745)	(130)
Held-to-maturity, Fair Value - Twelve Months or Longer	1,192	13,829
Held-to-maturity, Unrealized Losses, Twelve Months or Longer	$ (4)	$ (287)
Held-to-maturity, Number of Holdings - Total | holding	196	27
Held-to-maturity, Fair Value - Total	$ 385,987	$ 42,863
Held-to-maturity, Unrealized Losses - Total	$ (25,749)	$ (417)

Investment Securities (Narrativ

Investment Securities (Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Schedule of Investments [Line Items]
Gross unrealized losses	$ (40,898)	$ (33,290)
Available-for-sale securities, unrealized loss	40,898	33,290
Held-to-maturity securities, accumulated unrealized holding loss	(73,100)	(25,412)
Securities available-for-sale, at fair value	2,991,091	2,984,631
Securities pledged to secure public funds, carrying value	2,500,000	2,600,000
Agency collateralized mortgage obligations (agency CMO) [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(3,503)	(2,946)
Available-for-sale securities, unrealized loss	3,503	2,946
Held-to-maturity securities, accumulated unrealized holding loss	(3,824)	(2,058)
Securities available-for-sale, at fair value	419,706	548,754
Agency mortgage-backed securities (agency MBS) [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(19,509)	(17,291)
Available-for-sale securities, unrealized loss	19,509	17,291
Held-to-maturity securities, accumulated unrealized holding loss	(41,768)	(19,908)
Securities available-for-sale, at fair value	954,349	1,065,109
Agency commercial mortgage-backed securities (agency CMBS) [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(14,567)	(959)
Available-for-sale securities, unrealized loss	14,567	959
Held-to-maturity securities, accumulated unrealized holding loss	(1,348)	(325)
Securities available-for-sale, at fair value	573,272	215,350
Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(702)	(2,905)
Available-for-sale securities, unrealized loss	702	2,905
Held-to-maturity securities, accumulated unrealized holding loss	(411)	(2,704)
Securities available-for-sale, at fair value	477,365	579,266
Collateralized loan obligations (CLO) [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(519)	(3,270)
Available-for-sale securities, unrealized loss	519	3,270
Securities available-for-sale, at fair value	427,390	429,159
Single issuer trust preferred securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(1,748)	(4,998)
Available-for-sale securities, unrealized loss	1,748	4,998
Securities available-for-sale, at fair value	28,633	37,170
Corporate Debt Securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses	(350)	0
Available-for-sale securities, unrealized loss	350	0
Securities available-for-sale, at fair value	109,642	106,321
Municipal bonds and notes [Member]
Schedule of Investments [Line Items]
Held-to-maturity securities, accumulated unrealized holding loss	(25,749)	$ (417)
Callable at the option of the counterparty [Member]
Schedule of Investments [Line Items]
Securities available-for-sale, at fair value	$ 1,900,000

Investment Securities (Summar61

Investment Securities (Summary Of Sale Proceeds Of Available For Sale Securities) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$ 259,273	$ 95,101	$ 126,580
Gains	2,891	1,029	7,268
Losses	2,477	420	1,769
Available-for-sale Securities, Gross Realized Gain (Loss)	$ 414	$ 609	$ 5,499

Investment Securities (Summar62

Investment Securities (Summary Of Debt Securities By Contractual Maturity) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 75,466
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	21,781
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis	529,247
Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis	2,389,269
Available-for-sale Debt Securities, Amortized Cost Basis	3,015,763
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	76,383
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	22,190
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	532,352
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	2,360,166
Available for Sale, Fair Value - Total debt securities	2,991,091
Held-to-maturity Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis [Abstract]
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount	13,612
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	17,313
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	46,835
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	4,082,898
Amortized Cost	4,160,658	$ 3,923,052
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	13,721
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	17,611
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	47,780
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	4,046,013
Held-to-maturity Securities, Fair Value	$ 4,125,125	$ 3,961,534

Variable Interest Entities (Det

Variable Interest Entities (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Other Assets [Member]
Variable Interest Entity [Line Items]
Variable interest entities, investments, carrying value	$ 22.8	$ 25.9
Accounts Payable and Accrued Liabilities [Member]
Variable Interest Entity [Line Items]
Variable interest entities, unfunded commitments	14	16.5
Other Investments [Member]
Variable Interest Entity [Line Items]
Variable interest entities, investments, carrying value	12.3	12.1
Unfunded Loan Commitment [Member]
Variable Interest Entity [Line Items]
Variable interest entities, total exposure of other investments including unfunded commitments	$ 19.9	$ 19

Loans and Leases (Detail)

Loans and Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 17,026,588	[1],[2]	$ 15,671,735	[1],[2]	$ 13,900,025
Unamortized premiums	17,300		18,000
Pledged loans as collateral	6,400,000
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	4,254,682		4,061,001		3,509,175
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	2,684,500		2,702,560		2,549,401
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	4,940,931		4,315,999		3,749,270
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	4,510,846		3,991,649		3,554,428
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 635,629		$ 600,526		$ 537,751
[1]	At December 31, 2016, the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015, respectively.

Loans and Leases (Summary Of Lo

Loans and Leases (Summary Of Loan And Lease Portfolio Aging By Class Of Loan) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	$ 175,864		$ 179,403
90 or More Days Past Due and Accruing	749		2,051
Non-accrual	133,816		140,069
Current	16,850,724		15,492,332
Total Loans and Leases	17,026,588	[1],[2]	15,671,735	[1],[2]	$ 13,900,025
Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	58,519		71,298
90 or More Days Past Due and Accruing	0		2,029
Non-accrual	47,279		54,201
Current	4,196,163		3,989,703
Total Loans and Leases	4,254,682		4,061,001		3,509,175
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	2,684,500		2,702,560		2,549,401
Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	5,381		2,565
90 or More Days Past Due and Accruing	0		0
Non-accrual	1,663		560
Current	269,226		246,597
Total Loans and Leases	274,607		249,162
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	50,539		50,640
90 or More Days Past Due and Accruing	0		0
Non-accrual	35,926		37,337
Current	2,359,354		2,402,758
Total Loans and Leases	2,409,893		2,453,398
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	4,940,931		4,315,999		3,749,270
Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	40,898		31,115
90 or More Days Past Due and Accruing	749		22
Non-accrual	38,190		27,037
Current	4,094,727		3,531,669
Total Loans and Leases	4,135,625		3,562,784
Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	0		0
90 or More Days Past Due and Accruing	0		0
Non-accrual	0		0
Current	805,306		753,215
Total Loans and Leases	805,306		753,215
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	4,510,846		3,991,649		3,554,428
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	18,044		19,016
90 or More Days Past Due and Accruing	0		0
Non-accrual	9,871		16,767
Current	4,117,742		3,673,408
Total Loans and Leases	4,135,786		3,692,424
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	662		3,461
90 or More Days Past Due and Accruing	0		0
Non-accrual	662		3,461
Current	374,398		295,764
Total Loans and Leases	375,060		299,225
Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	1,821		1,308
90 or More Days Past Due and Accruing	0		0
Non-accrual	225		706
Current	633,808		599,218
Total Loans and Leases	635,629		600,526		$ 537,751
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	28,337		23,751
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	8,631		10,365
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	2,233		1,390
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	8,831		9,061
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	1,382		768
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	0		0
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	6,357		1,624
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	0		0
Financing Receivables, 30 to 59 Days Past Due [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	903		543
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	12,962		13,532
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	2,609		4,703
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Consumer Borrower [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	1,485		615
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	5,782		4,242
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	577		3,288
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member] | Asset Based Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	0		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	1,816		625
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	0		0
Financing Receivables, 60 to 89 Days Past Due [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-accrual	$ 693		$ 59
[1]	At December 31, 2016, the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015, respectively.

Loans and Leases (Narrative) (D

Loans and Leases (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans and Leases Receivable Disclosure [Abstract]
Interest on non-accrual loans that would have been recorded as additional interest income	$ 11	$ 8.2	$ 9.3
Write-down of TDR's	$ (18.6)	$ (11.8)	$ (13.5)

Loans and Leases (Allowance For

Loans and Leases (Allowance For Loan And Lease Losses By Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					$ 174,990					$ 159,264	$ 174,990		$ 159,264		$ 152,573
Provision (benefit) charged to expense	$ 12,500		$ 14,250	$ 14,000	15,600	$ 13,800		$ 13,000	$ 12,750	9,750	56,350		49,300		37,250
Losses charged off											(46,912)		(43,560)		(44,426)
Recoveries											9,892		9,986		13,867
Balance, end of period	194,320					174,990					194,320		174,990		159,264
Individually evaluated for impairment	18,593					22,204					18,593		22,204		25,301
Collectively evaluated for impairment	175,727					152,786					175,727		152,786		133,963
Individually evaluated for impairment	249,355					279,171					249,355		279,171		330,856
Collectively evaluated for impairment	16,777,233					15,392,564					16,777,233		15,392,564		13,569,169
Total Loans and Leases	17,026,588	[1],[2]				15,671,735	[1],[2]				17,026,588	[1],[2]	15,671,735	[1],[2]	13,900,025
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					25,876					25,452	25,876		25,452		23,027
Provision (benefit) charged to expense											230		6,057		7,315
Losses charged off											(4,636)		(6,508)		(6,214)
Recoveries											1,756		875		1,324
Balance, end of period	23,226					25,876					23,226		25,876		25,452
Individually evaluated for impairment	8,090					10,364					8,090		10,364		12,094
Collectively evaluated for impairment	15,136					15,512					15,136		15,512		13,358
Individually evaluated for impairment	119,424					134,448					119,424		134,448		141,982
Collectively evaluated for impairment	4,135,258					3,926,553					4,135,258		3,926,553		3,367,193
Total Loans and Leases	4,254,682					4,061,001					4,254,682		4,061,001		3,509,175
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					42,052					43,518	42,052		43,518		41,951
Provision (benefit) charged to expense											18,507		11,847		17,224
Losses charged off											(20,669)		(17,679)		(20,712)
Recoveries											5,343		4,366		5,055
Balance, end of period	45,233					42,052					45,233		42,052		43,518
Individually evaluated for impairment	2,903					3,477					2,903		3,477		4,237
Collectively evaluated for impairment	42,330					38,575					42,330		38,575		39,281
Individually evaluated for impairment	45,719					48,425					45,719		48,425		50,249
Collectively evaluated for impairment	2,638,781					2,654,135					2,638,781		2,654,135		2,499,152
Total Loans and Leases	2,684,500					2,702,560					2,684,500		2,702,560		2,549,401
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					59,977					47,068	59,977		47,068		46,655
Provision (benefit) charged to expense											28,662		21,693		9,712
Losses charged off											(18,360)		(11,522)		(13,668)
Recoveries											1,626		2,738		4,369
Balance, end of period	71,905					59,977					71,905		59,977		47,068
Individually evaluated for impairment	7,422					5,197					7,422		5,197		2,710
Collectively evaluated for impairment	64,483					54,780					64,483		54,780		44,358
Individually evaluated for impairment	53,037					56,581					53,037		56,581		36,176
Collectively evaluated for impairment	4,887,894					4,259,418					4,887,894		4,259,418		3,713,094
Total Loans and Leases	4,940,931					4,315,999					4,940,931		4,315,999		3,749,270
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					41,598					37,148	41,598		37,148		36,754
Provision (benefit) charged to expense											7,930		11,381		2,746
Losses charged off											(2,682)		(7,578)		(3,237)
Recoveries											631		647		885
Balance, end of period	47,477					41,598					47,477		41,598		37,148
Individually evaluated for impairment	169					3,163					169		3,163		6,232
Collectively evaluated for impairment	47,308					38,435					47,308		38,435		30,916
Individually evaluated for impairment	24,755					39,295					24,755		39,295		101,817
Collectively evaluated for impairment	4,486,091					3,952,354					4,486,091		3,952,354		3,452,611
Total Loans and Leases	4,510,846					3,991,649					4,510,846		3,991,649		3,554,428
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period					$ 5,487					$ 6,078	5,487		6,078		4,186
Provision (benefit) charged to expense											1,021		(1,678)		253
Losses charged off											(565)		(273)		(595)
Recoveries											536		1,360		2,234
Balance, end of period	6,479					5,487					6,479		5,487		6,078
Individually evaluated for impairment	9					3					9		3		28
Collectively evaluated for impairment	6,470					5,484					6,470		5,484		6,050
Individually evaluated for impairment	6,420					422					6,420		422		632
Collectively evaluated for impairment	629,209					600,104					629,209		600,104		537,119
Total Loans and Leases	$ 635,629					$ 600,526					$ 635,629		$ 600,526		$ 537,751
[1]	At December 31, 2016, the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015, respectively.

Loans and Leases (Impaired Loan

Loans and Leases (Impaired Loans And Leases By Class) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	$ 273,364	$ 316,542
Total Recorded Investment	249,355	279,171
Recorded Investment No Allowance	96,795	95,225
Recorded Investment With Allowance	152,560	183,946
Related Valuation Allowance	18,593	22,204
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	131,468	148,144
Total Recorded Investment	119,424	134,448
Recorded Investment No Allowance	21,068	23,024
Recorded Investment With Allowance	98,356	111,424
Related Valuation Allowance	8,090	10,364
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	52,432	56,680
Total Recorded Investment	45,719	48,425
Recorded Investment No Allowance	22,746	25,130
Recorded Investment With Allowance	22,973	23,295
Related Valuation Allowance	2,903	3,477
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	1,188	7,010
Total Recorded Investment	1,187	5,962
Recorded Investment No Allowance	1,187	5,939
Recorded Investment With Allowance	0	23
Related Valuation Allowance	0	3
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	6,398	612
Total Recorded Investment	6,420	422
Recorded Investment No Allowance	6,197	328
Recorded Investment With Allowance	223	94
Related Valuation Allowance	9	3
Commercial and Industrial Sector [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	57,732	67,116
Total Recorded Investment	53,037	56,581
Recorded Investment No Allowance	26,006	31,600
Recorded Investment With Allowance	27,031	24,981
Related Valuation Allowance	7,422	5,197
Commercial Real Estate [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	24,146	36,980
Total Recorded Investment	23,568	33,333
Recorded Investment No Allowance	19,591	9,204
Recorded Investment With Allowance	3,977	24,129
Related Valuation Allowance	$ 169	$ 3,160

Loans and Leases (Interest Inco

Loans and Leases (Interest Income From Impaired Loans And Leases, By Class) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 264,162	$ 305,015	$ 339,477
Accrued Interest Income	8,065	8,557	12,180
Cash Basis Interest Income	2,185	2,238	2,424
Residential Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	126,936	138,215	142,198
Accrued Interest Income	4,377	4,473	4,644
Cash Basis Interest Income	1,200	1,139	1,221
Consumer Portfolio Segment [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	47,072	49,337	51,171
Accrued Interest Income	1,361	1,451	1,484
Cash Basis Interest Income	985	1,099	1,203
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	3,574	6,062	8,381
Accrued Interest Income	92	133	269
Cash Basis Interest Income	0	0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	3,421	527	421
Accrued Interest Income	184	16	28
Cash Basis Interest Income	0	0	0
Commercial and Industrial Sector [Member] | Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	54,708	46,379	44,097
Accrued Interest Income	1,540	1,319	2,326
Cash Basis Interest Income	0	0	0
Commercial Real Estate [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	28,451	64,495	93,209
Accrued Interest Income	511	1,165	3,429
Cash Basis Interest Income	$ 0	$ 0	$ 0

Loans and Leases (Commercial, C

Loans and Leases (Commercial, Commercial Real Estate Loans And Equipment Financing Loans Segregated By Risk Rating Exposure) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	$ 17,026,588	[1],[2]	$ 15,671,735	[1],[2]	$ 13,900,025
Commercial Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	4,940,931		4,315,999		3,749,270
Commercial Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	4,655,007		4,023,255
Commercial Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	56,240		70,904
Commercial Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	226,603		220,389
Commercial Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	3,081		1,451
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	4,510,846		3,991,649		3,554,428
Commercial Real Estate Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	4,357,458		3,857,019
Commercial Real Estate Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	69,023		55,030
Commercial Real Estate Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	84,365		79,289
Commercial Real Estate Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	0		311
Finance Leases Portfolio Segment [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	635,629		600,526		$ 537,751
Finance Leases Portfolio Segment [Member] | (1) - (6) Pass [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	618,084		586,445
Finance Leases Portfolio Segment [Member] | (7) Special Mention [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	1,324		1,628
Finance Leases Portfolio Segment [Member] | (8) Substandard [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	16,221		12,453
Finance Leases Portfolio Segment [Member] | (9) Doubtful [Member]
Financing Receivable, Impaired [Line Items]
Total Loans and Leases	$ 0		$ 0
[1]	At December 31, 2016, the Company had pledged $6.4 billion of eligible loans as collateral to support borrowing capacity at the FHLB of Boston and the FRB of Boston.
[2]	Loans and leases include net deferred fees and net premiums and discounts of $17.3 million and $18.0 million at December 31, 2016 and December 31, 2015, respectively.

Loans and Leases (Summary Of Th

Loans and Leases (Summary Of The Recorded Investment Of Company's TDRs) (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDR	[1]	$ 223,528	$ 272,690
Accruing TDR performing under modified terms more than one year		57.10%	55.00%
Specific reserves for TDR included in the balance of ALLL		$ 194,320	$ 174,990	$ 159,264	$ 152,573
Additional funds committed to borrowers in TDR status		459	1,133
Performing Financial Instruments [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDR		147,809	171,784
Nonperforming Financial Instruments [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDR		75,719	100,906
Troubled Debt Restructures [Member]
Financing Receivable, Modifications [Line Items]
Interest receivable		700	1,100
Troubled Debt Restructures [Member] | Nonperforming Financial Instruments [Member]
Financing Receivable, Modifications [Line Items]
Specific reserves for TDR included in the balance of ALLL		$ 14,583	$ 21,405
[1]	Total recorded investment of TDRs exclude $0.7 million and $1.1 million at December 31, 2016 and December 31, 2015, respectively, of accrued interest receivable.

Loans and Leases (Information o

Loans and Leases (Information on How Loans and Leases were Modified as a TDR) (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2016USD ($)loan	Dec. 31, 2015USD ($)loan	Dec. 31, 2014USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		175	212	262
Post-Modification Recorded Investment | $	[1]	$ 43,669	$ 49,215	$ 47,031
Residential Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		17	27	27
Post-Modification Recorded Investment | $	[1]	$ 2,801	$ 4,909	$ 3,547
Residential Portfolio Segment [Member] | Adjusted Interest Rates [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		2	3	3
Post-Modification Recorded Investment | $	[1]	$ 528	$ 573	$ 448
Residential Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		13	26	22
Post-Modification Recorded Investment | $	[1]	$ 1,537	$ 5,315	$ 4,220
Residential Portfolio Segment [Member] | other concessions [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	24	30	55
Post-Modification Recorded Investment | $	[1],[2]	$ 4,090	$ 4,366	$ 11,791
Consumer Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		11	12	19
Post-Modification Recorded Investment | $	[1]	$ 484	$ 1,012	$ 944
Consumer Portfolio Segment [Member] | Adjusted Interest Rates [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		0	0	1
Post-Modification Recorded Investment | $	[1]	$ 0	$ 0	$ 51
Consumer Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		15	12	6
Post-Modification Recorded Investment | $	[1]	$ 1,156	$ 945	$ 411
Consumer Portfolio Segment [Member] | other concessions [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	52	68	90
Post-Modification Recorded Investment | $	[1],[2]	$ 3,131	$ 3,646	$ 4,931
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		12	3	7
Post-Modification Recorded Investment | $	[1]	$ 14,883	$ 254	$ 422
Commercial Portfolio Segment [Member] | Adjusted Interest Rates [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		0	1	1
Post-Modification Recorded Investment | $	[1]	$ 0	$ 24	$ 25
Commercial Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		2	7	22
Post-Modification Recorded Investment | $	[1]	$ 648	$ 5,361	$ 1,212
Commercial Portfolio Segment [Member] | other concessions [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	13	20	6
Post-Modification Recorded Investment | $	[1],[2]	$ 1,767	$ 22,048	$ 7,431
Commercial Real Estate Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		3	1	0
Post-Modification Recorded Investment | $	[1]	$ 4,921	$ 315	$ 0
Commercial Real Estate Portfolio Segment [Member] | Adjusted Interest Rates [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		1	0	0
Post-Modification Recorded Investment | $	[1]	$ 237	$ 0	$ 0
Commercial Real Estate Portfolio Segment [Member] | Combination Rate and Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		2	1	2
Post-Modification Recorded Investment | $	[1]	$ 335	$ 42	$ 11,106
Commercial Real Estate Portfolio Segment [Member] | other concessions [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	[2]	1	1	0
Post-Modification Recorded Investment | $	[1],[2]	$ 509	$ 405	$ 0
Finance Leases Portfolio Segment [Member] | Extended Maturity [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan		7	0	1
Post-Modification Recorded Investment | $	[1]	$ 6,642	$ 0	$ 492
[1]	Post-modification balances approximate pre-modification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant.
[2]	Other includes covenant modifications, forbearance, loans discharged under Chapter 7 bankruptcy, and/or other concessions.

Loans and Leases (Information73

Loans and Leases (Information on Loans and Leases Modified as TDR within the Previous 12 Months (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)loan	Dec. 31, 2015USD ($)loan	Dec. 31, 2014USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	2	9
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 58	$ 1,518
Residential Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	1	7
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 55	$ 1,494
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans and Leases | loan	0	1	2
Financing Receivable, Modifications, Subsequent Default, Recorded Investment | $	$ 0	$ 3	$ 24

Loans and Leases (Investments i

Loans and Leases (Investments in TDRs, Segregated by Risk Rating Exposure) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs	[1]	$ 223,528	$ 272,690
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		58,464	89,818
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (1) - (6) Pass [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		10,210	12,970
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (7) Special Mention [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		7	2,999
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (8) Substandard [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		45,509	72,132
Commerial, Commercial Real Estate, Equipment Financing TDR's [Member] | (9) Doubtful [Member]
Financing Receivable, Modifications [Line Items]
Total recorded investment of TDRs		$ 2,738	$ 1,717
[1]	Total recorded investment of TDRs exclude $0.7 million and $1.1 million at December 31, 2016 and December 31, 2015, respectively, of accrued interest receivable.

Transfers of Financial Assets75

Transfers of Financial Assets (Reserve for loan repurchases) (Details) - Loan Purchase Commitments [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 1,192	$ 1,059	$ 2,254
(Benefit) provision charged to expense	(303)	133	(493)
Repurchased loans and settlements charged off	(99)	0	(702)
Ending balance	$ 790	$ 1,192	$ 1,059

Transfers of Financial Assets76

Transfers of Financial Assets (Loans sold) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Servicing Assets at Fair Value [Line Items]
Net gain on sale	$ 11,103	$ 7,795	$ 4,070
Residential Mortgage [Member]
Servicing Assets at Fair Value [Line Items]
Proceeds from sale	438,925	452,590	287,132
Net gain on sale	11,629	7,795	4,070
Fair value option adjustment	(526)	0	0
Loans sold with servicing rights retained	$ 399,318	$ 416,277	$ 264,292

Transfers of Financial Assets77

Transfers of Financial Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from loans not originated for sale	$ 34,170	$ 33,644	$ 0
Net gain on sale	11,103	7,795	4,070
Residential Mortgage [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Retained servicing rights	2,600,000	2,500,000
Bank servicing fees	1,100	1,500	1,500
Proceeds from loans not originated for sale	7,600
Net gain on sale	11,629	7,795	$ 4,070
Commercial Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from loans not originated for sale	26,500	729
Net gain on sale	$ 2,100
Consumer Loan [Member]
Securitization or Asset-backed Financing Arrangement, Financial Asset for which Transfer is Accounted as Sale [Line Items]
Proceeds from loans not originated for sale		$ 32,900

Transfers of Financial Assets S

Transfers of Financial Assets Servicing Assets at Amortized Cost Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Beginning balance	$ 20,698	$ 19,379	$ 20,983
Additions	11,312	8,027	4,581
Amortization	(7,554)	(6,699)	(6,318)
Valuation recovery (provision)	10	(9)	133
Ending balance	24,466	20,698	19,379
Valuation allowance	$ 22	$ 32	$ 23

Premises and Equipment (Summary

Premises and Equipment (Summary of Premises and Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Land	$ 12,899	$ 12,595
Buildings and improvements	94,686	90,778
Leasehold improvements	79,917	83,995
Fixtures and equipment	73,686	76,146
Data processing and software	195,308	220,002
Total premises and equipment	456,496	483,516
Less: Accumulated depreciation and amortization	(327,070)	(346,103)
Premises and equipment, net	129,426	137,413
Depreciation and amortization	$ 28,400	$ 30,800	$ 27,900

Premises and Equipment (Disclos

Premises and Equipment (Disclosure of Long Lived Assets Held-for-sale) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Movement in Property, Plant and Equipment [Roll Forward]
Beginning balance	$ 637	$ 759
Additions	0	144
Write-downs	0	0
Sales	0	(266)
Ending balance	$ 637	$ 637

Goodwill and Other Intangible81

Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 92,420	$ 92,420
Accumulated Amortization	(58,746)	(53,094)
Net Carrying Amount	33,674	39,326
Goodwill	538,373	538,373
Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill	516,560	516,560
HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	43,000	43,000
Accumulated Amortization	(9,326)	(4,817)
Net Carrying Amount	33,674	38,183
Goodwill	21,813	21,813
Core Deposits [Member] | Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	49,420	49,420
Accumulated Amortization	(49,420)	(48,277)
Net Carrying Amount	0	1,143
Core Deposits [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,000	22,000
Accumulated Amortization	(6,162)	(3,269)
Net Carrying Amount	15,838	18,731
Customer Relationships [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000	21,000
Accumulated Amortization	(3,164)	(1,548)
Net Carrying Amount	$ 17,836	$ 19,452

Goodwill and Other Intangible82

Goodwill and Other Intangible Assets (Schedule Of Expected Future Amortization Expense) (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 4,062
2,018	3,847
2,019	3,847
2,020	3,847
2,021	3,847
Thereafter	$ 14,224

Income Taxes (Income Tax Expens

Income Taxes (Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal									$ 73,194	$ 97,575	$ 90,542
State and local									5,429	10,970	6,585
Total current									78,623	108,545	97,127
Deferred:
Federal									12,542	(7,279)	(3,784)
State and local									5,158	(8,234)	(1,370)
Total deferred									17,700	(15,513)	(5,154)
Total:
Total federal									85,736	90,296	86,758
Total state and local									10,587	2,736	5,215
Income tax expense	$ 23,845	$ 24,445	$ 24,599	$ 23,434	$ 23,627	$ 24,995	$ 20,426	$ 23,984	$ 96,323	$ 93,032	$ 91,973

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards			$ 3,000
Net tax credits		$ 1,000	$ 2,100	$ 300
Income tax expense at federal statutory rate, Percent		35.00%	35.00%	35.00%
Refundable income taxes		$ 700	$ 56,600
Increase (decrease) in deferred income taxes		(17,200)
Deferred tax expense (benefit)		17,700	(15,513)	$ (5,154)
Valuation allowance		71,474	74,918
Valuation allowance increase (decrease)		(1,800)
Net operating loss and credit carry forwards		64,644	68,735
Unrecognized deferred tax liability for thrift bad-debt reserves		21,400
Cumulative taxable temporary differences		58,000	58,000
Unrecognized tax benefits that would impact effective tax rate		2,500	3,300	3,000
Interest and penalties		(200)	1,100	$ 500
Accrued interest and penalties related to UTBs		1,700	$ 2,500
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance		67,800
Capital Loss Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance		3,700
Valuation allowance increase (decrease)		(1,700)
Capital Loss Equity Interest [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance increase (decrease)		(2,100)
Connecticut [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance		56,500
Net operating loss and credit carry forwards		1,200,000
Tax credit carryforwards		1,400
Minimum [Member] | Forecast [Member]
Operating Loss Carryforwards [Line Items]
Decrease in UTBs	$ 1,000
Maximum [Member] | Forecast [Member]
Operating Loss Carryforwards [Line Items]
Decrease in UTBs	$ 2,100
Latest Tax Year [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		12,300
Shareholders' Equity [Member]
Operating Loss Carryforwards [Line Items]
Increase (decrease) in deferred income taxes		$ 1,700

Income Taxes (Schedule of Effec

Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense at federal statutory rate									$ 106,208	$ 104,217	$ 102,095
State and local income taxes, net of federal benefit									6,882	7,563	3,390
Tax-exempt interest income, net									(8,917)	(7,117)	(7,335)
Decrease in valuation allowance applicable to net state deferred tax assets, net of federal effects									0	(5,785)	0
Increase in cash surrender value of life insurance									(5,166)	(4,557)	(4,612)
Other, net									(2,684)	(1,289)	(1,565)
Income tax expense	$ 23,845	$ 24,445	$ 24,599	$ 23,434	$ 23,627	$ 24,995	$ 20,426	$ 23,984	$ 96,323	$ 93,032	$ 91,973
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax expense at federal statutory rate, Percent									35.00%	35.00%	35.00%
State and local taxes, net of federal benefit, Percent									2.30%	2.50%	1.20%
Tax-exempt interest income, net, Percent									(2.90%)	(2.40%)	(2.50%)
Decrease in valuation allowance applicable to net state deferred tax assets, net of federal effects, Percent									0.00%	(1.90%)	0.00%
Increase in cash surrender value of life insurance, Percent									(1.70%)	(1.50%)	(1.60%)
Other, net, Percent									(1.00%)	(0.50%)	(0.60%)
Effective Tax Rate, Percent									31.70%	31.20%	31.50%

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Allowance for loan and lease losses	$ 77,908	$ 70,937
Net operating loss and credit carry forwards	64,644	68,735
Compensation and employee benefit plans	46,433	52,422
Net losses on derivative instruments	8,624	11,734
Net unrealized loss on securities available for sale	9,898	4,138
Other	17,682	21,663
Gross deferred tax assets	225,189	229,629
Valuation allowance	(71,474)	(74,918)
Total deferred tax assets, net of valuation allowance	153,715	154,711
Deferred tax liabilities:
Equipment-financing leases	41,910	23,934
Deferred income on repurchase of debt	4,251	6,376
Intangible assets	9,952	9,298
Mortgage servicing assets	7,313	7,127
Other	5,898	6,398
Gross deferred tax liabilities	69,324	53,133
Deferred tax assets, net	$ 84,391	$ 101,578

Income Taxes (Summary of Positi

Income Taxes (Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 5,094	$ 4,593	$ 3,109
Additions as a result of tax positions taken during the current year	613	865	956
Additions as a result of tax positions taken during prior years	0	1,254	1,031
Reductions as a result of tax positions taken during prior years	(625)	(247)	0
Reductions relating to settlements with taxing authorities	(693)	(992)	0
Reductions as a result of lapse of statute of limitations	(542)	(379)	(503)
Ending balance	$ 3,847	$ 5,094	$ 4,593

Deposits (Summary Of Deposits)

Deposits (Summary Of Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
Demand	$ 4,021,061	$ 3,713,063
Checking	2,528,274	2,369,971
Health savings accounts	4,362,503	3,802,313
Money market	2,047,121	1,933,460
Savings	4,320,090	4,047,817
Time deposits	2,024,808	2,086,154
Total interest-bearing	15,282,796	14,239,715
Total deposits	19,303,857	17,952,778
Time deposits and interest-bearing checking, included in above balances, obtained through brokers	848,618	910,304
Time deposits, included in above balance, that meet or exceed the FDIC limit	490,721	542,206
Demand deposit overdrafts reclassified as loan balances	$ 1,885	$ 1,356

Deposits (Scheduled Maturities

Deposits (Scheduled Maturities Of Time Deposits) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Banking and Thrift [Abstract]
2,017	$ 846,160
2,018	409,785
2,019	482,977
2,020	181,197
2,021	104,578
Thereafter	111
Total time deposits	$ 2,024,808	$ 2,086,154

Borrowings Borrowings - (Narrat

Borrowings Borrowings - (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2016	Dec. 31, 2015
Debt Disclosure [Abstract]
Total borrowings	$ 4	$ 4

Borrowings (Summary Of Securiti

Borrowings (Summary Of Securities Sold Under Agreements To Repurchase And Other Borrowings) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	$ 740,526	$ 834,400
Fed funds purchased	209,000	317,000
Securities sold under agreements to repurchase and other borrowings	949,526	1,151,400
Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	340,526	334,400
Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Total securities sold under agreements to repurchase	$ 400,000	$ 500,000
Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	1.82%	1.93%
Securities Sold under Agreements to Repurchase [Member] | Original maturity of one year or less [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.16%	0.15%
Securities Sold under Agreements to Repurchase [Member] | Original maturity of greater than one year, non-callable [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	3.09%	3.04%
Federal Funds Purchased [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	0.46%	0.21%
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Rate (as a percent)	1.53%	1.47%

Borrowings (Summary Of Advances

Borrowings (Summary Of Advances Payable To The Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Total Outstanding	$ 2,130,500	$ 2,025,934
FHLB advances maturing after 1 but within 2 years, Total Outstanding	200,000	500
FHLB advances maturing after 2 but within 3 years, Total Outstanding	128,026	200,000
FHLB advances maturing after 3 but within 4 years, Total Outstanding	175,000	103,026
FHLB advances maturing after 4 but within 5 years, Total Outstanding	200,000	175,000
FHLB advances maturing after 5 years, Total Outstanding	9,370	159,655
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances	2,842,896	2,664,115
Premiums on advances	12	24
Federal Home Loan Bank advances	$ 2,842,908	$ 2,664,139
Federal Home Loan Bank, Advances, Weighted Average Interest Rate [Abstract]
FHLB advances maturing within 1 year, Weighted-Average Contractual Coupon Rate (as a percent)	0.71%	0.55%
FHLB advances maturing after 1 but within 2 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.36%	5.66%
FHLB advances maturing after 2 but within 3 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.73%	1.36%
FHLB advances maturing after 3 but within 4 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.77%	1.54%
FHLB advances maturing after 4 but within 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.81%	1.77%
FHLB advances maturing after 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	2.59%	1.60%
Federal Home Loan Bank, Advances, Weighted Average Interest Rate (as a percent)	0.95%	0.79%
Aggregate carrying value of assets pledged as collateral	$ 5,967,318	$ 5,719,746
Remaining borrowing capacity	$ 1,192,758	$ 1,203,057

Borrowings (Long-Term Debt) (De

Borrowings (Long-Term Debt) (Details) - USD ($)		Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Notes and subordinated debt		$ 227,320,000	$ 227,320,000
Debt issuance cost on senior fixed-rate notes	[1]	(961,000)	(1,096,000)
Long-term debt		$ 225,514,000	$ 225,260,000
Long term debt, variable interest rate, percentage		3.94%	3.48%
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest rate spread of LIBOR plus (as a percent)		2.95%
Long-term Debt [Member]
Debt Instrument [Line Items]
Discount on senior fixed-rate notes		$ (845,000)	$ (964,000)
Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate, percentage		4.375%
Notes and subordinated debt		$ 150,000,000	150,000,000
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	[2]	$ 77,320,000	$ 77,320,000
[1]	In accordance with the adoption of ASU No. 2015-03, Interest-Imputation of Interest (Subtopic 835-30) - Simplifying the Presentation of Debt Issuance Costs, debt issuance cost is accounted for as a reduction to long-term debt. Previously debt issuance cost was included in accrued interest receivable and other assets within the accompanying Consolidated Balance Sheets.
[2]	The interest rate on Webster Statutory Trust I floating-rate notes, which varies quarterly based on 3-month LIBOR plus 2.95%, was 3.94% at December 31, 2016 and 3.48% at December 31, 2015.

Shareholders' Equity (Class of

Shareholders' Equity (Class of Stock Disclosure) (Details)	12 Months Ended
	Dec. 31, 2016shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock Held, beginning balance	2,090,409
Common Stock Outstanding, beginning balance	91,561,192
Restricted share activity	248,603
Stock options exercised	292,304
Common stock repurchased	350,000
Treasury Stock Held, ending balance	1,899,502
Common Stock Outstanding, ending balance	91,752,099
Series E Preferred Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, beginning balance	5,060
Shares, ending balance	5,060
Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, beginning balance	93,651,601
Shares, ending balance	93,651,601
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock Held, beginning balance	2,090,409
Restricted share activity	248,603
Stock options exercised	292,304
Common stock repurchased	350,000
Treasury Stock Held, ending balance	1,899,502

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($)	Jun. 01, 2015	Dec. 04, 2012	Dec. 31, 2016	Dec. 31, 2015	Dec. 06, 2012	Jun. 08, 2011
Class of Stock [Line Items]
Common stock par value (in usd per share)			$ 0.01	$ 0.01		$ 0.01
Exercise price of warrants or rights (in usd per share)			15.74
Preferred stock, par value (in usd per share)			0.01	$ 0.01
Conversion price (in usd per share)	$ 27.17
Common Stock [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized amount					$ 100,000,000
Treasury stock acquired, average cost per share (in usd per share)			$ 32.02
Stock repurchase program, remaining authorized repurchase amount			$ 15,500,000
Series A [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)	8.50%
Preferred stock, par value (in usd per share)	$ 0.01
Preferred stock, liquidation preference per share (in usd per share)	$ 1,000
Series A Preferred Stock [Member]
Class of Stock [Line Items]
Shares issued at conversion (in shares)	36.8046
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)		6.40%
Preferred stock, par value (in usd per share)		$ 0.01
Preferred stock, liquidation preference per share (in usd per share)		$ 25,000
Depository shares, issued		5,060,000
Depository share, par or stated value per share (in usd per share)		$ 25
Warrant [Member]
Class of Stock [Line Items]
Number of securities called by warrants or rights (in shares)						3,282,276
Exercise price of warrants or rights (in usd per share)						$ 18.28
Number of warrants repurchased (in shares)			10,317
Warrants outstanding (in shares)			53,027

Accumulated Other Comprehensi96

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ (78,106)	$ (56,261)	$ (48,549)
Other comprehensive income (loss) before reclassifications	(8,308)	(31,148)	(12,024)
Amounts reclassified from accumulated other comprehensive (loss) income	9,421	9,303	4,312
Other comprehensive income (loss), net of tax	1,113	(21,845)	(7,712)
Ending Balance	(76,993)	(78,106)	(56,261)
Available For Sale and Transferred Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(6,407)	16,421	(2,617)
Other comprehensive income (loss) before reclassifications	(8,901)	(22,512)	21,811
Amounts reclassified from accumulated other comprehensive (loss) income	(168)	(316)	(2,773)
Other comprehensive income (loss), net of tax	(9,069)	(22,828)	19,038
Ending Balance	(15,476)	(6,407)	16,421
Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(22,980)	(25,530)	(18,206)
Other comprehensive income (loss) before reclassifications	825	(3,136)	(12,506)
Amounts reclassified from accumulated other comprehensive (loss) income	5,087	5,686	5,182
Other comprehensive income (loss), net of tax	5,912	2,550	(7,324)
Ending Balance	(17,068)	(22,980)	(25,530)
Defined Benefit Pension and Postretirement Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(48,719)	(47,152)	(27,726)
Other comprehensive income (loss) before reclassifications	(232)	(5,500)	(21,329)
Amounts reclassified from accumulated other comprehensive (loss) income	4,502	3,933	1,903
Other comprehensive income (loss), net of tax	4,270	(1,567)	(19,426)
Ending Balance	$ (44,449)	$ (48,719)	$ (47,152)

Accumulated Other Comprehensi97

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Reclassifications from AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Impairment loss on securities recognized in earnings										$ (149)	$ (110)	$ (1,145)
Income before income tax expense		$ 81,505	$ 76,262	$ 75,202	$ 70,481	$ 75,439	$ 76,365	$ 72,469	$ 73,488	303,450	297,761	291,699
Income tax expense		$ (23,845)	$ (24,445)	$ (24,599)	$ (23,434)	$ (23,627)	$ (24,995)	$ (20,426)	$ (23,984)	(96,323)	(93,032)	(91,973)
Earnings applicable to common shareholders										198,423	195,361	188,496
Net of tax										(9,421)	(9,303)	(4,312)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of investment securities, net										414	609	5,499
Impairment loss on securities recognized in earnings										(149)	(110)	(1,145)
Income before income tax expense										265	499	4,354
Available For Sale and Transferred Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax										168	316	2,773
Available For Sale and Transferred Securities [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense										(97)	(183)	(1,581)
Earnings applicable to common shareholders										168	316	2,773
Derivative Instruments [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Net of tax										(5,087)	(5,686)	(5,182)
Derivative Instruments [Member] | Reclassification out of accumualted comprehensive income [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense										2,933	3,279	2,918
Earnings applicable to common shareholders										(5,087)	(5,686)	(5,182)
Total interest expense										(8,020)	(8,965)	(8,100)
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	[1]									(7,126)	(6,161)	(2,921)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost (Credit) [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax	[1]									(14)	(73)	(73)
Defined benefit pension and postretirement benefit plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Total before tax										(7,140)	(6,234)	(2,994)
Tax benefit										2,638	2,301	1,091
Net of tax										$ (4,502)	$ (3,933)	$ (1,903)
[1]	These accumulated other comprehensive income components are included in the computation of net periodic benefit cost (see Note 17 Retirement Benefit Plans for further details).

Accumulated Other Comprehensi98

Accumulated Other Comprehensive Loss, Net of Tax (Schedule of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale and transferred securities:
Net unrealized loss during the period	$ (14,113)	$ (35,701)	$ 34,242
Reclassification for net gain included in net income	(414)	(609)	(5,499)
Net non-credit other-than-temporary impairment	149	110	1,145
Amortization of unrealized loss on securities transferred to held-to-maturity	0	37	60
Total available-for-sale and transferred securities	(14,378)	(36,163)	29,948
Derivative instruments:
Net unrealized gain during the period	1,331	(4,945)	(19,589)
Reclassification adjustment for net loss included in net income	8,020	8,965	8,100
Total derivative instruments	9,351	4,020	(11,489)
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	(368)	(8,719)	(33,567)
Reclassification adjustment for amortization of net loss included in net income	7,126	6,161	2,921
Reclassification adjustment for prior service cost included in net income	14	73	73
Total defined benefit pension and postretirement benefit plans	6,772	(2,485)	(30,573)
Available-for-sale and transferred securities:
Net unrealized loss during the period	5,212	13,166	(12,469)
Reclassification for net gain included in net income	152	223	1,999
Net non-credit other-than-temporary impairment	(55)	(40)	(418)
Amortization of unrealized loss on securities transferred to held-to-maturity	0	(14)	(22)
Total available-for-sale and transferred securities	5,309	13,335	(10,910)
Derivative instruments:
Net unrealized gain during the period	(506)	1,809	7,083
Reclassification adjustment for net loss included in net income	(2,933)	(3,279)	(2,918)
Total derivative instruments	(3,439)	(1,470)	4,165
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	136	3,219	12,238
Reclassification adjustment for amortization of net loss included in net income	(2,633)	(2,274)	(1,065)
Reclassification adjustment for prior service cost included in net income	(5)	(27)	(26)
Total defined benefit pension and postretirement benefit plans	(2,502)	918	11,147
Available-for-sale and transferred securities:
Net unrealized loss during the period	(8,901)	(22,535)	21,773
Reclassification for net gain included in net income	(262)	(386)	(3,500)
Net non-credit other-than-temporary impairment	94	70	727
Amortization of unrealized loss on securities transferred to held-to-maturity	0	23	38
Total available-for-sale and transferred securities	(9,069)	(22,828)	19,038
Derivative instruments:
Net unrealized gains (losses) on derivative instruments	825	(3,136)	(12,506)
Reclassification adjustment for net loss included in net income	5,087	5,686	5,182
Total derivative instruments	5,912	2,550	(7,324)
Defined benefit pension and other postretirement benefit plans:
Current year actuarial loss	(232)	(5,500)	(21,329)
Reclassification adjustment for amortization of net loss included in net income	4,493	3,887	1,856
Reclassification adjustment for prior service cost included in net income	9	46	47
Total defined benefit pension and postretirement benefit plans	4,270	(1,567)	(19,426)
Other Comprehensive Income (Loss), Pre-Tax Amount	1,745	(34,628)	(12,114)
Other Comprehensive Income (Loss), Tax Benefit (Expense)	(632)	12,783	4,402
Other comprehensive income (loss), net of tax	$ 1,113	$ (21,845)	$ (7,712)

Regulatory Matters (Information

Regulatory Matters (Information On The Capital Ratios) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 1,932,171	$ 1,824,106
Common equity tier 1, Actual Ratio	10.50%	10.70%
Common equity tier 1, Capital Requirements, Minimum Amount	$ 826,504	$ 766,848
Common equity tier 1, Capital Requirements, Minimum Ratio	4.50%	4.50%
Common equity tier 1, Capital Requirements, Well Capitalized Amount	$ 1,193,840	$ 1,107,670
Common equity tier 1, Capital Requirements, Well Capitalized Ratio	6.50%	6.50%
Total risk-based capital, Actual Amount	$ 2,328,808	$ 2,201,245
Total risk-based capital, Actual Ratio	12.70%	12.90%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,469,341	$ 1,363,286
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%	8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,836,677	$ 1,704,107
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital, Actual Amount	$ 2,054,881	$ 1,966,146
Tier 1 risk-based capital, Actual Ratio	11.20%	11.50%
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 1,102,006	$ 1,022,464
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	6.00%	6.00%
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,469,341	$ 1,363,286
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	8.00%	8.00%
Tier 1 leverage capital, Actual Amount	$ 2,054,881	$ 1,966,146
Tier 1 leverage capital, Actual Ratio	8.10%	8.20%
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 1,010,857	$ 954,369
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	4.00%	4.00%
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 1,263,571	$ 1,192,962
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	5.00%	5.00%
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 1,945,332	$ 1,869,241
Common equity tier 1, Actual Ratio	10.60%	11.00%
Common equity tier 1, Capital Requirements, Minimum Amount	$ 825,228	$ 765,152
Common equity tier 1, Capital Requirements, Minimum Ratio	4.50%	4.50%
Common equity tier 1, Capital Requirements, Well Capitalized Amount	$ 1,191,995	$ 1,105,220
Common equity tier 1, Capital Requirements, Well Capitalized Ratio	6.50%	6.50%
Total risk-based capital, Actual Amount	$ 2,141,939	$ 2,046,350
Total risk-based capital, Actual Ratio	11.70%	12.00%
Total risk-based capital, Capital Requirements, Minimum Amount	$ 1,467,071	$ 1,360,271
Total risk-based capital, Capital Requirements, Minimum Ratio	8.00%	8.00%
Total risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,833,839	$ 1,700,338
Total risk-based capital, Capital Requirements, Well Capitalized Ratio	10.00%	10.00%
Tier 1 risk-based capital, Actual Amount	$ 1,945,332	$ 1,869,241
Tier 1 risk-based capital, Actual Ratio	10.60%	11.00%
Tier 1 risk-based capital, Capital Requirements, Minimum Amount	$ 1,100,304	$ 1,020,203
Tier 1 risk-based capital, Capital Requirements, Minimum Ratio	6.00%	6.00%
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Amount	$ 1,467,071	$ 1,360,271
Tier 1 risk-based capital, Capital Requirements, Well Capitalized Ratio	8.00%	8.00%
Tier 1 leverage capital, Actual Amount	$ 1,945,332	$ 1,869,241
Tier 1 leverage capital, Actual Ratio	7.70%	7.80%
Tier 1 leverage capital, Capital Requirements, Minimum Amount	$ 1,010,005	$ 953,300
Tier 1 leverage capital, Capital Requirements, Minimum Ratio	4.00%	4.00%
Tier 1 leverage capital, Capital Requirements, Well Capitalized Amount	$ 1,262,507	$ 1,191,626
Tier 1 leverage capital, Capital Requirements, Well Capitalized Ratio	5.00%	5.00%

Regulatory Matters Reulatory Ma

Regulatory Matters Reulatory Matters - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to parent company	$ 145	$ 110
Subsidiaries [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash held by Bank	$ 58.6	$ 109.4

Earnings Per Common Share (Earn

Earnings Per Common Share (Earnings Per Share Basic And Diluted) (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share Reconciliation [Abstract]
Net income	$ 57,660	$ 51,817	$ 50,603	$ 47,047	$ 51,812	$ 51,370	$ 52,043	$ 49,504	$ 207,127	$ 204,729	$ 199,726
Less: Preferred stock dividends									8,096	8,711	10,556
Net income available to common shareholders, basic	$ 55,501	$ 49,634	$ 48,398	$ 44,921	$ 49,646	$ 49,176	$ 49,819	$ 46,719	199,031	196,018	189,170
Net income available to common shareholders, diluted									199,031	196,018	189,170
Less: Earnings applicable to participating securities, basic									608	657	674
Less: Earnings applicable to participating securities, diluted									608	657	674
Earnings applicable to common shareholders									198,423	195,361	188,496
Earnings applicable to common shareholders, diluted									$ 198,423	$ 195,361	$ 188,496
Shares:
Weighted-average common shares outstanding - basic									91,367	90,968	89,899
Effect of dilutive securities:
Stock options and restricted stock (in shares)									461	524	466
Warrants (in shares)									28	41	255
Weighted Average Number of Shares Outstanding, Diluted									91,856	91,533	90,620
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 0.61	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.54	$ 0.55	$ 0.52	$ 2.17	$ 2.15	$ 2.10
Earnings per common share, Diluted (in dollars per share)	$ 0.60	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.53	$ 0.55	$ 0.51	$ 2.16	$ 2.13	$ 2.08

Earnings Per Common Share (Sche

Earnings Per Common Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities exluded from computation of earnings per share, shares	41	213	587
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities exluded from computation of earnings per share, shares	125	92	171

Derivative Financial Instrum103

Derivative Financial Instruments (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		$ 35,727	$ 4,945
Derivative Asset, Total, Amount Offset		35,727	4,945
Derivative Asset, Fair Value, Less: Cash collateral posted		42,500	20,200
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		25,300	41,727
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,854	36,275
Derivative Liability, Fair Value, Less: Cash collateral posted		18,700
Derivative Liability	[1],[2]	446	5,452
Mandatory forward commitments		99,000
Floating rate commitments		27,800
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		3,270	2,507
Derivative Asset, Total, Amount Offset		3,270	2,507
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		792	1,359
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		792	1,359
Derivative Liability	[1],[2]	0	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Fair Value, Subject to a Master Netting Agreement		32,457	2,438
Derivative Asset, Total, Amount Offset		32,457	2,438
Derivative Asset	[1],[2]	0	0
Derivative Liability, Fair Value, Subject to a Master Netting Agreement		24,508	40,368
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,062	34,916
Derivative Liability, Fair Value, Less: Cash collateral posted		10,900	31,300
Derivative Liability	[1],[2]	446	5,452
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	225,000	200,000
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	3,270	2,507
Derivative Liability, Notional Amount	[3]	100,000	100,000
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	792	1,359
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	1,943,485	989,695
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	32,226	2,255
Derivative Liability, Notional Amount	[3]	1,242,937	1,543,479
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	24,388	40,302
Derivatives Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[3]	10,634	8,237
Derivative Asset, Fair Value, Subject to a Master Netting Agreement	[3]	231	183
Derivative Liability, Notional Amount	[3]	14,265	4,561
Derivative Liability, Fair Value, Subject to a Master Netting Agreement	[3]	120	66
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	3,879,713	3,152,704
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	74,367	61,714
Derivative Liability, Notional Amount	[4]	2,856,313	2,123,823
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	44,397	41,193
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	1,734,679	2,050,460
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	38,668	58,304
Derivative Liability, Notional Amount	[4]	1,451,762	482,738
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	19,001	571
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	1,438	0
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	19	0
Derivative Liability, Notional Amount	[4]	181	60
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	11	9
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Buying Protection [Member] | Credit Risk Contract [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4]	86,037	41,798
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4]	139	153
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Buying Protection [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	[4],[5]	103,440	62,514
Derivative Asset, Fair Value, Not Subject to Master Netting Agreement	[4],[5]	3,084	819
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Selling Protection [Member] | Credit Risk Contract [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	[4]	87,273	92,985
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4]	166	245
Derivatives Not Subject to Master Netting Arrangement or Similar Arrangement [Member] | Not Designated as Hedging Instrument [Member] | Credit Default Swap, Selling Protection [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Derivative Liability, Notional Amount	[4],[5]	59,895	0
Derivative Liability, Fair Value, Not Subject to Master Netting Agreement	[4],[5]	711	0
Subject to and not subject to Master Netting Agreements [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount		4,104,713	3,352,704
Derivative Asset, Fair Value, Gross derivative instruments, before netting		77,637	64,221
Derivative Asset, Total, Amount Offset		24,253	4,945
Derivative Asset, Fair Value, Less: Cash collateral posted		11,475	0
Derivative Asset		41,909	59,276
Derivative Liability, Notional Amount		2,956,313	2,223,823
Derivative Liability, Fair Value, Gross derivative instruments, before netting		45,189	42,552
Derivative Liability, Fair Value, Less: Legally enforceable master netting agreements		24,253	4,945
Derivative Liability, Fair Value, Less: Cash collateral posted		600	31,330
Derivative Liability		$ 20,336	$ 6,277
[1]	Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets
[2]	Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015, respectively, as presented in the accompanying Consolidated Balance Sheets.
[3]	The Company has elected to report derivative positions subject to a legally enforceable master netting agreement on a net basis, net of cash collateral. Refer to the Offsetting Derivatives section of this footnote for additional information.
[4]	Derivative positions not subject to a legally enforceable master netting agreement are reported on a gross basis in the accompanying Consolidated Balance Sheets.
[5]	Notional amounts include mandatory forward commitments of $99.0 million, while notional amounts do not include approved floating rate commitments of $27.8 million, at December 31, 2016.

Derivative Financial Instrum104

Derivative Financial Instruments (Schedule of the changes in the fair value of non-hedge accounting derivatives) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Total impact on other non-interest income	$ 9,793	$ 5,066	$ 3,758
Operating Expense [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Total impact on other non-interest income	8,668	4,361	4,482
Operating Expense [Member] | Not Designated as Hedging Instrument [Member] | Credit Risk Contract [Member]
Derivative [Line Items]
Total impact on other non-interest income	(361)	(33)	51
Operating Expense [Member] | Not Designated as Hedging Instrument [Member] | Mortgage Banking Derivatives [Member]
Derivative [Line Items]
Total impact on other non-interest income	1,553	801	(522)
Operating Expense [Member] | Not Designated as Hedging Instrument [Member] | Other Contract [Member]
Derivative [Line Items]
Total impact on other non-interest income	$ (67)	$ (63)	$ (253)

Derivative Financial Instrum105

Derivative Financial Instruments (AOCL Cash Flow Derivatives - Narrative) (Details) - Cash Flow Hedging [Member] $ in Millions	12 Months Ended
	Dec. 31, 2016USD ($)
Derivative [Line Items]
Cash flow hedge to be reclassified from AOCL as an increase to interest expense	$ (6.4)
Remaining unamortized loss on termination of cash flow hedges	21.3
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Cash flow hedge to be reclassified from AOCL as an increase to interest expense	$ 1.7

Derivative Financial Instrum106

Derivative Financial Instruments (Schedule of offsetting financial assets and liabilities for non-customer derivative positions) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative Asset, Gross Amount		$ 35,727	$ 4,945
Derivative Asset, Total, Amount Offset		(35,727)	(4,945)
Derivative Asset, Net Amount	[1],[2]	0	0
Derivative Liability, Gross Amount		25,300	41,727
Derivative Liability, Total, Amount Offset		(24,854)	(36,275)
Derivative Liability, Net Amount	[1],[2]	446	5,452
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Gross Amount		3,270	2,507
Derivative Asset, Total, Amount Offset		(3,270)	(2,507)
Derivative Asset, Net Amount	[1],[2]	0	0
Derivative Liability, Gross Amount		792	1,359
Derivative Liability, Total, Amount Offset		(792)	(1,359)
Derivative Liability, Net Amount	[1],[2]	0	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Asset, Gross Amount		32,457	2,438
Derivative Asset, Total, Amount Offset		(32,457)	(2,438)
Derivative Asset, Net Amount	[1],[2]	0	0
Derivative Liability, Gross Amount		24,508	40,368
Derivative Liability, Total, Amount Offset		(24,062)	(34,916)
Derivative Liability, Net Amount	[1],[2]	$ 446	$ 5,452
[1]	Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets
[2]	Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015, respectively, as presented in the accompanying Consolidated Balance Sheets.

Derivative Financial Instrum107

Derivative Financial Instruments (Counterparty Credit Risk) (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Net margin collateral posted	$ 23.8
Initial margin	42.5	$ 20.2
Variation margin collateral received	18.7
Maximum exposure	38.7
Market Approach Valuation Technique [Member]
Derivative [Line Items]
Maximum exposure	$ 26.4

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,399,762	$ 5,031,030
Rabbi Trust [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets, fair value	3,300
Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total credit-related financial instruments with off-balance sheet risk	7,700
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Book value of other real estate owned (OREO) and repossessed assets	$ 3,900

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Assets And Liabilities Measured On Recurring Basis) (Detail) - USD ($) $ in Thousands		Dec. 31, 2016		Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	[1],[2]	$ 0		$ 0
Originated loans held for sale		60,260		0
Derivative liability	[1],[2]	446		5,452
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets held at fair value		3,139,609		3,063,026
Derivative liability	[3]	45,189		42,552
Total financial liabilities held at fair value		45,189		48,552
Fair Value, Measurements, Recurring [Member] | US Treasury Bill Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		734		924
Fair Value, Measurements, Recurring [Member] | Agency collateralized mortgage obligations (agency CMO) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		419,706		548,754
Fair Value, Measurements, Recurring [Member] | Agency mortgage-backed securities (agency MBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		954,349		1,065,109
Fair Value, Measurements, Recurring [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		573,272		215,350
Fair Value, Measurements, Recurring [Member] | Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		477,365		579,266
Fair Value, Measurements, Recurring [Member] | Collateralized loan obligations (CLO) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		427,390		429,159
Fair Value, Measurements, Recurring [Member] | Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		28,633		37,170
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		109,642		106,321
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities				2,578
Fair Value, Measurements, Recurring [Member] | Investments held In Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		5,119		5,372
Fair Value, Measurements, Recurring [Member] | Alternative investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		5,502		3,471
Fair Value, Measurements, Recurring [Member] | Loan Origination Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale	[4]	60,260
Fair Value, Measurements, Recurring [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	[3]	77,637		64,221
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets held at fair value		6,103		9,057
Derivative liability	[3]	120		66
Total financial liabilities held at fair value		120		66
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury Bill Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		734		924
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities				2,578
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Investments held In Rabbi Trust [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		5,119		5,372
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Alternative investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Loan Origination Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		0	[4]	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	[3]	250		183
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets held at fair value		3,128,004		3,045,167
Derivative liability	[3]	45,069		42,486
Total financial liabilities held at fair value		45,069		42,486
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Agency collateralized mortgage obligations (agency CMO) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		419,706		548,754
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Agency mortgage-backed securities (agency MBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		954,349		1,065,109
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		573,272		215,350
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		477,365		579,266
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Collateralized loan obligations (CLO) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		427,390		429,159
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Single issuer trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		28,633		37,170
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		109,642		106,321
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Alternative investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Loan Origination Commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		60,260	[4]	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	[3]	77,387		64,038
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets held at fair value		5,502		8,802
Total financial liabilities held at fair value				6,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agency commercial mortgage-backed securities (agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Non-agency commercial mortgage-backed securities (non-agency CMBS) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Alternative investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		5,502		3,471
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivative instruments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	[3]			0
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		2,991,091		2,984,631
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		734		3,502
Available-for-sale Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		2,990,357		2,981,129
Contingent Asset [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value				5,331
Contingent Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		0		0
Contingent Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value		0		0
Contingent Asset [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets, fair value				5,331
Contingent Liability [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability				6,000
Contingent Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability		0		0
Contingent Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability		$ 0		0
Contingent Liability [Member] | Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability				$ 6,000
[1]	Net amount excludes $42.5 million and $20.2 million of initial margin requirements posted at the derivative clearing organization at December 31, 2016 and December 31, 2015, respectively. Initial margin is recorded as a component of accrued interest receivable and other assets in the accompanying Consolidated Balance Sheets
[2]	Net amount is net of $10.9 million and $31.3 million of cash collateral at December 31, 2016 and December 31, 2015, respectively, as presented in the accompanying Consolidated Balance Sheets.
[3]	For information relating to the impact of netting derivative assets and derivative liabilities as well as the impact from offsetting cash collateral paid to the same derivative counterparties see Note 15: Derivative Financial Instruments.
[4]	Loans held for sale accounted for under the fair value option of ASC Topic 825 "Financial Instruments" at December 31, 2016. The Company made this policy election on loans originated for sale. See Note 1: Summary of Significant Accounting Policies.

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	$ 8,802
Level 3, beginning of period, Contingent Liability	6,000
Gain included in net income	3,039
Purchases/capital funding	1,682
Receipts	(8,021)
Payments	(6,000)
Level 3, end of period, Financial Assets	5,502
Level 3, end of period, Contingent Liability	0
Equity Method Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	3,471
Gain included in net income	349
Purchases/capital funding	1,682
Level 3, end of period, Financial Assets	5,502
Contingent Asset [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period, Financial Assets	5,331
Gain included in net income	2,690
Receipts	(8,021)
Level 3, end of period, Financial Assets	$ 0

Fair Value Measurements Schedul

Fair Value Measurements Schedule of Servicing Assets at Fair Value (Details) - Residential Mortgage [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning Balance	$ 33,568	$ 28,690
Originations of servicing assets	11,312	8,027
Due to payoffs/paydowns	(2,447)	(2,741)
Due to market changes	9,642	(408)
Ending Balance	$ 52,075	$ 33,568

Fair Value Measurements (Sch112

Fair Value Measurements (Schedule Of Valuation Methodology And Unobservable Inputs) (Detail) - Fair Value, Measurements, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
OREO	$ 166
Other Real Estate Owned [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	8.00%
Mortgage Servicing Rights [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Mortgage servicing assets	$ 52,075
Mortgage Servicing Rights [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	1.90%
Mortgage Servicing Rights [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	3.60%
Interest Rate Risk [Member] | Mortgage Servicing Rights [Member] | Minimum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	2.80%
Interest Rate Risk [Member] | Mortgage Servicing Rights [Member] | Maximum [Member] | Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Constant prepayment rate	27.70%
Nonperforming Financial Instruments [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Collateral dependent impaired loans and leases	$ 7,374
Nonperforming Financial Instruments [Member] | Market Approach Valuation Technique - Discount for cost to sell [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	8.00%
Nonperforming Financial Instruments [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	0.00%
Nonperforming Financial Instruments [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	15.00%
Other Real Estate Owned [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rates	0.00%

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Estimated Fair Values Of Significant Financial Instruments) (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LHFS, at fair value option		$ 60,260	$ 0
Mortgage servicing assets, Carrying Amount		24,466	20,698	$ 19,379	$ 20,983
Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LHFS, at fair value option	[1]	7,317	37,091
Loans and leases, net		16,832,268	15,496,745
Securities sold under agreements to repurchase and other borrowings		949,526	1,151,400
FHLB advances	[2]	2,842,908	2,664,139
Long-term debt	[2]	225,514	225,260
Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative investments		11,034	12,900
Reported Value Measurement [Member] | Securities held-to-maturity [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		4,160,658	3,923,052
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
LHFS, at fair value option	[1]	7,444	37,457
Securities sold under agreements to repurchase and other borrowings		955,660	1,163,974
FHLB advances	[2]	2,825,101	2,647,872
Long-term debt	[2]	225,514	218,143
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans and leases, net		16,678,106	15,453,892
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Alternative investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative investments		13,189	14,294
Estimate of Fair Value Measurement [Member] | Securities held-to-maturity [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity investment securities		4,125,125	3,961,534
Deposits other than time deposits [Member] | Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		17,279,049	15,866,624
Deposits other than time deposits [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		17,279,049	15,866,624
Time Deposits [Member] | Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		2,024,808	2,086,154
Time Deposits [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deposits		2,024,395	2,095,357
Residential Mortgage [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets		52,075	33,568	$ 28,690
Residential Mortgage [Member] | Reported Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets, Carrying Amount		24,466	20,698
Residential Mortgage [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage servicing assets		$ 52,075	$ 33,568
[1]	Loans held for sale that are accounted for at the lower of cost or market. At December 31, 2016, the amounts include transferred residential and commercial loans not originated for sale, and at December 31, 2015, the amounts include transferred commercial loans not originated for sale and residential loans originated for sale prior to the adoption of the fair value option of ASC Topic 825 "Financial Instruments."
[2]	The following adjustments to the carrying amount are not included for determination of fair value, see Note 10: Borrowings:•FHLB advances - unamortized premiums on advances•Long-term debt - unamortized discount and debt issuance cost on senior fixed-rate notes

Retirement Benefit Plans (Narra

Retirement Benefit Plans (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 01, 2015
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 227,200	$ 218,000
Net actuarial loss	$ 6,500
Assumed healthcare cost trend (as a percent)	8.25%
Healthcare-cost trend rate in 2024 (as a percent)	4.75%
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees' gross pay	2.00%
Employer matching contribution, additional percent of match	50.00%
Employer additional matching contribution, percent of employees' gross pay	6.00%
Compensation expense	$ 11,100	10,900	$ 10,600
Multiemployer Plans, Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Funded status of plan				$ (1,100)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 20,000	$ 0
Expected long-term return on assets (as a percent)	7.00%	7.00%	7.25%
Funded status of plan	$ (18,586)	$ (42,276)
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	124	241
Funded status of plan	(11,806)	(10,518)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 185	$ 225
Assumed healthcare cost trend (as a percent)	8.25%	8.00%
Increase in net periodic postretirement benefit cost if trend increased by 1%	$ 6
Increase in accumulated benefit obligation if trend increased by 1%	205
Decrease in net periodic postretirement benefit cost if trend rate decreased by 1%	6
Decrease in accumulated benefit obligation if trend rate decreased 1%	185
Funded status of plan	$ (3,852)	$ (3,853)
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of employees' gross pay	3.00%

Retirement Benefit Plans (Chang

Retirement Benefit Plans (Changes in Plan Assets and Funded Status of Pension Plans and Other Postretirement Benefit Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in plan assets:
Beginning balance	$ 161,369
Ending balance	192,734	$ 161,369
Pension Plan [Member]
Change in benefit obligation:
Beginning balance	203,645	210,548
Service cost	45	45	$ 40
Interest cost	8,441	8,008	8,068
Actuarial loss (gain)	6,108	(8,588)
Benefit payments, administrative expenses, and interest income, net	(6,731)	(6,368)
Ending balance	211,508	203,645	210,548
Change in plan assets:
Beginning balance	161,369	172,976
Actual return on plan assets	18,284	(5,239)
Employer contributions	20,000	0
Benefits paid and administrative expenses	(6,731)	(6,368)
Ending balance	192,922	161,369	172,976
Funded status of the plan at year end	(18,586)	(42,276)
SERP [Member]
Change in benefit obligation:
Beginning balance	10,518	10,041
Service cost	0	0	0
Interest cost	389	345	364
Actuarial loss (gain)	1,023	373
Benefit payments, administrative expenses, and interest income, net	(124)	(241)
Ending balance	11,806	10,518	10,041
Change in plan assets:
Beginning balance	0	0
Actual return on plan assets	0	0
Employer contributions	124	241
Benefits paid and administrative expenses	(124)	(241)
Ending balance	0	0	0
Funded status of the plan at year end	(11,806)	(10,518)
Other Benefits [Member]
Change in benefit obligation:
Beginning balance	3,853	4,133
Service cost	0	0	0
Interest cost	125	123	139
Actuarial loss (gain)	59	(178)
Benefit payments, administrative expenses, and interest income, net	(185)	(225)
Ending balance	3,852	3,853	4,133
Change in plan assets:
Beginning balance	0	0
Actual return on plan assets	0	0
Employer contributions	185	225
Benefits paid and administrative expenses	(185)	(225)
Ending balance	0	0	$ 0
Funded status of the plan at year end	$ (3,852)	$ (3,853)

Retirement Benefit Plans (Amoun

Retirement Benefit Plans (Amount Recognized in the Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued expenses and other liabilities	$ (18,586)	$ (42,276)
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued expenses and other liabilities	(11,806)	(10,518)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Accrued expenses and other liabilities	$ (3,852)	$ (3,853)

Retirement Benefit Plans (Summa

Retirement Benefit Plans (Summary of Components of Accumulated Other Comprehensive Loss Related to Pensions and Postretirement Benefits) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Deferred tax benefit		$ (2,502)	$ 918	$ 11,147
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 73,238	65,857	73,238
Prior service cost	0	0	0
Total pre-tax amounts included in AOCL	73,238	65,857	73,238
Deferred tax benefit	26,447	23,727
Amounts included in accumulated AOCL, net of tax	46,791	42,130	46,791
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	2,412	3,009	2,412
Prior service cost	0	0	0
Total pre-tax amounts included in AOCL	2,412	3,009	2,412
Deferred tax benefit	871	1,084
Amounts included in accumulated AOCL, net of tax	1,541	1,925	1,541
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	591	616	591
Prior service cost	14	0	14
Total pre-tax amounts included in AOCL	605	616	605
Deferred tax benefit	218	222
Amounts included in accumulated AOCL, net of tax	$ 387	$ 394	$ 387

Retirement Benefit Plans (Expec

Retirement Benefit Plans (Expected Future Benefit Payments) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
2,017	$ 7,786
2,018	8,604
2,019	8,654
2,020	9,072
2,021	9,828
2022-2026	53,711
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
2,017	1,208
2,018	1,091
2,019	8,104
2,020	141
2,021	140
2022-2026	683
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2,017	404
2,018	398
2,019	387
2,020	375
2,021	358
2022-2026	$ 1,457

Retirement Benefit Plans (Su119

Retirement Benefit Plans (Summary of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 45	$ 45	$ 40
Interest cost on benefit obligations	8,441	8,008	8,068
Expected return on plan assets	(11,461)	(11,873)	(11,495)
Amortization of prior service cost	0	0	0
Recognized net loss	6,665	5,724	2,781
Net periodic benefit cost (benefit)	3,690	1,904	(606)
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost on benefit obligations	389	345	364
Expected return on plan assets	0	0	0
Amortization of prior service cost	0	0	0
Recognized net loss	426	390	135
Net periodic benefit cost (benefit)	815	735	499
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost on benefit obligations	125	123	139
Expected return on plan assets	0	0	0
Amortization of prior service cost	14	73	73
Recognized net loss	35	47	5
Net periodic benefit cost (benefit)	$ 174	$ 243	$ 217

Retirement Benefit Plans (Ch120

Retirement Benefit Plans (Changes in Other Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	$ 368	$ 8,719	$ 33,567
Amounts reclassified from AOCL	(7,126)	(6,161)	(2,921)
Total (gain) loss recognized in OCI	(6,772)	2,485	30,573
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	(715)	8,525	31,951
Amounts reclassified from AOCL	(6,665)	(5,724)	(2,781)
Amortization of prior service cost	0	0	0
Total (gain) loss recognized in OCI	(7,380)	2,801	29,170
SERP [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	1,023	372	1,145
Amounts reclassified from AOCL	(426)	(390)	(134)
Amortization of prior service cost	0	0	0
Total (gain) loss recognized in OCI	597	(18)	1,011
Other Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net (gain) loss	60	(178)	470
Amounts reclassified from AOCL	(35)	(47)	(5)
Amortization of prior service cost	(14)	(73)	(73)
Total (gain) loss recognized in OCI	$ 11	$ (298)	$ 392

Retirement Benefit Plans (Su121

Retirement Benefit Plans (Summary of Fair Value of Plan Assets by Level) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 192,734	$ 161,369
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	32,227	28,624
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	159,714	131,811
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	793	934	$ 1,077
Exchange traded funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,526	28,329
Exchange traded funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31,526	28,329
Exchange traded funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Exchange traded funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	701	295
Cash and cash equivalents [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	701	295
Cash and cash equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,429	80,783
Fixed Income Funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed Income Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	96,429	80,783
Fixed Income Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	63,285	51,028
Equity Funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	63,285	51,028
Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Insurance Company Investment Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	793	934
Insurance Company Investment Contract [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Insurance Company Investment Contract [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Insurance Company Investment Contract [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 793	$ 934

Retirement Benefit Plans (Ch122

Retirement Benefit Plans (Changes in Fair Value of Level 3 Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Beginning balance	$ 161,369
Ending balance	192,734	$ 161,369
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Beginning balance	934	1,077
Unrealized gains relating to instruments still held at the reporting date	(10)	(28)
Benefit payments, administrative expenses, and interest income, net	(131)	(115)
Ending balance	$ 793	$ 934

Retirement Benefit Plans (Defin

Retirement Benefit Plans (Defined Benefit, Information about Plan Assets) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Target Allocation (as a percent)	100.00%
Percentage of Pension Plan assets	100.00%	100.00%
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation (as a percent)	50.00%
Percentage of Pension Plan assets	51.00%	51.00%
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation (as a percent)	50.00%
Percentage of Pension Plan assets	49.00%	49.00%

Retirement Benefit Plans (Weigh

Retirement Benefit Plans (Weighted Average Assumptions used to Determine Benefit Obligations) (Details)	Dec. 31, 2016	Dec. 31, 2015
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	4.01%	4.20%
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	3.63%	3.75%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	3.27%	3.35%

Retirement Benefit Plans (We125

Retirement Benefit Plans (Weighted Average Assumptions used to Determine Net Periodic Benefit Cost) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Assumed healthcare cost trend (as a percent)	8.25%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	4.20%	3.85%	4.80%
Expected long-term return on assets (as a percent)	7.00%	7.00%	7.25%
SERP [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	3.75%	3.50%	4.25%
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate (as a percent)	3.35%	3.15%	3.75%
Assumed healthcare cost trend (as a percent)	8.25%	8.00%

Retirement Benefit Plans (Contr

Retirement Benefit Plans (Contributions and Funding Status of the Fund) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Contributions by Webster Bank	$ 690	$ 340	$ 765
Funded Status of the Plan at December 31,	At least 80 percent	At least 80 percent

Share-Based Plans (Narrative) (

Share-Based Plans (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized	13,400,000
Number of common shares available for grant	3,100,000
Vesting period (in years)	1 year
Stock options granted	248,603
Aggregate intrinsic value	$ 35.5
Total intrinsic value of options exercised	$ 6.4	$ 4.3	$ 1.9
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted	248,418
Unrecognized stock compensation expense	$ 12.3
Unrecognized stock compensation expense, recognition period (in years)	1 year 11 months 1 day
Fair value of restricted stock awards	$ 11.6	$ 11.6	$ 9.4
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares available for grant	100,000
Time Based Restricted Stock Awards [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	1 year
Time Based Restricted Stock Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)	5 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock appreciation rights granted	150,392
Vesting period (in years)	3 years
Award vesting percentage	50.00%
Performance Shares [Member] | Minimum [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	0.00%
Performance Shares [Member] | Maximum [Member] | Share-based Compensation Award, Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage	150.00%
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	0
Number of options outstanding (in shares)	1,072,974	1,527,074
Employee Stock Option [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual life (in years)	P10Y0M
Non-Qualified Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	998,185
Incentive Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	74,789

Share-Based Plans (Summary of S

Share-Based Plans (Summary of Stock-based Compensation Expense Recognized) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 11,438	$ 10,935	$ 10,223
Income tax benefit	4,132	3,903	3,553
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	43	379	1,175
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 11,395	$ 10,556	$ 9,048

Share-Based Plans (Summary of R

Share-Based Plans (Summary of Restricted Stock and Stock Option Activity) (Detail)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options granted, Number of Shares	248,603
Options exercised, Number of Shares	292,304
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	236,145
Restricted Stock, Granted (in shares)	248,418
Restricted stock, Vested restricted stock awards (in shares)	216,933	[1]
Restricted stock, Forfeited (in shares)	14,269
Restricted stock, Outstanding at end of period (in shares)	253,361
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 32.58
Restricted stock, Granted (in dollars per share) | $ / shares	33.52
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	30.21	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	32.89
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 32.24
Time Based Restricted Stock Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	2,088
Restricted Stock, Granted (in shares)	12,946
Restricted stock, Vested restricted stock awards (in shares)	12,876	[1]
Restricted stock, Forfeited (in shares)	0
Restricted stock, Outstanding at end of period (in shares)	2,158
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 34.45
Restricted stock, Granted (in dollars per share) | $ / shares	32.89
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	33.23	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	0
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 32.89
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, Outstanding at beginning of period (in shares)	115,721
Restricted Stock, Granted (in shares)	150,392
Restricted stock, Vested restricted stock awards (in shares)	140,531	[1]
Restricted stock, Forfeited (in shares)	9,398
Restricted stock, Outstanding at end of period (in shares)	116,184
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Restricted stock, at beginning of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 34.14
Restricted stock, Granted (in dollars per share) | $ / shares	32.75
Restricted stock, Vested restricted stock awards (in dollars per share) | $ / shares	33.12	[1]
Restricted stock, Forfeited (in dollars per share) | $ / shares	33.63
Restricted stock, at end of period, Weighted-average Grant Date Fair Value (in dollars per share) | $ / shares	$ 33.62
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, at beginning of period, Number of Shares	1,527,074
Options granted, Number of Shares	0
Options exercised, Number of Shares	412,538
Options forfeited, Number of Shares	41,562
Options outstanding, at end of period, Number of Shares	1,072,974
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Options, at beginning of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 23.92
Options granted, Weighted-Average Exercise Price (in dollars per share) | $ / shares	0
Options exercised, Weighted-Average Exercise Price (in dollars per share) | $ / shares	28.47
Options forfeited, Weighted-Average Exercise Price (in dollars per share) | $ / shares	47.92
Options, at end of period, Weighted-average Exercise Price (in dollars per share) | $ / shares	$ 21.24
[1]	Vested for purposes of recording compensation expense.

Share-Based Plans (Options Outs

Share-Based Plans (Options Outstanding and Options Exercisable) (Details)	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares | shares	1,072,974
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	3 years 6 months 5 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 21.24
Options Exercisable, Number of Shares | shares	1,072,974
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	3 years 6 months 5 days
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	$ 21.24
$5.14 - 20.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, Minimum (in dollars per share)	5.14
Range of exercise prices, Maximum (in dollars per share)	$ 20
Options Outstanding, Number of Shares | shares	317,814
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	2 years 2 months 10 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 8.95
Options Exercisable, Number of Shares | shares	317,814
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	2 years 2 months 10 days
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	$ 8.95
20.01 - 30.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, Minimum (in dollars per share)	20.01
Range of exercise prices, Maximum (in dollars per share)	$ 30
Options Outstanding, Number of Shares | shares	562,040
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	5 years 2 months 10 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 23.53
Options Exercisable, Number of Shares | shares	562,040
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	5 years 2 months 10 days
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	$ 23.53
30.01 - 40.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, Minimum (in dollars per share)	30.01
Range of exercise prices, Maximum (in dollars per share)	$ 40
Options Outstanding, Number of Shares | shares	151,715
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	1 year
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 32.03
Options Exercisable, Number of Shares | shares	151,715
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	1 year
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	$ 32.03
40.01 - 48.88 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, Minimum (in dollars per share)	40.01
Range of exercise prices, Maximum (in dollars per share)	$ 48.88
Options Outstanding, Number of Shares | shares	41,405
Options Outstanding, Weighted-Average Remaining Contractual Life (years)	5 months 5 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 44.91
Options Exercisable, Number of Shares | shares	41,405
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	5 months 5 days
Options Exercisable, Weighted-Average Remaining Contractual Life (years)	$ 44.91

Segment Reporting - Operating R

Segment Reporting - Operating Results and Total Assets Reportable Segments (Detail) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2016USD ($)Segment	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment									4
Net interest income (loss)	$ 185,259	$ 180,197	$ 176,905	$ 176,152	$ 173,340	$ 168,010	$ 163,511	$ 159,764	$ 718,513	$ 664,625	$ 628,441
Provision for loan and lease losses	12,500	14,250	14,000	15,600	13,800	13,000	12,750	9,750	56,350	49,300	37,250
Net interest income (loss) after provision for loan and lease losses									662,163	615,325	591,191
Non-interest income									264,478	237,777	202,108
Non-interest expense	161,871	156,097	152,778	152,445	143,780	139,937	137,537	134,087	623,191	555,341	501,600
Income before income tax expense	81,505	76,262	75,202	70,481	75,439	76,365	72,469	73,488	303,450	297,761	291,699
Income tax expense (benefit)	23,845	24,445	24,599	23,434	23,627	24,995	20,426	23,984	96,323	93,032	91,973
Net income	57,660	$ 51,817	$ 50,603	$ 47,047	51,812	$ 51,370	$ 52,043	$ 49,504	207,127	204,729	199,726
Total Assets	26,072,529				24,641,118				26,072,529	24,641,118
HSA Bank [Member]
Segment Reporting Information [Line Items]
Net income										37,443
Operating Segments [Member] | Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)									276,246	255,845	238,186
Provision for loan and lease losses									36,594	30,160	13,088
Net interest income (loss) after provision for loan and lease losses									239,652	225,685	225,098
Non-interest income									47,435	37,784	37,270
Non-interest expense									118,159	109,718	102,374
Income before income tax expense									168,928	153,751	159,994
Income tax expense (benefit)									53,622	48,037	50,446
Net income									115,306	105,714	109,548
Total Assets	8,518,830				7,505,513				8,518,830	7,505,513
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)									365,151	354,709	354,781
Provision for loan and lease losses									21,690	19,603	26,345
Net interest income (loss) after provision for loan and lease losses									343,461	335,106	328,436
Non-interest income									110,157	108,604	103,543
Non-interest expense									364,549	330,692	324,312
Income before income tax expense									89,069	113,018	107,667
Income tax expense (benefit)									28,273	35,310	33,947
Net income									60,796	77,708	73,720
Total Assets	8,655,789				8,441,950				8,655,789	8,441,950
Operating Segments [Member] | HSA Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)									81,451	73,433	38,822
Provision for loan and lease losses									0	0	0
Net interest income (loss) after provision for loan and lease losses									81,451	73,433	38,822
Non-interest income									71,710	62,475	28,553
Non-interest expense									97,152	81,449	40,900
Income before income tax expense									56,009	54,459	26,475
Income tax expense (benefit)									17,779	17,016	8,311
Net income									38,230	37,443	18,164
Total Assets	83,987				95,815				83,987	95,815
Operating Segments [Member] | Private Banking [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)									11,350	10,240	8,877
Provision for loan and lease losses									861	386	765
Net interest income (loss) after provision for loan and lease losses									10,489	9,854	8,112
Non-interest income									9,818	9,183	9,843
Non-interest expense									20,220	19,781	18,691
Income before income tax expense									87	(744)	(736)
Income tax expense (benefit)									27	(233)	(232)
Net income									60	(511)	(504)
Total Assets	550,615				493,571				550,615	493,571
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Net interest income (loss)									(15,685)	(29,602)	(12,225)
Provision for loan and lease losses									(2,795)	(849)	(2,948)
Net interest income (loss) after provision for loan and lease losses									(12,890)	(28,753)	(9,277)
Non-interest income									25,358	19,731	22,899
Non-interest expense									23,111	13,701	15,323
Income before income tax expense									(10,643)	(22,723)	(1,701)
Income tax expense (benefit)									(3,378)	(7,098)	(499)
Net income									(7,265)	(15,625)	$ (1,202)
Total Assets	$ 8,263,308				$ 8,104,269				$ 8,263,308	$ 8,104,269

Commitments and Contingencie132

Commitments and Contingencies (Narrative) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Rental expense under leases	$ 30.4	$ 21.5	$ 20.5
Rental income	$ 0.8	$ 0.8	$ 0.8

Commitments and Contingencie133

Commitments and Contingencies (Schedule of Future Minimum Rental Payments and Receipts for Leases) (Details) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Rental Payments, 2017	$ 28,713
Rental Payments, 2018	27,046
Rental Payments, 2019	25,644
Rental Payments, 2020	23,900
Rental Payments, 2021	21,860
Rental Payments, Thereafter	88,211
Rental Payments, Total	215,374
Rental Receipts, 2017	601
Rental Receipts, 2018	451
Rental Receipts, 2019	364
Rental Receipts, 2020	293
Rental Receipts, 2021	202
Rental Receipts, Thereafter	918
Rental Receipts, Total	$ 2,829

Commitments and Contingencie134

Commitments and Contingencies (Outstanding Financial Instruments Contract Amounts Represent Credit Risk) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,399,762	$ 5,031,030
Standby letters of credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	128,985	133,294
Letter of Credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	46,497	45,742
Commitments to extend credit [Member]
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 5,224,280	$ 4,851,994

Commitments and Contingencie135

Commitments and Contingencies (Schedule for Unfunded Commitments) (Details) - Reserve for Off-balance Sheet Activities [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 2,119	$ 5,151	$ 4,384
Provision (benefit)	168	(3,032)	767
Ending balance	$ 2,287	$ 2,119	$ 5,151

Parent Company Information (Com

Parent Company Information (Components of Condensed Balance Sheets The Parent Company) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets:
Cash and due from banks	$ 190,663	$ 199,693	$ 213,914	$ 205,921
Securities available-for-sale, at fair value	2,991,091	2,984,631
Other assets	294,462	343,856
Total assets	26,072,529	24,641,118
Liabilities and shareholders’ equity:
Total liabilities	23,545,517	22,227,158
Total liabilities and shareholders' equity	26,072,529	24,641,118
Parent Company [Member]
Assets:
Cash and due from banks	152,947	279,644	$ 272,492	$ 273,573
Securities available-for-sale, at fair value	0	2,578
Intercompany debt securities	150,000	0
Investment in subsidiaries	2,425,398	2,345,457
Alternative investments	4,275	6,795
Other assets	24,659	15,263
Total assets	2,757,279	2,649,737
Liabilities and shareholders’ equity:
Senior notes	148,194	147,940
Junior subordinated debt	77,320	77,320
Accrued interest payable	2,589	2,591
Due to subsidiaries	365	48
Other liabilities	1,799	7,878
Total liabilities	230,267	235,777
Shareholders’ equity	2,527,012	2,413,960
Total liabilities and shareholders' equity	$ 2,757,279	$ 2,649,737

Parent Company Information (137

Parent Company Information (Components of Condensed Income Statement The Parent Company) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Income:
(Loss) gain on sale of investment securities, net									$ 414	$ 609	$ 5,499
Other non-interest income	$ 70,617	$ 66,412	$ 65,075	$ 62,374	$ 59,679	$ 61,292	$ 59,245	$ 57,561
Operating Expense:
Compensation and benefits									331,726	297,517	270,151
Other non-interest expense									85,127	70,584	73,101
Income tax benefit	$ (23,845)	$ (24,445)	$ (24,599)	$ (23,434)	$ (23,627)	$ (24,995)	$ (20,426)	$ (23,984)	(96,323)	(93,032)	(91,973)
Parent Company [Member]
Operating Income:
Dividend income from bank subsidiary									145,000	110,000	100,000
Interest on securities and deposits									1,911	546	613
(Loss) gain on sale of investment securities, net									(2,410)	0	1,185
Alternative investments income									176	2,274	804
Other non-interest income									7,485	152	151
Total operating income									152,162	112,972	102,753
Operating Expense:
Interest expense on borrowings									9,981	9,665	10,041
Compensation and benefits									11,461	10,965	10,290
Other non-interest expense									6,278	6,005	4,562
Total operating expense									27,720	26,635	24,893
Income before income tax benefit and equity in undistributed earnings of subsidiaries and associated companies									124,442	86,337	77,860
Income tax benefit									3,086	2,929	8,798
Equity in undistributed earnings of subsidiaries and associated companies									79,599	115,463	113,068
Net income									$ 207,127	$ 204,729	$ 199,726

Parent Company Information (138

Parent Company Information (Components of Condensed Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on available for sale securities	$ (9,069)	$ (22,828)	$ 19,038
Net unrealized gains (losses) on derivative instruments	825	(3,136)	(12,506)
Other comprehensive loss of subsidiaries and associated companies	208,240	182,884	192,014
Other comprehensive income (loss), net of tax	1,113	(21,845)	(7,712)
Parent Company [Member]
Condensed Statement of Income Captions [Line Items]
Net income	207,127	204,729	199,726
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on available for sale securities	584	(2,109)	725
Net unrealized gains (losses) on derivative instruments	1,223	1,223	(2,932)
Other comprehensive loss of subsidiaries and associated companies	(694)	(20,959)	(5,505)
Other comprehensive income (loss), net of tax	1,113	(21,845)	(7,712)
Comprehensive income	$ 208,240	$ 182,884	$ 192,014

Parent Company Information (139

Parent Company Information (Components of Condensed Cash Flow The Parent Company) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	$ 11,438	$ 10,935	$ 10,223
Gain on redemption of other assets	(7,331)	0	0
Net cash provided by operating activities	398,145	302,792	242,995
Investing activities:
Purchases of available-for-sale securities	(980,870)	(903,240)	(217,920)
Proceeds from sales of available-for-sale securities	259,283	123,270	98,402
Purchases of intercompany debt securities	(381)	458	(115)
Net cash used for investing activities	(1,635,006)	(774,184)	(1,669,785)
Financing activities:
Issuance of long-term debt	0	0	150,000
Repayment of long-term debt	0	0	(150,000)
Cash dividends paid to common shareholders	(89,522)	(80,964)	(67,431)
Cash dividends paid to preferred shareholders	(8,096)	(8,711)	(10,556)
Exercise of stock options	11,762	3,060	2,221
Excess tax benefits from stock-based compensation	3,204	2,338	1,161
Common stock issued	0	0	435
Common stock repurchased/shares acquired related to employee share-based plans	(11,206)	(12,564)	(10,741)
Common stock warrants repurchased	(163)	(23)	(3)
Net cash (used for) provided by financing activities	1,227,831	457,171	1,434,783
Net (decrease) increase in cash and due from banks	(9,030)	(14,221)	7,993
Cash and due from banks at beginning of period	199,693	213,914	205,921
Cash and due from banks at end of period	190,663	199,693	213,914
Parent Company [Member]
Operating activities:
Net income	207,127	204,729	199,726
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries and associated companies	(79,599)	(115,463)	(113,068)
Stock-based compensation	11,438	10,935	10,223
Gain on redemption of other assets	(7,331)	0	0
Other, net	(3,736)	9,066	(10,721)
Net cash provided by operating activities	127,899	109,267	86,160
Investing activities:
Purchases of available-for-sale securities	0	0	(3,500)
Proceeds from sales of available-for-sale securities	1,089	0	3,499
Purchases of intercompany debt securities	(150,000)	0	0
Net cash used for investing activities	(148,911)	0	(1)
Financing activities:
Issuance of long-term debt	0	0	150,000
Repayment of long-term debt	0	0	(150,000)
Cash dividends paid to common shareholders	(89,522)	(80,964)	(67,431)
Cash dividends paid to preferred shareholders	(8,096)	(8,711)	(10,556)
Exercise of stock options	11,762	3,060	2,221
Excess tax benefits from stock-based compensation	3,204	2,338	1,161
Common stock issued	0	0	435
Common stock repurchased/shares acquired related to employee share-based plans	(22,870)	(17,815)	(13,067)
Common stock warrants repurchased	(163)	(23)	(3)
Net cash (used for) provided by financing activities	(105,685)	(102,115)	(87,240)
Net (decrease) increase in cash and due from banks	(126,697)	7,152	(1,081)
Cash and due from banks at beginning of period	279,644	272,492	273,573
Cash and due from banks at end of period	$ 152,947	$ 279,644	$ 272,492

Selected Quarterly Consolida140

Selected Quarterly Consolidated Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Selected Quarterly Financial Information [Abstract]
Interest income	$ 211,432	$ 205,715	$ 202,431	$ 202,335	$ 198,160	$ 191,998	$ 186,970	$ 182,912	$ 821,913	$ 760,040	$ 718,941
Interest expense	26,173	25,518	25,526	26,183	24,820	23,988	23,459	23,148	103,400	95,415	90,500
Net interest income	185,259	180,197	176,905	176,152	173,340	168,010	163,511	159,764	718,513	664,625	628,441
Provision for loan and lease losses	12,500	14,250	14,000	15,600	13,800	13,000	12,750	9,750	56,350	49,300	37,250
Non-interest income	70,617	66,412	65,075	62,374	59,679	61,292	59,245	57,561
Non-interest expense	161,871	156,097	152,778	152,445	143,780	139,937	137,537	134,087	623,191	555,341	501,600
Income before income tax expense	81,505	76,262	75,202	70,481	75,439	76,365	72,469	73,488	303,450	297,761	291,699
Income tax expense	23,845	24,445	24,599	23,434	23,627	24,995	20,426	23,984	96,323	93,032	91,973
Net income	57,660	51,817	50,603	47,047	51,812	51,370	52,043	49,504	207,127	204,729	199,726
Earnings applicable to common shareholders	$ 55,501	$ 49,634	$ 48,398	$ 44,921	$ 49,646	$ 49,176	$ 49,819	$ 46,719	$ 199,031	$ 196,018	$ 189,170
Earnings per common share:
Earnings per common share, Basic (in dollars per share)	$ 0.61	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.54	$ 0.55	$ 0.52	$ 2.17	$ 2.15	$ 2.10
Earnings per common share, Diluted (in dollars per share)	$ 0.60	$ 0.54	$ 0.53	$ 0.49	$ 0.54	$ 0.53	$ 0.55	$ 0.51	$ 2.16	$ 2.13	$ 2.08