People's United Financial (PBCT) 10-Q 9 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Trading Symbol	PBCT
Entity Registrant Name	People's United Financial, Inc.
Entity Central Index Key	1,378,946
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		310,233,412

Consolidated Statements of Cond

Consolidated Statements of Condition - (Unaudited) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 300.3	$ 345.1
Short-term investments (note 2)	244.6	668.6
Total cash and cash equivalents	544.9	1,013.7
Securities purchased under agreements to resell (note 2)		100
Securities (note 2):
Trading account securities, at fair value	8.3	8.3
Securities available for sale, at fair value	4,221.2	3,993.7
Securities held to maturity, at amortized cost (fair value of $1.4 billion and $881.6 million)	1,377.1	834.3
Federal Home Loan Bank and Federal Reserve Bank stock, at cost	314.7	175.7
Total securities	5,921.3	5,012
Loans held for sale	36.2	34.2
Loans (note 3):
Consumer	2,192.1	2,200.6
Total loans	27,672.2	26,592
Less allowance for loan losses	(207.5)	(198.3)
Total loans, net	27,464.7	26,393.7
Goodwill (note 6)	1,954.5	1,954.5
Bank-owned life insurance	345.6	343.3
Premises and equipment, net	258.7	277.8
Other acquisition-related intangible assets (note 6)	130.2	148
Other assets (notes 1, 3 and 11)	821.6	719.9
Total assets	37,477.7	35,997.1
Deposits:
Non-interest-bearing	5,877.2	5,655.1
Savings, interest-bearing checking and money market	17,236.6	15,252.4
Time	5,165.9	5,230.7
Total deposits	28,279.7	26,138.2
Borrowings:
Federal Home Loan Bank advances	2,164.5	2,291.7
Customer repurchase agreements		1
Federal funds purchased	360	913
Other borrowings		1
Total borrowings	2,996.8	3,691.7
Notes and debentures	1,044.9	1,033.5
Other liabilities (note 11)	425.5	500.6
Total liabilities	$ 32,746.9	$ 31,364
Commitments and contingencies (notes 1 and 8)
Stockholders' Equity
Common stock ($0.01 par value; 1.95 billion shares authorized; 398.8 million shares and 396.8 million shares issued)	$ 3.9	$ 3.9
Additional paid-in capital	5,327.3	5,291.2
Retained earnings	861	826.7
Accumulated other comprehensive loss (note 4)	(146.1)	(168.2)
Unallocated common stock of Employee Stock Ownership Plan, at cost (7.4 million shares and 7.7 million shares) (note 7)	(153.6)	(159)
Treasury stock, at cost (89.1 million shares and 89.0 million shares) (note 4)	(1,161.7)	(1,161.5)
Total stockholders' equity	4,730.8	4,633.1
Total liabilities and stockholders' equity	37,477.7	35,997.1
Commercial Customers [Member]
Borrowings:
Customer repurchase agreements	472.3	486
Commercial Loans [Member]
Loans (note 3):
Commercial	10,313.3	10,055.1
Commercial Real Estate Loan [Member]
Loans (note 3):
Commercial	9,785.4	9,404.3
Residential Mortgage Loan [Member]
Loans (note 3):
Residential mortgage	$ 5,381.4	$ 4,932

Consolidated Statements of Con3

Consolidated Statements of Condition - (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Securities held to maturity, at fair value	$ 1,421.6	$ 881.6
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,950,000,000	1,950,000,000
Common stock, shares issued	398,800,000	396,800,000
Unallocated common stock of Employee Stock Ownership Plan, shares	7,404,613	7,700,000
Treasury stock, shares	89,100,000	89,000,000

Consolidated Statements of Inco

Consolidated Statements of Income - (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest and dividend income:
Commercial	$ 92.5	$ 89.1	$ 271.7	$ 261.9
Commercial real estate	85.7	89.2	257.4	266.5
Residential mortgage	41.9	38.1	122.4	113.7
Consumer	18.1	18.5	54.2	55.2
Total interest on loans	238.2	234.9	705.7	697.3
Securities	31.2	23.6	87.7	72.8
Loans held for sale	0.4	0.3	1	0.6
Short-term investments	0.1	0.1	0.3	0.3
Total interest and dividend income	269.9	258.9	794.7	771
Interest expense:
Deposits	24.8	20.2	70.9	59.2
Borrowings	2.9	2.8	8.2	8.7
Notes and debentures	7.4	7.4	22.3	19.3
Total interest expense	35.1	30.4	101.4	87.2
Net interest income	234.8	228.5	693.3	683.8
Provision for loan losses (note 3)	6.2	12.4	23.7	30.7
Net interest income after provision for loan losses	228.6	216.1	669.6	653.1
Non-interest income:
Bank service charges	32.5	33.3	94.1	96.6
Investment management fees	10.8	10.7	32.9	31.1
Operating lease income	10.5	10.2	31.8	31.4
Commercial banking lending fees	9.7	8.6	31	24.8
Insurance revenue	9.1	8.8	23.2	23.3
Brokerage commissions	3.1	3.4	9.5	10.2
Net gains on sales of residential mortgage loans	1.5	1.1	4.2	1.9
Gain on merchant services joint venture, net of expenses				20.6
Other non-interest income	9.9	7.9	32.4	24.1
Total non-interest income	87.1	84	259.1	264
Non-interest expense:
Compensation and benefits	113.4	108.1	337.5	327.8
Occupancy and equipment	37	36.4	112.5	111
Professional and outside services	17	14.3	50.1	44.5
Regulatory assessments	9.5	8.5	28	26.2
Operating lease expense	9.2	8.7	27.7	28.5
Amortization of other acquisition-related intangible assets (note 6)	5.9	6.2	17.8	18.6
Other non-interest expense	22.2	26.6	70	77.2
Total non-interest expense	214.2	208.8	643.6	633.8
Income before income tax expense	101.5	91.3	285.1	283.3
Income tax expense (note 1)	33.1	29.7	95.8	96.3
Net income	$ 68.4	$ 61.6	$ 189.3	$ 187
Earnings per common share (note 5):
Basic	$ 0.23	$ 0.21	$ 0.63	$ 0.62
Diluted	$ 0.23	$ 0.21	$ 0.63	$ 0.62

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 68.4	$ 61.6	$ 189.3	$ 187
Other comprehensive income, net of tax:
Net actuarial loss and prior service credit related to pension and other postretirement benefit plans	1.1	0.6	3.3	1.9
Net unrealized gains and losses on securities available for sale	16.9	0.1	17.5	27
Amortization of unrealized losses on securities transferred to held to maturity	0.5	0.4	1.5	1.3
Net unrealized gains and losses on derivatives accounted for as cash flow hedges	(0.1)	0.6	(0.2)	0.4
Current period other comprehensive income (loss)	18.4	1.7	22.1	30.6
Total comprehensive income	$ 86.8	$ 63.3	$ 211.4	$ 217.6

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity - (Unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Unallocated ESOP Common Stock [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2013	$ 4,568.4	$ 3.9	$ 5,277	$ 779	$ (155.1)	$ (166.2)	$ (1,170.2)
Net income	187			187
Total other comprehensive income, net of tax (note 4)	30.6				30.6
Cash dividends on common stock	(147.4)			(147.4)
Restricted stock awards	7.3		0.5	(2)			8.8
Employee Stock Ownership Plan common stock committed to be released (note 7)	3.8			(1.6)		5.4
Common stock repurchased and retired upon vesting of restricted stock awards	(2.9)			(2.9)
Stock options and related tax benefits	8.2		8.2
Ending Balance at Sep. 30, 2014	4,655	3.9	5,285.7	812.1	(124.5)	(160.8)	(1,161.4)
Beginning Balance at Dec. 31, 2014	4,633.1	3.9	5,291.2	826.7	(168.2)	(159)	(1,161.5)
Net income	189.3			189.3
Total other comprehensive income, net of tax (note 4)	22.1				22.1
Cash dividends on common stock	(150.6)			(150.6)
Restricted stock awards	8		8.1	0.1			(0.2)
Employee Stock Ownership Plan common stock committed to be released (note 7)	4			(1.4)		5.4
Common stock repurchased and retired upon vesting of restricted stock awards	(3.1)			(3.1)
Stock options and related tax benefits	28		28
Ending Balance at Sep. 30, 2015	$ 4,730.8	$ 3.9	$ 5,327.3	$ 861	$ (146.1)	$ (153.6)	$ (1,161.7)

Consolidated Statements of Cha7

Consolidated Statements of Changes in Stockholders' Equity - (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash dividends on common stock, per share	$ 0.50	$ 0.4925
Retained Earnings [Member]
Cash dividends on common stock, per share	$ 0.50	$ 0.4925

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash Flows from Operating Activities:
Net income	$ 189.3	$ 187
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	23.7	30.7
Depreciation and amortization of premises and equipment	29.4	29.6
Expense related to operating leases	27.7	28.5
Amortization of other acquisition-related intangible assets	17.8	18.6
Gain on merchant services joint venture, net of expenses		(20.6)
Net security gains		(0.3)
Net gains on sales of residential mortgage loans	(4.2)	(1.9)
Net (gains) losses on sales of acquired loans	(1.7)	0.6
Employee Stock Ownership Plan common stock committed to be released	4	3.8
Expense related to share-based awards	13.1	11.2
Originations of loans held-for-sale	(350.7)	(218.9)
Proceeds from sales of loans held-for-sale	353	210.7
Net changes in other assets and liabilities	(102.2)	(41.5)
Net cash provided by operating activities	199.2	237.5
Cash Flows from Investing Activities:
Net decrease (increase) in securities purchased under agreements to resell	100	(300)
Proceeds from principal repayments and maturities of securities available for sale	623.7	517
Proceeds from sales of securities available for sale	201.2	410
Proceeds from principal repayments and maturities of securities held to maturity	12.4	63.5
Purchases of securities available for sale	(1,106.4)	(520)
Purchases of securities held to maturity	(555.2)	(48.4)
Net purchases of Federal Reserve Bank stock	(139)
Proceeds from sales of loans	30.9	7.2
Loan disbursements, net of principal collections	(1,112.5)	(1,595.1)
Purchases of loans	(9.5)
Purchases of premises and equipment	(18.3)	(14.2)
Purchases of leased equipment	(28.1)	(16.3)
Proceeds from sales of real estate owned	14.9	9.3
Return of premiums on bank-owned life insurance, net	1.2	0.5
Net cash used in investing activities	(1,984.7)	(1,486.5)
Cash Flows from Financing Activities:
Net increase in deposits	2,141.5	2,704
Net decrease in borrowings with terms of three months or less	(691.6)	(1,638.9)
Repayments of borrowings with terms of more than three months	(1.3)	(0.4)
Repayments of notes and debentures		(19)
Net proceeds from issuance of notes and debentures		394.4
Cash dividends paid on common stock	(150.6)	(147.4)
Common stock repurchases	(3.1)	(2.9)
Proceeds from stock options exercised, including excess income tax benefits	21.8	4.4
Net cash provided by financing activities	1,316.7	1,294.2
Net (decrease) increase in cash and cash equivalents	(468.8)	45.2
Cash and cash equivalents at beginning of period	1,013.7	474.4
Cash and cash equivalents at end of period	544.9	519.6
Supplemental Information:
Interest payments	100.9	77.8
Income tax payments	85.7	95.6
Real estate properties acquired by foreclosure	11.3	15.2
Unsettled purchases of securities	$ 7.4	$ 56.3

General

General	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	NOTE 1. GENERAL In the opinion of management, the accompanying unaudited consolidated financial statements of People’s United Financial, Inc. (“People’s United” or the “Company”) have been prepared to reflect all adjustments necessary to present fairly the financial position and results of operations as of the dates and for the periods shown. All significant intercompany transactions and balances are eliminated in consolidation. Certain reclassifications have been made to prior period amounts to conform to the current period presentation. In preparing the consolidated financial statements, management is required to make significant estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. Actual results could differ from management’s current estimates, as a result of changing conditions and future events. Several accounting estimates are particularly critical and are susceptible to significant near-term change, including the allowance for loan losses and asset impairment judgments, such as the recoverability of goodwill and other intangible assets. These accounting estimates are reviewed with the Audit Committee of the Board of Directors. The judgments used by management in applying critical accounting policies may be affected by economic conditions, which may result in changes to future financial results. For example, subsequent evaluations of the loan portfolio, in light of the factors then prevailing, may result in significant changes in the allowance for loan losses in future periods, and the inability to collect outstanding principal may result in increased loan losses. Note 1 to People’s United’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2014, as supplemented by the Quarterly Reports for the periods ended March 31, 2015 and June 30, 2015 and this Quarterly Report for the period ended September 30, 2015, provides disclosure of People’s United’s significant accounting policies. People’s United holds ownership interests in limited partnerships formed to develop and operate affordable housing units for lower income tenants throughout its franchise area. The underlying partnerships, which are considered variable interest entities, are not consolidated into the Company’s Consolidated Financial Statements. These investments have historically played a role in enabling People’s United Bank, N.A. (the “Bank”) to meet its Community Reinvestment Act requirements while, at the same time, providing federal income tax credits. The balance of the Company’s affordable housing investments reflected in the Consolidated Statement of Condition at September 30, 2015 totaled $78.6 million (included in other assets). Future contingent commitments (capital calls) related to such investments, the timing of which cannot be reasonably estimated, totaled $35.5 million at that date. The cost of the Company’s investments is amortized on a straight-line basis over the period during which the related federal income tax credits are realized (generally ten years). Amortization expense, which is included as a component of income tax expense, totaled $2.8 million and $2.6 million for the three months ended September 30, 2015 and 2014, respectively, and $8.3 million and $7.5 million for the nine months ended September 30, 2015 and 2014, respectively. Certain information and footnote disclosures normally included in consolidated financial statements prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) have been omitted or condensed. As a result, the accompanying consolidated financial statements should be read in conjunction with People’s United’s Annual Report on Form 10-K for the year ended December 31, 2014. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results of operations that may be expected for the entire year or any other interim period.

Securities and Short-Term Inves

Securities and Short-Term Investments	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Securities and Short-Term Investments	NOTE 2. SECURITIES AND SHORT-TERM INVESTMENTS The amortized cost, gross unrealized gains and losses, and fair value of People’s United’s securities available for sale and securities held to maturity are as follows: As of September 30, 2015 (in millions) Amortized Gross Gross Fair Securities available for sale: Debt securities: U.S. Treasury and agency $ 374.1 $ 2.1 $ — $ 376.2 GSE (1) residential mortgage-backed securities and CMOs (2) 3,823.3 40.5 (19.0 ) 3,844.8 Total debt securities 4,197.4 42.6 (19.0 ) 4,221.0 Equity securities 0.2 — — 0.2 Total securities available for sale $ 4,197.6 $ 42.6 $ (19.0 ) $ 4,221.2 Securities held to maturity: Debt securities: State and municipal $ 946.3 $ 43.7 $ (1.6 ) $ 988.4 GSE residential mortgage-backed securities 429.3 2.4 — 431.7 Other 1.5 — — 1.5 Total securities held to maturity $ 1,377.1 $ 46.1 $ (1.6 ) $ 1,421.6 (1) Government sponsored enterprise (2) Collateralized mortgage obligations As of December 31, 2014 (in millions) Amortized Gross Gross Fair Securities available for sale: Debt securities: U.S. Treasury and agency $ 56.5 $ 0.3 $ — $ 56.8 GSE residential mortgage-backed securities and CMOs 3,943.4 39.7 (46.4 ) 3,936.7 Total debt securities 3,999.9 40.0 (46.4 ) 3,993.5 Equity securities 0.2 — — 0.2 Total securities available for sale $ 4,000.1 $ 40.0 $ (46.4 ) $ 3,993.7 Securities held to maturity: Debt securities: State and municipal $ 832.8 $ 47.4 $ (0.1 ) $ 880.1 Other 1.5 — — 1.5 Total securities held to maturity $ 834.3 $ 47.4 $ (0.1 ) $ 881.6 Securities available for sale with a fair value of $1.61 billion and $1.43 billion at September 30, 2015 and December 31, 2014, respectively, were pledged as collateral for public deposits and for other purposes. The following table is a summary of the amortized cost and fair value of debt securities as of September 30, 2015, based on remaining period to contractual maturity. Information for GSE residential mortgage-backed securities and CMOs is based on the final contractual maturity dates without considering repayments and prepayments. Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair U.S. Treasury and agency: Within 1 year $ 41.1 $ 41.2 $ — $ — After 1 but within 5 years 333.0 335.0 — — Total 374.1 376.2 — — GSE residential mortgage-backed securities and CMOs: After 5 but within 10 years 742.6 755.3 — — After 10 years 3,080.7 3,089.5 429.3 431.7 Total 3,823.3 3,844.8 429.3 431.7 State and municipal: Within 1 year — — 3.8 3.8 After 1 but within 5 years — — 21.6 21.9 After 5 but within 10 years — — 323.5 342.7 After 10 years — — 597.4 620.0 Total — — 946.3 988.4 Other: After 1 but within 5 years — — 1.5 1.5 Total — — 1.5 1.5 Total: Within 1 year 41.1 41.2 3.8 3.8 After 1 but within 5 years 333.0 335.0 23.1 23.4 After 5 but within 10 years 742.6 755.3 323.5 342.7 After 10 years 3,080.7 3,089.5 1,026.7 1,051.7 Total $ 4,197.4 $ 4,221.0 $ 1,377.1 $ 1,421.6 Management conducts a periodic review and evaluation of the securities portfolio to determine if the decline in fair value of any security is deemed to be other-than-temporary. Other-than-temporary impairment losses are recognized on debt securities when: (i) People’s United has an intention to sell the security; (ii) it is more likely than not that People’s United will be required to sell the security prior to recovery; or (iii) People’s United does not expect to recover the entire amortized cost basis of the security. Other-than-temporary The following tables summarize debt securities with unrealized losses, segregated by the length of time the securities have been in a continuous unrealized loss position at the respective dates. Continuous Unrealized Loss Position Less Than 12 Months 12 Months Or Longer Total As of September 30, 2015 (in millions) Fair Unrealized Fair Unrealized Fair Unrealized Securities available for sale: GSE residential mortgage-backed securities and CMOs $ 776.2 $ (2.8 ) $ 993.9 $ (16.2 ) $ 1,770.1 $ (19.0 ) Securities held to maturity: State and municipal 129.4 (1.6 ) — — 129.4 (1.6 ) Total $ 905.6 $ (4.4 ) $ 993.9 $ (16.2 ) $ 1,899.5 $ (20.6 ) Continuous Unrealized Loss Position Less Than 12 Months 12 Months Or Longer Total As of December 31, 2014 (in millions) Fair Unrealized Fair Unrealized Fair Unrealized Securities available for sale: GSE residential mortgage-backed securities and CMOs $ 111.9 $ (0.1 ) $ 1,744.2 $ (46.3 ) $ 1,856.1 $ (46.4 ) Securities held to maturity: State and municipal 31.8 (0.1 ) — — 31.8 (0.1 ) Total $ 143.7 $ (0.2 ) $ 1,744.2 $ (46.3 ) $ 1,887.9 $ (46.5 ) At September 30, 2015, approximately 12% of the 1,264 securities owned by the Company, consisting of 48 securities classified as available for sale and 106 securities classified as held to maturity, had gross unrealized losses totaling $19.0 million and $1.6 million, respectively. All of the GSE residential mortgage-backed securities and CMOs had AAA credit ratings and an average maturity of 13 years. The state and municipal securities had an average credit rating of AA and an average maturity of 16 years. The cause of the temporary impairment with respect to all of these securities is directly related to changes in interest rates. Management believes that all gross unrealized losses within the securities portfolio at September 30, 2015 and December 31, 2014 are temporary impairments. Management does not intend to sell such securities nor is it more likely than not that management will be required to sell such securities prior to recovery. No other-than-temporary impairment losses were recognized in the Consolidated Statements of Income for the three or nine months ended September 30, 2015 and 2014. Security transactions are recorded on the trade date. Realized gains and losses are determined using the specific identification method and reported in non-interest income. The Bank, as a member of the Federal Home Loan Bank (“FHLB”) of Boston, is currently required to purchase and hold shares of FHLB capital stock (total cost of $164.4 million at both September 30, 2015 and December 31, 2014) in an amount equal to its membership base investment plus an activity based investment determined according to the Bank’s level of outstanding FHLB advances. As a result of the Smithtown Bancorp, Inc. (“Smithtown”) acquisition completed in 2010, People’s United acquired shares of capital stock in the FHLB of New York (total cost of $11.3 million at both September 30, 2015 and December 31, 2014). Based on the current capital adequacy and liquidity position of both the FHLB of Boston and the FHLB of New York, management believes there is no impairment in the Company’s investment at September 30, 2015 and the cost of the investment approximates fair value. The Bank, as a member of the Federal Reserve Bank (“FRB”) system, is currently required to purchase and hold shares of FRB of New York capital stock in an amount equal to six percent of its capital and surplus. In the first nine months of 2015, the Bank’s net purchases of FRB capital stock totaled $139.0 million. Based on the current capital adequacy and liquidity position of the FRB of New York, management believes there is no impairment in the Company’s investment at September 30, 2015 and the cost of the investment approximates fair value. Included in short-term investments are interest-bearing deposits at the FRB of New York totaling $164.1 million at September 30, 2015 and $626.5 million at December 31, 2014. These deposits represent an alternative to overnight federal funds sold and had a yield of 0.25% at both dates. People’s United accounts for securities purchased under agreements to resell as secured lending transactions. In connection with such agreements, People’s United takes delivery of collateral from all counterparties. The fair value of the collateral securing the agreements outstanding at December 31, 2014 was $100.4 million (no agreements were outstanding at September 30, 2015).

Loans

Loans	9 Months Ended
	Sep. 30, 2015
Receivables [Abstract]
Loans	NOTE 3. LOANS For purposes of disclosures related to the credit quality of financing receivables and the allowance for loan losses, People’s United has identified two loan portfolio segments, Commercial and Retail, which are comprised of the following loan classes: • Commercial Portfolio • Retail Portfolio Loans acquired in connection with business combinations beginning in 2010 are referred to as ‘acquired’ loans as a result of the manner in which they are accounted for (see further discussion under ‘Acquired Loans’). All other loans are referred to as ‘originated’ loans. Accordingly, selected credit quality disclosures that follow are presented separately for the ‘originated’ loan portfolio and the ‘acquired’ loan portfolio. People’s United maintains several significant accounting policies with respect to loans, including: • Establishment of the allowance for loan losses (including the identification of ‘impaired’ loans and related impairment measurement considerations); • Income recognition (including the classification of a loan as ‘non-accrual’ and the treatment of loan origination costs); and • Recognition of loan charge-offs. The Company did not change its policies with respect to loans or its methodology for determining the allowance for loan losses during the nine months ended September 30, 2015. The following table summarizes People’s United’s loans by loan portfolio segment and class: September 30, 2015 December 31, 2014 (in millions) Originated Acquired Total Originated Acquired Total Commercial: Commercial real estate $ 9,436.7 $ 348.7 $ 9,785.4 $ 8,960.3 $ 444.0 $ 9,404.3 Commercial and industrial 7,257.2 235.0 7,492.2 6,891.1 298.5 7,189.6 Equipment financing 2,802.4 18.7 2,821.1 2,839.0 26.5 2,865.5 Total commercial 10,059.6 253.7 10,313.3 9,730.1 325.0 10,055.1 Total Commercial Portfolio 19,496.3 602.4 20,098.7 18,690.4 769.0 19,459.4 Retail: Residential mortgage: Adjustable-rate 4,655.7 125.4 4,781.1 4,254.7 139.1 4,393.8 Fixed-rate 527.5 72.8 600.3 446.8 91.4 538.2 Total residential mortgage 5,183.2 198.2 5,381.4 4,701.5 230.5 4,932.0 Consumer: Home equity 2,101.3 39.9 2,141.2 2,092.9 50.2 2,143.1 Other consumer 49.9 1.0 50.9 56.3 1.2 57.5 Total consumer 2,151.2 40.9 2,192.1 2,149.2 51.4 2,200.6 Total Retail Portfolio 7,334.4 239.1 7,573.5 6,850.7 281.9 7,132.6 Total loans $ 26,830.7 $ 841.5 $ 27,672.2 $ 25,541.1 $ 1,050.9 $ 26,592.0 Net deferred loan costs, which are included in total loans and accounted for as interest yield adjustments, totaled $58.9 million at September 30, 2015 and $54.8 million at December 31, 2014. The following table presents a summary, by loan portfolio segment, of activity in the allowance for loan losses. With respect to the originated portfolio, an allocation of a portion of the allowance to one segment does not preclude its availability to absorb losses in another segment. Three months ended Commercial Retail September 30, 2015 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 176.4 $ 10.1 $ 186.5 $ 18.7 $ 0.2 $ 18.9 $ 205.4 Charge-offs (4.1 ) — (4.1 ) (2.0 ) — (2.0 ) (6.1 ) Recoveries 1.2 — 1.2 0.8 — 0.8 2.0 Net loan charge-offs (2.9 ) — (2.9 ) (1.2 ) — (1.2 ) (4.1 ) Provision for loan losses 3.8 (0.9 ) 2.9 3.3 — 3.3 6.2 Balance at end of period $ 177.3 $ 9.2 $ 186.5 $ 20.8 $ 0.2 $ 21.0 $ 207.5 Nine months ended Commercial Retail September 30, 2015 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 169.6 $ 9.8 $ 179.4 $ 18.5 $ 0.4 $ 18.9 $ 198.3 Charge-offs (14.4 ) — (14.4 ) (5.8 ) — (5.8 ) (20.2 ) Recoveries 4.0 — 4.0 1.7 — 1.7 5.7 Net loan charge-offs (10.4 ) — (10.4 ) (4.1 ) — (4.1 ) (14.5 ) Provision for loan losses 18.1 (0.6 ) 17.5 6.4 (0.2 ) 6.2 23.7 Balance at end of period $ 177.3 $ 9.2 $ 186.5 $ 20.8 $ 0.2 $ 21.0 $ 207.5 Three months ended Commercial Retail September 30, 2014 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 163.5 $ 9.6 $ 173.1 $ 19.0 $ 0.5 $ 19.5 $ 192.6 Charge-offs (6.2 ) (0.2 ) (6.4 ) (2.9 ) — (2.9 ) (9.3 ) Recoveries 0.5 — 0.5 0.7 — 0.7 1.2 Net loan charge-offs (5.7 ) (0.2 ) (5.9 ) (2.2 ) — (2.2 ) (8.1 ) Provision for loan losses 8.2 2.1 10.3 2.2 (0.1 ) 2.1 12.4 Balance at end of period $ 166.0 $ 11.5 $ 177.5 $ 19.0 $ 0.4 $ 19.4 $ 196.9 Nine months ended Commercial Retail September 30, 2014 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 158.5 $ 9.8 $ 168.3 $ 19.0 $ 0.5 $ 19.5 $ 187.8 Charge-offs (15.3 ) (2.6 ) (17.9 ) (8.3 ) (0.1 ) (8.4 ) (26.3 ) Recoveries 3.1 — 3.1 1.6 — 1.6 4.7 Net loan charge-offs (12.2 ) (2.6 ) (14.8 ) (6.7 ) (0.1 ) (6.8 ) (21.6 ) Provision for loan losses 19.7 4.3 24.0 6.7 — 6.7 30.7 Balance at end of period $ 166.0 $ 11.5 $ 177.5 $ 19.0 $ 0.4 $ 19.4 $ 196.9 The following is a summary, by loan portfolio segment and impairment methodology, of the allowance for loan losses and related portfolio balances: As of September 30, 2015 Originated Loans Originated Loans Acquired Loans Total (in millions) Portfolio Allowance Portfolio Allowance Portfolio Allowance Portfolio Allowance Commercial $ 169.0 $ 8.2 $ 19,327.3 $ 169.1 $ 602.4 $ 9.2 $ 20,098.7 $ 186.5 Retail 97.2 3.7 7,237.2 17.1 239.1 0.2 7,573.5 21.0 Total $ 266.2 $ 11.9 $ 26,564.5 $ 186.2 $ 841.5 $ 9.4 $ 27,672.2 $ 207.5 As of December 31, 2014 Originated Loans Originated Loans Acquired Loans Total (in millions) Portfolio Allowance Portfolio Allowance Portfolio Allowance Portfolio Allowance Commercial $ 174.5 $ 7.6 $ 18,515.9 $ 162.0 $ 769.0 $ 9.8 $ 19,459.4 $ 179.4 Retail 95.0 3.9 6,755.7 14.6 281.9 0.4 7,132.6 18.9 Total $ 269.5 $ 11.5 $ 25,271.6 $ 176.6 $ 1,050.9 $ 10.2 $ 26,592.0 $ 198.3 The recorded investments, by class of loan, of originated non-performing loans are summarized as follows: (in millions) September 30, December 31, Commercial: Commercial and industrial $ 62.9 $ 55.8 Commercial real estate 31.8 60.2 Equipment financing 29.4 25.4 Total (1) 124.1 141.4 Retail: Residential mortgage 38.2 37.6 Home equity 21.0 17.9 Other consumer — 0.1 Total (2) 59.2 55.6 Total $ 183.3 $ 197.0 (1) Reported net of government guarantees totaling $17.3 million and $17.6 million at September 30, 2015 and December 31, 2014, respectively. These government guarantees relate, almost entirely, to guarantees provided by the Small Business Administration as well as selected other Federal agencies and represent the carrying value of the loans that are covered by such guarantees, the extent of which (i.e. full or partial) varies by loan. At September 30, 2015, the principal loan classes to which these government guarantees relate are commercial and industrial loans (99%) and commercial real estate loans (1%). (2) Includes $19.8 million and $18.9 million of loans in the process of foreclosure at September 30, 2015 and December 31, 2014, respectively. The preceding table excludes acquired loans that are (i) accounted for as purchased credit impaired loans or (ii) covered by a Federal Deposit Insurance Corporation (“FDIC”) loss-share agreement (“LSA”) totaling $36.6 million and $1.8 million, respectively, at September 30, 2015 and $100.6 million and $3.0 million, respectively, at December 31, 2014. Such loans otherwise meet People’s United’s definition of a non-performing loan but are excluded because the loans are included in loan pools that are considered performing and/or credit losses are covered by an FDIC LSA. The discounts arising from recording these loans at fair value were due, in part, to credit quality. The acquired loans are generally accounted for on a pool basis and the accretable yield on the pools is being recognized as interest income over the life of the loans based on expected cash flows at the pool level. A loan is generally considered “non-performing” when it is placed on non-accrual status. A loan is generally placed on non-accrual A loan is considered impaired when, based on current information and events, it is probable that 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. Impaired loans also include certain originated loans whose terms have been modified in such a way that they are considered troubled debt restructurings (“TDRs”). Originated loans are considered TDRs if the borrower is experiencing financial difficulty and is afforded a concession by People’s United, such as, but not limited to: (i) payment deferral; (ii) a reduction of the stated interest rate for the remaining contractual life of the loan; (iii) an extension of the loan’s original contractual term at a stated interest rate lower than the current market rate for a new loan with similar risk; (iv) capitalization of interest; or (v) forgiveness of principal or interest. Generally, TDRs are placed on non-accrual status (and reported as non-performing loans) until the loan qualifies for return to 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 in the case of a commercial loan or, in the case of a retail loan, when the loan is less than 90 days past due. Loans may continue to be reported as TDRs after they are returned to accrual status. In accordance with regulatory guidance, residential mortgage and home equity loans restructured in connection with the borrower’s bankruptcy and meeting certain criteria are also required to be classified as TDRs, included in non-performing loans and written down to the estimated collateral value, regardless of delinquency status. Acquired loans that are modified are not considered for TDR classification provided they are evaluated for impairment on a pool basis. People’s United’s recorded investment in originated loans classified as TDRs totaled $199.2 million and $181.6 million at September 30, 2015 and December 31, 2014, respectively. The related allowance for loan losses at September 30, 2015 and December 31, 2014 was $6.8 million and $7.1 million, respectively. Interest income recognized on TDRs totaled $1.1 million for both the three months ended September 30, 2015 and 2014, and $3.2 million and $3.1 million for the nine months ended September 30, 2015 and 2014, respectively. Fundings under commitments to lend additional amounts to borrowers with loans classified as TDRs were immaterial for the three and nine months ended September 30, 2015 and 2014. Originated loans that were modified and classified as TDRs during the three and nine months ended September 30, 2015 and 2014 principally involve reduced payment and/or payment deferral, extension of term (generally no more than two years for commercial loans and nine years for retail loans) and/or a temporary reduction of interest rate (generally less than 200 basis points). The following tables summarize, by class of loan, the recorded investments in loans modified as TDRs during the three and nine months ended September 30, 2015 and 2014. For purposes of this disclosure, recorded investments represent amounts immediately prior to and subsequent to the restructuring. Three Months Ended September 30, 2015 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 10 $ 7.0 $ 7.0 Commercial and industrial (2) 7 24.4 24.4 Equipment financing (3) 8 4.2 4.2 Total 25 35.6 35.6 Retail: Residential mortgage (4) 15 5.0 5.0 Home equity (5) 17 1.3 1.3 Other consumer — — — Total 32 6.3 6.3 Total 57 $ 41.9 $ 41.9 (1) Represents the following concessions: extension of term (7 contracts; recorded investment of $2.1 million); reduced payment and/or payment deferral (2 contracts; recorded investment of $1.2 million); or a combination of concessions (1 contract; recorded investment of $3.7 million). (2) Represents the following concessions: extension of term (3 contracts; recorded investment of $9.8 million); reduced payment and/or payment deferral (3 contracts; recorded investment of $13.6 million); or a combination of concessions (1 contract; recorded investment of $1.0 million). (3) Represents the following concessions: reduced payment and/or payment deferral (3 contracts; recorded investment of $2.0 million); or a combination of concessions (5 contracts; recorded investment of $2.2 million). (4) Represents the following concessions: loans restructured through bankruptcy (6 contracts; recorded investment of $1.2 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.8 million); or a combination of concessions (5 contracts; recorded investment of $3.0 million). (5) Represents the following concessions: loans restructured through bankruptcy (12 contracts; recorded investment of $0.9 million); reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million); or a combination of concessions (4 contracts; recorded investment of $0.3 million). Nine Months Ended September 30, 2015 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 20 $ 12.3 $ 12.3 Commercial and industrial (2) 35 59.2 59.2 Equipment financing (3) 18 19.6 19.6 Total 73 91.1 91.1 Retail: Residential mortgage (4) 50 16.9 16.9 Home equity (5) 70 6.2 6.2 Other consumer — — — Total 120 23.1 23.1 Total 193 $ 114.2 $ 114.2 (1) Represents the following concessions: extension of term (17 contracts; recorded investment of $7.4 million); reduced payment and/or payment deferral (2 contracts; recorded investment of $1.2 million); or a combination of concessions (1 contract; recorded investment of $3.7 million). (2) Represents the following concessions: extension of term (19 contracts; recorded investment of $22.9 million); reduced payment and/or payment deferral (11 contracts; recorded investment of $33.0 million); or a combination of concessions (5 contracts; recorded investment of $3.3 million). (3) Represents the following concessions: reduced payment and/or payment deferral (8 contracts; recorded investment of $12.7 million); or a combination of concessions (10 contracts; recorded investment of $6.9 million). (4) Represents the following concessions: loans restructured through bankruptcy (16 contracts; recorded investment of $5.1 million); reduced payment and/or payment deferral (11 contracts; recorded investment of $3.6 million); temporary rate reduction (2 contracts; recorded investment of $0.3 million); or a combination of concessions (21 contracts; recorded investment of $7.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (48 contracts; recorded investment of $3.8 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.3 million); temporary rate reduction (1 contract; recorded investment of $0.5 million); or a combination of concessions (17 contracts; recorded investment of $1.6 million). Three Months Ended September 30, 2014 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 9 $ 5.8 $ 5.8 Commercial and industrial (2) 7 2.9 2.9 Equipment financing (3) 6 1.4 1.4 Total 22 10.1 10.1 Retail: Residential mortgage (4) 28 6.6 6.6 Home equity (5) 36 3.3 3.3 Other consumer — — — Total 64 9.9 9.9 Total 86 $ 20.0 $ 20.0 (1) Represents the following concessions: extension of term (8 contracts; recorded investment of $5.5 million); or reduced payment and/or payment deferral (1 contract; recorded investment of $0.3 million). (2) Represents the following concessions: extension of term (6 contracts; recorded investment of $2.8 million); or reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million). (3) Represents the following concessions: reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million); or a combination of concessions (5 contracts; recorded investment of $1.3 million). (4) Represents the following concessions: loans restructured through bankruptcy (11 contracts; recorded investment of $1.0 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.7 million); or a combination of concessions (13 contracts; recorded investment of $4.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (22 contracts; recorded investment of $1.6 million); reduced payment and/or payment deferral (7 contracts; recorded investment of $0.8 million); temporary rate reduction (1 contract; recorded investment of $0.5 million); or a combination of concessions (6 contracts; recorded investment of $0.4 million). Nine Months Ended September 30, 2014 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 22 $ 32.1 $ 32.1 Commercial and industrial (2) 36 27.2 27.2 Equipment financing (3) 17 5.1 5.1 Total 75 64.4 64.4 Retail: Residential mortgage (4) 113 32.0 32.0 Home equity (5) 108 10.2 10.2 Other consumer — — — Total 221 42.2 42.2 Total 296 $ 106.6 $ 106.6 (1) Represents the following concessions: extension of term (14 contracts; recorded investment of $10.9 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $1.8 million); temporary rate reduction (1 contract; recorded investment of $18.2 million); or a combination of concessions (3 contracts; recorded investment of $1.2 million). (2) Represents the following concessions: extension of term (13 contracts; recorded investment of $5.9 million); reduced payment and/or payment deferral (8 contracts; recorded investment of $2.5 million); or a combination of concessions (15 contracts; recorded investment of $18.8 million). (3) Represents the following concessions: reduced payment and/or payment deferral (2 contracts; recorded investment of $0.3 million); or a combination of concessions (15 contracts; recorded investment of $4.8 million). (4) Represents the following concessions: loans restructured through bankruptcy (28 contracts; recorded investment of $5.0 million); extension of term (1 contract; recorded investment of $0.5 million); reduced payment and/or payment deferral (26 contracts; recorded investment of $8.6 million); or a combination of concessions (58 contracts; recorded investment of $17.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (53 contracts; recorded investment of $4.7 million); reduced payment and/or payment deferral (16 contracts; recorded investment of $2.1 million); temporary rate reduction (2 contracts; recorded investment of $0.6 million); or a combination of concessions (37 contracts; recorded investment of $2.8 million). The following is a summary, by class of loan, of information related to TDRs of originated loans completed within the previous 12 months that subsequently defaulted during the three and nine months ended September 30, 2015 and 2014. For purposes of this disclosure, the previous 12 months is measured from October 1 of the respective prior year and a default represents a previously-modified Three Months Ended September 30, 2015 2014 (dollars in millions) Number Recorded Number Recorded Commercial: Commercial real estate — $ — 3 $ 3.7 Commercial and industrial 1 0.6 1 0.7 Equipment financing 1 0.3 — — Total 2 0.9 4 4.4 Retail: Residential mortgage 2 0.2 13 2.1 Home equity 2 0.1 6 0.3 Other consumer — — — — Total 4 0.3 19 2.4 Total 6 $ 1.2 23 $ 6.8 Nine Months Ended September 30, 2015 2014 (dollars in millions) Number Recorded Number Recorded Commercial: Commercial real estate 2 $ 3.4 5 $ 4.1 Commercial and industrial 4 1.4 2 0.8 Equipment financing 8 4.1 8 1.0 Total 14 8.9 15 5.9 Retail: Residential mortgage 18 6.7 39 12.7 Home equity 16 1.5 23 1.6 Other consumer — — — — Total 34 8.2 62 14.3 Total 48 $ 17.1 77 $ 20.2 People’s United’s impaired loans consist of certain originated loans, including all TDRs. The following table summarizes, by class of loan, information related to individually-evaluated impaired loans within the originated portfolio. As of September 30, 2015 As of December 31, 2014 (in millions) Unpaid Recorded Related Unpaid Recorded Related Without a related allowance for loan losses: Commercial: Commercial real estate $ 48.0 $ 47.4 $ — $ 57.1 $ 55.8 $ — Commercial and industrial 63.5 59.6 — 51.7 48.6 — Equipment financing 21.5 17.7 — 30.2 21.4 — Retail: Residential mortgage 67.9 61.1 — 65.4 58.9 — Home equity 22.3 19.5 — 21.3 18.3 — Other consumer — — — — — — Total $ 223.2 $ 205.3 $ — $ 225.7 $ 203.0 $ — With a related allowance for loan losses: Commercial: Commercial real estate $ 17.8 $ 13.5 $ 1.9 $ 52.1 $ 27.8 $ 4.0 Commercial and industrial 22.2 21.3 5.6 21.4 17.4 3.5 Equipment financing 12.5 9.5 0.7 3.6 3.5 0.1 Retail: Residential mortgage 14.9 14.8 2.9 15.6 15.3 2.6 Home equity 1.9 1.8 0.8 2.6 2.5 1.3 Other consumer — — — — — — Total $ 69.3 $ 60.9 $ 11.9 $ 95.3 $ 66.5 $ 11.5 Total impaired loans: Commercial: Commercial real estate $ 65.8 $ 60.9 $ 1.9 $ 109.2 $ 83.6 $ 4.0 Commercial and industrial 85.7 80.9 5.6 73.1 66.0 3.5 Equipment financing 34.0 27.2 0.7 33.8 24.9 0.1 Total 185.5 169.0 8.2 216.1 174.5 7.6 Retail: Residential mortgage 82.8 75.9 2.9 81.0 74.2 2.6 Home equity 24.2 21.3 0.8 23.9 20.8 1.3 Other consumer — — — — — — Total 107.0 97.2 3.7 104.9 95.0 3.9 Total $ 292.5 $ 266.2 $ 11.9 $ 321.0 $ 269.5 $ 11.5 The following table summarizes, by class of loan, the average recorded investment and interest income recognized on impaired loans for the periods indicated. The average recorded investment amounts are based on month-end balances. Three Months Ended September 30, 2015 2014 (in millions) Average Interest Average Interest Commercial: Commercial real estate $ 59.2 $ 0.5 $ 81.8 $ 0.3 Commercial and industrial 83.0 0.2 51.0 0.2 Equipment financing 26.7 0.1 30.6 0.2 Total 168.9 0.8 163.4 0.7 Retail: Residential mortgage 74.4 0.4 72.3 0.4 Home equity 21.2 0.1 18.4 0.1 Other consumer — — — — Total 95.6 0.5 90.7 0.5 Total $ 264.5 $ 1.3 $ 254.1 $ 1.2 Nine Months Ended September 30, 2015 2014 (in millions) Average Interest Average Interest Commercial: Commercial real estate $ 67.8 $ 1.2 $ 75.7 $ 1.2 Commercial and industrial 71.1 1.2 42.9 0.8 Equipment financing 28.9 0.3 29.4 0.6 Total 167.8 2.7 148.0 2.6 Retail: Residential mortgage 75.3 1.1 71.4 1.0 Home equity 21.3 0.2 17.3 0.2 Other consumer — — — — Total 96.6 1.3 88.7 1.2 Total $ 264.4 $ 4.0 $ 236.7 $ 3.8 The following tables summarize, by class of loan, aging information for originated loans: Past Due As of September 30, 2015 (in millions) Current 30-89 90 Days Total Total Commercial: Commercial real estate $ 9,403.2 $ 21.0 $ 12.5 $ 33.5 $ 9,436.7 Commercial and industrial 7,173.6 29.2 54.4 83.6 7,257.2 Equipment financing 2,733.3 59.0 10.1 69.1 2,802.4 Total 19,310.1 109.2 77.0 186.2 19,496.3 Retail: Residential mortgage 5,117.5 39.9 25.8 65.7 5,183.2 Home equity 2,084.6 6.3 10.4 16.7 2,101.3 Other consumer 49.6 0.3 — 0.3 49.9 Total 7,251.7 46.5 36.2 82.7 7,334.4 Total originated loans $ 26,561.8 $ 155.7 $ 113.2 $ 268.9 $ 26,830.7 Included in the “Current” and “30-89 Days” categories above are early non-performing commercial real estate loans, commercial and industrial loans, and equipment financing loans totaling $19.3 million, $25.8 million and $19.3 million, respectively, and $23.0 million of retail loans in the process of foreclosure or bankruptcy. These loans are less than 90 days past due but have been placed on non-accrual status as a result of having been identified as presenting uncertainty with respect to the collectability of interest and principal. Past Due As of December 31, 2014 (in millions) Current 30-89 90 Days Total Total Commercial: Commercial real estate $ 8,908.0 $ 17.6 $ 34.7 $ 52.3 $ 8,960.3 Commercial and industrial 6,814.9 32.4 43.8 76.2 6,891.1 Equipment financing 2,793.3 41.0 4.7 45.7 2,839.0 Total 18,516.2 91.0 83.2 174.2 18,690.4 Retail: Residential mortgage 4,647.3 29.1 25.1 54.2 4,701.5 Home equity 2,079.3 5.0 8.6 13.6 2,092.9 Other consumer 55.8 0.4 0.1 0.5 56.3 Total 6,782.4 34.5 33.8 68.3 6,850.7 Total originated loans $ 25,298.6 $ 125.5 $ 117.0 $ 242.5 $ 25,541.1 Included in the “Current” and “30-89 Days” categories above are early non-performing commercial real estate loans, commercial and industrial loans, and equipment financing loans totaling $25.6 million, $29.5 million and $20.7 million, respectively, and $21.8 million of retail loans in the process of foreclosure or bankruptcy. These loans are less than 90 days past due but have been placed on non-accrual status as a result of having been identified as presenting uncertainty with respect to the collectability of interest and principal. Commercial Credit Quality Indicators The Company utilizes an internal loan risk rating system as a means of monitoring portfolio credit quality and identifying both problem and potential problem loans. Under the Company’s risk rating system, loans not meeting the criteria for problem and potential problem loans as specified below are considered to be “Pass”-rated loans. Problem and potential problem loans are classified as either “Special Mention,” “Substandard” or “Doubtful.” Loans that do not currently expose the Company to sufficient enough risk of loss to warrant classification as either Substandard or Doubtful, but possess weaknesses that deserve management’s close attention, are classified as Special Mention. Substandard loans represent those credits characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. Loans classified as Doubtful possess all the weaknesses inherent in those classified Substandard with the added characteristic that collection or liquidation in full, on the basis of existing facts, conditions and values, is highly questionable and/or improbable. Risk ratings on commercial loans are subject to ongoing monitoring by lending and credit personnel with such ratings updated annually or more frequently, if warranted. The Company’s internal Loan Review function is responsible for independently evaluating the appropriateness of those credit risk ratings in connection with its cyclical reviews, the approach to which is risk-based and determined by reference to underlying portfolio credit quality and the results of prior reviews. Differences in risk ratings noted in conjunction with such periodic portfolio loan reviews, if any, are reported to management each month. Retail Credit Quality Indicators Pools of smaller-balance, homogeneous loans with similar risk and loss characteristics are also assessed for probable losses. These loan pools include residential mortgage, home equity and other consumer loans that are not assigned individual loan risk ratings. Rather, the assessment of these portfolios is based upon a consideration of recent historical loss experience, broader portfolio indicators, including trends in delinquencies, non-performing loans and portfolio concentrations, and portfolio-specific risk characteristics, the combination of which determines whether a loan is classified as “High”, “Moderate” or “Low” risk. The portfolio-specific risk characteristics considered include: (i) collateral values/ loan-to-value (“LTV”) ratios (above and below 70%); (ii) borrower credit scores under the FICO scoring system (above and below a score of 680); and (iii) other relevant portfolio risk elements such as income verification at the time of underwriting (stated income vs. non-stated income) and the property’s intended use (owner occupied, non-owner occupied, second home, etc.). In classifying a loan as either “High”, “Moderate” or “Low” risk, the combination of each of the aforementioned risk characteristics is considered for that loan, resulting, effectively, in a “matrix approach” to its risk classification. These risk classifications are reviewed periodically to ensure that they continue to be appropriate in light of changes within the portfolio and/or economic indicators as well as other industry developments. For example, to the extent LTV ratios exceed 70% (reflecting a weaker collateral position for the Company) or borrower FICO scores are less than 680 (reflecting weaker financial standing and/or credit history of the customer), the loans are considered to have an increased level of inherent loss. As a result, a loan with a combination of these characteristics would generally be classified as “High” risk. Conversely, as LTV ratios decline (reflecting a stronger collateral position for the Company) or borrower FICO scores exceed 680 (reflecting stronger financial standing and/or credit history of the customer), the loans are considered to have a decreased level of inherent loss. A loan with a combination of these characteristics would generally be classified as “Low” risk. This analysis also considers (i) the extent of underwriting that occurred at the time of origination (direct income verification provides further support for credit decisions) and (ii) the property’s intended use (owner-occupied properties are less likely to default compared to ‘investment-type’ non-owner occupied properties, second homes, etc.). Loans not otherwise deemed to be “High” or “Low” risk are classified as “Moderate” risk. LTV ratios and FICO scores are determined at origination and updated periodically throughout the life of the loan. LTV ratios are updated for loans 90 days past due and FICO scores are updated for the entire portfolio quarterly. The portfolio stratification (“High”, “Moderate” and “Low” risk) and identification of the corresponding credit quality indicators also occurs quarterly. Commercial and Retail loans are also evaluated to determine whether they are impaired loans, which are included in the tabular disclosures of credit quality indicators that follow. Acquired Loans Credit Quality Indicators Upon acquiring a loan portfolio, the Company’s internal Loan Review function undertakes the process of assigning risk ratings to all commercial loans in accordance with the Company’s established policy, which may differ in certain respects from the risk rating policy of the predecessor company. The length of time necessary to complete this process varies based on the size of the acquired portfolio, the quality of the documentation maintained in the underlying loan files and the extent to which the predecessor company followed a risk rating approach comparable to People’s United’s. As a result, while acquired loans are risk rated, there are occasions when such ratings may be deemed “preliminary” until the Company’s re-rating process has been completed. Acquired loans are initially recorded at fair value, determined based upon an estimate of the amount and timing of both principal and interest cash flows expected to be collected and discounted using a market interest rate. The difference between contractually required principal and interest payments at the acquisition date and the undiscounted cash flows expected to be collected at the acquisition date is referred to as the “nonaccretable difference”, which includes an estimate of future credit losses expected to be incurred over the life of the portfolio. A decrease in the expected cash flows in subsequent periods requires the establishment of an allowance for loan losses at that time. At September 30, 2015 and December 31, 2014, the allowance for loan losses on acquired loans was $9.4 million and $10.2 million, respectively. The following is a summary, by class of loan, of credit quality indicators: As of September 30, 2015 (in millions) Commercial Commercial Equipment Total Commercial: Originated loans: Pass $ 9,211.9 $ 6,864.3 $ 2,434.7 $ 18,510.9 Special mention 93.9 106.0 95.3 295.2 Substandard 130.9 283.8 272.4 687.1 Doubtful — 3.1 — 3.1 Total originated loans 9,436.7 7,257.2 2,802.4 19,496.3 Acquired loans: Pass 269.6 184.9 5.5 460.0 Special mention 22.3 5.4 0.4 28.1 Substandard 55.0 44.1 12.8 111.9 Doubtful 1.8 0.6 — 2.4 Total acquired loans 348.7 235.0 18.7 602.4 Total $ 9,785.4 $ 7,492.2 $ 2,821.1 $ 20,098.7 As of September 30, 2015 (in millions) Residential Home Other Total Retail: Originated loans: Low risk $ 2,502.4 $ 950.7 $ 25.9 $ 3,479.0 Moderate risk 2,171.3 636.9 8.3 2,816.5 High risk 509.5 513.7 15.7 1,038.9 Total originated loans 5,183.2 2,101.3 49.9 7,334.4 Acquired loans: Low risk 99.3 — — 99.3 Moderate risk 40.3 — — 40.3 High risk 58.6 39.9 1.0 99.5 Total acquired loans 198.2 39.9 1.0 239.1 Total $ 5,381.4 $ 2,141.2 $ 50.9 $ 7,573.5 As of December 31, 2014 (in millions) Commercial Commercial Equipment Total Commercial: Originated loans: Pass $ 8,730.9 $ 6,477.4 $ 2,481.2 $ 17,68

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Stockholders' Equity	NOTE 4. STOCKHOLDERS’ EQUITY Treasury Stock Treasury stock includes (i) common stock repurchased by People’s United, either directly or through agents, in the open market at prices and terms satisfactory to management in connection with stock repurchases authorized by its Board of Directors (88.8 million shares at September 30, 2015) and (ii) common stock purchased in the open market by a trustee with funds provided by People’s United and originally intended for awards under the People’s United Financial, Inc. 2007 Recognition and Retention Plan (the “RRP”) (0.3 million shares at September 30, 2015). Following shareholder approval of the People’s United Financial, Inc. 2014 Long-Term Incentive Plan in the second quarter of 2014, no new awards may be granted under the RRP. Comprehensive Income Comprehensive income represents the sum of net income and items of “other comprehensive income or loss,” including (on an after-tax basis): (i) net actuarial gains and losses, prior service credits and costs, and transition assets and obligations related to People’s United’s pension and other postretirement benefit plans; (ii) net unrealized gains and losses on securities available for sale; (iii) net unrealized gains and losses on securities transferred to held to maturity; and (iv) net unrealized gains and losses on derivatives accounted for as cash flow hedges. People’s United’s total comprehensive income for the three and nine months ended September 30, 2015 and 2014 is reported in the Consolidated Statements of Comprehensive Income. The following is a summary of the changes in the components of accumulated other comprehensive loss (“AOCL”), which are included in People’s United’s stockholders’ equity on an after-tax basis: (in millions) Pension Net Unrealized Net Unrealized Net Unrealized Total Balance at December 31, 2014 $ (142.9 ) $ (3.7 ) $ (21.5 ) $ (0.1 ) $ (168.2 ) Other comprehensive income (loss) before reclassifications — 17.5 — (0.8 ) 16.7 Amounts reclassified from AOCL (1) 3.3 — 1.5 0.6 5.4 Current period other comprehensive income (loss) 3.3 17.5 1.5 (0.2 ) 22.1 Balance at September 30, 2015 $ (139.6 ) $ 13.8 $ (20.0 ) $ (0.3 ) $ (146.1 ) (in millions) Pension Net Unrealized Net Unrealized Net Unrealized Total Balance at December 31, 2013 $ (85.0 ) $ (46.5 ) $ (23.3 ) $ (0.3 ) $ (155.1 ) Other comprehensive income (loss) before reclassifications — 27.2 — (0.2 ) 27.0 Amounts reclassified from AOCL (1) 1.9 (0.2 ) 1.3 0.6 3.6 Current period other comprehensive income (loss) 1.9 27.0 1.3 0.4 30.6 Balance at September 30, 2014 $ (83.1 ) $ (19.5 ) $ (22.0 ) $ 0.1 $ (124.5 ) (1) See the following table for details about these reclassifications. The following is a summary of the amounts reclassified from AOCL: Amounts Reclassified from AOCL Three Months Ended Nine Months Ended Affected Line Item in the Statement Where (in millions) 2015 2014 2015 2014 Net Income is Presented Details about components of AOCL: Amortization of pension and other postretirement benefits items: Net actuarial loss $ (2.0 ) $ (1.2 ) $ (6.0 ) $ (3.9 ) (1) Prior service credit 0.3 0.2 0.8 0.8 (1) (1.7 ) (1.0 ) (5.2 ) (3.1 ) Income before income tax expense 0.6 0.4 1.9 1.2 Income tax expense (1.1 ) (0.6 ) (3.3 ) (1.9 ) Net income Reclassification adjustment for net realized gains on securities available for sale — 0.2 — 0.3 Income before income tax expense (2) — (0.1 ) — (0.1 ) Income tax expense — 0.1 — 0.2 Net income Amortization of unrealized losses on securities transferred to held to maturity (0.8 ) (0.7 ) (2.3 ) (2.2 ) Income before income tax expense (3) 0.2 0.3 0.8 0.9 Income tax expense (0.6 ) (0.4 ) (1.5 ) (1.3 ) Net income Amortization of unrealized gains and losses on cash flow hedges: Interest rate swaps (0.3 ) (0.3 ) (1.0 ) (1.0 ) (4) Interest rate locks 0.1 0.1 0.1 0.1 (4) (0.2 ) (0.2 ) (0.9 ) (0.9 ) Income before income tax expense 0.1 0.1 0.3 0.3 Income tax expense (0.1 ) (0.1 ) (0.6 ) (0.6 ) Net income Total reclassifications for the period $ (1.8 ) $ (1.0 ) $ (5.4 ) $ (3.6 ) (1) Included in the computation of net periodic pension cost reflected in compensation and benefits expense (see Note 7 for additional details). (2) Included in other non-interest income. (3) Included in interest and dividend income - securities. (4) Included in interest expense - notes and debentures.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Common Share	NOTE 5. EARNINGS PER COMMON SHARE The following is an analysis of People’s United’s basic and diluted earnings per share (“EPS”), reflecting the application of the two-class method, as described below: Three Months Ended Nine Months Ended (in millions, except per share data) 2015 2014 2015 2014 Net income $ 68.4 $ 61.6 $ 189.3 $ 187.0 Dividends and undistributed earnings allocated to participating securities (0.3 ) (0.3 ) (0.9 ) (0.9 ) Income attributable to common shareholders $ 68.1 $ 61.3 $ 188.4 $ 186.1 Average common shares outstanding for basic EPS 301.0 298.4 300.1 298.1 Effect of dilutive equity-based awards — — — — Average common and common-equivalent shares for diluted EPS 301.0 298.4 300.1 298.1 Basic EPS $ 0.23 $ 0.21 $ 0.63 $ 0.62 Diluted EPS $ 0.23 $ 0.21 $ 0.63 $ 0.62 Unvested share-based payment awards, which include the right to receive non-forfeitable dividends or dividend equivalents, are considered to participate with common stock in undistributed earnings for purposes of computing EPS. Companies that have such participating securities, including People’s United, are required to calculate basic and diluted EPS using the two-class method. Restricted stock awards granted by People’s United are considered participating securities. Calculations of EPS under the two-class method (i) exclude from the numerator any dividends paid or owed on participating securities and any undistributed earnings considered to be attributable to participating securities and (ii) exclude from the denominator the dilutive impact of the participating securities. All unallocated Employee Stock Ownership Plan (“ESOP”) common shares and all common shares accounted for as treasury shares have been excluded from the calculation of basic and diluted EPS. Anti-dilutive equity-based awards totaling 20.3 million shares for both the three and nine months ended September 30, 2015 and 17.9 million shares for both the three and nine months ended September 30, 2014 have been excluded from the calculation of diluted EPS.

Goodwill and Other Acquisition-

Goodwill and Other Acquisition-Related Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Acquisition-Related Intangible Assets	NOTE 6. GOODWILL AND OTHER ACQUISITION-RELATED INTANGIBLE ASSETS People’s United’s goodwill totaled $1.95 billion at both September 30, 2015 and December 31, 2014. At both dates, goodwill was allocated to People’s United’s operating segments as follows: Commercial Banking ($1.22 billion); Retail Banking ($681.9 million); and Wealth Management ($49.8 million). Acquisitions have been undertaken with the objective of expanding the Company’s business, both geographically and through product offerings, as well as realizing synergies and economies of scale by combining with the acquired entities. For these reasons, a market-based premium was generally paid for the acquired entities which, in turn, resulted in the recognition of goodwill, representing the excess of the respective purchase prices over the estimated fair value of the net assets acquired. All of People’s United’s tax deductible goodwill was created in transactions in which the Company purchased the assets of the target (as opposed to purchasing the issued and outstanding stock of the target). At September 30, 2015 and December 31, 2014, tax deductible goodwill totaled $12.1 million and $13.0 million, respectively, and related, almost entirely, to the Butler Bank acquisition completed in 2010. People’s United’s other acquisition-related intangible assets totaled $130.2 million and $148.0 million at September 30, 2015 and December 31, 2014, respectively. At September 30, 2015, the carrying amounts of other acquisition-related intangible assets were as follows: trade name intangible ($81.9 million); core deposit intangible ($27.0 million); trust relationship intangible ($20.6 million); and insurance relationship intangible ($0.7 million). Amortization expense of other acquisition-related intangible assets totaled $5.9 million and $6.2 million for the three months ended September 30, 2015 and 2014, respectively, and $17.8 million and $18.6 million for the nine months ended September 30, 2015 and 2014, respectively. Scheduled amortization expense attributable to other acquisition-related intangible assets for the full-year acquisition-related

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	NOTE 7. EMPLOYEE BENEFIT PLANS People’s United Employee Pension and Other Postretirement Benefit Plans People’s United maintains a qualified noncontributory defined benefit pension plan (the “Qualified Plan”) that covers substantially all full-time and part-time employees who (i) meet certain age and length of service requirements and (ii) were employed by the Bank prior to August 14, 2006. Benefits are based upon the employee’s years of credited service and either the average compensation for the last five years or the average compensation for the five consecutive years of the last ten years that produce the highest average. New employees of the Bank starting on or after August 14, 2006 are not eligible to participate in the Qualified Plan. Instead, the Bank makes contributions on behalf of these employees to a qualified defined contribution plan in an annual amount equal to 3% of the employee’s eligible compensation. Employee participation in this plan is restricted to employees who (i) are at least 18 years of age and (ii) worked at least 1,000 hours in a year. Both full-time and part-time employees are eligible to participate as long as they meet these requirements. In July 2011, the Bank amended the Qualified Plan to “freeze”, effective December 31, 2011, the accrual of pension benefits for Qualified Plan participants. As such, participants will not earn any additional benefits after that date. Instead, effective January 1, 2012, the Bank began making contributions on behalf of these participants to a qualified defined contribution plan in an annual amount equal to 3% of the employee’s eligible compensation. People’s United’s funding policy is to contribute the amounts required by applicable regulations, although additional amounts may be contributed from time to time. In the first quarter of 2015, the Company made a voluntary employer contribution of $40.0 million to the Qualified Plan as a consequence of lower discount rates and the adoption of updated mortality tables. People’s United also maintains (i) unfunded, nonqualified supplemental plans to provide retirement benefits to certain senior officers and (ii) an unfunded plan that provides retirees with optional medical, dental and life insurance benefits (“the other postretirement benefits plan”). People’s United accrues the cost of these postretirement benefits over the employees’ years of service to the date of their eligibility for such benefit. Components of the net periodic benefit (income) expense and other amounts recognized in other comprehensive income for the plans described above are as follows: Pension Benefits Other Three months ended September 30 (in millions) 2015 2014 2015 2014 Net periodic benefit (income) expense: Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 4.8 4.8 0.1 — Expected return on plan assets (7.8 ) (7.1 ) — — Recognized net actuarial loss 1.5 1.0 — — Settlements 0.1 0.4 — — Net periodic benefit (income) expense $ (1.4 ) $ (0.9 ) $ 0.2 $ 0.1 Pension Benefits Other Nine months ended September 30 (in millions) 2015 2014 2015 2014 Net periodic benefit (income) expense: Service cost $ — $ — $ 0.2 $ 0.2 Interest cost 14.4 14.4 0.4 0.3 Expected return on plan assets (22.8 ) (21.3 ) — — Recognized net actuarial loss 4.5 3.0 0.2 — Recognized prior service credit — — (0.1 ) (0.2 ) Settlements 0.3 1.4 — — Net periodic benefit (income) expense (3.6 ) (2.5 ) 0.7 0.3 Other changes in plan assets and benefit obligations recognized in other comprehensive income: Net actuarial loss (4.5 ) (3.0 ) (0.2 ) — Prior service credit — — 0.1 0.2 Total pre-tax changes recognized in other comprehensive income (4.5 ) (3.0 ) (0.1 ) 0.2 Total recognized in net periodic benefit (income) expense and other comprehensive income $ (8.1 ) $ (5.5 ) $ 0.6 $ 0.5 Chittenden Pension Plan In addition to the benefit plans described above, People’s United continues to maintain a qualified defined benefit pension plan that covers former Chittenden Corporation employees who meet certain eligibility requirements (the “Chittenden Plan”). Effective December 31, 2005, accrued benefits were frozen based on participants’ then-current service and pay levels. During April 2010, participants who were in payment status as of April 1, 2010, or whose accrued benefit as of that date was scheduled to be paid in the form of an annuity commencing May 1, 2010, based upon elections made by April 15, 2010, were transferred into the Qualified Plan. Net periodic benefit income for the Chittenden Plan totaled $0.1 million and $0.2 million for the nine months ended September 30, 2015 and 2014, respectively. In the first quarter of 2015, the Company made a voluntary employer contribution of $10.0 million to the Chittenden Plan as a consequence of lower discount rates and the adoption of updated mortality tables. Employee Stock Ownership Plan In April 2007, People’s United established an ESOP. At that time, People’s United loaned the ESOP $216.8 million to purchase 10,453,575 shares of People’s United common stock in the open market. In order for the ESOP to repay the loan, People’s United expects to make annual cash contributions of approximately $18.8 million until 2036. Such cash contributions may be reduced by the cash dividends paid on unallocated ESOP shares, which totaled $3.8 million for the nine months ended September 30, 2015. The loan balance totaled $192.1 million at September 30, 2015. Employee participation in this plan is restricted to those employees who (i) are at least 18 years of age and (ii) worked at least 1,000 hours within 12 months of their hire date or any plan year (January 1 to December 31) after their date of hire. Employees meeting the aforementioned eligibility criteria during the plan year must continue to be employed as of the last day of the plan year in order to receive an allocation of shares for that plan year. Shares of People’s United common stock are held by the ESOP and allocated to eligible participants annually based upon a percentage of each participant’s eligible compensation. Since the ESOP was established, a total of 3,048,962 shares of People’s United common stock have been allocated or committed to be released to participants’ accounts. At September 30, 2015, 7,404,613 shares of People’s United common stock, with a fair value of $116.5 million at that date, have not been allocated or committed to be released. Compensation expense related to the ESOP is recognized at an amount equal to the number of common shares committed to be released by the ESOP for allocation to participants’ accounts multiplied by the average fair value of People’s United’s common stock during the reporting period. The difference between the fair value of the shares of People’s United’s common stock committed to be released and the cost of those common shares is recorded as a credit to additional paid-in capital (if fair value exceeds cost) or, to the extent that no such credits remain in additional paid-in capital, as a charge to retained earnings (if fair value is less than cost). Expense recognized for the ESOP totaled $4.0 million and $3.8 million for the nine months ended September 30, 2015 and 2014, respectively.

Legal Proceedings

Legal Proceedings	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	NOTE 8. LEGAL PROCEEDINGS In the normal course of business, People’s United is subject to various legal proceedings. Management has discussed with legal counsel the nature of the pending actions described below, as well as other legal proceedings. Based on the information currently available, advice of counsel, available insurance coverage and the recorded liability for probable legal settlements and costs, People’s United believes that the eventual outcome of these matters will not (individually or in the aggregate) have a material adverse effect on its financial condition, results of operations or liquidity. Litigation Relating to the Smithtown Transaction On February 25, 2010 and March 29, 2010, Smithtown and several of its officers and directors were named in lawsuits commenced in United States District Court, Eastern District of New York ( Waterford Township Police & Fire Retirement v. Smithtown Bancorp, Inc., et al. Yourgal v. Smithtown Bancorp, Inc. et al. Following extensive preliminary filings with the Court by both parties, an agreement in principle to settle this matter was reached on October 23, 2014, subject to completion of appropriate documentation and Court approval. On January 12, 2015, the plaintiffs filed a Motion for Preliminary Approval of the settlement with the Court. On April 17, 2015, the U.S. Magistrate Judge recommended that the Court overseeing the case preliminarily approve of the settlement. On September 28, 2015, the Court issued a final order approving the settlement, thus concluding this matter. The amount of the agreed upon settlement did not have a significant impact on the Company’s Consolidated Financial Statements.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	NOTE 9. SEGMENT INFORMATION See “Segment Results” included in Item 2 for segment information for the three and nine months ended September 30, 2015 and 2014.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 10. FAIR VALUE MEASUREMENTS Accounting standards related to fair value measurements define fair value, provide a framework for measuring fair value and establish related disclosure requirements. Broadly, fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Accordingly, an “exit price” approach is required in determining fair value. In support of this principle, a fair value hierarchy has been established that prioritizes the inputs used to measure fair value, requiring entities to maximize the use of market or observable inputs (as more reliable measures) and minimize the use of unobservable inputs. Observable inputs reflect market data obtained from independent sources, while unobservable inputs generally require significant management judgment. The three levels within the fair value hierarchy are as follows: • Level 1 – Unadjusted quoted market prices for identical assets or liabilities in active markets that the entity has the ability to access at the measurement date (such as active exchange-traded equity securities or mutual funds and certain U.S. and government agency debt securities). • Level 2 – Observable inputs other than quoted prices included in Level 1, such as: • quoted prices for similar assets or liabilities in active markets (such as U.S. agency and GSE issued mortgage-backed • quoted prices for identical or similar assets or liabilities in less active markets (such as certain U.S. and government agency debt securities, and corporate and municipal debt securities that trade infrequently); and • other inputs that (i) are observable for substantially the full term of the asset or liability (e.g. interest rates, yield curves, prepayment speeds, default rates, etc.) or (ii) can be corroborated by observable market data (such as interest rate and currency derivatives and certain other securities). • Level 3 – Valuation techniques that require unobservable inputs that are supported by little or no market activity and are significant to the fair value measurement of the asset or liability (such as pricing models, discounted cash flow methodologies and similar techniques that typically reflect management’s own estimates of the assumptions a market participant would use in pricing the asset or liability). People’s United maintains policies and procedures to value assets and liabilities using the most relevant data available. Described below are the valuation methodologies used by People’s United and the resulting fair values for those financial instruments measured at fair value on both a recurring and a non-recurring basis, as well as for those financial assets and financial liabilities not measured at fair value but for which fair value is disclosed. Recurring Fair Value Measurements Trading Account Securities and Securities Available For Sale When available, People’s United uses quoted market prices for identical securities received from an independent, nationally-recognized, Substantially all of the Company’s available-for-sale securities represent GSE residential mortgage-backed securities and CMOs. The fair values of these securities are based on prices obtained from the independent pricing service. The pricing service uses various techniques to determine pricing for the Company’s mortgage-backed securities, including option pricing and discounted cash flow analysis. The inputs include benchmark yields, reported trades, broker/dealer quotes, issuer spreads, benchmark securities, bids, offers, reference data, monthly payment information and collateral performance. At both September 30, 2015 and December 31, 2014, the entire available-for-sale residential mortgage-backed securities portfolio was comprised of 10- and 15-year GSE securities. An active market exists for securities that are similar to the Company’s GSE residential mortgage-backed securities and CMOs, making observable inputs readily available. Changes in the prices obtained from the pricing service are analyzed from month to month, taking into consideration changes in market conditions including changes in mortgage spreads, changes in U.S. Treasury security yields and changes in generic pricing of 15-year securities. As a further point of validation, the Company generates its own month-end fair value estimate for all mortgage-backed Other Assets As discussed in Note 7, certain unfunded, nonqualified supplemental benefit plans have been established to provide retirement benefits to certain senior officers. People’s United has funded two trusts to provide benefit payments to the extent such benefits are not paid directly by People’s United, the assets of which are included in other assets in the Consolidated Statements of Condition. When available, People’s United determines the fair value of the trust assets using quoted market prices for identical securities received from a third-party nationally recognized pricing service. Derivatives People’s United values its derivatives using internal models that are based on market or observable inputs including interest rate curves and forward/spot prices for selected currencies. Derivative assets and liabilities included in Level 2 represent interest rate swaps, foreign exchange contracts, risk participation agreements, forward commitments to sell residential mortgage loans and interest rate-lock commitments on residential mortgage loans. The following tables summarize People’s United’s financial instruments that are measured at fair value on a recurring basis: Fair Value Measurements Using As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Financial assets: Trading account securities: U.S. Treasury $ 8.3 $ — $ — $ 8.3 Securities available for sale: U.S. Treasury and agency 376.2 — — 376.2 GSE residential mortgage-backed securities and CMOs — 3,844.8 — 3,844.8 Equity securities — 0.2 — 0.2 Other assets: Exchange-traded funds 28.3 — — 28.3 Fixed income securities — 5.4 — 5.4 Mutual funds 1.6 — — 1.6 Interest rate swaps — 198.7 — 198.7 Foreign exchange contracts — 0.3 — 0.3 Forward commitments to sell residential mortgage loans — 1.2 — 1.2 Total $ 414.4 $ 4,050.6 $ — $ 4,465.0 Financial liabilities: Interest rate swaps $ — $ 146.6 $ — $ 146.6 Interest rate-lock commitments on residential mortgage loans — 1.5 — 1.5 Total $ — $ 148.1 $ — $ 148.1 Fair Value Measurements Using As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Financial assets: Trading account securities: U.S. Treasury $ 8.3 $ — $ — $ 8.3 Securities available for sale: U.S. Treasury and agency 56.8 — — 56.8 GSE residential mortgage-backed securities and CMOs — 3,936.7 — 3,936.7 Equity securities — 0.2 — 0.2 Other assets: Exchange-traded funds 30.3 — — 30.3 Fixed income securities — 6.0 — 6.0 Mutual funds 0.8 — — 0.8 Interest rate swaps — 131.1 — 131.1 Foreign exchange contracts — 0.8 — 0.8 Forward commitments to sell residential mortgage loans — 0.5 — 0.5 Total $ 96.2 $ 4,075.3 $ — $ 4,171.5 Financial liabilities: Interest rate swaps $ — $ 95.8 $ — $ 95.8 Foreign exchange contracts — 0.5 — 0.5 Interest rate-lock commitments on residential mortgage loans — 0.7 — 0.7 Total $ — $ 97.0 $ — $ 97.0 As of September 30, 2015 and December 31, 2014, the fair value of risk participation agreements totaled less than $0.1 million (see Note 11). There were no transfers into or out of the Level 1 or Level 2 categories during the nine months ended September 30, 2015 and 2014. Non-Recurring Fair Value Measurements Loans Held for Sale Residential mortgage loans held for sale are recorded at the lower of cost or fair value and are therefore measured at fair value on a non-recurring basis. When available, People’s United uses observable secondary market data, including pricing on recent closed market transactions for loans with similar characteristics. Accordingly, such loans are classified as Level 2 measurements. When observable data is unavailable, valuation methodologies using current market interest rate data adjusted for inherent credit risk are used, and such loans are included in Level 3. Impaired Loans Loan impairment is deemed to exist when full repayment of principal and interest according to the contractual terms of the loan is no longer probable. Impaired loans are reported based on one of three measures: the present value of expected future cash flows discounted at the loan’s original effective interest rate; the loan’s observable market price; or the fair value of the collateral (less estimated cost to sell) if the loan is collateral dependent. Accordingly, certain impaired loans may be subject to measurement at fair value on a non-recurring basis. People’s United has estimated the fair values of these assets using Level 3 inputs, such as discounted cash flows based on inputs that are largely unobservable and, instead, reflect management’s own estimates of the assumptions a market participant would use in pricing such loans and/or the fair value of collateral based on independent third-party appraisals for collateral-dependent loans. Such appraisals are based on the market and/or income approach to value and are subject to a discount (to reflect estimated cost to sell) that generally approximates 10%. REO and Repossessed Assets REO and repossessed assets are recorded at the lower of cost or fair value, less estimated selling costs, and are therefore measured at fair value on a non-recurring basis. People’s United has estimated the fair values of these assets using Level 3 inputs, such as independent third-party appraisals and price opinions. Such appraisals are based on the market and/or income approach to value and are subject to a discount (to reflect estimated cost to sell) that generally approximates 10%. Assets that are acquired through loan default are recorded as held for sale initially at the lower of the recorded investment in the loan or fair value (less estimated selling costs) upon the date of foreclosure/repossession. Subsequent to foreclosure/repossession, valuations are updated periodically and the carrying amounts of these assets may be reduced further. The following tables summarize People’s United’s assets that are measured at fair value on a non-recurring basis: Fair Value Measurements Using As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Loans held for sale (1) $ — $ 36.2 $ — $ 36.2 Impaired loans (2) — — 60.9 60.9 REO and repossessed assets (3) — — 26.3 26.3 Total $ — $ 36.2 $ 87.2 $ 123.4 Fair Value Measurements Using As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Loans held for sale (1) $ — $ 34.2 $ — $ 34.2 Impaired loans (2) — — 66.5 66.5 REO and repossessed assets (3) — — 27.1 27.1 Total $ — $ 34.2 $ 93.6 $ 127.8 (1) Consists of residential mortgage loans; no fair value adjustments were recorded for the nine months ended September 30, 2015 and 2014. (2) Represents the recorded investment in originated impaired loans with a related allowance for loan losses measured in accordance with applicable accounting guidance. The total consists of $44.3 million of Commercial loans and $16.6 million of Retail loans at September 30, 2015. The provision for loan losses on impaired loans totaled $6.0 million and $6.7 million for the nine months ended September 30, 2015 and 2014, respectively. (3) Represents: (i) $10.8 million of residential REO; (ii) $8.2 million of commercial REO; and (iii) $7.3 million of repossessed assets at September 30, 2015. Charge-offs to the allowance for loan losses related to loans that were transferred to REO or repossessed assets totaled $1.5 million and $1.0 million for the nine months ended September 30, 2015 and 2014, respectively. Write downs and net loss on sale of foreclosed/repossessed assets charged to non-interest expense totaled $1.2 million and $3.7 million for the same periods. Financial Assets and Financial Liabilities Not Measured At Fair Value As discussed previously, fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date (an “exit price” approach to fair value). Acceptable valuation techniques (when quoted market prices are not available) that might be used to estimate the fair value of financial instruments include discounted cash flow analyses and comparison to similar instruments. Such estimates are highly subjective and require judgments regarding significant matters such as the amount and timing of future cash flows and the selection of discount rates that appropriately reflect market and credit risks. Changes in these judgments often have a material impact on the fair value estimates. In addition, since these estimates are made as of a specific point in time, they are susceptible to material near-term changes. Fair values estimated in this manner do not reflect any premium or discount that could result from the sale of a large volume of a particular financial instrument, nor do they reflect possible tax ramifications or estimated transaction costs. The following is a description of the principal valuation methods used by People’s United for those financial instruments that are not measured at fair value either on a recurring or non-recurring basis: Cash, Short-Term Investments and Securities Purchased Under Agreements to Resell Cash and due from banks are classified as Level 1. Short-term investments and securities purchased under agreements to resell have fair values that approximate the respective carrying amounts because the instruments are payable on demand or have short-term maturities, and present relatively low credit risk and interest rate risk (“IRR”). As such, these fair values are classified as Level 2. Securities Held to Maturity When available, the fair values of investment securities held to maturity are measured based on quoted market prices for identical securities in active markets and, accordingly, are classified as Level 1 assets. When quoted market prices for identical securities are not available, fair values are estimated based on quoted prices for similar assets in active markets or through the use of pricing models containing observable inputs (i.e. market interest rates, financial information and credit ratings of the issuer, etc.). These fair values are included in Level 2. In cases where there may be limited information available and/or little or no market activity for the underlying security, fair value is estimated using pricing models containing unobservable inputs and classified as Level 3. FHLB and FRB Stock Both FHLB and FRB stock are non-marketable equity securities classified as Level 2 and reported at cost, which equals par value (the amount at which shares have been redeemed in the past). No significant observable market data is available for either of these securities. Loans For valuation purposes, the loan portfolio is segregated into its significant categories, which are commercial real estate, commercial and industrial, equipment financing, residential mortgage, home equity and other consumer. These categories are further segregated, where appropriate, into components based on significant financial characteristics such as type of interest rate (fixed or adjustable) and payment status (performing or non-performing). Fair values are estimated for each component using a valuation method selected by management. The fair values of performing loans were estimated by discounting the anticipated cash flows from the respective portfolios, assuming future prepayments and using market interest rates for new loans with comparable credit risk. As a result, the valuation method for performing loans, which is consistent with certain guidance provided in accounting standards, does not fully incorporate the “exit price” approach to fair value. The fair values of non-performing loans were based on recent collateral appraisals or management’s analysis of estimated cash flows discounted at rates commensurate with the credit risk involved. The estimated fair values of residential mortgage loans are classified as Level 2 as a result of the observable market inputs (i.e. market interest rates, prepayment assumptions, etc.) available for this loan type. The fair values of all other loan types are classified as Level 3 as the inputs contained within the respective discounted cash flow models are largely unobservable and, instead, reflect management’s own estimates of the assumptions a market participant would use in pricing such loans. The fair value of home equity lines of credit was based on the outstanding loan balances, and therefore does not reflect the value associated with earnings from future loans to existing customers. Deposit Liabilities The fair values of time deposits represent contractual cash flows discounted at current rates determined by reference to observable inputs including a LIBOR/swap curve over the remaining period to maturity. As such, these fair values are classified as Level 2. The fair values of other deposit liabilities (those with no stated maturity, such as checking and savings accounts) are equal to the carrying amounts payable on demand. Deposit fair values do not include the intangible value of core deposit relationships that comprise a significant portion of People’s United’s deposit base. Management believes that People’s United’s core deposit relationships provide a relatively stable, low-cost funding source that has a substantial intangible value separate from the deposit balances. Borrowings and Notes and Debentures The fair values of federal funds purchased and repurchase agreements are equal to the carrying amounts due to the short maturities (generally overnight). The fair values of FHLB advances and other borrowings represent contractual repayments discounted using interest rates currently available on borrowings with similar characteristics and remaining maturities and are classified as Level 2. The fair values of notes and debentures were based on dealer quotes and are classified as Level 2. Lending-Related Financial Instruments The estimated fair values of People’s United’s lending-related financial instruments approximate the respective carrying amounts. Such instruments include commitments to extend credit, unadvanced lines of credit and letters of credit, for which fair values were estimated based on an analysis of the interest rates and fees currently charged to enter into similar transactions, considering the remaining terms of the instruments and the creditworthiness of the potential borrowers. The following tables summarize the carrying amounts, estimated fair values and placement in the fair value hierarchy of People’s United’s financial instruments that are not measured at fair value either on a recurring or non-recurring basis: Estimated Fair Value Carrying Measurements Using As of September 30, 2015 (in millions) Amount Level 1 Level 2 Level 3 Total Financial assets: Cash and due from banks $ 300.3 $ 300.3 $ — $ — $ 300.3 Short-term investments 244.6 — 244.6 — 244.6 Securities held to maturity 1,377.1 — 1,420.1 1.5 1,421.6 FHLB and FRB stock 314.7 — 314.7 — 314.7 Total loans, net (1) 27,403.8 — 5,260.9 22,308.0 27,568.9 Financial liabilities: Time deposits 5,165.9 — 5,205.9 — 5,205.9 Other deposits 23,113.8 — 23,113.8 — 23,113.8 FHLB advances 2,164.5 — 2,172.6 — 2,172.6 Customer repurchase agreements 472.3 — 472.3 — 472.3 Federal funds purchased 360.0 — 360.0 — 360.0 Notes and debentures 1,044.9 — 1,018.3 — 1,018.3 (1) Excludes impaired loans totaling $60.9 million measured at fair value on a non-recurring basis. Estimated Fair Value Carrying Measurements Using As of December 31, 2014 (in millions) Amount Level 1 Level 2 Level 3 Total Financial assets: Cash and due from banks $ 345.1 $ 345.1 $ — $ — $ 345.1 Short-term investments 668.6 — 668.6 — 668.6 Securities purchased under agreements to resell 100.0 — 100.0 — 100.0 Securities held to maturity 834.3 — 880.1 1.5 881.6 FHLB stock 175.7 — 175.7 — 175.7 Total loans, net (1) 26,327.2 — 4,798.5 21,508.8 26,307.3 Financial liabilities: Time deposits 5,230.7 — 5,262.6 — 5,262.6 Other deposits 20,907.5 — 20,907.5 — 20,907.5 FHLB advances 2,291.7 — 2,298.5 — 2,298.5 Federal funds purchased 913.0 — 913.0 — 913.0 Customer repurchase agreements 486.0 — 486.0 — 486.0 Repurchase agreements (2) 1.0 — 1.0 — 1.0 Notes and debentures 1,033.5 — 1,040.8 — 1,040.8 (1) Excludes impaired loans totaling $66.5 million measured at fair value on a non-recurring basis. (2) Included in other borrowings in the Consolidated Statements of Condition.

Derivative Financial Instrument

Derivative Financial Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments and Hedging Activities	NOTE 11. DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES People’s United uses derivative financial instruments as components of its market risk management (principally to manage IRR). Certain other derivatives are entered into in connection with transactions with commercial customers. Derivatives are not used for speculative purposes. All derivatives are recognized as either assets or liabilities in the Consolidated Statements of Condition, reported at fair value and presented on a gross basis. Until a derivative is settled, a favorable change in fair value results in an unrealized gain that is recognized as an asset, while an unfavorable change in fair value results in an unrealized loss that is recognized as a liability. The Company generally applies hedge accounting to its derivatives used for market risk management purposes. Hedge accounting is permitted only if specific criteria are met, including a requirement that a highly effective relationship exist between the derivative instrument and the hedged item, both at inception of the hedge and on an ongoing basis. The hedge accounting method depends upon whether the derivative instrument is classified as a fair value hedge (i.e. hedging an exposure related to a recognized asset or liability, or a firm commitment) or a cash flow hedge (i.e. hedging an exposure related to the variability of future cash flows associated with a recognized asset or liability, or a forecasted transaction). Changes in the fair value of effective fair value hedges are recognized in current earnings (with the change in fair value of the hedged asset or liability also recorded in earnings). Changes in the fair value of effective cash flow hedges are recognized in other comprehensive income (loss) until earnings are affected by the variability in cash flows of the designated hedged item. Ineffective portions of hedge results are recognized in current earnings. Changes in the fair value of derivatives for which hedge accounting is not applied are recognized in current earnings. People’s United formally documents at inception all relationships between the derivative instruments and the hedged items, as well as its risk management objectives and strategies for undertaking the hedge transactions. This process includes linking all derivatives that are designated as hedges to specific assets and liabilities, or to specific firm commitments or forecasted transactions. People’s United also formally assesses, both at inception of the hedge and on an ongoing basis, whether the derivatives that are used in hedging transactions are highly effective in offsetting changes in the fair values or cash flows of the hedged items. If it is determined that a derivative is not highly effective or has ceased to be a highly effective hedge, People’s United would discontinue hedge accounting prospectively. Gains or losses resulting from the termination of a derivative accounted for as a cash flow hedge remain in accumulated other comprehensive income (loss) and are amortized to earnings over the remaining period of the former hedging relationship, provided the hedged item continues to be outstanding or it is probable the forecasted transaction will occur. People’s United uses the dollar offset method, regression analysis and scenario analysis to assess hedge effectiveness at inception and on an ongoing basis. Such methods are chosen based on the nature of the hedge strategy and are used consistently throughout the life of the hedging relationship. Certain derivative financial instruments are offered to commercial customers to assist them in meeting their financing and investing objectives and for their risk management purposes. These derivative financial instruments consist primarily of interest rate swaps, but also include foreign exchange contracts. The IRR associated with customer interest rate swaps is mitigated by entering into similar derivatives having essentially offsetting terms with institutional counterparties. Interest rate-lock commitments extended to borrowers relate to the origination of residential mortgage loans. To mitigate the IRR inherent in these commitments, People’s United enters into mandatory delivery and best efforts contracts to sell adjustable-rate and fixed-rate residential mortgage loans (servicing released). Forward commitments to sell and interest rate-lock commitments on residential mortgage loans are considered derivatives and their respective estimated fair values are adjusted based on changes in interest rates. Changes in the fair value of derivatives for which hedge accounting is not applied are recognized in current earnings, including customer derivatives, interest-rate lock commitments and forward sale commitments. By using derivatives, People’s United is exposed to credit risk to the extent that counterparties to the derivative contracts do not perform as required. Should a counterparty fail to perform under the terms of a derivative contract, the Company’s counterparty credit risk is equal to the amount reported as a derivative asset in the Consolidated Statements of Condition. In accordance with the Company’s balance sheet offsetting policy (see Note 12), amounts reported as derivative assets represent derivative contracts in a gain position, without consideration for derivative contracts in a loss position with the same counterparty (to the extent subject to master netting arrangements) and posted collateral. People’s United seeks to minimize counterparty credit risk through credit approvals, limits, monitoring procedures, execution of master netting arrangements and obtaining collateral, where appropriate. Counterparties to People’s United’s derivatives include major financial institutions and exchanges that undergo comprehensive and periodic internal credit analysis as well as maintain investment grade credit ratings from the major credit rating agencies. As such, management believes the risk of incurring credit losses on derivative contracts with those counterparties is remote and losses, if any, would be immaterial. Certain of People’s United’s derivative contracts contain provisions establishing collateral requirements (subject to minimum collateral posting thresholds) based on the Company’s external credit rating. If the Company’s senior unsecured debt rating were to fall below the level generally recognized as investment grade, the counterparties to such derivative contracts could require additional collateral on those derivative transactions in a net liability position (after considering the effect of master netting arrangements and posted collateral). The aggregate fair value of derivative instruments with such credit-related contingent features that were in a net liability position at September 30, 2015 was $11.8 million, for which People’s United had posted collateral of $11.3 million in the normal course of business. If the Company’s senior unsecured debt rating had fallen below investment grade as of that date, $0.5 million in additional collateral would have been required. The following sections further discuss each class of derivative financial instrument used by People’s United, including management’s principal objectives and risk management strategies. Interest Rate Swaps People’s United may, from time to time, enter into interest rate swaps that are used to manage IRR associated with certain interest-earning assets and interest-bearing liabilities. People’s United has entered into a pay fixed/receive floating interest rate swap to hedge the LIBOR-based floating rate payments on the Company’s $125 million subordinated notes (such payments began in February 2012). These notes had a fixed interest rate of 5.80% until February 2012, at which time the interest rate converted to the three-month LIBOR plus 68.5 basis points. People’s United has agreed with the swap counterparty to exchange, at specified intervals, the difference between fixed-rate (1.99%) and floating-rate interest amounts calculated based on a notional amount of $125 million. The floating-rate interest amounts received under the swap are calculated using the same floating-rate paid on these notes. The swap effectively converts the variable-rate The Bank has entered into a pay floating/receive fixed interest rate swap to hedge the change in fair value of the Bank’s $400 million subordinated notes due to changes in interest rates. The Bank has agreed with the swap counterparty to exchange, at specified intervals, the difference between fixed-rate and floating-rate interest amounts calculated based on a notional amount of $375 million. The fixed-rate interest payments received on the swap will essentially offset the fixed-rate interest payments made on these notes, notwithstanding the notional difference between these notes and the swap. The floating-rate interest amounts paid under the swap are calculated based on three-month LIBOR plus 126.5 basis points. The swap effectively converts the fixed-rate subordinated notes to a floating-rate liability. This swap is accounted for as a fair value hedge. Interest Rate Locks In connection with its planned issuance of senior notes in the fourth quarter of 2012, People’s United entered into U.S. Treasury forward interest rate locks (“T-Locks”) to hedge the risk that the 10-year U.S. Treasury yield component of the underlying coupon of the fixed rate senior notes would rise prior to establishing the fixed interest rate on the senior notes. Upon pricing the senior notes, the T-Locks were terminated and the unrealized gain of $0.9 million was included (on a net-of-tax basis) as a component of AOCL. The gain is being recognized as a reduction of interest expense over the ten-year period during which the hedged item ($500 million senior note issuance) affects earnings. Foreign Exchange Contracts Foreign exchange contracts are commitments to buy or sell foreign currency on a future date at a contractual price. People’s United uses these instruments on a limited basis to (i) eliminate its exposure to fluctuations in currency exchange rates on certain of its commercial loans that are denominated in foreign currencies and (ii) provide foreign exchange contracts on behalf of commercial customers within credit exposure limits. Gains and losses on foreign exchange contracts substantially offset the translation gains and losses on the related loans. Risk Participation Agreements People’s United enters into risk participation agreements under which it may either assume or sell credit risk associated with a borrower’s performance under certain interest rate derivative contracts. In those instances in which People’s United has assumed credit risk, it is not a party to the derivative contract and has entered into the risk participation agreement because it is also a party to the related loan agreement with the borrower. In those instances in which People’s United has sold credit risk, it is a party to the derivative contract and has entered into the risk participation agreement because it sold a portion of the related loan. People’s United manages its credit risk under risk participation agreements by monitoring the creditworthiness of the borrower, based on its normal credit review process. The notional amounts of the risk participation agreements reflect People’s United’s pro-rata share of the derivative contracts, consistent with its share of the related loans. Customer Derivatives People’s United enters into interest rate swaps with certain of its commercial customers. In order to minimize its risk, these customer derivatives (pay floating/receive fixed swaps) have been offset with essentially matching interest rate swaps with People’s United’s institutional counterparties (pay fixed/receive floating swaps). Hedge accounting has not been applied for these derivatives. Accordingly, changes in the fair value of all such swaps are recognized in current earnings. Forward Commitments to Sell Residential Mortgage Loans and Related Interest Rate-Lock Commitments People’s United enters into forward commitments to sell adjustable-rate and fixed-rate residential mortgage loans (all to be sold servicing released) in order to reduce the market risk associated with originating loans for sale in the secondary market. In order to fulfill a forward commitment, People’s United delivers originated loans at prices or yields specified by the contract. The risks associated with such contracts arise from the possible inability of counterparties to meet the contract terms or People’s United’s inability to originate the necessary loans. Gains and losses realized on the forward contracts are reported in the Consolidated Statements of Income as a component of the net gains on sales of residential mortgage loans. In the normal course of business, People’s United will commit to an interest rate on a mortgage loan application at the time of application, or anytime thereafter. The risks associated with these interest rate-lock commitments arise if market interest rates change prior to the closing of these loans. Both forward sales commitments and interest rate-lock commitments made to borrowers on held-for-sale loans are accounted for as derivatives, with changes in fair value recognized in current earnings. The table below provides a summary of the notional amounts and fair values (presented on a gross basis) of derivatives outstanding: Fair Values (1) Notional Amounts Assets Liabilities (in millions) Type of Sept. 30, Dec. 31, Sept. 30, Dec. 31, Sept. 30, Dec. 31, Derivatives Not Designated as Hedging Instruments: Interest rate swaps: Commercial customers N/A $ 4,287.5 $ 3,380.2 $ 172.1 $ 104.2 $ 1.0 $ 8.3 Institutional counterparties N/A 4,287.5 3,380.2 1.3 11.8 144.4 86.5 Risk participation agreements (2) N/A 240.4 150.1 — — — — Foreign exchange contracts N/A 46.9 49.6 0.3 0.8 — 0.5 Forward commitments to sell residential mortgage loans N/A 62.3 35.3 1.2 0.5 — — Interest rate-lock commitments on residential mortgage loans N/A 83.4 57.5 — — 1.5 0.7 Total 174.9 117.3 146.9 96.0 Derivatives Designated as Hedging Instruments: Interest rate swaps: Subordinated notes Cash flow 125.0 125.0 — — 1.2 1.0 Subordinated notes Fair value 375.0 375.0 25.3 15.1 — — Total 25.3 15.1 1.2 1.0 Total derivatives $ 200.2 $ 132.4 $ 148.1 $ 97.0 (1) Assets are recorded in other assets and liabilities are recorded in other liabilities. (2) Fair value totaled less than $0.1 million at both dates. The following table summarizes the impact of People’s United’s derivatives on pre-tax income and AOCL: Amount of Pre-Tax Gain (Loss) Amount of Pre-Tax Gain (Loss) Type of Recognized in Earnings (1) Recognized in AOCL Nine months ended September 30 (in millions) Hedge 2015 2014 2015 2014 Derivatives Not Designated as Hedging Instruments: Interest rate swaps: Commercial customers N/A $ 127.8 $ 100.1 $ — $ — Institutional counterparties N/A (116.9 ) (94.6 ) — — Foreign exchange contracts N/A — 0.4 — — Risk participation agreements N/A (0.2 ) (0.1 ) — — Forward commitments to sell residential mortgage loans N/A 0.7 0.2 — — Interest rate-lock commitments on residential mortgage loans N/A (0.8 ) (0.3 ) — — Total 10.6 5.7 — — Derivatives Designated as Hedging Instruments: Interest rate swaps Cash flow (1.0 ) (1.0 ) (1.2 ) (0.4 ) Interest rate locks Cash flow 0.1 0.1 — — Interest rate swaps Fair value 6.9 2.3 — — Total 6.0 1.4 (1.2 ) (0.4 ) Total derivatives $ 16.6 $ 7.1 $ (1.2 ) $ (0.4 ) (1) Amounts recognized in earnings are recorded in interest income, interest expense or other non-interest income for derivatives designated as hedging instruments and in other non-interest income for derivatives not designated as hedging instruments.

Balance Sheet Offsetting

Balance Sheet Offsetting	9 Months Ended
	Sep. 30, 2015
Text Block [Abstract]
Balance Sheet Offsetting	NOTE 12. BALANCE SHEET OFFSETTING Assets and liabilities relating to certain financial instruments, including derivatives, may be eligible for offset in the Consolidated Statements of Condition and/or subject to enforceable master netting arrangements or similar agreements. People’s United’s derivative transactions with institutional counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements, which include “right of set-off” provisions that provide for a single net settlement of all interest rate swap positions, as well as collateral, in the event of default on, or the termination of, any one contract. Nonetheless, the Company does not offset asset and liabilities under such arrangements in the Consolidated Statements of Condition. Collateral (generally in the form of marketable debt securities) pledged by counterparties in connection with derivative transactions is not reported in the Consolidated Statements of Condition unless the counterparty defaults. Collateral that has been pledged by People’s United to counterparties continues to be reported in the Consolidated Statements of Condition unless the Company defaults. The following tables provide a gross presentation, the effects of offsetting, and a net presentation of the Company’s financial instruments that are eligible for offset in the Consolidated Statements of Condition. The collateral amounts in these tables are limited to the outstanding balances of the related asset or liability (after netting is applied) and, therefore, instances of overcollateralization are not presented. The net amounts of the derivative assets and liabilities can be reconciled to the fair value of the Company’s derivative financial instruments in Note 11. The Company’s derivative contracts with commercial customers and customer repurchase agreements are not subject to master netting arrangements and, therefore, have been excluded from the tables below. Gross Gross Net Gross Amounts Not Offset As of September 30, 2015 (in millions) Amount Amount Amount Financial Collateral Net Amount Financial assets: Interest rate swaps: Counterparty A $ 0.2 $ — $ 0.2 $ (0.2 ) $ — $ — Counterparty B 0.4 — 0.4 (0.4 ) — — Counterparty C — — — — — — Counterparty D 0.5 — 0.5 (0.5 ) — — Counterparty E 25.5 — 25.5 (25.5 ) — — Other counterparties — — — — — — Foreign exchange contracts 0.3 — 0.3 — — 0.3 Total $ 26.9 $ — $ 26.9 $ (26.6 ) $ — $ 0.3 Financial liabilities: Interest rate swaps: Counterparty A $ 11.7 $ — $ 11.7 $ (0.2 ) $ (11.5 ) $ — Counterparty B 13.4 — 13.4 (0.4 ) (13.0 ) — Counterparty C 7.1 — 7.1 — (7.0 ) 0.1 Counterparty D 11.1 — 11.1 (0.5 ) (9.9 ) 0.7 Counterparty E 95.9 — 95.9 (25.5 ) (70.4 ) — Other counterparties 6.4 — 6.4 — (6.3 ) 0.1 Total $ 145.6 $ — $ 145.6 $ (26.6 ) $ (118.1 ) $ 0.9 Gross Gross Net Gross Amounts Not Offset As of December 31, 2014 (in millions) Amount Amount Amount Financial Collateral Net Amount Financial assets: Interest rate swaps: Counterparty A $ 2.7 $ — $ 2.7 $ (2.7 ) $ — $ — Counterparty B 1.5 — 1.5 (1.5 ) — — Counterparty C 2.5 — 2.5 (2.5 ) — — Counterparty D 3.2 — 3.2 (0.4 ) (2.8 ) — Counterparty E 15.7 — 15.7 (15.7 ) — — Other counterparties 1.3 — 1.3 (1.3 ) — — Securities purchased under agreements to resell 100.0 — 100.0 — (100.0 ) — Foreign exchange contracts 0.8 — 0.8 — — 0.8 Total $ 127.7 $ — $ 127.7 $ (24.1 ) $ (102.8 ) $ 0.8 Financial liabilities: Interest rate swaps: Counterparty A $ 11.8 $ — $ 11.8 $ (2.7 ) $ (9.1 ) $ — Counterparty B 11.8 — 11.8 (1.5 ) (10.3 ) — Counterparty C 4.5 — 4.5 (2.5 ) (1.9 ) 0.1 Counterparty D 0.4 — 0.4 (0.4 ) — — Counterparty E 47.8 — 47.8 (15.7 ) (32.1 ) — Other counterparties 11.2 — 11.2 (1.3 ) (8.9 ) 1.0 Repurchase agreements (1) 1.0 — 1.0 — (1.0 ) — Foreign exchange contracts 0.5 — 0.5 — — 0.5 Total $ 89.0 $ — $ 89.0 $ (24.1 ) $ (63.3 ) $ 1.6 (1) Included in other borrowings in the Consolidated Statements of Condition.

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2015
Accounting Changes and Error Corrections [Abstract]
New Accounting Standards	NOTE 13. NEW ACCOUNTING STANDARDS Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans Upon Foreclosure In January 2014, the Financial Accounting Standards Board (the “FASB”) amended its standards with respect to the accounting for consumer mortgage loans collateralized by residential real estate to clarify that such loans should, upon foreclosure, be reclassified by a creditor as REO when either (i) the creditor obtains legal title to the real estate collateral or (ii) a deed in lieu of foreclosure, conveying all interest in the real estate to the creditor, is completed. In addition, the amendment requires a creditor to provide additional disclosures with respect to (i) the amount of residential real estate meeting the conditions set forth above and (ii) the recorded investment in consumer mortgage loans secured by residential real estate properties that are in the process of foreclosure. This amendment, which is being applied prospectively, became effective for People’s United on January 1, 2015 and did not have a significant impact on the Company’s Consolidated Financial Statements. Revenue Recognition In May 2014, the FASB amended its standards with respect to revenue recognition. The amended guidance serves to replace all current U.S. GAAP guidance on this topic and eliminate all industry-specific guidance, providing a unified model to determine when and how revenue is recognized. The underlying principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The amendments also require enhanced disclosures regarding the nature, amount, timing and uncertainty of revenue and cash flows arising from an entity’s contracts with customers. As originally issued, this new guidance, which can be applied retrospectively or through the use of the cumulative effect transition method, was to become effective for fiscal years, and interim periods within those fiscal years, beginning on or after December 15, 2016 (January 1, 2017 for People’s United) and early adoption was not permitted. In July 2015, the FASB approved a one-year deferral of the effective date (to January 1, 2018 for People’s United) with early adoption, as of the original effective date, permitted. The Company is currently evaluating the impact of the amended guidance on the Company’s Consolidated Financial Statements. Repurchase Agreements In June 2014, the FASB amended its standards with respect to repurchase agreements to (i) require that repurchase-to-maturity transactions be accounted for as secured borrowings, thereby eliminating the possibility of such transactions qualifying for sale accounting treatment, and (ii) eliminate existing guidance for repurchase financings. The amendment also requires enhanced disclosures for certain transactions accounted for as secured borrowings and transfers accounted for as sales when the transferor also retains substantially all of the exposure to the economic return on the transferred financial assets throughout the term of the transaction. In adopting this new guidance, all entities must report changes in accounting for transactions outstanding on the effective date as a cumulative-effect adjustment to retained earnings as of the beginning of the period of adoption. This amendment became effective for People’s United on January 1, 2015 and did not have a significant impact on the Company’s Consolidated Financial Statements as none of the Company’s repurchase agreements represent repurchase-to-maturity transactions or repurchase financings and all repurchase agreements have been accounted for as secured borrowings. Stock Compensation In June 2014, the FASB amended its standards with respect to stock compensation to require that a performance target that affects vesting, and that could be achieved after the requisite service period, be treated as a performance condition. As such, the performance target should not be reflected in estimating the grant date fair value of the award. The amendment further clarifies that compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to those periods for which the requisite service has already been rendered. This new guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for People’s United) and can be applied either prospectively or retrospectively to all awards outstanding as of the beginning of the earliest annual period presented as an adjustment to opening retained earnings. The adoption of this amendment, for which early adoption is permitted, is not expected to have a significant impact on the Company’s Consolidated Financial Statements. Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure In August 2014, the FASB amended its standards with respect to the classification of certain government-guaranteed residential mortgage loans to clarify that upon foreclosure of mortgage loans within the scope of the standard, a creditor will be required to reclassify the previously existing mortgage loan to a separate receivable from the guarantor, measured at the amount of the guarantee that it expects to collect. This amendment, which is being applied prospectively, became effective for People’s United on January 1, 2015 and did not have a significant impact on the Company’s Consolidated Financial Statements. Consolidation In February 2015, the FASB amended its standards with respect to the analysis that a reporting entity must perform in determining whether certain types of legal entities should be consolidated. The amendment modifies the evaluation of whether limited partnerships or similar legal entities are variable interest entities (“VIEs”) or voting interest entities, eliminates the presumption that a general partner should consolidate a limited partnership and affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships. This new guidance, which can be applied retrospectively or through the use of the cumulative effect transition method, is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for People’s United) with early adoption permitted. The Company is currently evaluating the impact of the amended guidance on the Company’s Consolidated Financial Statements. Presentation of Debt Issuance Costs In April 2015, the FASB amended its standards with respect to the presentation of debt issuance costs by changing the required presentation of such costs from an asset on the balance sheet to a deduction from the related debt liability. For public business entities this new guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for People’s United) and is to be applied retrospectively. The adoption of this amendment is not expected to have a significant impact on the Company’s Consolidated Financial Statements. Retirement Benefits In April 2015, the FASB amended its standards with respect to the accounting for retirement benefits by providing a practical expedient, for entities with fiscal year-ends that do not coincide with a month-end, permitting such entities to measure defined benefit plan assets and obligations using the month-end that is closest to its fiscal year-end. This practical expedient is to be applied consistently from year to year and to all plans if an entity has more than one plan. Further, in cases where a significant event caused by the entity (such as a plan amendment, curtailment or settlement) that requires the remeasurement of defined benefit plan assets and obligations does not coincide with a month-end, entities may elect to remeasure both plan assets and obligations using the month-end that is closest to the date of the significant event. These amendments are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015 (January 1, 2016 for People’s United) and are to be applied prospectively. The adoption of this new guidance is not expected to have a significant impact on the Company’s Consolidated Financial Statements. Business Combinations In September 2015, the FASB amended its standards with respect to business combinations to eliminate the requirement to restate prior period financial statements for measurement period adjustments. Instead, the amended guidance requires that, during the measurement period, an acquirer recognize adjustments of previously recorded provisional amounts in the reporting period in which such adjustments are determined. In doing so, the acquirer would be required to record the cumulative effect of measurement period adjustments on current and prior period earnings, including the prior period impact on depreciation, amortization or other income statement items. The amended standard also contains additional disclosure requirements with respect to measurement period adjustments. This new guidance is effective for fiscal years beginning after December 15, 2015 (January 1, 2016 for People’s United) and is to be applied prospectively. Earlier application is permitted for financial statements that have not yet been made available for issuance. The adoption of this amendment is not expected to have a significant impact on the Company’s Consolidated Financial Statements.

Securities and Short-Term Inv22

Securities and Short-Term Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Available-for-Sale and Held-to-Maturity Securities Gains (Losses)	The amortized cost, gross unrealized gains and losses, and fair value of People’s United’s securities available for sale and securities held to maturity are as follows: As of September 30, 2015 (in millions) Amortized Gross Gross Fair Securities available for sale: Debt securities: U.S. Treasury and agency $ 374.1 $ 2.1 $ — $ 376.2 GSE (1) residential mortgage-backed securities and CMOs (2) 3,823.3 40.5 (19.0 ) 3,844.8 Total debt securities 4,197.4 42.6 (19.0 ) 4,221.0 Equity securities 0.2 — — 0.2 Total securities available for sale $ 4,197.6 $ 42.6 $ (19.0 ) $ 4,221.2 Securities held to maturity: Debt securities: State and municipal $ 946.3 $ 43.7 $ (1.6 ) $ 988.4 GSE residential mortgage-backed securities 429.3 2.4 — 431.7 Other 1.5 — — 1.5 Total securities held to maturity $ 1,377.1 $ 46.1 $ (1.6 ) $ 1,421.6 (1) Government sponsored enterprise (2) Collateralized mortgage obligations As of December 31, 2014 (in millions) Amortized Gross Gross Fair Securities available for sale: Debt securities: U.S. Treasury and agency $ 56.5 $ 0.3 $ — $ 56.8 GSE residential mortgage-backed securities and CMOs 3,943.4 39.7 (46.4 ) 3,936.7 Total debt securities 3,999.9 40.0 (46.4 ) 3,993.5 Equity securities 0.2 — — 0.2 Total securities available for sale $ 4,000.1 $ 40.0 $ (46.4 ) $ 3,993.7 Securities held to maturity: Debt securities: State and municipal $ 832.8 $ 47.4 $ (0.1 ) $ 880.1 Other 1.5 — — 1.5 Total securities held to maturity $ 834.3 $ 47.4 $ (0.1 ) $ 881.6
Summary of Amortized Cost and Fair Value of Debt Securities Based on Remaining Period to Contractual Maturity	The following table is a summary of the amortized cost and fair value of debt securities as of September 30, 2015, based on remaining period to contractual maturity. Information for GSE residential mortgage-backed securities and CMOs is based on the final contractual maturity dates without considering repayments and prepayments. Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair U.S. Treasury and agency: Within 1 year $ 41.1 $ 41.2 $ — $ — After 1 but within 5 years 333.0 335.0 — — Total 374.1 376.2 — — GSE residential mortgage-backed securities and CMOs: After 5 but within 10 years 742.6 755.3 — — After 10 years 3,080.7 3,089.5 429.3 431.7 Total 3,823.3 3,844.8 429.3 431.7 State and municipal: Within 1 year — — 3.8 3.8 After 1 but within 5 years — — 21.6 21.9 After 5 but within 10 years — — 323.5 342.7 After 10 years — — 597.4 620.0 Total — — 946.3 988.4 Other: After 1 but within 5 years — — 1.5 1.5 Total — — 1.5 1.5 Total: Within 1 year 41.1 41.2 3.8 3.8 After 1 but within 5 years 333.0 335.0 23.1 23.4 After 5 but within 10 years 742.6 755.3 323.5 342.7 After 10 years 3,080.7 3,089.5 1,026.7 1,051.7 Total $ 4,197.4 $ 4,221.0 $ 1,377.1 $ 1,421.6
Continuous Unrealized Loss Position on Available-for-Sale and Held-to-Maturities Securities	The following tables summarize debt securities with unrealized losses, segregated by the length of time the securities have been in a continuous unrealized loss position at the respective dates. Continuous Unrealized Loss Position Less Than 12 Months 12 Months Or Longer Total As of September 30, 2015 (in millions) Fair Unrealized Fair Unrealized Fair Unrealized Securities available for sale: GSE residential mortgage-backed securities and CMOs $ 776.2 $ (2.8 ) $ 993.9 $ (16.2 ) $ 1,770.1 $ (19.0 ) Securities held to maturity: State and municipal 129.4 (1.6 ) — — 129.4 (1.6 ) Total $ 905.6 $ (4.4 ) $ 993.9 $ (16.2 ) $ 1,899.5 $ (20.6 ) Continuous Unrealized Loss Position Less Than 12 Months 12 Months Or Longer Total As of December 31, 2014 (in millions) Fair Unrealized Fair Unrealized Fair Unrealized Securities available for sale: GSE residential mortgage-backed securities and CMOs $ 111.9 $ (0.1 ) $ 1,744.2 $ (46.3 ) $ 1,856.1 $ (46.4 ) Securities held to maturity: State and municipal 31.8 (0.1 ) — — 31.8 (0.1 ) Total $ 143.7 $ (0.2 ) $ 1,744.2 $ (46.3 ) $ 1,887.9 $ (46.5 )

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2015
Receivables [Abstract]
Summary of Loans by Loan Portfolio Segment and Class	The following table summarizes People’s United’s loans by loan portfolio segment and class: September 30, 2015 December 31, 2014 (in millions) Originated Acquired Total Originated Acquired Total Commercial: Commercial real estate $ 9,436.7 $ 348.7 $ 9,785.4 $ 8,960.3 $ 444.0 $ 9,404.3 Commercial and industrial 7,257.2 235.0 7,492.2 6,891.1 298.5 7,189.6 Equipment financing 2,802.4 18.7 2,821.1 2,839.0 26.5 2,865.5 Total commercial 10,059.6 253.7 10,313.3 9,730.1 325.0 10,055.1 Total Commercial Portfolio 19,496.3 602.4 20,098.7 18,690.4 769.0 19,459.4 Retail: Residential mortgage: Adjustable-rate 4,655.7 125.4 4,781.1 4,254.7 139.1 4,393.8 Fixed-rate 527.5 72.8 600.3 446.8 91.4 538.2 Total residential mortgage 5,183.2 198.2 5,381.4 4,701.5 230.5 4,932.0 Consumer: Home equity 2,101.3 39.9 2,141.2 2,092.9 50.2 2,143.1 Other consumer 49.9 1.0 50.9 56.3 1.2 57.5 Total consumer 2,151.2 40.9 2,192.1 2,149.2 51.4 2,200.6 Total Retail Portfolio 7,334.4 239.1 7,573.5 6,850.7 281.9 7,132.6 Total loans $ 26,830.7 $ 841.5 $ 27,672.2 $ 25,541.1 $ 1,050.9 $ 26,592.0
Summary, by Loan Portfolio Segment, of Activity in Allowance for Loan Losses	Three months ended Commercial Retail September 30, 2015 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 176.4 $ 10.1 $ 186.5 $ 18.7 $ 0.2 $ 18.9 $ 205.4 Charge-offs (4.1 ) — (4.1 ) (2.0 ) — (2.0 ) (6.1 ) Recoveries 1.2 — 1.2 0.8 — 0.8 2.0 Net loan charge-offs (2.9 ) — (2.9 ) (1.2 ) — (1.2 ) (4.1 ) Provision for loan losses 3.8 (0.9 ) 2.9 3.3 — 3.3 6.2 Balance at end of period $ 177.3 $ 9.2 $ 186.5 $ 20.8 $ 0.2 $ 21.0 $ 207.5 Nine months ended Commercial Retail September 30, 2015 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 169.6 $ 9.8 $ 179.4 $ 18.5 $ 0.4 $ 18.9 $ 198.3 Charge-offs (14.4 ) — (14.4 ) (5.8 ) — (5.8 ) (20.2 ) Recoveries 4.0 — 4.0 1.7 — 1.7 5.7 Net loan charge-offs (10.4 ) — (10.4 ) (4.1 ) — (4.1 ) (14.5 ) Provision for loan losses 18.1 (0.6 ) 17.5 6.4 (0.2 ) 6.2 23.7 Balance at end of period $ 177.3 $ 9.2 $ 186.5 $ 20.8 $ 0.2 $ 21.0 $ 207.5 Three months ended Commercial Retail September 30, 2014 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 163.5 $ 9.6 $ 173.1 $ 19.0 $ 0.5 $ 19.5 $ 192.6 Charge-offs (6.2 ) (0.2 ) (6.4 ) (2.9 ) — (2.9 ) (9.3 ) Recoveries 0.5 — 0.5 0.7 — 0.7 1.2 Net loan charge-offs (5.7 ) (0.2 ) (5.9 ) (2.2 ) — (2.2 ) (8.1 ) Provision for loan losses 8.2 2.1 10.3 2.2 (0.1 ) 2.1 12.4 Balance at end of period $ 166.0 $ 11.5 $ 177.5 $ 19.0 $ 0.4 $ 19.4 $ 196.9 Nine months ended Commercial Retail September 30, 2014 (in millions) Originated Acquired Total Originated Acquired Total Total Balance at beginning of period $ 158.5 $ 9.8 $ 168.3 $ 19.0 $ 0.5 $ 19.5 $ 187.8 Charge-offs (15.3 ) (2.6 ) (17.9 ) (8.3 ) (0.1 ) (8.4 ) (26.3 ) Recoveries 3.1 — 3.1 1.6 — 1.6 4.7 Net loan charge-offs (12.2 ) (2.6 ) (14.8 ) (6.7 ) (0.1 ) (6.8 ) (21.6 ) Provision for loan losses 19.7 4.3 24.0 6.7 — 6.7 30.7 Balance at end of period $ 166.0 $ 11.5 $ 177.5 $ 19.0 $ 0.4 $ 19.4 $ 196.9
Summary of Allowance for Loan Losses by Loan Portfolio Segment and Impairment Methodology	The following is a summary, by loan portfolio segment and impairment methodology, of the allowance for loan losses and related portfolio balances: As of September 30, 2015 Originated Loans Originated Loans Acquired Loans Total (in millions) Portfolio Allowance Portfolio Allowance Portfolio Allowance Portfolio Allowance Commercial $ 169.0 $ 8.2 $ 19,327.3 $ 169.1 $ 602.4 $ 9.2 $ 20,098.7 $ 186.5 Retail 97.2 3.7 7,237.2 17.1 239.1 0.2 7,573.5 21.0 Total $ 266.2 $ 11.9 $ 26,564.5 $ 186.2 $ 841.5 $ 9.4 $ 27,672.2 $ 207.5 As of December 31, 2014 Originated Loans Originated Loans Acquired Loans Total (in millions) Portfolio Allowance Portfolio Allowance Portfolio Allowance Portfolio Allowance Commercial $ 174.5 $ 7.6 $ 18,515.9 $ 162.0 $ 769.0 $ 9.8 $ 19,459.4 $ 179.4 Retail 95.0 3.9 6,755.7 14.6 281.9 0.4 7,132.6 18.9 Total $ 269.5 $ 11.5 $ 25,271.6 $ 176.6 $ 1,050.9 $ 10.2 $ 26,592.0 $ 198.3
Summarized Recorded Investments, by Class of Loan, of Originated Non-Performing Loans	The recorded investments, by class of loan, of originated non-performing loans are summarized as follows: (in millions) September 30, December 31, Commercial: Commercial and industrial $ 62.9 $ 55.8 Commercial real estate 31.8 60.2 Equipment financing 29.4 25.4 Total (1) 124.1 141.4 Retail: Residential mortgage 38.2 37.6 Home equity 21.0 17.9 Other consumer — 0.1 Total (2) 59.2 55.6 Total $ 183.3 $ 197.0 (1) Reported net of government guarantees totaling $17.3 million and $17.6 million at September 30, 2015 and December 31, 2014, respectively. These government guarantees relate, almost entirely, to guarantees provided by the Small Business Administration as well as selected other Federal agencies and represent the carrying value of the loans that are covered by such guarantees, the extent of which (i.e. full or partial) varies by loan. At September 30, 2015, the principal loan classes to which these government guarantees relate are commercial and industrial loans (99%) and commercial real estate loans (1%). (2) Includes $19.8 million and $18.9 million of loans in the process of foreclosure at September 30, 2015 and December 31, 2014, respectively.
Summary of Recorded Investments in TDRs by Class of Loan	The following tables summarize, by class of loan, the recorded investments in loans modified as TDRs during the three and nine months ended September 30, 2015 and 2014. For purposes of this disclosure, recorded investments represent amounts immediately prior to and subsequent to the restructuring. Three Months Ended September 30, 2015 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 10 $ 7.0 $ 7.0 Commercial and industrial (2) 7 24.4 24.4 Equipment financing (3) 8 4.2 4.2 Total 25 35.6 35.6 Retail: Residential mortgage (4) 15 5.0 5.0 Home equity (5) 17 1.3 1.3 Other consumer — — — Total 32 6.3 6.3 Total 57 $ 41.9 $ 41.9 (1) Represents the following concessions: extension of term (7 contracts; recorded investment of $2.1 million); reduced payment and/or payment deferral (2 contracts; recorded investment of $1.2 million); or a combination of concessions (1 contract; recorded investment of $3.7 million). (2) Represents the following concessions: extension of term (3 contracts; recorded investment of $9.8 million); reduced payment and/or payment deferral (3 contracts; recorded investment of $13.6 million); or a combination of concessions (1 contract; recorded investment of $1.0 million). (3) Represents the following concessions: reduced payment and/or payment deferral (3 contracts; recorded investment of $2.0 million); or a combination of concessions (5 contracts; recorded investment of $2.2 million). (4) Represents the following concessions: loans restructured through bankruptcy (6 contracts; recorded investment of $1.2 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.8 million); or a combination of concessions (5 contracts; recorded investment of $3.0 million). (5) Represents the following concessions: loans restructured through bankruptcy (12 contracts; recorded investment of $0.9 million); reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million); or a combination of concessions (4 contracts; recorded investment of $0.3 million). Nine Months Ended September 30, 2015 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 20 $ 12.3 $ 12.3 Commercial and industrial (2) 35 59.2 59.2 Equipment financing (3) 18 19.6 19.6 Total 73 91.1 91.1 Retail: Residential mortgage (4) 50 16.9 16.9 Home equity (5) 70 6.2 6.2 Other consumer — — — Total 120 23.1 23.1 Total 193 $ 114.2 $ 114.2 (1) Represents the following concessions: extension of term (17 contracts; recorded investment of $7.4 million); reduced payment and/or payment deferral (2 contracts; recorded investment of $1.2 million); or a combination of concessions (1 contract; recorded investment of $3.7 million). (2) Represents the following concessions: extension of term (19 contracts; recorded investment of $22.9 million); reduced payment and/or payment deferral (11 contracts; recorded investment of $33.0 million); or a combination of concessions (5 contracts; recorded investment of $3.3 million). (3) Represents the following concessions: reduced payment and/or payment deferral (8 contracts; recorded investment of $12.7 million); or a combination of concessions (10 contracts; recorded investment of $6.9 million). (4) Represents the following concessions: loans restructured through bankruptcy (16 contracts; recorded investment of $5.1 million); reduced payment and/or payment deferral (11 contracts; recorded investment of $3.6 million); temporary rate reduction (2 contracts; recorded investment of $0.3 million); or a combination of concessions (21 contracts; recorded investment of $7.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (48 contracts; recorded investment of $3.8 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.3 million); temporary rate reduction (1 contract; recorded investment of $0.5 million); or a combination of concessions (17 contracts; recorded investment of $1.6 million). Three Months Ended September 30, 2014 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 9 $ 5.8 $ 5.8 Commercial and industrial (2) 7 2.9 2.9 Equipment financing (3) 6 1.4 1.4 Total 22 10.1 10.1 Retail: Residential mortgage (4) 28 6.6 6.6 Home equity (5) 36 3.3 3.3 Other consumer — — — Total 64 9.9 9.9 Total 86 $ 20.0 $ 20.0 (1) Represents the following concessions: extension of term (8 contracts; recorded investment of $5.5 million); or reduced payment and/or payment deferral (1 contract; recorded investment of $0.3 million). (2) Represents the following concessions: extension of term (6 contracts; recorded investment of $2.8 million); or reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million). (3) Represents the following concessions: reduced payment and/or payment deferral (1 contract; recorded investment of $0.1 million); or a combination of concessions (5 contracts; recorded investment of $1.3 million). (4) Represents the following concessions: loans restructured through bankruptcy (11 contracts; recorded investment of $1.0 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $0.7 million); or a combination of concessions (13 contracts; recorded investment of $4.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (22 contracts; recorded investment of $1.6 million); reduced payment and/or payment deferral (7 contracts; recorded investment of $0.8 million); temporary rate reduction (1 contract; recorded investment of $0.5 million); or a combination of concessions (6 contracts; recorded investment of $0.4 million). Nine Months Ended September 30, 2014 (dollars in millions) Number Pre-Modification Post-Modification Commercial: Commercial real estate (1) 22 $ 32.1 $ 32.1 Commercial and industrial (2) 36 27.2 27.2 Equipment financing (3) 17 5.1 5.1 Total 75 64.4 64.4 Retail: Residential mortgage (4) 113 32.0 32.0 Home equity (5) 108 10.2 10.2 Other consumer — — — Total 221 42.2 42.2 Total 296 $ 106.6 $ 106.6 (1) Represents the following concessions: extension of term (14 contracts; recorded investment of $10.9 million); reduced payment and/or payment deferral (4 contracts; recorded investment of $1.8 million); temporary rate reduction (1 contract; recorded investment of $18.2 million); or a combination of concessions (3 contracts; recorded investment of $1.2 million). (2) Represents the following concessions: extension of term (13 contracts; recorded investment of $5.9 million); reduced payment and/or payment deferral (8 contracts; recorded investment of $2.5 million); or a combination of concessions (15 contracts; recorded investment of $18.8 million). (3) Represents the following concessions: reduced payment and/or payment deferral (2 contracts; recorded investment of $0.3 million); or a combination of concessions (15 contracts; recorded investment of $4.8 million). (4) Represents the following concessions: loans restructured through bankruptcy (28 contracts; recorded investment of $5.0 million); extension of term (1 contract; recorded investment of $0.5 million); reduced payment and/or payment deferral (26 contracts; recorded investment of $8.6 million); or a combination of concessions (58 contracts; recorded investment of $17.9 million). (5) Represents the following concessions: loans restructured through bankruptcy (53 contracts; recorded investment of $4.7 million); reduced payment and/or payment deferral (16 contracts; recorded investment of $2.1 million); temporary rate reduction (2 contracts; recorded investment of $0.6 million); or a combination of concessions (37 contracts; recorded investment of $2.8 million).
Summary of Recorded Investments in TDRs by Class of Loan, Subsequently Defaulted	The following is a summary, by class of loan, of information related to TDRs of originated loans completed within the previous 12 months that subsequently defaulted during the three and nine months ended September 30, 2015 and 2014. For purposes of this disclosure, the previous 12 months is measured from October 1 of the respective prior year and a default represents a previously-modified Three Months Ended September 30, 2015 2014 (dollars in millions) Number Recorded Number Recorded Commercial: Commercial real estate — $ — 3 $ 3.7 Commercial and industrial 1 0.6 1 0.7 Equipment financing 1 0.3 — — Total 2 0.9 4 4.4 Retail: Residential mortgage 2 0.2 13 2.1 Home equity 2 0.1 6 0.3 Other consumer — — — — Total 4 0.3 19 2.4 Total 6 $ 1.2 23 $ 6.8 Nine Months Ended September 30, 2015 2014 (dollars in millions) Number Recorded Number Recorded Commercial: Commercial real estate 2 $ 3.4 5 $ 4.1 Commercial and industrial 4 1.4 2 0.8 Equipment financing 8 4.1 8 1.0 Total 14 8.9 15 5.9 Retail: Residential mortgage 18 6.7 39 12.7 Home equity 16 1.5 23 1.6 Other consumer — — — — Total 34 8.2 62 14.3 Total 48 $ 17.1 77 $ 20.2
Summary of Individually-Evaluated Impaired Loans by Class of Loan	People’s United’s impaired loans consist of certain originated loans, including all TDRs. The following table summarizes, by class of loan, information related to individually-evaluated impaired loans within the originated portfolio. As of September 30, 2015 As of December 31, 2014 (in millions) Unpaid Recorded Related Unpaid Recorded Related Without a related allowance for loan losses: Commercial: Commercial real estate $ 48.0 $ 47.4 $ — $ 57.1 $ 55.8 $ — Commercial and industrial 63.5 59.6 — 51.7 48.6 — Equipment financing 21.5 17.7 — 30.2 21.4 — Retail: Residential mortgage 67.9 61.1 — 65.4 58.9 — Home equity 22.3 19.5 — 21.3 18.3 — Other consumer — — — — — — Total $ 223.2 $ 205.3 $ — $ 225.7 $ 203.0 $ — With a related allowance for loan losses: Commercial: Commercial real estate $ 17.8 $ 13.5 $ 1.9 $ 52.1 $ 27.8 $ 4.0 Commercial and industrial 22.2 21.3 5.6 21.4 17.4 3.5 Equipment financing 12.5 9.5 0.7 3.6 3.5 0.1 Retail: Residential mortgage 14.9 14.8 2.9 15.6 15.3 2.6 Home equity 1.9 1.8 0.8 2.6 2.5 1.3 Other consumer — — — — — — Total $ 69.3 $ 60.9 $ 11.9 $ 95.3 $ 66.5 $ 11.5 Total impaired loans: Commercial: Commercial real estate $ 65.8 $ 60.9 $ 1.9 $ 109.2 $ 83.6 $ 4.0 Commercial and industrial 85.7 80.9 5.6 73.1 66.0 3.5 Equipment financing 34.0 27.2 0.7 33.8 24.9 0.1 Total 185.5 169.0 8.2 216.1 174.5 7.6 Retail: Residential mortgage 82.8 75.9 2.9 81.0 74.2 2.6 Home equity 24.2 21.3 0.8 23.9 20.8 1.3 Other consumer — — — — — — Total 107.0 97.2 3.7 104.9 95.0 3.9 Total $ 292.5 $ 266.2 $ 11.9 $ 321.0 $ 269.5 $ 11.5
Schedule of Impaired Financing Receivable	The following table summarizes, by class of loan, the average recorded investment and interest income recognized on impaired loans for the periods indicated. The average recorded investment amounts are based on month-end balances. Three Months Ended September 30, 2015 2014 (in millions) Average Interest Average Interest Commercial: Commercial real estate $ 59.2 $ 0.5 $ 81.8 $ 0.3 Commercial and industrial 83.0 0.2 51.0 0.2 Equipment financing 26.7 0.1 30.6 0.2 Total 168.9 0.8 163.4 0.7 Retail: Residential mortgage 74.4 0.4 72.3 0.4 Home equity 21.2 0.1 18.4 0.1 Other consumer — — — — Total 95.6 0.5 90.7 0.5 Total $ 264.5 $ 1.3 $ 254.1 $ 1.2 Nine Months Ended September 30, 2015 2014 (in millions) Average Interest Average Interest Commercial: Commercial real estate $ 67.8 $ 1.2 $ 75.7 $ 1.2 Commercial and industrial 71.1 1.2 42.9 0.8 Equipment financing 28.9 0.3 29.4 0.6 Total 167.8 2.7 148.0 2.6 Retail: Residential mortgage 75.3 1.1 71.4 1.0 Home equity 21.3 0.2 17.3 0.2 Other consumer — — — — Total 96.6 1.3 88.7 1.2 Total $ 264.4 $ 4.0 $ 236.7 $ 3.8
Summary of Aging Information by Class of Loan	The following tables summarize, by class of loan, aging information for originated loans: Past Due As of September 30, 2015 (in millions) Current 30-89 90 Days Total Total Commercial: Commercial real estate $ 9,403.2 $ 21.0 $ 12.5 $ 33.5 $ 9,436.7 Commercial and industrial 7,173.6 29.2 54.4 83.6 7,257.2 Equipment financing 2,733.3 59.0 10.1 69.1 2,802.4 Total 19,310.1 109.2 77.0 186.2 19,496.3 Retail: Residential mortgage 5,117.5 39.9 25.8 65.7 5,183.2 Home equity 2,084.6 6.3 10.4 16.7 2,101.3 Other consumer 49.6 0.3 — 0.3 49.9 Total 7,251.7 46.5 36.2 82.7 7,334.4 Total originated loans $ 26,561.8 $ 155.7 $ 113.2 $ 268.9 $ 26,830.7 Past Due As of December 31, 2014 (in millions) Current 30-89 90 Days Total Total Commercial: Commercial real estate $ 8,908.0 $ 17.6 $ 34.7 $ 52.3 $ 8,960.3 Commercial and industrial 6,814.9 32.4 43.8 76.2 6,891.1 Equipment financing 2,793.3 41.0 4.7 45.7 2,839.0 Total 18,516.2 91.0 83.2 174.2 18,690.4 Retail: Residential mortgage 4,647.3 29.1 25.1 54.2 4,701.5 Home equity 2,079.3 5.0 8.6 13.6 2,092.9 Other consumer 55.8 0.4 0.1 0.5 56.3 Total 6,782.4 34.5 33.8 68.3 6,850.7 Total originated loans $ 25,298.6 $ 125.5 $ 117.0 $ 242.5 $ 25,541.1
Summary of Credit Quality Indicators by Class of Loan	The following is a summary, by class of loan, of credit quality indicators: As of September 30, 2015 (in millions) Commercial Commercial Equipment Total Commercial: Originated loans: Pass $ 9,211.9 $ 6,864.3 $ 2,434.7 $ 18,510.9 Special mention 93.9 106.0 95.3 295.2 Substandard 130.9 283.8 272.4 687.1 Doubtful — 3.1 — 3.1 Total originated loans 9,436.7 7,257.2 2,802.4 19,496.3 Acquired loans: Pass 269.6 184.9 5.5 460.0 Special mention 22.3 5.4 0.4 28.1 Substandard 55.0 44.1 12.8 111.9 Doubtful 1.8 0.6 — 2.4 Total acquired loans 348.7 235.0 18.7 602.4 Total $ 9,785.4 $ 7,492.2 $ 2,821.1 $ 20,098.7 As of September 30, 2015 (in millions) Residential Home Other Total Retail: Originated loans: Low risk $ 2,502.4 $ 950.7 $ 25.9 $ 3,479.0 Moderate risk 2,171.3 636.9 8.3 2,816.5 High risk 509.5 513.7 15.7 1,038.9 Total originated loans 5,183.2 2,101.3 49.9 7,334.4 Acquired loans: Low risk 99.3 — — 99.3 Moderate risk 40.3 — — 40.3 High risk 58.6 39.9 1.0 99.5 Total acquired loans 198.2 39.9 1.0 239.1 Total $ 5,381.4 $ 2,141.2 $ 50.9 $ 7,573.5 As of December 31, 2014 (in millions) Commercial Commercial Equipment Total Commercial: Originated loans: Pass $ 8,730.9 $ 6,477.4 $ 2,481.2 $ 17,689.5 Special mention 82.4 114.2 110.6 307.2 Substandard 135.3 297.3 247.2 679.8 Doubtful 11.7 2.2 — 13.9 Total originated loans 8,960.3 6,891.1 2,839.0 18,690.4 Acquired loans: Pass 302.5 174.5 7.6 484.6 Special mention 20.9 52.8 0.7 74.4 Substandard 113.5 55.0 18.2 186.7 Doubtful 7.1 16.2 — 23.3 Total acquired loans 444.0 298.5 26.5 769.0 Total $ 9,404.3 $ 7,189.6 $ 2,865.5 $ 19,459.4 As of December 31, 2014 (in millions) Residential Home Other Total Retail: Originated loans: Low risk $ 2,280.6 $ 931.5 $ 29.5 $ 3,241.6 Moderate risk 1,921.6 597.1 8.3 2,527.0 High risk 499.3 564.3 18.5 1,082.1 Total originated loans 4,701.5 2,092.9 56.3 6,850.7 Acquired loans: Low risk 107.0 — — 107.0 Moderate risk 50.5 — — 50.5 High risk 73.0 50.2 1.2 124.4 Total acquired loans 230.5 50.2 1.2 281.9 Total $ 4,932.0 $ 2,143.1 $ 57.5 $ 7,132.6
Summarized Activity in Accretable Yield for Acquired Loan Portfolio	The following table summarizes activity in the accretable yield for the acquired loan portfolio: Three Months Ended (in millions) 2015 2014 Balance at beginning of period $ 316.9 $ 447.7 Accretion (13.3 ) (18.9 ) Reclassification from nonaccretable difference for loans with improved cash flows (1) — 0.3 Other changes in expected cash flows (2) 5.0 (15.7 ) Balance at end of period $ 308.6 $ 413.4 Nine Months Ended (in millions) 2015 2014 Balance at beginning of period $ 396.3 $ 639.7 Accretion (42.9 ) (63.9 ) Reclassification from nonaccretable difference for loans with improved cash flows (1) 1.1 6.7 Other changes in expected cash flows (2) (45.9 ) (169.1 ) Balance at end of period $ 308.6 $ 413.4 (1) Results in increased interest accretion as a prospective yield adjustment over the remaining life of the corresponding pool of loans. (2) Represents changes in cash flows expected to be collected due to factors other than credit (e.g. changes in prepayment assumptions and/or changes in interest rates on variable rate loans), as well as loan sales, modifications and payoffs.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following is a summary of the changes in the components of accumulated other comprehensive loss (“AOCL”), which are included in People’s United’s stockholders’ equity on an after-tax basis: (in millions) Pension Net Unrealized Net Unrealized Net Unrealized Total Balance at December 31, 2014 $ (142.9 ) $ (3.7 ) $ (21.5 ) $ (0.1 ) $ (168.2 ) Other comprehensive income (loss) before reclassifications — 17.5 — (0.8 ) 16.7 Amounts reclassified from AOCL (1) 3.3 — 1.5 0.6 5.4 Current period other comprehensive income (loss) 3.3 17.5 1.5 (0.2 ) 22.1 Balance at September 30, 2015 $ (139.6 ) $ 13.8 $ (20.0 ) $ (0.3 ) $ (146.1 ) (in millions) Pension Net Unrealized Net Unrealized Net Unrealized Total Balance at December 31, 2013 $ (85.0 ) $ (46.5 ) $ (23.3 ) $ (0.3 ) $ (155.1 ) Other comprehensive income (loss) before reclassifications — 27.2 — (0.2 ) 27.0 Amounts reclassified from AOCL (1) 1.9 (0.2 ) 1.3 0.6 3.6 Current period other comprehensive income (loss) 1.9 27.0 1.3 0.4 30.6 Balance at September 30, 2014 $ (83.1 ) $ (19.5 ) $ (22.0 ) $ 0.1 $ (124.5 ) (1) See the following table for details about these reclassifications.
Summary of Amounts Reclassified from AOCL	The following is a summary of the amounts reclassified from AOCL: Amounts Reclassified from AOCL Three Months Ended Nine Months Ended Affected Line Item in the Statement Where (in millions) 2015 2014 2015 2014 Net Income is Presented Details about components of AOCL: Amortization of pension and other postretirement benefits items: Net actuarial loss $ (2.0 ) $ (1.2 ) $ (6.0 ) $ (3.9 ) (1) Prior service credit 0.3 0.2 0.8 0.8 (1) (1.7 ) (1.0 ) (5.2 ) (3.1 ) Income before income tax expense 0.6 0.4 1.9 1.2 Income tax expense (1.1 ) (0.6 ) (3.3 ) (1.9 ) Net income Reclassification adjustment for net realized gains on securities available for sale — 0.2 — 0.3 Income before income tax expense (2) — (0.1 ) — (0.1 ) Income tax expense — 0.1 — 0.2 Net income Amortization of unrealized losses on securities transferred to held to maturity (0.8 ) (0.7 ) (2.3 ) (2.2 ) Income before income tax expense (3) 0.2 0.3 0.8 0.9 Income tax expense (0.6 ) (0.4 ) (1.5 ) (1.3 ) Net income Amortization of unrealized gains and losses on cash flow hedges: Interest rate swaps (0.3 ) (0.3 ) (1.0 ) (1.0 ) (4) Interest rate locks 0.1 0.1 0.1 0.1 (4) (0.2 ) (0.2 ) (0.9 ) (0.9 ) Income before income tax expense 0.1 0.1 0.3 0.3 Income tax expense (0.1 ) (0.1 ) (0.6 ) (0.6 ) Net income Total reclassifications for the period $ (1.8 ) $ (1.0 ) $ (5.4 ) $ (3.6 ) (1) Included in the computation of net periodic pension cost reflected in compensation and benefits expense (see Note 7 for additional details). (2) Included in other non-interest income. (3) Included in interest and dividend income - securities. (4) Included in interest expense - notes and debentures.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Share, Reflecting Application of Two-Class Method	The following is an analysis of People’s United’s basic and diluted earnings per share (“EPS”), reflecting the application of the two-class method, as described below: Three Months Ended Nine Months Ended (in millions, except per share data) 2015 2014 2015 2014 Net income $ 68.4 $ 61.6 $ 189.3 $ 187.0 Dividends and undistributed earnings allocated to participating securities (0.3 ) (0.3 ) (0.9 ) (0.9 ) Income attributable to common shareholders $ 68.1 $ 61.3 $ 188.4 $ 186.1 Average common shares outstanding for basic EPS 301.0 298.4 300.1 298.1 Effect of dilutive equity-based awards — — — — Average common and common-equivalent shares for diluted EPS 301.0 298.4 300.1 298.1 Basic EPS $ 0.23 $ 0.21 $ 0.63 $ 0.62 Diluted EPS $ 0.23 $ 0.21 $ 0.63 $ 0.62

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Components of Net Periodic Benefit (Income) Expense and Other Amounts	Components of the net periodic benefit (income) expense and other amounts recognized in other comprehensive income for the plans described above are as follows: Pension Benefits Other Three months ended September 30 (in millions) 2015 2014 2015 2014 Net periodic benefit (income) expense: Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 4.8 4.8 0.1 — Expected return on plan assets (7.8 ) (7.1 ) — — Recognized net actuarial loss 1.5 1.0 — — Settlements 0.1 0.4 — — Net periodic benefit (income) expense $ (1.4 ) $ (0.9 ) $ 0.2 $ 0.1 Pension Benefits Other Nine months ended September 30 (in millions) 2015 2014 2015 2014 Net periodic benefit (income) expense: Service cost $ — $ — $ 0.2 $ 0.2 Interest cost 14.4 14.4 0.4 0.3 Expected return on plan assets (22.8 ) (21.3 ) — — Recognized net actuarial loss 4.5 3.0 0.2 — Recognized prior service credit — — (0.1 ) (0.2 ) Settlements 0.3 1.4 — — Net periodic benefit (income) expense (3.6 ) (2.5 ) 0.7 0.3 Other changes in plan assets and benefit obligations recognized in other comprehensive income: Net actuarial loss (4.5 ) (3.0 ) (0.2 ) — Prior service credit — — 0.1 0.2 Total pre-tax changes recognized in other comprehensive income (4.5 ) (3.0 ) (0.1 ) 0.2 Total recognized in net periodic benefit (income) expense and other comprehensive income $ (8.1 ) $ (5.5 ) $ 0.6 $ 0.5

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables summarize People’s United’s financial instruments that are measured at fair value on a recurring basis: Fair Value Measurements Using As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Financial assets: Trading account securities: U.S. Treasury $ 8.3 $ — $ — $ 8.3 Securities available for sale: U.S. Treasury and agency 376.2 — — 376.2 GSE residential mortgage-backed securities and CMOs — 3,844.8 — 3,844.8 Equity securities — 0.2 — 0.2 Other assets: Exchange-traded funds 28.3 — — 28.3 Fixed income securities — 5.4 — 5.4 Mutual funds 1.6 — — 1.6 Interest rate swaps — 198.7 — 198.7 Foreign exchange contracts — 0.3 — 0.3 Forward commitments to sell residential mortgage loans — 1.2 — 1.2 Total $ 414.4 $ 4,050.6 $ — $ 4,465.0 Financial liabilities: Interest rate swaps $ — $ 146.6 $ — $ 146.6 Interest rate-lock commitments on residential mortgage loans — 1.5 — 1.5 Total $ — $ 148.1 $ — $ 148.1 Fair Value Measurements Using As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Financial assets: Trading account securities: U.S. Treasury $ 8.3 $ — $ — $ 8.3 Securities available for sale: U.S. Treasury and agency 56.8 — — 56.8 GSE residential mortgage-backed securities and CMOs — 3,936.7 — 3,936.7 Equity securities — 0.2 — 0.2 Other assets: Exchange-traded funds 30.3 — — 30.3 Fixed income securities — 6.0 — 6.0 Mutual funds 0.8 — — 0.8 Interest rate swaps — 131.1 — 131.1 Foreign exchange contracts — 0.8 — 0.8 Forward commitments to sell residential mortgage loans — 0.5 — 0.5 Total $ 96.2 $ 4,075.3 $ — $ 4,171.5 Financial liabilities: Interest rate swaps $ — $ 95.8 $ — $ 95.8 Foreign exchange contracts — 0.5 — 0.5 Interest rate-lock commitments on residential mortgage loans — 0.7 — 0.7 Total $ — $ 97.0 $ — $ 97.0
Assets Measured at Fair Value on Non-Recurring Basis	The following tables summarize People’s United’s assets that are measured at fair value on a non-recurring basis: Fair Value Measurements Using As of September 30, 2015 (in millions) Level 1 Level 2 Level 3 Total Loans held for sale (1) $ — $ 36.2 $ — $ 36.2 Impaired loans (2) — — 60.9 60.9 REO and repossessed assets (3) — — 26.3 26.3 Total $ — $ 36.2 $ 87.2 $ 123.4 Fair Value Measurements Using As of December 31, 2014 (in millions) Level 1 Level 2 Level 3 Total Loans held for sale (1) $ — $ 34.2 $ — $ 34.2 Impaired loans (2) — — 66.5 66.5 REO and repossessed assets (3) — — 27.1 27.1 Total $ — $ 34.2 $ 93.6 $ 127.8 (1) Consists of residential mortgage loans; no fair value adjustments were recorded for the nine months ended September 30, 2015 and 2014. (2) Represents the recorded investment in originated impaired loans with a related allowance for loan losses measured in accordance with applicable accounting guidance. The total consists of $44.3 million of Commercial loans and $16.6 million of Retail loans at September 30, 2015. The provision for loan losses on impaired loans totaled $6.0 million and $6.7 million for the nine months ended September 30, 2015 and 2014, respectively. (3) Represents: (i) $10.8 million of residential REO; (ii) $8.2 million of commercial REO; and (iii) $7.3 million of repossessed assets at September 30, 2015. Charge-offs to the allowance for loan losses related to loans that were transferred to REO or repossessed assets totaled $1.5 million and $1.0 million for the nine months ended September 30, 2015 and 2014, respectively. Write downs and net loss on sale of foreclosed/repossessed assets charged to non-interest expense totaled $1.2 million and $3.7 million for the same periods.
Carrying Amounts and Estimated Fair Values of Financial Instruments	The following tables summarize the carrying amounts, estimated fair values and placement in the fair value hierarchy of People’s United’s financial instruments that are not measured at fair value either on a recurring or non-recurring basis: Estimated Fair Value Carrying Measurements Using As of September 30, 2015 (in millions) Amount Level 1 Level 2 Level 3 Total Financial assets: Cash and due from banks $ 300.3 $ 300.3 $ — $ — $ 300.3 Short-term investments 244.6 — 244.6 — 244.6 Securities held to maturity 1,377.1 — 1,420.1 1.5 1,421.6 FHLB and FRB stock 314.7 — 314.7 — 314.7 Total loans, net (1) 27,403.8 — 5,260.9 22,308.0 27,568.9 Financial liabilities: Time deposits 5,165.9 — 5,205.9 — 5,205.9 Other deposits 23,113.8 — 23,113.8 — 23,113.8 FHLB advances 2,164.5 — 2,172.6 — 2,172.6 Customer repurchase agreements 472.3 — 472.3 — 472.3 Federal funds purchased 360.0 — 360.0 — 360.0 Notes and debentures 1,044.9 — 1,018.3 — 1,018.3 (1) Excludes impaired loans totaling $60.9 million measured at fair value on a non-recurring basis. Estimated Fair Value Carrying Measurements Using As of December 31, 2014 (in millions) Amount Level 1 Level 2 Level 3 Total Financial assets: Cash and due from banks $ 345.1 $ 345.1 $ — $ — $ 345.1 Short-term investments 668.6 — 668.6 — 668.6 Securities purchased under agreements to resell 100.0 — 100.0 — 100.0 Securities held to maturity 834.3 — 880.1 1.5 881.6 FHLB stock 175.7 — 175.7 — 175.7 Total loans, net (1) 26,327.2 — 4,798.5 21,508.8 26,307.3 Financial liabilities: Time deposits 5,230.7 — 5,262.6 — 5,262.6 Other deposits 20,907.5 — 20,907.5 — 20,907.5 FHLB advances 2,291.7 — 2,298.5 — 2,298.5 Federal funds purchased 913.0 — 913.0 — 913.0 Customer repurchase agreements 486.0 — 486.0 — 486.0 Repurchase agreements (2) 1.0 — 1.0 — 1.0 Notes and debentures 1,033.5 — 1,040.8 — 1,040.8 (1) Excludes impaired loans totaling $66.5 million measured at fair value on a non-recurring basis. (2) Included in other borrowings in the Consolidated Statements of Condition.

Derivative Financial Instrume28

Derivative Financial Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts and Fair Values of Derivatives Outstanding	The table below provides a summary of the notional amounts and fair values (presented on a gross basis) of derivatives outstanding: Fair Values (1) Notional Amounts Assets Liabilities (in millions) Type of Sept. 30, Dec. 31, Sept. 30, Dec. 31, Sept. 30, Dec. 31, Derivatives Not Designated as Hedging Instruments: Interest rate swaps: Commercial customers N/A $ 4,287.5 $ 3,380.2 $ 172.1 $ 104.2 $ 1.0 $ 8.3 Institutional counterparties N/A 4,287.5 3,380.2 1.3 11.8 144.4 86.5 Risk participation agreements (2) N/A 240.4 150.1 — — — — Foreign exchange contracts N/A 46.9 49.6 0.3 0.8 — 0.5 Forward commitments to sell residential mortgage loans N/A 62.3 35.3 1.2 0.5 — — Interest rate-lock commitments on residential mortgage loans N/A 83.4 57.5 — — 1.5 0.7 Total 174.9 117.3 146.9 96.0 Derivatives Designated as Hedging Instruments: Interest rate swaps: Subordinated notes Cash flow 125.0 125.0 — — 1.2 1.0 Subordinated notes Fair value 375.0 375.0 25.3 15.1 — — Total 25.3 15.1 1.2 1.0 Total derivatives $ 200.2 $ 132.4 $ 148.1 $ 97.0 (1) Assets are recorded in other assets and liabilities are recorded in other liabilities. (2) Fair value totaled less than $0.1 million at both dates.
Impact of Derivatives on Pre-Tax Income and Accumulated Other Comprehensive Loss	The following table summarizes the impact of People’s United’s derivatives on pre-tax income and AOCL: Amount of Pre-Tax Gain (Loss) Amount of Pre-Tax Gain (Loss) Type of Recognized in Earnings (1) Recognized in AOCL Nine months ended September 30 (in millions) Hedge 2015 2014 2015 2014 Derivatives Not Designated as Hedging Instruments: Interest rate swaps: Commercial customers N/A $ 127.8 $ 100.1 $ — $ — Institutional counterparties N/A (116.9 ) (94.6 ) — — Foreign exchange contracts N/A — 0.4 — — Risk participation agreements N/A (0.2 ) (0.1 ) — — Forward commitments to sell residential mortgage loans N/A 0.7 0.2 — — Interest rate-lock commitments on residential mortgage loans N/A (0.8 ) (0.3 ) — — Total 10.6 5.7 — — Derivatives Designated as Hedging Instruments: Interest rate swaps Cash flow (1.0 ) (1.0 ) (1.2 ) (0.4 ) Interest rate locks Cash flow 0.1 0.1 — — Interest rate swaps Fair value 6.9 2.3 — — Total 6.0 1.4 (1.2 ) (0.4 ) Total derivatives $ 16.6 $ 7.1 $ (1.2 ) $ (0.4 ) (1) Amounts recognized in earnings are recorded in interest income, interest expense or other non-interest income for derivatives designated as hedging instruments and in other non-interest income for derivatives not designated as hedging instruments.

Balance Sheet Offsetting (Table

Balance Sheet Offsetting (Tables)	9 Months Ended
	Sep. 30, 2015
Text Block [Abstract]
Summary of Gross Presentation, Financial Instruments that are Eligible for Offset Not Offset in Consolidated Statement of Condition	Gross Gross Net Gross Amounts Not Offset As of September 30, 2015 (in millions) Amount Amount Amount Financial Collateral Net Amount Financial assets: Interest rate swaps: Counterparty A $ 0.2 $ — $ 0.2 $ (0.2 ) $ — $ — Counterparty B 0.4 — 0.4 (0.4 ) — — Counterparty C — — — — — — Counterparty D 0.5 — 0.5 (0.5 ) — — Counterparty E 25.5 — 25.5 (25.5 ) — — Other counterparties — — — — — — Foreign exchange contracts 0.3 — 0.3 — — 0.3 Total $ 26.9 $ — $ 26.9 $ (26.6 ) $ — $ 0.3 Financial liabilities: Interest rate swaps: Counterparty A $ 11.7 $ — $ 11.7 $ (0.2 ) $ (11.5 ) $ — Counterparty B 13.4 — 13.4 (0.4 ) (13.0 ) — Counterparty C 7.1 — 7.1 — (7.0 ) 0.1 Counterparty D 11.1 — 11.1 (0.5 ) (9.9 ) 0.7 Counterparty E 95.9 — 95.9 (25.5 ) (70.4 ) — Other counterparties 6.4 — 6.4 — (6.3 ) 0.1 Total $ 145.6 $ — $ 145.6 $ (26.6 ) $ (118.1 ) $ 0.9 Gross Gross Net Gross Amounts Not Offset As of December 31, 2014 (in millions) Amount Amount Amount Financial Collateral Net Amount Financial assets: Interest rate swaps: Counterparty A $ 2.7 $ — $ 2.7 $ (2.7 ) $ — $ — Counterparty B 1.5 — 1.5 (1.5 ) — — Counterparty C 2.5 — 2.5 (2.5 ) — — Counterparty D 3.2 — 3.2 (0.4 ) (2.8 ) — Counterparty E 15.7 — 15.7 (15.7 ) — — Other counterparties 1.3 — 1.3 (1.3 ) — — Securities purchased under agreements to resell 100.0 — 100.0 — (100.0 ) — Foreign exchange contracts 0.8 — 0.8 — — 0.8 Total $ 127.7 $ — $ 127.7 $ (24.1 ) $ (102.8 ) $ 0.8 Financial liabilities: Interest rate swaps: Counterparty A $ 11.8 $ — $ 11.8 $ (2.7 ) $ (9.1 ) $ — Counterparty B 11.8 — 11.8 (1.5 ) (10.3 ) — Counterparty C 4.5 — 4.5 (2.5 ) (1.9 ) 0.1 Counterparty D 0.4 — 0.4 (0.4 ) — — Counterparty E 47.8 — 47.8 (15.7 ) (32.1 ) — Other counterparties 11.2 — 11.2 (1.3 ) (8.9 ) 1.0 Repurchase agreements (1) 1.0 — 1.0 — (1.0 ) — Foreign exchange contracts 0.5 — 0.5 — — 0.5 Total $ 89.0 $ — $ 89.0 $ (24.1 ) $ (63.3 ) $ 1.6 (1) Included in other borrowings in the Consolidated Statements of Condition.

General - Additional Informatio

General - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Collaboration Arrangement Disclosure [Abstract]
Company's housing investment	$ 78.6		$ 78.6
Future contingent commitments	35.5		$ 35.5
Amortization period			10 years
Amortization expense included in income tax expense	$ 2.8	$ 2.6	$ 8.3	$ 7.5

Securities and Short-Term Inv31

Securities and Short-Term Investments - Available-for-Sale and Held-to-Maturity Securities Gains (Losses) (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Investment Holdings [Line Items]
Amortized Cost	$ 4,197.6	$ 4,000.1
Gross Unrealized Gains	42.6	40
Gross Unrealized Losses	(19)	(46.4)
Fair Value	4,221.2	3,993.7
Held to maturity Securities, Amortized Cost	1,377.1	834.3
Securities held to maturity, Gross Unrealized Gains	46.1	47.4
Securities held to maturity, Gross Unrealized Losses	(1.6)	(0.1)
Total securities held to maturity, Fair Value	1,421.6	881.6
U.S. Treasury and Agency [Member]
Investment Holdings [Line Items]
Amortized Cost	374.1	56.5
Gross Unrealized Gains	2.1	0.3
Fair Value	376.2	56.8
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Investment Holdings [Line Items]
Amortized Cost	3,823.3	3,943.4
Gross Unrealized Gains	40.5	39.7
Gross Unrealized Losses	(19)	(46.4)
Fair Value	3,844.8	3,936.7
Held to maturity Securities, Amortized Cost	429.3
Securities held to maturity, Gross Unrealized Gains	2.4
Total securities held to maturity, Fair Value	431.7
Debt Securities [Member]
Investment Holdings [Line Items]
Amortized Cost	4,197.4	3,999.9
Gross Unrealized Gains	42.6	40
Gross Unrealized Losses	(19)	(46.4)
Fair Value	4,221	3,993.5
Equity Securities [Member]
Investment Holdings [Line Items]
Amortized Cost	0.2	0.2
Fair Value	0.2	0.2
State and Municipal [Member]
Investment Holdings [Line Items]
Held to maturity Securities, Amortized Cost	946.3	832.8
Securities held to maturity, Gross Unrealized Gains	43.7	47.4
Securities held to maturity, Gross Unrealized Losses	(1.6)	(0.1)
Total securities held to maturity, Fair Value	988.4	880.1
Other [Member]
Investment Holdings [Line Items]
Held to maturity Securities, Amortized Cost	1.5	1.5
Total securities held to maturity, Fair Value	$ 1.5	$ 1.5

Securities and Short-Term Inv32

Securities and Short-Term Investments - Additional Information (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)SecuritiesSecurity	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)SecuritiesSecurity	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Investment [Line Items]
Security available for sale with a fair value pledged with collateral for public deposits	$ 1,610,000,000		$ 1,610,000,000		$ 1,430,000,000
Number of securities available for sale | Security	48		48
Number of securities held to maturity | Securities	106		106
Total number of securities owned | Security			1,264
Percentage of securities available for sale	12.00%		12.00%
Available for sale of securities gross unrealized losses	$ 19,000,000		$ 19,000,000		46,400,000
Held to maturity securities gross unrealized losses	1,600,000		1,600,000
Impairment losses on securities recognized in earnings	0	$ 0	0	$ 0
Impairment of investments			0
Purchase of Federal Reserve Bank stock	139,000,000		$ 139,000,000
Federal Reserve Bank stock percentage			6.00%
Fair value of collateral securing securities purchased under agreements to resell	0		$ 0		100,400,000
State and Municipal [Member]
Investment [Line Items]
Held to maturity securities gross unrealized losses	1,600,000		$ 1,600,000		100,000
Available for sale securities average maturity period			16 years
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Investment [Line Items]
Available for sale of securities gross unrealized losses	19,000,000		$ 19,000,000		46,400,000
Available for sale securities average maturity period			13 years
FHLB of Boston [Member]
Investment [Line Items]
Acquired shares of capital stock	164,400,000		$ 164,400,000		164,400,000
FHLB of New York [Member]
Investment [Line Items]
Acquired shares of capital stock	11,300,000		11,300,000		11,300,000
Federal Reserve Bank of New York [Member]
Investment [Line Items]
Interest-bearing deposits	$ 164,100,000		$ 164,100,000		$ 626,500,000
Federal funds sold and yield			0.25%		0.25%

Securities and Short-Term Inv33

Securities and Short-Term Investments - Summary of Amortized Cost and Fair Value of Debt Securities Remaining Period to Contractual Maturity (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Investment [Line Items]
Available for Sale, Amortized Cost, Within 1 year	$ 41.1
Available for Sale, Amortized Cost, After 1 but within 5 years	333
Available for Sale, Amortized Cost, After 5 but within 10 years	742.6
Available for Sale, Amortized Cost, After 10 years	3,080.7
Available for Sale, Amortized Cost, Total	4,197.4
Available for Sale, Fair Value, Within 1 year	41.2
Available for Sale, Fair Value, After 1 but within 5 years	335
Available for Sale, Fair Value, After 5 but within 10 years	755.3
Available for Sale, Fair Value, After 10 years	3,089.5
Available for Sale, Fair Value, Total	4,221
Held to Maturity, Amortized Cost, Within 1 year	3.8
Held to Maturity, Amortized Cost, After 1 but within 5 years	23.1
Held to Maturity, Amortized Cost, After 5 but within 10 years	323.5
Held to Maturity, Amortized Cost, After 10 years	1,026.7
Held to maturity Securities, Amortized Cost	1,377.1	$ 834.3
Held to Maturity, Fair Value, Within 1 year	3.8
Held to Maturity, Fair Value, After 1 but within 5 years	23.4
Held to Maturity, Fair Value, After 5 but within 10 years	342.7
Held to Maturity, Fair Value, After 10 years	1,051.7
Held to Maturity, Fair Value, Total	1,421.6	881.6
U.S. Treasury and Agency [Member]
Investment [Line Items]
Available for Sale, Amortized Cost, Within 1 year	41.1
Available for Sale, Amortized Cost, After 1 but within 5 years	333
Available for Sale, Amortized Cost, Total	374.1
Available for Sale, Fair Value, Within 1 year	41.2
Available for Sale, Fair Value, After 1 but within 5 years	335
Available for Sale, Fair Value, Total	376.2
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Investment [Line Items]
Available for Sale, Amortized Cost, After 5 but within 10 years	742.6
Available for Sale, Amortized Cost, After 10 years	3,080.7
Available for Sale, Amortized Cost, Total	3,823.3
Available for Sale, Fair Value, After 5 but within 10 years	755.3
Available for Sale, Fair Value, After 10 years	3,089.5
Available for Sale, Fair Value, Total	3,844.8
Held to Maturity, Amortized Cost, After 10 years	429.3
Held to maturity Securities, Amortized Cost	429.3
Held to Maturity, Fair Value, After 10 years	431.7
Held to Maturity, Fair Value, Total	431.7
Other [Member]
Investment [Line Items]
Held to Maturity, Amortized Cost, After 1 but within 5 years	1.5
Held to maturity Securities, Amortized Cost	1.5	1.5
Held to Maturity, Fair Value, After 1 but within 5 years	1.5
Held to Maturity, Fair Value, Total	1.5	1.5
State and Municipal [Member]
Investment [Line Items]
Held to Maturity, Amortized Cost, Within 1 year	3.8
Held to Maturity, Amortized Cost, After 1 but within 5 years	21.6
Held to Maturity, Amortized Cost, After 5 but within 10 years	323.5
Held to Maturity, Amortized Cost, After 10 years	597.4
Held to maturity Securities, Amortized Cost	946.3	832.8
Held to Maturity, Fair Value, Within 1 year	3.8
Held to Maturity, Fair Value, After 1 but within 5 years	21.9
Held to Maturity, Fair Value, After 5 but within 10 years	342.7
Held to Maturity, Fair Value, After 10 years	620
Held to Maturity, Fair Value, Total	$ 988.4	$ 880.1

Securities and Short-Term Inv34

Securities and Short-Term Investments - Continuous Unrealized Loss Position on Available-for-Sale and Held-to-Maturities Securities (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value	$ 905.6	$ 143.7
Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	(4.4)	(0.2)
Continuous Unrealized Loss Position, 12 Months Or Longer, Fair Value	993.9	1,744.2
Continuous Unrealized Loss Position, 12 Months Or Longer, Unrealized Losses	(16.2)	(46.3)
Continuous Unrealized Loss Position, Total, Fair Value	1,899.5	1,887.9
Continuous Unrealized Loss Position, Total, Unrealized Losses	(20.6)	(46.5)
Held To Maturity Securities, Continuous Unrealized Loss Position, Total, Unrealized Losses	(1.6)
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Available for Sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value	776.2	111.9
Available for Sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	(2.8)	(0.1)
Available for Sale Securities, Continuous Unrealized Loss Position, 12 Months Or Longer, Fair Value	993.9	1,744.2
Available for Sale Securities, Continuous Unrealized Loss Position, 12 Months Or Longer, Unrealized Losses	(16.2)	(46.3)
Available for Sale Securities, Continuous Unrealized Loss Position, Total, Fair Value	1,770.1	1,856.1
Available for Sale Securities, Continuous Unrealized Loss Position, Total, Unrealized Losses	(19)	(46.4)
State and Municipal [Member]
Schedule Of Available For Sale And Held To Maturity Securities [Line Items]
Held To Maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Fair Value	129.4	31.8
Held To Maturity Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Unrealized Losses	(1.6)	(0.1)
Held To Maturity Securities, Continuous Unrealized Loss Position, Total, Fair Value	129.4	31.8
Held To Maturity Securities, Continuous Unrealized Loss Position, Total, Unrealized Losses	$ (1.6)	$ (0.1)

Loans - Additional Information

Loans - Additional Information (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)SegmentsRating	Sep. 30, 2014USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2014USD ($)	Jun. 30, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2011USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of segments | Segments			2
Net deferred loan costs	$ 58.9		$ 58.9			$ 54.8
Recorded investments, non-performing loans	183.3		183.3			197
Allowance for loan losses	207.5	$ 196.9	207.5	$ 196.9	$ 205.4	198.3	$ 192.6	$ 187.8
Interest Income Recognized	1.3	1.2	$ 4	3.8
Temporary reduction of interest rate for TDRs, basis points			2.00%
Collateral values/LTV ratios, minimum			70.00%
Borrower credit scores, minimum | Rating			680
Principal and interest payments receivable									$ 7,570
Expected cash flows									7,020
Loan portfolio fair value									5,360
Aggregate loan nonaccretable difference	83.4		$ 83.4						550.9
Portfolio accretable yield	308.6	413.4	308.6	413.4	316.9	396.3	447.7	639.7	$ 1,660
Portfolio outstanding balance	946.1		946.1			1,180
Portfolio carrying value	841.5		841.5			1,050
Repossessed assets	7.3		7.3			2.5
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	124.1		124.1			141.4
Allowance for loan losses	186.5	177.5	186.5	177.5	186.5	179.4	173.1	168.3
Interest Income Recognized	0.8	0.7	2.7	2.6
Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	59.2		59.2			55.6
Allowance for loan losses	21	19.4	21	19.4	18.9	18.9	19.5	19.5
Interest Income Recognized	0.5	0.5	$ 1.3	1.2
Duration of extension for payment deferral on TDRs, months			9 years
Commercial Real Estate Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Early non-performing loans					0	25.6
Real estate owned	8.2		$ 8.2			11
Commercial Real Estate Loan [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	31.8		31.8			60.2
Interest Income Recognized	0.5	0.3	1.2	1.2
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Early non-performing loans					0	29.5
Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	62.9		62.9			55.8
Interest Income Recognized	0.2	0.2	1.2	0.8
Equipment Financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Early non-performing loans					0	20.7
Equipment Financing [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	29.4		29.4			25.4
Interest Income Recognized	0.1	0.2	0.3	0.6
Residential Mortgage Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Real estate owned	10.8		10.8			13.6
Residential Mortgage Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	38.2		38.2			37.6
Interest Income Recognized	0.4	0.4	$ 1.1	1
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan agreement			6 months
Maximum [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Duration of extension for payment deferral on TDRs, months			2 years
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	9.4		$ 9.4			10.2
Acquired Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	9.2	11.5	9.2	11.5	10.1	9.8	9.6	9.8
Acquired Loans [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0.2	0.4	0.2	0.4	0.2	0.4	$ 0.5	$ 0.5
Foreclosure or Bankruptcy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Early non-performing loans					$ 0	21.8
Purchased Credit Impaired Loans [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	36.6		36.6			100.6
Covered by FDIC Loss-Share [Member] | Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investments, non-performing loans	1.8		1.8			3
Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in originated loans classified as TDRs	199.2		199.2			181.6
Allowance for loan losses	6.8		6.8			$ 7.1
Interest Income Recognized	$ 1.1	$ 1.1	$ 3.2	$ 3.1

Loans - Summary of Loans by Loa

Loans - Summary of Loans by Loan Portfolio Segment and Class (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	$ 2,192.1	$ 2,200.6
Total Retail Portfolio	7,573.5	7,132.6
Total loans	27,672.2	26,592
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	20,098.7	19,459.4
Total loans	20,098.7	19,459.4
Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	7,573.5	7,132.6
Commercial Real Estate Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	9,785.4	9,404.3
Commercial Real Estate Loan [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	9,785.4	9,404.3
Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	7,492.2	7,189.6
Equipment Financing [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	2,821.1	2,865.5
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	10,313.3	10,055.1
Commercial Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	10,313.3	10,055.1
Residential Mortgage Adjustable Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	4,781.1	4,393.8
Residential Mortgage Fixed Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	600.3	538.2
Residential Mortgage Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	5,381.4	4,932
Residential Mortgage Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	5,381.4	4,932
Home Equity Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	2,141.2	2,143.1
Consumer Loans [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	50.9	57.5
Originated [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	2,151.2	2,149.2
Total Retail Portfolio	7,334.4	6,850.7
Total loans	26,830.7	25,541.1
Originated [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	19,496.3	18,690.4
Originated [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Retail Portfolio	7,334.4	6,850.7
Originated [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	9,436.7	8,960.3
Originated [Member] | Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	7,257.2	6,891.1
Originated [Member] | Equipment Financing [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	2,802.4	2,839
Originated [Member] | Commercial Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	10,059.6	9,730.1
Originated [Member] | Residential Mortgage Adjustable Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	4,655.7	4,254.7
Originated [Member] | Residential Mortgage Fixed Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	527.5	446.8
Originated [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	5,183.2	4,701.5
Originated [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	2,101.3	2,092.9
Originated [Member] | Consumer Loans [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	49.9	56.3
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	40.9	51.4
Total Retail Portfolio	239.1	281.9
Total loans	841.5	1,050.9
Acquired Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	602.4	769
Acquired Loans [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	348.7	444
Acquired Loans [Member] | Commercial and Industrial [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	235	298.5
Acquired Loans [Member] | Equipment Financing [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	18.7	26.5
Acquired Loans [Member] | Commercial Loans [Member] | Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Commercial Portfolio	253.7	325
Acquired Loans [Member] | Residential Mortgage Adjustable Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	125.4	139.1
Acquired Loans [Member] | Residential Mortgage Fixed Rate [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	72.8	91.4
Acquired Loans [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total residential mortgage	198.2	230.5
Acquired Loans [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	39.9	50.2
Acquired Loans [Member] | Consumer Loans [Member] | Retail Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total consumer	$ 1	$ 1.2

Loans - Summary, by Loan Portfo

Loans - Summary, by Loan Portfolio Segment, of Activity in Allowance for Loan Losses (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 205.4	$ 192.6	$ 198.3	$ 187.8
Charge-offs	(6.1)	(9.3)	(20.2)	(26.3)
Recoveries	2	1.2	5.7	4.7
Net loan charge-offs	(4.1)	(8.1)	(14.5)	(21.6)
Provision for loan losses	6.2	12.4	23.7	30.7
Balance at end of period	207.5	196.9	207.5	196.9
Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period			10.2
Balance at end of period	9.4		9.4
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	186.5	173.1	179.4	168.3
Charge-offs	(4.1)	(6.4)	(14.4)	(17.9)
Recoveries	1.2	0.5	4	3.1
Net loan charge-offs	(2.9)	(5.9)	(10.4)	(14.8)
Provision for loan losses	2.9	10.3	17.5	24
Balance at end of period	186.5	177.5	186.5	177.5
Commercial [Member] | Originated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	176.4	163.5	169.6	158.5
Charge-offs	(4.1)	(6.2)	(14.4)	(15.3)
Recoveries	1.2	0.5	4	3.1
Net loan charge-offs	(2.9)	(5.7)	(10.4)	(12.2)
Provision for loan losses	3.8	8.2	18.1	19.7
Balance at end of period	177.3	166	177.3	166
Commercial [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	10.1	9.6	9.8	9.8
Charge-offs		(0.2)		(2.6)
Net loan charge-offs		(0.2)		(2.6)
Provision for loan losses	(0.9)	2.1	(0.6)	4.3
Balance at end of period	9.2	11.5	9.2	11.5
Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	18.9	19.5	18.9	19.5
Charge-offs	(2)	(2.9)	(5.8)	(8.4)
Recoveries	0.8	0.7	1.7	1.6
Net loan charge-offs	(1.2)	(2.2)	(4.1)	(6.8)
Provision for loan losses	3.3	2.1	6.2	6.7
Balance at end of period	21	19.4	21	19.4
Retail Loans [Member] | Originated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	18.7	19	18.5	19
Charge-offs	(2)	(2.9)	(5.8)	(8.3)
Recoveries	0.8	0.7	1.7	1.6
Net loan charge-offs	(1.2)	(2.2)	(4.1)	(6.7)
Provision for loan losses	3.3	2.2	6.4	6.7
Balance at end of period	20.8	19	20.8	19
Retail Loans [Member] | Acquired Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	0.2	0.5	0.4	0.5
Charge-offs				(0.1)
Net loan charge-offs				(0.1)
Provision for loan losses		(0.1)	(0.2)
Balance at end of period	$ 0.2	$ 0.4	$ 0.2	$ 0.4

Loans - Summary of Allowance fo

Loans - Summary of Allowance for Loan Losses by Loan Portfolio Segment and Impairment Methodology (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Financing Receivable, Allowance for Credit Losses [Line Items]
Originated Loans Individually Evaluated for Impairment, Portfolio	$ 266.2		$ 269.5
Originated Loans Individually Evaluated for Impairment, Allowance	11.9		11.5
Originated Loans Collectively Evaluated for Impairment, Portfolio	26,564.5		25,271.6
Originated Loans Collectively Evaluated for Impairment, Allowance	186.2		176.6
Loans, Portfolio	27,672.2		26,592
Total Allowance	207.5	$ 205.4	198.3	$ 196.9	$ 192.6	$ 187.8
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans, Portfolio	841.5		1,050.9
Total Allowance	9.4		10.2
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Originated Loans Individually Evaluated for Impairment, Portfolio	169		174.5
Originated Loans Individually Evaluated for Impairment, Allowance	8.2		7.6
Originated Loans Collectively Evaluated for Impairment, Portfolio	19,327.3		18,515.9
Originated Loans Collectively Evaluated for Impairment, Allowance	169.1		162
Loans, Portfolio	20,098.7		19,459.4
Total Allowance	186.5	186.5	179.4	177.5	173.1	168.3
Commercial [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans, Portfolio	602.4		769
Total Allowance	9.2		9.8
Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Originated Loans Individually Evaluated for Impairment, Portfolio	97.2		95
Originated Loans Individually Evaluated for Impairment, Allowance	3.7		3.9
Originated Loans Collectively Evaluated for Impairment, Portfolio	7,237.2		6,755.7
Originated Loans Collectively Evaluated for Impairment, Allowance	17.1		14.6
Loans, Portfolio	7,573.5		7,132.6
Total Allowance	21	$ 18.9	18.9	$ 19.4	$ 19.5	$ 19.5
Retail Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans, Portfolio	239.1		281.9
Total Allowance	$ 0.2		$ 0.4

Loans - Summarized Recorded Inv

Loans - Summarized Recorded Investments, by Class of Loan, of Originated Non-Performing Loans (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	$ 183.3	$ 197
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	124.1	141.4
Retail Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	59.2	55.6
Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	62.9	55.8
Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	31.8	60.2
Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	29.4	25.4
Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	38.2	37.6
Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	$ 21	17.9
Consumer Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans		$ 0.1

Loans - Summarized Recorded I40

Loans - Summarized Recorded Investments, by Class of Loan, of Originated Non-Performing Loans (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Government guarantees	$ 17.3	$ 17.6
Recorded investments, non-performing loans	$ 183.3	197
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Guarantee rate	99.00%
Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Guarantee rate	1.00%
Foreclosure [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded investments, non-performing loans	$ 19.8	$ 18.9

Loans - Summary of Recorded Inv

Loans - Summary of Recorded Investments in TDRs by Class of Loan (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	57	86	193	296
Pre-Modification Outstanding Recorded Investment	$ 41.9	$ 20	$ 114.2	$ 106.6
Post-Modification Outstanding Recorded Investment	$ 41.9	$ 20	$ 114.2	$ 106.6
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	25	22	73	75
Pre-Modification Outstanding Recorded Investment	$ 35.6	$ 10.1	$ 91.1	$ 64.4
Post-Modification Outstanding Recorded Investment	$ 35.6	$ 10.1	$ 91.1	$ 64.4
Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	32	64	120	221
Pre-Modification Outstanding Recorded Investment	$ 6.3	$ 9.9	$ 23.1	$ 42.2
Post-Modification Outstanding Recorded Investment	$ 6.3	$ 9.9	$ 23.1	$ 42.2
Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	10	9	20	22
Pre-Modification Outstanding Recorded Investment	$ 7	$ 5.8	$ 12.3	$ 32.1
Post-Modification Outstanding Recorded Investment	$ 7	$ 5.8	$ 12.3	$ 32.1
Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	7	7	35	36
Pre-Modification Outstanding Recorded Investment	$ 24.4	$ 2.9	$ 59.2	$ 27.2
Post-Modification Outstanding Recorded Investment	$ 24.4	$ 2.9	$ 59.2	$ 27.2
Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	8	6	18	17
Pre-Modification Outstanding Recorded Investment	$ 4.2	$ 1.4	$ 19.6	$ 5.1
Post-Modification Outstanding Recorded Investment	$ 4.2	$ 1.4	$ 19.6	$ 5.1
Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	15	28	50	113
Pre-Modification Outstanding Recorded Investment	$ 5	$ 6.6	$ 16.9	$ 32
Post-Modification Outstanding Recorded Investment	$ 5	$ 6.6	$ 16.9	$ 32
Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contracts	17	36	70	108
Pre-Modification Outstanding Recorded Investment	$ 1.3	$ 3.3	$ 6.2	$ 10.2
Post-Modification Outstanding Recorded Investment	$ 1.3	$ 3.3	$ 6.2	$ 10.2

Loans - Summary of Recorded I42

Loans - Summary of Recorded Investments in TDRs by Class of Loan (Parenthetical) (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts
Financing Receivable, Modifications [Line Items]
Number of Contracts	57	86	193	296
Recorded investment | $	$ 41.9	$ 20	$ 114.2	$ 106.6
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	25	22	73	75
Recorded investment | $	$ 35.6	$ 10.1	$ 91.1	$ 64.4
Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	32	64	120	221
Recorded investment | $	$ 6.3	$ 9.9	$ 23.1	$ 42.2
Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	10	9	20	22
Recorded investment | $	$ 7	$ 5.8	$ 12.3	$ 32.1
Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	7	7	35	36
Recorded investment | $	$ 24.4	$ 2.9	$ 59.2	$ 27.2
Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	8	6	18	17
Recorded investment | $	$ 4.2	$ 1.4	$ 19.6	$ 5.1
Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	15	28	50	113
Recorded investment | $	$ 5	$ 6.6	$ 16.9	$ 32
Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	17	36	70	108
Recorded investment | $	$ 1.3	$ 3.3	$ 6.2	$ 10.2
Extended Maturity [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	7	8	17	14
Recorded investment | $	$ 2.1	$ 5.5	$ 7.4	$ 10.9
Extended Maturity [Member] | Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	3	6	19	13
Recorded investment | $	$ 9.8	$ 2.8	$ 22.9	$ 5.9
Extended Maturity [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts				1
Recorded investment | $				$ 0.5
Payment Deferral [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	1	2	4
Recorded investment | $	$ 1.2	$ 0.3	$ 1.2	$ 1.8
Payment Deferral [Member] | Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	3	1	11	8
Recorded investment | $	$ 13.6	$ 0.1	$ 33	$ 2.5
Payment Deferral [Member] | Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	3	1	8	2
Recorded investment | $	$ 2	$ 0.1	$ 12.7	$ 0.3
Payment Deferral [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	4	11	26
Recorded investment | $	$ 0.8	$ 0.7	$ 3.6	$ 8.6
Payment Deferral [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	7	4	16
Recorded investment | $	$ 0.1	$ 0.8	$ 0.3	$ 2.1
Combination of Concessions [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1		1	3
Recorded investment | $	$ 3.7		$ 3.7	$ 1.2
Combination of Concessions [Member] | Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1		5	15
Recorded investment | $	$ 1		$ 3.3	$ 18.8
Combination of Concessions [Member] | Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	5	5	10	15
Recorded investment | $	$ 2.2	$ 1.3	$ 6.9	$ 4.8
Combination of Concessions [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	5	13	21	58
Recorded investment | $	$ 3	$ 4.9	$ 7.9	$ 17.9
Combination of Concessions [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	6	17	37
Recorded investment | $	$ 0.3	$ 0.4	$ 1.6	$ 2.8
Bankruptcy [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	6	11	16	28
Recorded investment | $	$ 1.2	$ 1	$ 5.1	$ 5
Bankruptcy [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	12	22	48	53
Recorded investment | $	$ 0.9	$ 1.6	$ 3.8	$ 4.7
Contractual Interest Rate Reduction [Member] | Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts				1
Recorded investment | $				$ 18.2
Contractual Interest Rate Reduction [Member] | Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts			2
Recorded investment | $			$ 0.3
Contractual Interest Rate Reduction [Member] | Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts		1	1	2
Recorded investment | $		$ 0.5	$ 0.5	$ 0.6

Loans - Summary of Recorded I43

Loans - Summary of Recorded Investments in TDRs by Class of Loan, Subsequently Defaulted (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts	Sep. 30, 2015USD ($)Contracts	Sep. 30, 2014USD ($)Contracts
Financing Receivable, Modifications [Line Items]
Number of Contracts	6	23	48	77
Recorded Investment | $	$ 1.2	$ 6.8	$ 17.1	$ 20.2
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	4	14	15
Recorded Investment | $	$ 0.9	$ 4.4	$ 8.9	$ 5.9
Commercial [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts		3	2	5
Recorded Investment | $		$ 3.7	$ 3.4	$ 4.1
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	1	4	2
Recorded Investment | $	$ 0.6	$ 0.7	$ 1.4	$ 0.8
Commercial [Member] | Equipment Financing [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1		8	8
Recorded Investment | $	$ 0.3		$ 4.1	$ 1
Retail Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	19	34	62
Recorded Investment | $	$ 0.3	$ 2.4	$ 8.2	$ 14.3
Retail Loans [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	13	18	39
Recorded Investment | $	$ 0.2	$ 2.1	$ 6.7	$ 12.7
Retail Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	2	6	16	23
Recorded Investment | $	$ 0.1	$ 0.3	$ 1.5	$ 1.6

Loans - Summary of Individually

Loans - Summary of Individually-Evaluated Impaired Loans by Class of Loan (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	$ 223.2	$ 225.7
With no related allowance for loan losses, Recorded Investment	205.3	203
With a related allowance for loan losses, Unpaid Principal Balance	69.3	95.3
With a related allowance for loan losses, Recorded Investment	60.9	66.5
Unpaid Principal Balance	292.5	321
Recorded Investment	266.2	269.5
Related Allowance for Loan Losses	11.9	11.5
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance	185.5	216.1
Recorded Investment	169	174.5
Related Allowance for Loan Losses	8.2	7.6
Commercial [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	48	57.1
With no related allowance for loan losses, Recorded Investment	47.4	55.8
With a related allowance for loan losses, Unpaid Principal Balance	17.8	52.1
With a related allowance for loan losses, Recorded Investment	13.5	27.8
Unpaid Principal Balance	65.8	109.2
Recorded Investment	60.9	83.6
Related Allowance for Loan Losses	1.9	4
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	63.5	51.7
With no related allowance for loan losses, Recorded Investment	59.6	48.6
With a related allowance for loan losses, Unpaid Principal Balance	22.2	21.4
With a related allowance for loan losses, Recorded Investment	21.3	17.4
Unpaid Principal Balance	85.7	73.1
Recorded Investment	80.9	66
Related Allowance for Loan Losses	5.6	3.5
Commercial [Member] | Equipment Financing [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	21.5	30.2
With no related allowance for loan losses, Recorded Investment	17.7	21.4
With a related allowance for loan losses, Unpaid Principal Balance	12.5	3.6
With a related allowance for loan losses, Recorded Investment	9.5	3.5
Unpaid Principal Balance	34	33.8
Recorded Investment	27.2	24.9
Related Allowance for Loan Losses	0.7	0.1
Retail Loans [Member]
Financing Receivable, Impaired [Line Items]
With a related allowance for loan losses, Recorded Investment	16.6
Unpaid Principal Balance	107	104.9
Recorded Investment	97.2	95
Related Allowance for Loan Losses	3.7	3.9
Retail Loans [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	67.9	65.4
With no related allowance for loan losses, Recorded Investment	61.1	58.9
With a related allowance for loan losses, Unpaid Principal Balance	14.9	15.6
With a related allowance for loan losses, Recorded Investment	14.8	15.3
Unpaid Principal Balance	82.8	81
Recorded Investment	75.9	74.2
Related Allowance for Loan Losses	2.9	2.6
Retail Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance for loan losses, Unpaid Principal Balance	22.3	21.3
With no related allowance for loan losses, Recorded Investment	19.5	18.3
With a related allowance for loan losses, Unpaid Principal Balance	1.9	2.6
With a related allowance for loan losses, Recorded Investment	1.8	2.5
Unpaid Principal Balance	24.2	23.9
Recorded Investment	21.3	20.8
Related Allowance for Loan Losses	$ 0.8	$ 1.3

Loans - Schedule of Impaired Fi

Loans - Schedule of Impaired Financing Receivable (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 264.5	$ 254.1	$ 264.4	$ 236.7
Interest Income Recognized	1.3	1.2	4	3.8
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	168.9	163.4	167.8	148
Interest Income Recognized	0.8	0.7	2.7	2.6
Commercial [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	59.2	81.8	67.8	75.7
Interest Income Recognized	0.5	0.3	1.2	1.2
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	83	51	71.1	42.9
Interest Income Recognized	0.2	0.2	1.2	0.8
Commercial [Member] | Equipment Financing [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	26.7	30.6	28.9	29.4
Interest Income Recognized	0.1	0.2	0.3	0.6
Retail Loans [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	95.6	90.7	96.6	88.7
Interest Income Recognized	0.5	0.5	1.3	1.2
Retail Loans [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	74.4	72.3	75.3	71.4
Interest Income Recognized	0.4	0.4	1.1	1
Retail Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	21.2	18.4	21.3	17.3
Interest Income Recognized	$ 0.1	$ 0.1	$ 0.2	$ 0.2

Loans - Summary of Aging Inform

Loans - Summary of Aging Information by Class of Loan (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Consumer	$ 2,192.1	$ 2,200.6
Total Retail Portfolio	7,573.5	7,132.6
Total loans	27,672.2	26,592
Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Other	5,381.4	4,932
Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Commercial	9,785.4	9,404.3
Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	26,561.8	25,298.6
Total Past Due	268.9	242.5
Total Consumer	2,151.2	2,149.2
Total Retail Portfolio	7,334.4	6,850.7
Total loans	26,830.7	25,541.1
Originated [Member] | 30-89 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	155.7	125.5
Originated [Member] | 90 Days or More [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	113.2	117
Retail Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total loans	7,573.5	7,132.6
Retail Loans [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Consumer	50.9	57.5
Retail Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Consumer	2,141.2	2,143.1
Retail Loans [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Other	5,381.4	4,932
Retail Loans [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,251.7	6,782.4
Total Past Due	82.7	68.3
Total Retail Portfolio	7,334.4	6,850.7
Retail Loans [Member] | Originated [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	49.6	55.8
Total Past Due	0.3	0.5
Total Consumer	49.9	56.3
Retail Loans [Member] | Originated [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,084.6	2,079.3
Total Past Due	16.7	13.6
Total Consumer	2,101.3	2,092.9
Retail Loans [Member] | Originated [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,117.5	4,647.3
Total Past Due	65.7	54.2
Total Other	5,183.2	4,701.5
Retail Loans [Member] | Originated [Member] | 30-89 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	46.5	34.5
Retail Loans [Member] | Originated [Member] | 30-89 Days [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0.3	0.4
Retail Loans [Member] | Originated [Member] | 30-89 Days [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6.3	5
Retail Loans [Member] | Originated [Member] | 30-89 Days [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	39.9	29.1
Retail Loans [Member] | Originated [Member] | 90 Days or More [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	36.2	33.8
Retail Loans [Member] | Originated [Member] | 90 Days or More [Member] | Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		0.1
Retail Loans [Member] | Originated [Member] | 90 Days or More [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	10.4	8.6
Retail Loans [Member] | Originated [Member] | 90 Days or More [Member] | Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	25.8	25.1
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Commercial	20,098.7	19,459.4
Total loans	20,098.7	19,459.4
Commercial [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Commercial	9,785.4	9,404.3
Commercial [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Commercial	7,492.2	7,189.6
Commercial [Member] | Equipment Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Commercial	2,821.1	2,865.5
Commercial [Member] | Originated [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	19,310.1	18,516.2
Total Past Due	186.2	174.2
Total Commercial	19,496.3	18,690.4
Commercial [Member] | Originated [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	9,403.2	8,908
Total Past Due	33.5	52.3
Total Commercial	9,436.7	8,960.3
Commercial [Member] | Originated [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	7,173.6	6,814.9
Total Past Due	83.6	76.2
Total Commercial	7,257.2	6,891.1
Commercial [Member] | Originated [Member] | Equipment Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,733.3	2,793.3
Total Past Due	69.1	45.7
Total Commercial	2,802.4	2,839
Commercial [Member] | Originated [Member] | 30-89 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	109.2	91
Commercial [Member] | Originated [Member] | 30-89 Days [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	21	17.6
Commercial [Member] | Originated [Member] | 30-89 Days [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	29.2	32.4
Commercial [Member] | Originated [Member] | 30-89 Days [Member] | Equipment Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	59	41
Commercial [Member] | Originated [Member] | 90 Days or More [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	77	83.2
Commercial [Member] | Originated [Member] | 90 Days or More [Member] | Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12.5	34.7
Commercial [Member] | Originated [Member] | 90 Days or More [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	54.4	43.8
Commercial [Member] | Originated [Member] | 90 Days or More [Member] | Equipment Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 10.1	$ 4.7

Loans - Summary of Credit Quali

Loans - Summary of Credit Quality Indicators by Class of Loan (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 2,192.1	$ 2,200.6
Financing Receivable	7,573.5	7,132.6
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	20,098.7	19,459.4
Originated Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,334.4	6,850.7
Originated Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3,479	3,241.6
Originated Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,816.5	2,527
Originated Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1,038.9	1,082.1
Originated Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	19,496.3	18,690.4
Originated Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	18,510.9	17,689.5
Originated Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	295.2	307.2
Originated Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	687.1	679.8
Originated Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3.1	13.9
Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	40.9	51.4
Financing Receivable	239.1	281.9
Acquired Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	99.3	107
Acquired Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	40.3	50.5
Acquired Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	99.5	124.4
Acquired Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	602.4	769
Acquired Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	460	484.6
Acquired Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	28.1	74.4
Acquired Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	111.9	186.7
Acquired Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2.4	23.3
Commercial Real Estate Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,785.4	9,404.3
Commercial Real Estate Loan [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,785.4	9,404.3
Commercial Real Estate Loan [Member] | Originated Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,436.7	8,960.3
Commercial Real Estate Loan [Member] | Originated Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	9,211.9	8,730.9
Commercial Real Estate Loan [Member] | Originated Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	93.9	82.4
Commercial Real Estate Loan [Member] | Originated Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	130.9	135.3
Commercial Real Estate Loan [Member] | Originated Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable		11.7
Commercial Real Estate Loan [Member] | Acquired Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	348.7	444
Commercial Real Estate Loan [Member] | Acquired Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	269.6	302.5
Commercial Real Estate Loan [Member] | Acquired Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	22.3	20.9
Commercial Real Estate Loan [Member] | Acquired Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	55	113.5
Commercial Real Estate Loan [Member] | Acquired Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1.8	7.1
Commercial and Industrial [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,492.2	7,189.6
Commercial and Industrial [Member] | Originated Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	7,257.2	6,891.1
Commercial and Industrial [Member] | Originated Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	6,864.3	6,477.4
Commercial and Industrial [Member] | Originated Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	106	114.2
Commercial and Industrial [Member] | Originated Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	283.8	297.3
Commercial and Industrial [Member] | Originated Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	3.1	2.2
Commercial and Industrial [Member] | Acquired Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	235	298.5
Commercial and Industrial [Member] | Acquired Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	184.9	174.5
Commercial and Industrial [Member] | Acquired Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5.4	52.8
Commercial and Industrial [Member] | Acquired Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	44.1	55
Commercial and Industrial [Member] | Acquired Loans [Member] | Commercial [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0.6	16.2
Equipment Financing [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,821.1	2,865.5
Equipment Financing [Member] | Originated Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,802.4	2,839
Equipment Financing [Member] | Originated Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,434.7	2,481.2
Equipment Financing [Member] | Originated Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	95.3	110.6
Equipment Financing [Member] | Originated Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	272.4	247.2
Equipment Financing [Member] | Acquired Loans [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	18.7	26.5
Equipment Financing [Member] | Acquired Loans [Member] | Commercial [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5.5	7.6
Equipment Financing [Member] | Acquired Loans [Member] | Commercial [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	0.4	0.7
Equipment Financing [Member] | Acquired Loans [Member] | Commercial [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	12.8	18.2
Residential Mortgage Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5,381.4	4,932
Residential Mortgage Loan [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5,381.4	4,932
Residential Mortgage Loan [Member] | Originated Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	5,183.2	4,701.5
Residential Mortgage Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,502.4	2,280.6
Residential Mortgage Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,171.3	1,921.6
Residential Mortgage Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	509.5	499.3
Residential Mortgage Loan [Member] | Acquired Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	198.2	230.5
Residential Mortgage Loan [Member] | Acquired Loans [Member] | Retail Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	99.3	107
Residential Mortgage Loan [Member] | Acquired Loans [Member] | Retail Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	40.3	50.5
Residential Mortgage Loan [Member] | Acquired Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	58.6	73
Home Equity Loan [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,141.2	2,143.1
Home Equity Loan [Member] | Originated Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	2,101.3	2,092.9
Home Equity Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	950.7	931.5
Home Equity Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	636.9	597.1
Home Equity Loan [Member] | Originated Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	513.7	564.3
Home Equity Loan [Member] | Acquired Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	39.9	50.2
Home Equity Loan [Member] | Acquired Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	39.9	50.2
Consumer Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	50.9	57.5
Consumer Loans [Member] | Originated Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	49.9	56.3
Consumer Loans [Member] | Originated Loans [Member] | Retail Loans [Member] | Low Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	25.9	29.5
Consumer Loans [Member] | Originated Loans [Member] | Retail Loans [Member] | Moderate Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	8.3	8.3
Consumer Loans [Member] | Originated Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	15.7	18.5
Consumer Loans [Member] | Acquired Loans [Member] | Retail Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	1	1.2
Consumer Loans [Member] | Acquired Loans [Member] | Retail Loans [Member] | High Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable	$ 1	$ 1.2

Loans - Summarized Activity in

Loans - Summarized Activity in Accretable Yield for Acquired Loan Portfolio (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Receivables [Abstract]
Balance at beginning of period	$ 316.9	$ 447.7	$ 396.3	$ 639.7
Accretion	(13.3)	(18.9)	(42.9)	(63.9)
Reclassification from nonaccretable difference for loans with improved cash flows		0.3	1.1	6.7
Other changes in expected cash flows	5	(15.7)	(45.9)	(169.1)
Balance at end of period	$ 308.6	$ 413.4	$ 308.6	$ 413.4

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - shares	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Stockholders Equity [Line Items]
Number of common stock purchased	89,100,000	89,000,000
Repurchases Authorized by Board of Directors [Member]
Schedule Of Stockholders Equity [Line Items]
Number of common stock purchased	88,800,000
2007 Recognition and Retention Plan [Member]
Schedule Of Stockholders Equity [Line Items]
Number of common stock purchased	300,000
2014 Long-Term Incentive Plan [Member]
Schedule Of Stockholders Equity [Line Items]
Additional awards under RRP	0

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 4,633.1	$ 4,568.4
Amounts reclassified from AOCL	$ 1.8	$ 1	5.4	3.6
Current period other comprehensive income (loss)	18.4	1.7	22.1	30.6
Ending Balance	4,730.8	4,655	4,730.8	4,655
Pension and Other Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(142.9)	(85)
Amounts reclassified from AOCL			3.3	1.9
Current period other comprehensive income (loss)			3.3	1.9
Ending Balance	(139.6)	(83.1)	(139.6)	(83.1)
Net Unrealized Gains (Losses) on Securities Available for Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(3.7)	(46.5)
Other comprehensive income (loss) before reclassifications			17.5	27.2
Amounts reclassified from AOCL				(0.2)
Current period other comprehensive income (loss)			17.5	27
Ending Balance	13.8	(19.5)	13.8	(19.5)
Net Unrealized Gain (Losses) On Securities Transferred To Held To Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(21.5)	(23.3)
Amounts reclassified from AOCL			1.5	1.3
Current period other comprehensive income (loss)			1.5	1.3
Ending Balance	(20)	(22)	(20)	(22)
Net Unrealized Gains (Losses) on Derivatives Accounted for as Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(0.1)	(0.3)
Other comprehensive income (loss) before reclassifications			(0.8)	(0.2)
Amounts reclassified from AOCL			0.6	0.6
Current period other comprehensive income (loss)			(0.2)	0.4
Ending Balance	(0.3)	0.1	(0.3)	0.1
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(168.2)	(155.1)
Other comprehensive income (loss) before reclassifications			16.7	27
Amounts reclassified from AOCL			5.4	3.6
Current period other comprehensive income (loss)			22.1	30.6
Ending Balance	$ (146.1)	$ (124.5)	$ (146.1)	$ (124.5)

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Amounts Reclassified from AOCL (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income tax expense	$ (101.5)	$ (91.3)	$ (285.1)	$ (283.3)
Income tax expense	33.1	29.7	95.8	96.3
Net income	(68.4)	(61.6)	(189.3)	(187)
Interest expense - notes and debentures	(7.4)	(7.4)	(22.3)	(19.3)
Total reclassifications for the period	(1.8)	(1)	(5.4)	(3.6)
Pension and Other Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net actuarial loss	(2)	(1.2)	(6)	(3.9)
Prior service credit	0.3	0.2	0.8	0.8
Income before income tax expense	(1.7)	(1)	(5.2)	(3.1)
Income tax expense	0.6	0.4	1.9	1.2
Net income	(1.1)	(0.6)	(3.3)	(1.9)
Total reclassifications for the period			(3.3)	(1.9)
Net Unrealized Gains (Losses) on Securities Available for Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income tax expense		0.2		0.3
Income tax expense		(0.1)		(0.1)
Net income		0.1		0.2
Total reclassifications for the period				0.2
Net Unrealized Gain (Losses) On Securities Transferred To Held To Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income tax expense	(0.8)	(0.7)	(2.3)	(2.2)
Income tax expense	0.2	0.3	0.8	0.9
Net income	(0.6)	(0.4)	(1.5)	(1.3)
Total reclassifications for the period			(1.5)	(1.3)
Net Unrealized Gains (Losses) on Derivatives Accounted for as Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income before income tax expense	(0.2)	(0.2)	(0.9)	(0.9)
Income tax expense	0.1	0.1	0.3	0.3
Net income	(0.1)	(0.1)	(0.6)	(0.6)
Total reclassifications for the period			(0.6)	(0.6)
Net Unrealized Gains (Losses) on Derivatives Accounted for as Cash Flow Hedges [Member] | Interest Rate Swaps [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense - notes and debentures	(0.3)	(0.3)	(1)	(1)
Net Unrealized Gains (Losses) on Derivatives Accounted for as Cash Flow Hedges [Member] | Interest Rate Locks [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest expense - notes and debentures	$ 0.1	$ 0.1	$ 0.1	$ 0.1

Earnings Per Common Share - Bas

Earnings Per Common Share - Basic and Diluted Earnings Per Share, Reflecting Application of Two-Class Method (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 68.4	$ 61.6	$ 189.3	$ 187
Dividends and undistributed earnings allocated to participating securities	(0.3)	(0.3)	(0.9)	(0.9)
Income attributable to common shareholders	$ 68.1	$ 61.3	$ 188.4	$ 186.1
Average common shares outstanding for basic EPS	301	298.4	300.1	298.1
Effect of dilutive equity-based awards	0	0	0	0
Average common and common-equivalent shares for diluted EPS	301	298.4	300.1	298.1
Basic EPS	$ 0.23	$ 0.21	$ 0.63	$ 0.62
Diluted EPS	$ 0.23	$ 0.21	$ 0.63	$ 0.62

Earnings Per Common Share - Add

Earnings Per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Anti-dilutive equity-based awards excluded from calculation of diluted EPS	20.3	17.9	20.3	17.9

Goodwill and Other Acquisitio54

Goodwill and Other Acquisition-Related Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 1,954,500,000		$ 1,954,500,000		$ 1,954,500,000
Tax deductible goodwill amount	12,100,000		12,100,000		13,000,000
Other acquisition-related intangible assets	130,200,000		130,200,000		148,000,000
Amortization of other acquisition-related intangible assets	5,900,000	$ 6,200,000	17,800,000	$ 18,600,000
Amortization expense attributable to other acquisition-related intangible assets, 2015	23,800,000		23,800,000
Amortization expense attributable to other acquisition-related intangible assets, 2016	22,700,000		22,700,000
Amortization expense attributable to other acquisition-related intangible assets, 2017	21,600,000		21,600,000
Amortization expense attributable to other acquisition-related intangible assets, 2018	10,200,000		10,200,000
Amortization expense attributable to other acquisition-related intangible assets, 2019	9,400,000		9,400,000
Amortization expense attributable to other acquisition-related intangible assets, 2020	9,000,000		9,000,000
Impairment losses relating to goodwill or other acquisition-related intangible assets			0	$ 0
Trade Name Intangible [Member]
Goodwill And Other Intangible Assets [Line Items]
Other acquisition-related intangible assets	81,900,000		81,900,000
Core Deposit Intangibles [Member]
Goodwill And Other Intangible Assets [Line Items]
Other acquisition-related intangible assets	27,000,000		27,000,000
Customer Relationships [Member]
Goodwill And Other Intangible Assets [Line Items]
Other acquisition-related intangible assets	20,600,000		20,600,000
Insurance Relationships [Member]
Goodwill And Other Intangible Assets [Line Items]
Other acquisition-related intangible assets	700,000		700,000
Commercial Banking Loan [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill	1,220,000,000		1,220,000,000		1,220,000,000
Retail Banking [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill	681,900,000		681,900,000		681,900,000
Wealth Management [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 49,800,000		$ 49,800,000		$ 49,800,000

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	Apr. 30, 2007	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Average compensation term on which pension plan benefits are based, in years			5 years
Average compensation term within last ten years on which pension plan benefits are based, in years			5 years
Term considered when determining employee pension benefits, in years			10 years
Minimum age requirement to participate in pension plan, years			18 years
Minimum service hours per year requirement to participate in pension plan			1000 hours
Employer contributions		$ 40
ESOP, shares to be purchased	10,453,575
ESOP loan	$ 216.8		$ 192.1
Loan repayments expected annual through 2036			18.8
Cash dividends paid on unallocated ESOP shares			$ 3.8
Minimum age requirement to participate in ESOP			18 years
Minimum work experience within 12 months of hire needed to participate in ESOP			1000 hours
ESOP common stock allocated			3,048,962
Unallocated common stock of Employee Stock Ownership Plan, shares			7,404,613		7,700,000
Fair value of deferred ESOP shares			$ 116.5
ESOP compensation expense			4	$ 3.8
Chittenden Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions		$ 10
Net periodic benefit income			$ 0.1	$ 0.2
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of covered employee's eligible compensation			3.00%

Employee Benefit Plans - Compon

Employee Benefit Plans - Components of Net Periodic Benefit (Income) Expense and Other Amounts (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 4.8	$ 4.8	$ 14.4	$ 14.4
Expected return on plan assets	(7.8)	(7.1)	(22.8)	(21.3)
Recognized net actuarial loss	1.5	1	4.5	3
Settlements	0.1	0.4	0.3	1.4
Net periodic benefit (income) expense	(1.4)	(0.9)	(3.6)	(2.5)
Net actuarial loss			(4.5)	(3)
Total pre-tax changes recognized in other comprehensive income			(4.5)	(3)
Total recognized in net periodic benefit (income) expense and other comprehensive income			(8.1)	(5.5)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.1	0.1	0.2	0.2
Interest cost	0.1		0.4	0.3
Recognized net actuarial loss			0.2
Recognized prior service credit			(0.1)	(0.2)
Net periodic benefit (income) expense	$ 0.2	$ 0.1	0.7	0.3
Net actuarial loss			(0.2)
Prior service credit			0.1	0.2
Total pre-tax changes recognized in other comprehensive income			(0.1)	0.2
Total recognized in net periodic benefit (income) expense and other comprehensive income			$ 0.6	$ 0.5

Legal Proceedings - Additional

Legal Proceedings - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015
Waterford Township Police & Fire Retirement [Member]
Loss Contingencies [Line Items]
Complaint filed date	February 25, 2010
Yourgal [Member]
Loss Contingencies [Line Items]
Complaint filed date	March 29, 2010

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value transfers between level 1 and level 2	$ 0	$ 0
Maximum [Member] | Risk Participation Agreements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of Derivatives, Net	$ 100,000		$ 100,000
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity period of available-for-sale residential mortgage-backed securities portfolio	10 years		15 years
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount to impaired loans	10.00%

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	$ 8.3	$ 8.3
Securities available for sale, at fair value	4,221.2	3,993.7
Other assets	821.6	719.9
Fair Values, Assets	200.2	132.4
Fair Values, Liabilities	148.1	97
Fair value of total assets measured at fair value on a recurring basis	4,465	4,171.5
Fair value of total liabilities measured at fair value on a recurring basis	148.1	97
Exchange Traded Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	28.3	30.3
Fixed Income Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	5.4	6
Equity Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	1.6	0.8
US Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	8.3	8.3
U.S. Treasury and Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	376.2	56.8
GSE Residential Mortgage-Backed Securities and CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	3,844.8	3,936.7
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	0.2	0.2
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	198.7	131.1
Fair Values, Liabilities	146.6	95.8
Foreign Exchange Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	0.3	0.8
Fair Values, Liabilities		0.5
Forward Commitments to Sell Residential Mortgage Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	1.2	0.5
Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Liabilities	1.5	0.7
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of total assets measured at fair value on a recurring basis	414.4	96.2
Level 1 [Member] | Exchange Traded Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	28.3	30.3
Level 1 [Member] | Equity Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	1.6	0.8
Level 1 [Member] | US Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	8.3	8.3
Level 1 [Member] | U.S. Treasury and Agency [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	376.2	56.8
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of total assets measured at fair value on a recurring basis	4,050.6	4,075.3
Fair value of total liabilities measured at fair value on a recurring basis	148.1	97
Level 2 [Member] | Fixed Income Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	5.4	6
Level 2 [Member] | GSE Residential Mortgage-Backed Securities and CMOs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	3,844.8	3,936.7
Level 2 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale, at fair value	0.2	0.2
Level 2 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	198.7	131.1
Fair Values, Liabilities	146.6	95.8
Level 2 [Member] | Foreign Exchange Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	0.3	0.8
Fair Values, Liabilities		0.5
Level 2 [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Assets	1.2	0.5
Level 2 [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Values, Liabilities	$ 1.5	$ 0.7

Fair Value Measurements - Ass60

Fair Value Measurements - Assets Measured at Fair Value on Non-Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	$ 36.2	$ 34.2
Impaired loans	60.9	66.5
REO and repossessed assets	26.3	27.1
Total assets measured at fair value on non-recurring basis	123.4	127.8
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	36.2	34.2
Total assets measured at fair value on non-recurring basis	36.2	34.2
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	60.9	66.5
REO and repossessed assets	26.3	27.1
Total assets measured at fair value on non-recurring basis	$ 87.2	$ 93.6

Fair Value Measurements - Ass61

Fair Value Measurements - Assets Measured at Fair Value on Non-Recurring Basis (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 60,900,000		$ 60,900,000		$ 66,500,000
Charge-offs to the allowance for loan losses related to loans	6,200,000	$ 12,400,000	23,700,000	$ 30,700,000
Repossessed assets	7,300,000		7,300,000		2,500,000
Write downs and net loss on sale of foreclosed/repossessed assets charged to non-interest expense total	214,200,000	208,800,000	643,600,000	633,800,000
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Charge-offs to the allowance for loan losses related to loans			6,000,000	6,700,000
REO and Repossessed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Charge-offs to the allowance for loan losses related to loans			1,500,000	1,000,000
Write Down Net Loss on Sale of Foreclosed Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Write downs and net loss on sale of foreclosed/repossessed assets charged to non-interest expense total			1,200,000	3,700,000
Retail Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	16,600,000		16,600,000
Charge-offs to the allowance for loan losses related to loans	3,300,000	$ 2,100,000	6,200,000	6,700,000
Residential Mortgage Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustments			0	$ 0
Real estate owned	10,800,000		10,800,000		13,600,000
Residential Mortgage Loan [Member] | Retail Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	14,800,000		14,800,000		15,300,000
Commercial Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	44,300,000		44,300,000
Commercial Real Estate Loan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Real estate owned	$ 8,200,000		$ 8,200,000		$ 11,000,000

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Amounts and Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	$ 300.3	$ 345.1
Short-term investments	244.6	668.6
Securities held to maturity	1,377.1	834.3
FHLB and FRB stock	314.7	175.7
Time deposits	5,165.9	5,230.7
FHLB advances	2,164.5	2,291.7
Customer repurchase agreements		1
Federal funds purchased	360	913
Notes and debentures	1,044.9	1,033.5
Securities purchased under agreements to resell		100
Commercial Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements	472.3	486
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	300.3	345.1
Short-term investments	244.6	668.6
Securities held to maturity	1,377.1	834.3
FHLB and FRB stock	314.7
Total loans, net	27,403.8	26,327.2
Time deposits	5,165.9	5,230.7
Other deposits	23,113.8	20,907.5
FHLB advances	2,164.5	2,291.7
Federal funds purchased	360	913
Notes and debentures	1,044.9	1,033.5
Securities purchased under agreements to resell		100
FHLB stock		175.7
Carrying Amount [Member] | Commercial Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements	472.3	486
Carrying Amount [Member] | Institutional Counterparties [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements		1
Estimated Fair Value Measurements [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	300.3	345.1
Short-term investments	244.6	668.6
Securities held to maturity	1,421.6	881.6
FHLB and FRB stock	314.7
Total loans, net	27,568.9	26,307.3
Time deposits	5,205.9	5,262.6
Other deposits	23,113.8	20,907.5
FHLB advances	2,172.6	2,298.5
Federal funds purchased	360	913
Notes and debentures	1,018.3	1,040.8
Securities purchased under agreements to resell		100
FHLB stock		175.7
Estimated Fair Value Measurements [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and due from banks	300.3	345.1
Estimated Fair Value Measurements [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term investments	244.6	668.6
Securities held to maturity	1,420.1	880.1
FHLB and FRB stock	314.7
Total loans, net	5,260.9	4,798.5
Time deposits	5,205.9	5,262.6
Other deposits	23,113.8	20,907.5
FHLB advances	2,172.6	2,298.5
Federal funds purchased	360	913
Notes and debentures	1,018.3	1,040.8
Securities purchased under agreements to resell		100
FHLB stock		175.7
Estimated Fair Value Measurements [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities held to maturity	1.5	1.5
Total loans, net	22,308	21,508.8
Estimated Fair Value Measurements [Member] | Commercial Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements	472.3	486
Estimated Fair Value Measurements [Member] | Commercial Customers [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements	$ 472.3	486
Estimated Fair Value Measurements [Member] | Institutional Counterparties [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements		1
Estimated Fair Value Measurements [Member] | Institutional Counterparties [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Customer repurchase agreements		$ 1

Fair Value Measurements - Car63

Fair Value Measurements - Carrying Amounts and Estimated Fair Values of Financial Instruments (Parenthetical) (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Impaired loans	$ 60.9	$ 66.5

Derivative Financial Instrume64

Derivative Financial Instruments and Hedging Activities - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Dec. 31, 2012	Sep. 30, 2015
Derivative [Line Items]
Aggregate fair value of derivative instruments		$ 11,800,000
Collateral posted in normal course of business		11,300,000
Additional collateral required if senior unsecured debt had fallen below investment grade		500,000
Subordinated notes		$ 125,000,000
Subordinated notes fixed interest rate		5.80%
Subordinated Notes [Member]
Derivative [Line Items]
LIBOR basis points		Three-month LIBOR
Basis points		0.685%
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative; fixed-rate (Pay fixed/receive floating interest Interest rate swap)		1.99%
Notional amount of derivatives		$ 125,000,000
Interest Rate Swaps [Member] | Fair Value [Member]
Derivative [Line Items]
Subordinated notes		$ 400,000,000
LIBOR basis points		Three-month LIBOR
Basis points		1.265%
Notional amount of derivatives		$ 375,000,000
Treasury Forward Interest Rate Locks ("T-Locks") [Member]
Derivative [Line Items]
Derivative instruments hedge description		To hedge the risk that the 10-year U.S. Treasury yield would rise
Unrealized gain on derivatives	$ 900,000
Period hedged items affected earnings, years	10 years
Treasury Forward Interest Rate Locks ("T-Locks") [Member] | Subordinated Notes [Member]
Derivative [Line Items]
Senior notes issuance		$ 500,000,000

Derivative Financial Instrume65

Derivative Financial Instruments and Hedging Activities - Schedule of Notional Amounts and Fair Values of Derivatives Outstanding (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Forward commitments to sell residential mortgage loans	$ 174,900,000	$ 117,300,000
Total, Derivatives Designated as Hedging Instruments, Fair Values, Assets	25,300,000	15,100,000
Total Derivatives Fair value,Assets	200,200,000	132,400,000
Total, Derivatives Not Designated as Hedging Instruments, Fair Values, Liabilities	146,900,000	96,000,000
Total, Derivatives Designated as Hedging Instruments, Fair Values, Liabilities	1,200,000	1,000,000
Fair Values, Liabilities	148,100,000	97,000,000
Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	83,400,000	57,500,000
Derivatives Not Designated as Hedging Instruments, Foreign exchange contracts, Fair Values, Liabilities	1,500,000	700,000
Fair Values, Liabilities	1,500,000	700,000
Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	62,300,000	35,300,000
Forward commitments to sell residential mortgage loans	1,200,000	500,000
Risk Participation Agreements [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	240,400,000	150,100,000
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	125,000,000
Interest Rate Swaps [Member] | Fair Value [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	375,000,000
Interest Rate Swaps [Member] | Commercial Customers [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	4,287,500,000	3,380,200,000
Derivatives Not Designated as Hedging Instruments, Interest rate swaps, Fair Values, Assets	172,100,000	104,200,000
Derivatives Not Designated as Hedging Instruments, Foreign exchange contracts, Fair Values, Liabilities	1,000,000	8,300,000
Interest Rate Swaps [Member] | Institutional Counterparties [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	4,287,500,000	3,380,200,000
Derivatives Not Designated as Hedging Instruments, Interest rate swaps, Fair Values, Assets	1,300,000	11,800,000
Derivatives Not Designated as Hedging Instruments, Foreign exchange contracts, Fair Values, Liabilities	144,400,000	86,500,000
Interest Rate Swaps [Member] | Subordinated Notes [Member] | Cash Flow [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	125,000,000	125,000,000
Derivative Assets Designated as Hedging Instruments, Fair Values, Assets	0	0
Total, Derivatives Designated as Hedging Instruments, Fair Values, Liabilities	1,200,000	1,000,000
Interest Rate Swaps [Member] | Subordinated Notes [Member] | Fair Value [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	375,000,000	375,000,000
Derivative Assets Designated as Hedging Instruments, Fair Values, Assets	25,300,000	15,100,000
Total, Derivatives Designated as Hedging Instruments, Fair Values, Liabilities	0	0
Foreign Exchange Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional Amounts	46,900,000	49,600,000
Derivatives Not Designated as Hedging Instruments, Foreign exchange contracts, Fair Values, Assets	300,000	800,000
Total Derivatives Fair value,Assets	$ 300,000	800,000
Derivatives Not Designated as Hedging Instruments, Interest rate swaps, Fair Values, Liabilities		500,000
Fair Values, Liabilities		$ 500,000

Derivative Financial Instrume66

Derivative Financial Instruments and Hedging Activities - Schedule of Notional Amounts and Fair Values of Derivatives Outstanding (Parenthetical) (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Derivatives Not Designated as Hedging Instruments [Member] | Maximum [Member] | Risk Participation Agreements [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Fair Value of Derivatives, Net	$ 100,000	$ 100,000

Derivative Financial Instrume67

Derivative Financial Instruments and Hedging Activities - Impact of Derivatives on Pre-Tax Income and Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	$ 16.6	$ 7.1
Amount of Pre-Tax Gain (Loss) Recognized in AOCL	(1.2)	(0.4)
Derivatives Not Designated as Hedging Instruments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	10.6	5.7
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	(0.8)	(0.3)
Derivatives Not Designated as Hedging Instruments [Member] | Forward Commitments to Sell Residential Mortgage Loans [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	0.7	0.2
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Commercial Customers [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	127.8	100.1
Derivatives Not Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Institutional Counterparties [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	(116.9)	(94.6)
Derivatives Not Designated as Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings		0.4
Derivatives Not Designated as Hedging Instruments [Member] | Risk Participation Agreements [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	(0.2)	(0.1)
Derivatives Designated as Hedging Instruments [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	6	1.4
Amount of Pre-Tax Gain (Loss) Recognized in AOCL	(1.2)	(0.4)
Derivatives Designated as Hedging Instruments [Member] | Cash Flow [Member] | Interest Rate-Lock Commitments on Residential Mortgage Loans [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	0.1	0.1
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Cash Flow [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	(1)	(1)
Amount of Pre-Tax Gain (Loss) Recognized in AOCL	(1.2)	(0.4)
Derivatives Designated as Hedging Instruments [Member] | Interest Rate Swaps [Member] | Fair Value [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in Earnings	$ 6.9	$ 2.3

Balance Sheet Offsetting - Summ

Balance Sheet Offsetting - Summary of Gross Presentation, Financial Instruments that are Eligible for Offset in Consolidated Statement of Condition (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Offsetting Assets And Liabilities [Line Items]
Financial liabilities, Gross Amount Recognized	$ 145.6
Financial liabilities, Gross Amount Offset	0
Financial liabilities, Net Amount Presented	145.6
Financial liabilities, Financial Instruments	(26.6)
Financial liabilities, Collateral	(118.1)
Financial liabilities, Net Amount	0.9
Financial assets, Gross Amount Recognized	26.9	$ 127.7
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	26.9	127.7
Financial assets, Financial Instruments	(26.6)	(24.1)
Financial assets, Collateral		(102.8)
Financial assets, Net Amount	0.3	0.8
Financial assets, Gross Amount Recognized	200.2	132.4
Financial liabilities, Gross Amount Recognized	148.1	97
Financial assets, Gross Amount Recognized		100
Financial assets, Gross Amount Offset		0
Financial assets, Net Amount Presented		100
Financial assets, Financial Instruments		0
Financial assets, Collateral		(100)
Financial assets, Net Amount		0
Financial liabilities, Gross Amount Recognized		1
Financial liabilities, Gross Amount Offset		0
Financial liabilities, Net Amount Presented		1
Financial liabilities, Financial Instruments		0
Financial liabilities, Collateral		(1)
Financial liabilities, Net Amount		0
Foreign Exchange Contracts [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized	0.3	0.8
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	0.3	0.8
Financial assets, Net Amount	0.3	0.8
Financial liabilities, Gross Amount Recognized		0.5
Financial liabilities, Gross Amount Offset		0
Financial liabilities, Net Amount Presented		0.5
Financial liabilities, Net Amount		0.5
Counterparty A [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized	0.2	2.7
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	0.2	2.7
Financial assets, Financial Instruments	(0.2)	(2.7)
Financial liabilities, Gross Amount Recognized	11.7	11.8
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	11.7	11.8
Financial liabilities, Financial Instruments	(0.2)	(2.7)
Financial liabilities, Collateral	(11.5)	(9.1)
Counterparty B [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized	0.4	1.5
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	0.4	1.5
Financial assets, Financial Instruments	(0.4)	(1.5)
Financial liabilities, Gross Amount Recognized	13.4	11.8
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	13.4	11.8
Financial liabilities, Financial Instruments	(0.4)	(1.5)
Financial liabilities, Collateral	(13)	(10.3)
Counterparty C [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized		2.5
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented		2.5
Financial assets, Financial Instruments		(2.5)
Financial liabilities, Gross Amount Recognized	7.1	4.5
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	7.1	4.5
Financial liabilities, Financial Instruments		(2.5)
Financial liabilities, Collateral	(7)	(1.9)
Financial liabilities, Net Amount	0.1	0.1
Counterparty D [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized	0.5	3.2
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	0.5	3.2
Financial assets, Financial Instruments	(0.5)	(0.4)
Financial assets, Collateral		(2.8)
Financial liabilities, Gross Amount Recognized	11.1	0.4
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	11.1	0.4
Financial liabilities, Financial Instruments	(0.5)	(0.4)
Financial liabilities, Collateral	(9.9)
Financial liabilities, Net Amount	0.7
Counterparty E [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized	25.5	15.7
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented	25.5	15.7
Financial assets, Financial Instruments	(25.5)	(15.7)
Financial liabilities, Gross Amount Recognized	95.9	47.8
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	95.9	47.8
Financial liabilities, Financial Instruments	(25.5)	(15.7)
Financial liabilities, Collateral	(70.4)	(32.1)
Other Counterparties [Member] | Interest Rate Swaps [Member]
Offsetting Assets And Liabilities [Line Items]
Financial assets, Gross Amount Recognized		1.3
Financial assets, Gross Amount Offset	0	0
Financial assets, Net Amount Presented		1.3
Financial assets, Financial Instruments		(1.3)
Financial liabilities, Gross Amount Recognized	6.4	11.2
Financial liabilities, Gross Amount Offset	0	0
Financial liabilities, Net Amount Presented	6.4	11.2
Financial liabilities, Financial Instruments		(1.3)
Financial liabilities, Collateral	(6.3)	(8.9)
Financial liabilities, Net Amount	$ 0.1	$ 1