First Niagara Financial (FNFG) 10-K 17 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Mar. 16, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	FIRST NIAGARA FINANCIAL GROUP INC
Entity Central Index Key	1051741
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		353,343,381
Public Float			$3,084,373,688
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated_Statements_of_Con

Consolidated Statements of Condition (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
ASSETS
Cash and cash equivalents	$420	$463
Investment securities:
Available for sale, at fair value (amortized cost of $5,830 and $7,319 in 2014 and 2013; includes pledged securities that can be sold or repledged of $39 and $303 in 2014 and 2013)	5,915	7,423
Held to maturity, at amortized cost (fair value of $5,964 and $3,988 in 2014 and 2013; includes pledged securities that can be sold or repledged of $128 and $388 in 2014 and 2013)	5,942	4,042
Federal Home Loan Bank and Federal Reserve Bank common stock, at amortized cost	412	469
Loans held for sale	40	50
Loans and leases (net of allowance for loan losses of $234 and $209 in 2014 and 2013)	22,803	21,230
Bank owned life insurance	426	415
Premises and equipment, net	407	418
Goodwill	1,350	2,449
Core deposit and other intangibles, net	67	94
Other assets	769	574
Total assets	38,551	37,628
Liabilities:
Deposits	27,781	26,665
Short-term borrowings	5,472	4,822
Long-term borrowings	734	734
Other	471	414
Total liabilities	34,458	32,635
Stockholders’ equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized; Series B, noncumulative perpetual preferred stock, $25 liquidation preference; 14,000,000 shares issued in 2014 and 2013	338	338
Common stock, $0.01 par value, 500,000,000 shares authorized; 366,002,045 shares issued in 2014 and 2013	4	4
Additional paid-in capital	4,235	4,235
(Accumulated deficit) retained earnings	-330	536
Accumulated other comprehensive income	9	62
Common stock held by employee stock ownership plan, 2,001,373 shares in 2013	0	-17
Treasury stock, at cost, 12,613,836 and 12,060,739 shares in 2014 and 2013	-162	-165
Total stockholders’ equity	4,093	4,993
Total liabilities and stockholders’ equity	$38,551	$37,628

Consolidated_Statements_of_Con1

Consolidated Statements of Condition (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Amortized cost for securities available for sale	$5,830	$7,319
Fair value of pledged securities that can be sold or repledged	39	303
Fair value for securities held-to-maturity	5,964	3,988
Amortized cost of pledged securities that can be sold or repledged	128	388
Allowance for credit losses on loans and leases	$234	$209
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	14,000,000	14,000,000
Liquidation preference	$25	$25
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares issued	366,002,045	366,002,045
Common stock held by employee stock ownership plan, shares	0	2,001,373
Treasury stock, shares	12,613,836	12,060,739

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest income:
Loans and leases	$847	$845	$814
Investment securities and other	361	365	362
Total interest income	1,207	1,210	1,176
Interest expense:
Deposits	53	53	67
Borrowings	69	64	86
Total interest expense	122	117	153
Net interest income	1,086	1,093	1,023
Provision for credit losses	96	105	92
Net interest income after provision for credit losses	990	988	931
Noninterest income:
Deposit service charges	90	104	91
Insurance commissions	66	67	68
Merchant and card fees	50	49	39
Wealth management services	61	58	41
Mortgage banking	18	18	32
Capital markets income	18	22	27
Lending and leasing	18	17	15
Bank owned life insurance	15	17	14
Gain on securities portfolio repositioning	0	0	21
Other income	-26	12	12
Total noninterest income	310	366	360
Noninterest expense:
Salaries and employee benefits	463	461	427
Occupancy and equipment	112	111	99
Technology and communications	127	115	101
Marketing and advertising	35	20	32
Professional services	56	39	41
Amortization of intangibles	27	40	45
Federal deposit insurance premiums	40	35	35
Restructuring charges	22	0	6
Goodwill impairment	1,100	0	0
Deposit account remediation	22	0	0
Merger and acquisition integration expenses	0	0	178
Other expense	120	110	88
Total noninterest expense	2,124	931	1,051
(Loss) income before income taxes	-824	423	239
Income tax (benefit)	-109	128	71
Net (loss) income	-715	295	168
Preferred stock dividend	30	30	28
Net (loss) income available to common stockholders	($745)	$265	$141
(Loss) earnings per share:
Basic (dollars per share)	($2.13)	$0.75	$0.40
Diluted (dollars per share)	($2.13)	$0.75	$0.40
Weighted average common shares outstanding:
Basic	350	350	349
Diluted	350	350	349
Dividends per common share	$0.32	$0.32	$0.32

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net (loss) income	($715)	$295	$168
Securities available for sale:
Net unrealized (losses) gains arising during the year	-12	-109	109
Reclassification adjustment for realized gains included in net income	0	0	-10
Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity during the year	0	-34	2
Net unrealized (losses) gains on securities available for sale	-12	-143	101
Net unrealized holding gains on securities transferred between available for sale and held to maturity:
Net unrealized holding gains on securities transferred during the year	0	34	-2
Less: amortization of net unrealized holding gains to income during the year	-8	-12	-2
Net unrealized holding gains on securities transferred during the year	-8	22	-4
Net unrealized gains on interest rate swaps designated as cash flow hedges arising during the year	1	1	7
Pension and post-retirement actuarial (losses) gains	-34	25	-14
Total other comprehensive (loss) income	-53	-95	89
Total comprehensive (loss) income	($768)	$200	$258

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Preferred stock	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income	Common stock held by ESOP	Treasury stock
In Millions
Beginning Balance at Dec. 31, 2011	$4,798	$338	$4	$4,228	$375	$68	($19)	($196)
Net (loss) income	168				168
Other comprehensive (loss) income	89					89
ESOP shares committed to be released (177,942 shares, 177,942 shares, and 297,080 shares in 2012, 2013 and 2014, respectively)	2			0			1
Stock-based compensation expense	11			11
Net tax expense from stock-based compensation	-1			-1
Restricted stock activity (786,670 shares, 1,320,324 shares, 1,151,193 shares in 2012, 2013, and 2014, respectively)	-2			-9	-5			12
Preferred stock dividends	-28				-28
Common stock dividends of $0.32 per share	-112				-112
Ending Balance at Dec. 31, 2012	4,927	338	4	4,231	399	157	-18	-184
Net (loss) income	295				295
Other comprehensive (loss) income	-95					-95
ESOP shares committed to be released (177,942 shares, 177,942 shares, and 297,080 shares in 2012, 2013 and 2014, respectively)	2			0			1
Stock-based compensation expense	9			9
Net tax expense from stock-based compensation	-1			-1
Restricted stock activity (786,670 shares, 1,320,324 shares, 1,151,193 shares in 2012, 2013, and 2014, respectively)	-1			-4	-15			19
Preferred stock dividends	-30				-30
Common stock dividends of $0.32 per share	-112				-112
Ending Balance at Dec. 31, 2013	4,993	338	4	4,235	536	62	-17	-165
Net (loss) income	-715				-715
Other comprehensive (loss) income	-53					-53
ESOP shares committed to be released (177,942 shares, 177,942 shares, and 297,080 shares in 2012, 2013 and 2014, respectively)	2				0		2
Repurchase of shares upon ESOP termination (1,704,290)	1						15	-14
Stock-based compensation expense	11			11
Net tax expense from stock-based compensation	-1			-1
Restricted stock activity (786,670 shares, 1,320,324 shares, 1,151,193 shares in 2012, 2013, and 2014, respectively)	-2			-11	-8			17
Preferred stock dividends	-30				-30
Common stock dividends of $0.32 per share	-113				-113
Ending Balance at Dec. 31, 2014	$4,093	$338	$4	$4,235	($330)	$9	$0	($162)

Consolidated_Statements_of_Cha1

Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Repurchase of shares upon ESOP termination	1,704,290
ESOP shares committed to be released	297,080	177,942	177,942
Restricted stock activity, shares	1,151,193	1,320,324	786,670
Common stock, dividend per share	$0.32	$0.32	$0.32

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net (loss) income	($715)	$295	$168
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Goodwill impairment	1,100	0	0
Amortization of fees and discounts, net	45	49	30
Provision for credit losses	96	105	92
Depreciation of premises and equipment	58	53	43
Amortization of intangibles	27	40	45
Gain on securities portfolio repositioning	0	0	-21
Origination of loans held for sale	-648	-1,295	-1,504
Proceeds from sales of loans held for sale	668	1,412	1,453
ESOP and stock based-compensation expense	13	11	13
Deferred income tax (benefit) expense	-150	5	34
Contributions to defined benefit pension plans	0	0	-112
Other, net	-10	40	-82
Net cash provided by operating activities	484	716	159
Cash flows from investing activities:
Proceeds from sales of securities available for sale	331	485	3,239
Proceeds from maturities of securities available for sale	371	196	242
Principal payments received on securities available for sale	952	1,124	2,108
Purchases of securities available for sale	-162	-1,497	-6,273
Principal payments received on securities held to maturity	781	868	481
Purchases of securities held to maturity	-2,743	-636	0
Proceeds from maturities of securities held to maturity	35	0	0
Proceeds from sales of (payments for purchases of) Federal Home Loan Bank and Federal Reserve Bank common stock	57	-49	-62
Net increase in loans and leases	-1,634	-1,767	-1,814
Acquisitions, net of cash and cash equivalents	0	0	7,703
Purchases of premises and equipment	-57	-67	-104
Other, net	-68	-32	53
Net cash (used in) provided by investing activities	-2,136	-1,375	5,574
Cash flows from financing activities:
Net increase (decrease) in deposits	1,119	-1,004	-1,645
Proceeds from short-term borrowings, net	650	1,839	775
Repayments of long-term borrowings	-2	0	-5,127
Repurchase of shares upon ESOP termination	-14	0	0
Dividends paid on noncumulative preferred stock	-30	-30	-28
Dividends paid on common stock	-113	-112	-112
Other, net	-1	-1	-1
Net cash provided by (used in) financing activities	1,610	692	-6,138
Net (decrease) increase in cash and cash equivalents	-43	32	-406
Cash and cash equivalents at beginning of period	463	431	837
Cash and cash equivalents at end of period	420	463	431
Cash paid during the period for:
Income taxes	52	57	16
Interest expense	123	126	241
Acquisition of noncash assets and liabilities:
Assets acquired	0	0	2,408
Liabilities assumed	0	0	10,111
Other noncash activity:
Securities available for sale purchased not settled	18	0	0
Securities transferred from available for sale to held to maturity (at fair value)	0	3,001	0
Securities transferred from held to maturity to available for sale	$0	$0	$861

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 1. Summary of Significant Accounting Policies
	First Niagara Financial Group, Inc. (the “Company”), a Delaware corporation, and its subsidiaries provide financial services to individuals and businesses in New York, Western and Eastern Pennsylvania, Connecticut, and Western Massachusetts. Through our wholly owned subsidiary, First Niagara Bank, N.A. (the “Bank”), a federally chartered national bank, we provide a full range of products and services through our retail consumer, commercial, business services, and wealth management operations, including retail banking, consumer and commercial lending, cash management, insurance and wealth management products.
	Our accounting and reporting policies conform to U.S. generally accepted accounting principles (“GAAP”) and general practices within the banking industry. Reclassifications of prior years’ amounts are made whenever necessary to conform to the current year’s presentation. The following is a description of our significant accounting policies:
	Principles of Consolidation
	Our Consolidated Financial Statements include the accounts of the Company and its subsidiaries. We have eliminated all significant intercompany balances in consolidation.
	Subsequent Events
	We reviewed subsequent events and determined that no further disclosures or measurements were required.
	Cash and Cash Equivalents
	For purposes of our Consolidated Statement of Cash Flows, cash and cash equivalents include cash and due from banks, money market investments, and federal funds sold which have an original term of less than three months.
	Investment Securities
	We have classified our investments in debt and equity securities as held to maturity or available for sale. We classify investment securities as held to maturity if we have the positive intent and ability to hold them to maturity. Held to maturity securities are reported at amortized cost. We classify investment securities not classified as held to maturity as available for sale, and report them at fair value with unrealized gains and losses, net of deferred taxes, reported in other comprehensive income as a separate component of stockholders’ equity.
	We are required to maintain an investment in common stock of the Federal Home Loan Bank (“FHLB”) of New York and Boston as well as the Federal Reserve Bank because our Bank is a member of the FHLB and the Federal Reserve System. We consider these stocks to be nonmarketable equity securities and carry them at cost.
	We conduct a quarterly review and evaluation of our investment securities portfolio to determine if any declines in fair value below amortized cost are other than temporary. In making this determination, we consider some or all of the following factors: the period of time the securities have been in an unrealized loss position, the percentage decline in fair value in comparison to the securities’ amortized cost, credit rating, the financial condition of the issuer and guarantor, where applicable, the delinquency or default rates of underlying collateral, credit enhancement, projected losses, level of credit loss, and projected cash flows. If we intend to sell a security with a fair value below amortized cost or if it is more likely than not that we will be required to sell such a security before recovery, we record an other than temporary impairment charge through current period earnings for the full decline in fair value below amortized cost. For debt securities that we do not intend to sell or it is more likely than not that we will not be required to sell before recovery, we record an other than temporary impairment charge through current period earnings for the amount of the valuation decline below amortized cost that is attributable to credit losses. The remaining difference between the debt security’s fair value and amortized cost (that is, decline in fair value not attributable to credit losses) is recognized in other comprehensive income.
	Our investment securities portfolio includes residential mortgage-backed securities and collateralized mortgage obligations. As the underlying collateral of each of these securities is comprised of a large number of similar residential mortgage loans for which prepayments are probable and the timing and amount of such prepayments can be reasonably estimated, we consider estimates of future principal prepayments of these underlying residential mortgage loans in the calculation of the constant effective yield used to apply the interest method for income recognition, with retroactive adjustments made as warranted.
	Purchases and sales of investment securities are recorded on trade date, with realized gains and losses on sales included in our Consolidated Statements of Income using the specific identification method. We amortize premiums and accrete discounts on our investment securities to interest income utilizing the interest method.
	Originated Loans and Leases
	Loans we originate and intend to hold in our portfolio are stated at the principal amount outstanding, adjusted for unamortized deferred fees and costs which we amortize to interest income over the expected life of the loan using the interest method. We discontinue accrual of interest on originated loans after payments become more than 90 days past due, or earlier if we do not expect the full collection of principal or interest, with the exception of credit cards. Credit cards are placed on nonaccrual status at 180 days past due. The delinquency status is based upon the contractual terms of the loans. We reverse all uncollected interest income that we previously recognized on nonaccrual loans. When we have doubt as to the collectibility of a loan’s principal, we apply interest payments to principal. With the exception of residential mortgage loans that are well secured and in the process of collection, cash receipts received on nonperforming impaired loans are first applied to the loan’s principal. Once the remaining principal balance has been collected in full, cash receipts are then applied as recoveries of any partially charged-off amount on the loan. Once a loan’s principal balance, including any previously charged-off amounts are collected in full, cash receipts are recorded as interest income. For residential mortgage loans, where the loan is both well secured and in the process of collection, we recognize interest income on a cash basis. Interest income on performing troubled debt restructurings, which are considered impaired loans, are applied in accordance with the terms of the modified loan.
	We return loans to accrual status when principal and interest payments are current, we expect full collectibility of principal and interest, and a consistent repayment record, generally six consecutive payments, has been demonstrated.
	We charge loans off against our allowance for loan losses when it becomes evident that we will not fully collect the balance of the loan. For business and commercial real estate loans, we record a charge off when it is determined that the collection of all or a portion of a loan may not be collected and the amount of that loss is reasonably estimable. For our consumer loans secured by real estate, including our residential mortgages, home equity loans and home equity lines of credit, we order broker price opinions (“BPOs”) at 90 days past due and record partial or full charge-offs based upon the results of such valuations by no later than 180 days past due. All other closed end consumer loans are charged off at 120 days past due and all other open ended consumer lines, including credit card loans, are charged off at 180 days past due.
	We consider a loan impaired when, based on current information, it is probable that we will be unable to collect all amounts of principal and interest due under the original terms of the agreement. Beginning in the second quarter of 2014, we raised the threshold for evaluating commercial loans individually for impairment from $200 thousand to $1 million. Additionally, all loans modified in a troubled debt restructuring (“TDR”), regardless of size, are considered impaired. The impact of this change to our allowance for loan losses was not significant. This change was implemented on a prospective basis, accordingly, prior period financial disclosures were not revised. We measure the impairment in these loans based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical alternative, the loan’s observable market price or the fair value of the underlying collateral, if the loan is collateral dependent.
	At origination, a determination is made whether a loan will be held in our portfolio or is intended for sale in the secondary market. Loans that will be held in our portfolio are carried at amortized cost. Beginning in the second quarter of 2011, we elected the fair value option for substantially all residential mortgage loans held for sale as we believe the fair value measurement of such loans reduces certain timing differences in our Statement of Income and better aligns with our management of the portfolio from a business perspective. This loan by loan election is made at the time of origination and is irrevocable. Residential mortgage loans held for sale for which the fair value option has not been elected, are recorded at the lower of the aggregate cost or market value (“LOCOM”). For residential mortgage loans held for sale where we have elected the fair value option any change in fair value subsequent to origination is recognized immediately in earnings in mortgage banking income. For residential mortgage loans held for sale that are recorded at LOCOM, we recognize any subsequent decreases in fair value in a valuation allowance through a charge to earnings at the time the decline in value occurs. We include gains and losses occurring during the holding period as well as those resulting from sales of our loans held for sale in mortgage banking income.
	Acquired Loans
	Loans that we acquired in acquisitions subsequent to January 1, 2009 were recorded at fair value with no carryover of the related allowance for loan losses at the time of acquisition. Determining the fair value of the loans involved estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest.
	We have acquired loans in four separate acquisitions between January 2009 and May 2012. For each acquisition, we reviewed all loans greater than $1 million and considered the following factors as indicators that such an acquired loan had evidence of deterioration in credit quality and was therefore in the scope of Accounting Standards Codification (“ASC”) 310-30 (Loans and Debt Securities Acquired with Deteriorated Credit Quality):
	•	Loans that were 90 days or more past due;
	•	Loans that had an internal risk rating of substandard or worse. Substandard is consistent with regulatory definitions and is defined as having a well defined weakness that jeopardizes liquidation of the loan;
	•	Loans that were classified as nonaccrual by the acquired bank at the time of acquisition; or
	•	Loans that had been previously modified in a troubled debt restructuring.
	Individual acquired loans determined to have evidence of deterioration in credit quality are accounted for individually in accordance with ASC 310-30. Any acquired loans that were not individually in the scope of ASC 310-30 because they did not meet the criteria above were either (i) pooled into groups of similar loans based on the borrower type, loan purpose, and collateral type and accounted for under ASC 310-30 by analogy or (ii) accounted for under ASC 310-20 (Nonrefundable Fees and Other Costs.)
	Based on the guidance included in the December 18, 2009 letter from the AICPA Depository Institutions Panel to the Office of the Chief Accountant of the SEC, we have made an accounting policy election to apply ASC 310-30 by analogy to qualifying acquired pools of loans that (i) were acquired in a business combination or asset purchase, (ii) resulted in recognition of a discount attributable, at least in part, to credit quality; and (iii) were not subsequently accounted for at fair value.
	Acquired loans accounted for under ASC 310-30
	The excess of expected cash flows from acquired loans over the estimated fair value of acquired loans at acquisition is referred to as the accretable discount and is recognized into interest income over the remaining life of the acquired loans using the interest method. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the acquired loans. Subsequent decreases to the expected cash flows require us to evaluate the need for an addition to the allowance for loan losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Our evaluation of the amount of future cash flows that we expect to collect takes into account actual credit performance of the acquired loans to date and our best estimates for the expected lifetime credit performance of the loans using currently available information. Charge-offs on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment. To the extent that we experience a deterioration in credit quality in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loans.
	In accordance with ASC 310-30, recognition of income is dependent on having a reasonable expectation about the timing and amount of cash flows expected to be collected.  We perform such an evaluation on a quarterly basis on both our acquired loans individually accounted for under ASC 310-30 and those in pools accounted for under ASC 310-30 by analogy.
	Cash flows for acquired loans individually accounted for under ASC 310-30 are estimated on a quarterly basis.  Based on this evaluation, a determination is made as to whether or not we have a reasonable expectation about the timing and amount of cash flows.  Such an expectation includes cash flows from normal customer repayment, foreclosure or other collection efforts.  Cash flows for acquired loans accounted for on a pooled basis under ASC 310-30 by analogy are also estimated on a quarterly basis.  For residential real estate, home equity and other consumer loans, cash flow loss estimates are calculated by a vintage and FICO based model which incorporates a projected forward loss curve.  For commercial loans, lifetime loss rates are assigned to each pool with consideration given for pool make-up, including risk rating profile.  Lifetime loss rates are developed from internally generated loss data and are applied to each pool.
	To the extent that we cannot reasonably estimate cash flows, interest income recognition is discontinued.  The unit of account for loans in pools accounted for under ASC 310-30 by analogy is the pool of loans.  Accordingly, as long as we can reasonably estimate cash flows for the pool as a whole, accretable yield on the pool is recognized and all individual loans within the pool - even those more than 90 days past due - would be considered to be accruing interest in our financial statement disclosures, regardless of whether or not we expected to collect any principal or interest cash flows on an individual loan 90 days or more past due.
	Allowance for Loan Losses
	We establish our allowance for loan losses through a provision for credit losses. The level of the allowance for loan losses is based on our evaluation of the overall credit quality of our total loan portfolio. We segregate our loans between loans we originated which are accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired (referred to as “acquired” loans), as acquired loans were originally recorded at fair value, which included an estimate of lifetime credit losses, resulting in no carryover of the related allowance for loan losses. We continue to monitor and modify the level of our allowance for loan losses to ensure it is adequate to cover losses inherent in our loan portfolio.
	Originated loans
	We determine our allowance for loan losses by portfolio segment, which consists of commercial loans and consumer loans. Our commercial loan portfolio includes both business and commercial real estate loans. Our consumer loan portfolio includes residential real estate, home equity, indirect auto, credit card and other consumer loans. The allowance for loan losses is comprised of two components. The first component covers pools of loans for which there are incurred losses that are not yet individually identifiable. The allowance for pools of loans is based on net historical loan loss experience for similar loans with similar inherent risk characteristics and performance trends adjusted, as appropriate, for quantitative and qualitative risk factors specific to respective loan types. The second component covers loans that have been identified as impaired or are nonperforming as well as troubled debt restructurings (“TDRs”.)
	Commercial loan portfolio
	Commercial loans are initially evaluated using quantitative models whereby loans are grouped into pools based on similar risk characteristics such as loan type and grade to determine the historical loss rate. By loan type, the historical loss experience over an established loss emergence and look back period for each loan pool is used to calculate historical loss rates that are used as the primary driver of the quantitative historical allowance estimate. The loss emergence and historical loss look-back periods may vary based on a variety of factors. For example, a relatively long look-back may be the appropriate measure during times of economic stability; however, during a period of significant or rapid economic expansion or contraction, a shorter measurement period may be more appropriate. The loss emergence and look back periods may vary by loan pool and are considered in the determination of the historical loss rates for each pool.
	Once the quantitative historical loss rates are established they may be adjusted for qualitative factors to reflect portfolio characteristics, credit concentrations and model imprecision conditions that are not captured in the historical loss rates, recent trends in loan volume and mix, delinquency, local and national economic factors, changes to the Bank’s lending policies and procedures, experience of lending staff, industrial and geographic factors, competition and legal or regulatory requirements. In addition, historical loss rates are modified when loan growth patterns or other trends indicate that the historical loss factors would not accurately reflect losses inherent in the current portfolio. Final adjustments to the historical loss rate calculation are made for known portfolio characteristics such as 100% cash secured loans and SBA guaranteed loans not captured in the modeling approach. Simulation techniques such as Monte Carlo modeling, using varying levels of confidence, are used to make such qualitative adjustments. These simulations help estimate the impact of concentrations such as large loan risk aspects within a loan portfolio and ensure that a reasonable amount of tail risk is captured. The Monte Carlo output may be adjusted for changes in loss severity based on recent trends that would affect charge-off levels. All qualitative adjustments are supported with trend (or other relevant data), which are documented in the quarterly allowance for loan loss analysis. Combining the quantitative and qualitative measurements, the Commercial loan component of our allowance for loan losses is recorded.
	Consumer loan portfolio
	We estimate the allowance for loan losses for our consumer loan portfolio by estimating the amount of loans that will eventually default based on their current delinquency severity. We then apply a loss rate to the amount of loans that we predict will default based on our historical net loss experience. This amount is then adjusted, as necessary, for qualitative considerations to reflect changes in underwriting, market or industry conditions or based on changes in trends in the composition of the portfolio, including risk composition, seasoning, and underlying collateral. We obtain and review refreshed FICO scores on a quarterly basis, and trends are evaluated for consideration as a qualitative adjustment to the allowance. Other qualitative considerations include, but are not limited to, the evaluation of trends in property values, building permits and unemployment.
	Impaired loans
	We consider a commercial loan impaired, when, based on current information, it is probable that we will be unable to collect all amounts of principal and interest due under the original terms of the agreement. Beginning in the second quarter of 2014, we raised the threshold for evaluating commercial loans individually for impairment from $200 thousand to $1 million. Additionally, all loans (commercial and consumer) modified in a troubled debt restructuring (“TDR”), regardless of size, are considered impaired. The impact of this change to our allowance for loan losses was not significant. This change was implemented on a prospective basis, accordingly, prior period financial disclosures were not revised. The need for specific valuation allowances are determined for impaired loans and recorded as necessary. We measure the impairment in these loans based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical alternative, the loan’s observable market price or the fair value of the underlying collateral, if the loan is collateral dependent. We then factor any related allowance for loan losses for these loans. Confirmed losses are charged off immediately. We typically would obtain an appraisal to use as the basis for the fair value of the underlying collateral.
	Acquired Loans
	Acquired loans accounted for under ASC 310-30 (including those accounted for under ASC 310-30 by analogy)
	For our acquired loans accounted for under ASC 310-30 for which subsequent decreases to the expected cash flows requires us to evaluate the need for an addition to the allowance for loan losses, our modeling techniques are similar to those we utilize for our originated loans. To the extent that we experience a deterioration in borrower credit quality resulting in a decrease in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loans.
	Acquired loans accounted for under ASC 310-20
	We establish our allowance for loan losses through a provision for credit losses based upon an evaluation process that is similar to our evaluation process used for originated loans. This evaluation, which includes a review of loans on which full collectability may not be reasonably assured, considers, among other matters, the estimated fair value of the underlying collateral, economic conditions, historical net loan loss experience, carrying value of the loans, which includes the remaining net purchase discount or premium, and other factors that warrant recognition in determining our allowance for loan losses.
	Premises and Equipment
	Our premises and equipment are carried at cost, net of accumulated depreciation and amortization. We compute depreciation on the straight-line method over the estimated useful lives of the assets. We amortize our leasehold improvements on the straight-line method over the lesser of the life of the improvements or the lease term. We generally depreciate buildings over a period of 20 to 39 years, furniture and equipment over a period of 3 to 10 years, and capital leases over the lesser of the useful life or the respective lease term.
	Goodwill and Intangible Assets
	We record the excess of the cost of acquired entities over the fair value of identifiable tangible and intangible assets acquired less the fair value of liabilities assumed as goodwill. We amortize our acquired identifiable intangible assets with definite useful economic lives over their useful economic life utilizing an accelerated amortization method. On a periodic basis, we assess whether events or changes in circumstances indicate that the carrying amounts of our core deposit and other intangible assets may be impaired. We do not amortize goodwill or any acquired identifiable intangible assets with an indefinite useful economic life, but we review them for impairment on an annual basis, or when events or changes in circumstances indicate that the carrying amounts may be impaired. Goodwill is reviewed for impairment at the reporting unit level. We define a reporting unit as a distinct, separately identifiable component of one of our operating segments for which complete, discrete financial information is available and reviewed regularly by that segment’s management.
	We have the option to first assess qualitative factors to determine whether there are events or circumstances that exist that make it more likely than not that the fair value of the reporting unit is less than its carrying amount (Step 0). If it is more likely than not that the fair value of the reporting unit is less than its carrying amount, or if we choose to bypass the qualitative assessment, we proceed to compare each reporting unit's fair value to carrying value to identify potential impairment (Step 1). If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired. However, if the carrying amount of the reporting unit were to exceed its estimated fair value, a second step (Step 2) would be performed that would compare the implied fair value of the reporting unit's goodwill with the carrying amount of the goodwill for the reporting unit. The implied fair value of goodwill is determined in the same manner as goodwill that is recognized in a business combination. Significant judgment and estimates are involved in estimating the fair value of the assets and liabilities of the reporting units.
	We perform our annual impairment review of goodwill on November 1 of each year utilizing valuation methods we believe appropriate, given the availability and applicability of market-based inputs for those methods.
	Derivative Instruments
	We use interest rate swaps to manage our interest rate risk. We also act as an interest rate swap counterparty for certain commercial customers, and manage the interest rate risk of these positions by entering into offsetting interest rate swap agreements with third parties. Interest rate swaps are recorded on our Consolidated Statements of Condition as either an asset or liability at estimated fair value and recognition of the changes in fair value in the income statement depends upon whether the interest rate swaps are in a designated hedging relationship. The change in the fair value of interest rate swaps designated as fair value hedges, including both the effective and ineffective portions, is recognized in earnings. These amounts are offset by the change in fair value of the hedged item, which is also recognized in earnings. The gain or loss associated with the effective portion of our cash flow hedges is recognized in other comprehensive income and is subsequently reclassified into earnings in the period during which the hedged forecasted transactions affects earnings. The gain or loss associated with the ineffective portion of our cash flow hedges is recognized immediately in earnings. We formally document our risk management objectives, strategy, and the relationship between the hedging instrument and the hedged items. We evaluate the effectiveness of the hedge relationship both at inception of the hedge and on an ongoing basis. If the interest rate swap is not designated in a hedge relationship, gains or losses reflecting changes in fair value are recorded in earnings.
	Employee Benefits
	We maintain an employer sponsored 401(k) plan where participants may make contributions in the form of salary deferrals and we provide matching contributions in accordance with the terms of the plan. Contributions due under the terms of our defined contribution plans are accrued as earned by employees.
	We also maintain noncontributory, qualified, defined benefit pension plans for certain employees who meet age and service requirements. We provide post-retirement benefits, principally health care and group life insurance, to employees who meet certain age and service requirements. We have frozen all benefit participation in our pension and post-retirement plans. Pension plans that we acquired in connection with our previous whole-bank acquisitions were frozen prior to or shortly after the completion of the transactions. The actuarially determined pension benefit in the form of a life annuity is based on the employee’s combined years of service, age, and compensation. The cost of our pension plan is based on actuarial estimates of current and future benefits for employees and is charged to current operating expenses.
	We recognize an asset for a plan’s overfunded status or a liability for a plan’s underfunded status in our financial statements. We report changes in the funded status of our pension and postretirement plans as a component of other comprehensive income, net of applicable taxes, in the year in which changes occur.
	We measure our plans’ assets and obligations that determine its future funded status as of December 31st each year.
Stock-Based Compensation
We maintain various long-term incentive stock benefit plans under which we grant stock options, restricted stock awards, and restricted stock units to certain key employees and directors. We recognize compensation expense in our income statement over the requisite service period, based on the grant-date fair value of the award. The fair values of stock options are estimated using the Black-Scholes option pricing model. For restricted stock awards and units, we recognize compensation expense on a straight-line basis over the vesting period for the fair value of the award, measured at the grant date.
Income Taxes
We account for income taxes under the asset and liability method. Our deferred tax assets and liabilities are reflected at currently enacted income tax rates applicable to the periods in which we expect the deferred tax assets or liabilities to be realized or settled. Deferred tax assets are recognized only to the extent that it is probable that sufficient taxable profit will be available against which those unused tax losses, unused tax credits or deductible temporary differences can be utilized. As changes in tax laws or rates are enacted, we adjust our deferred tax assets and liabilities through income tax expense. We recognize penalties and accrued interest related to unrecognized tax benefits in income tax expense. Federal and State tax credits are accounted for as a reduction of income tax expense.
Earnings per Share
We compute earnings per common share (“EPS”) in accordance with the two-class method, which requires that our unvested restricted stock awards that contain nonforfeitable rights to dividends be treated as participating securities in the computation of EPS pursuant to the two-class method. The two-class method is an earnings allocation that determines EPS for each class of common stock and participating security. Our basic EPS is computed by dividing net income allocable to common stockholders by the weighted average number of our common shares outstanding for the period. Our diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in our earnings. Unallocated common shares held by the Employee Stock Ownership Plan (“ESOP”) are not included in the weighted-average number of common shares outstanding for either basic or diluted earnings per share calculations.
Investment and Fiduciary Services
Assets that we hold in a fiduciary or agency capacity for our customers are not included in our accompanying Consolidated Statements of Condition, since these assets are not our assets and we are not the primary beneficiary. We recognize fee income from the management of these assets using the accrual method.
Use of Estimates
We have made a number of estimates and assumptions relating to the reporting of assets and liabilities and disclosure of contingent assets and liabilities in order to prepare these financial statements in conformity with GAAP. The estimates and assumptions that we deem to be critical involve our accounting policies relating to our valuation of our investment securities, prepayment assumptions on our collateralized mortgage obligations and mortgage-backed securities, the accounting treatment and valuation of our acquired loans, adequacy of our allowance for loan losses, and the analysis of the carrying value of goodwill for impairment. These estimates and assumptions are based on management’s best estimates and judgment and we evaluate them on an ongoing basis using historical experience and other factors, including the current economic environment. We adjust our estimates and assumptions when facts and circumstances dictate. As future events cannot be determined with precision, actual results could differ significantly from our estimates.
Accounting Standards Adopted in 2014
In February 2013, the FASB issued guidance for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. Examples of obligations within the scope of the guidance include debt arrangements, other contractual obligations, and settled litigation and judicial rulings. The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
In June 2013, the FASB released amended guidance to improve the accounting for determining whether an entity is an investment company.  The amendments change the approach to assessing investment company status and provide two required fundamental characteristics and five typical characteristics for determining whether an entity is an investment company.  The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
In July 2013, the FASB issued guidance to reduce diversity in practice related to the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  Some entities present the unrecognized tax benefit as a liability and other entities present the unrecognized tax benefit as a reduction to a deferred tax asset.  The guidance requires an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset. The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
In November 2014, the FASB issued guidance that allows, through an option, an acquired entity to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. The guidance became effective in November 2014 on a prospective basis to future change-in-control events.
Accounting Standards Not Yet Required to be Adopted as of December 31, 2014
In January 2014, the FASB issued guidance on accounting for investments by a reporting entity in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for the low-income housing tax credit.  The low-income housing tax credit program is designed to encourage private capital investment in the construction and rehabilitation of low-income housing.  The guidance becomes effective for us on January 1, 2015 with early adoption permitted.  We have not early adopted this guidance and we do not expect this to have a significant impact on our financial statements.
In January 2014, the FASB issued guidance on when a creditor should reclassify a collateralized mortgage loan such that the loan should be derecognized and the collateral asset recognized.  The objective of the guidance is to reduce diversity by clarifying when an in substance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized.  The guidance becomes effective for us on January 1, 2015 with early adoption permitted.  We have not early adopted this guidance and we do not expect this to have a significant impact on our financial statements.
In April 2014, the FASB issued guidance that will change the requirements for reporting discontinued operations.  The new guidance will require that a disposal of an entity or a group of components of an entity be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results.  The guidance becomes effective for us on January 1, 2015 and we do not expect this to have a significant impact on our financial statements.
In May 2014, the FASB issued guidance that improves the revenue recognition requirements for contracts with customers. The core principle is that an entity 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 guidance becomes effective for us on January 1, 2017, and we are currently evaluating the impact on our financial statements.
In June 2014, the FASB issued guidance that clarifies the accounting for share-based payments granted to employees in which the terms of the award provide that a performance target, that affects vesting, could be achieved after the requisite service period. The amendments require that those performance targets should be treated as performance conditions. The guidance becomes effective for us on January 1, 2016, with early adoption permitted, and we are currently evaluating the impact on our financial statements.
In August 2014, the FASB issued guidance that requires a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the following conditions are met: (1) the loan has a government guarantee that is not separable from the loan before foreclosure; (2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim; and (3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal plus interest) expected to be recovered from the guarantor. The guidance becomes effective for us on January 1, 2015, and we do not expect this to have a significant impact on our financial statements.
In August 2014, the FASB issued guidance on determining when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if “conditions or events raise substantial doubt about the entity’s ability to continue as a going concern.” The guidance applies to all entities and is effective for us for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted, and we do not expect this to have a significant impact on our financial statements.
In November 2014, the FASB issued guidance for determining whether the nature of the host contract within a hybrid instrument is more akin to debt or equity. The guidance requires evaluating the nature of the host contract by considering the economic characteristics and risks of the entire hybrid, including the embedded feature that is being evaluated for separation. The guidance becomes effective for us on January 1, 2016, and we do not expect this to have a significant impact on our financial statements.
In January 2015, the FASB issued guidance that eliminates the concept of extraordinary items from GAAP. The guidance becomes effective for us on January 1, 2016 and may be applied on either a prospective or retrospective basis and we do not expect this to have a significant impact on our financial statements.
In February 2015, the FASB issued guidance which amends existing standards regarding the evaluation of certain legal entities and their consolidation in the financial statements. The amendments modify the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities and eliminate the presumption that a general partner should consolidate a limited partnership. The amendments also affect the consolidation analysis of reporting entities that are involved with variable interest entities and provide a scope exception from consolidation guidance for reporting entities with interests in legal entities that are required to comply with or operate in accordance with requirements that are similar to those in Rule 2a-7 of the Investment Company Act of 1940 for registered money market funds. The guidance becomes effective for us on January 1, 2016 and we are evaluating the impact of this guidance on our financial statements.
Pending FASB Rule Proposals
The FASB currently has two projects underway that could have a meaningful impact on bank financial statements, capital levels and regulatory capital ratios. The first project, which addresses the amount and timing of loss recognition for loans and investment securities, would generally result in an increase in overall allowance levels and lower capital levels. This project has been exposed for public comment three times since 2010. The most recent exposure draft did not contain an effective date, and the FASB has not indicated when they expect to issue a final standard or the final effective date.
The second project relates to leases and requires an operating lease to be recognized on the balance sheet as a "right to use" asset and as a corresponding liability representing the obligation to pay rent. This project would result in an increase to assets and liabilities recognized and therefore increase risk-weighted assets for regulatory capital purposes. This project has been exposed for public comment twice since 2010. The most recent exposure draft did not contain an effective date, and the FASB has not indicated when they expect to issue a final standard or the final effective date.
We are evaluating the projects as proposed and the possible range of impacts and will determine any impact of these projects to capital or future earnings once the final rules are issued.

Investment_Securities

Investment Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities
	The amortized cost, gross unrealized gains and losses, and fair value of our investment securities are as follows at December 31:
		Amortized		Unrealized			Unrealized			Fair
	2014	cost		gains			losses			value
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	444	$	10		$	—		$	453
	U.S. Treasury	25		—			—			25
	U.S. government sponsored enterprises	187		5			—			191
	Corporate	820		15			(12		)	823
	Total debt securities	1,476		29			(12		)	1,492
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	34		1			(1		)	34
	Federal National Mortgage Association	96		5			—			100
	Federal Home Loan Mortgage Corporation	115		5			—			120
	Collateralized mortgage obligations:
	Federal National Mortgage Association	694		2			(13		)	682
	Federal Home Loan Mortgage Corporation	353		1			(4		)	350
	Total collateralized mortgage obligations	1,047		3			(18		)	1,032
	Total residential mortgage-backed securities	1,291		13			(19		)	1,286
	Commercial mortgage-backed securities, non-agency issued	1,450		51			—			1,500
	Total mortgage-backed securities	2,741		64			(19		)	2,786
	Collateralized loan obligations, non-agency issued	1,001		18			(3		)	1,016
	Asset-backed securities collateralized by:
	Student loans	228		7			—			235
	Credit cards	42		—			—			42
	Auto loans	193		1			—			194
	Other	127		1			(1		)	127
	Total asset-backed securities	591		9			(1		)	599
	Other	22		—			—			22
	Total securities available for sale	$	5,830	$	121		$	(35	)	$	5,915
	Investment securities held to maturity:
	Debt securities, U.S. government agencies	$	60	$	—		$	—		$	60
	Residential mortgage-backed securities:
	Government National Mortgage Association	12		—			—			12
	Federal National Mortgage Association	118		1			(1		)	118
	Federal Home Loan Mortgage Corporation	65		1			—			65
	Collateralized mortgage obligations:
	Government National Mortgage Association	1,755		27			(3		)	1,779
	Federal National Mortgage Association	1,965		11			(22		)	1,954
	Federal Home Loan Mortgage Corporation	1,967		25			(17		)	1,976
	Total collateralized mortgage obligations	5,687		63			(41		)	5,709
	Total residential mortgage-backed securities	5,882		64			(42		)	5,904
	Total securities held to maturity	$	5,942	$	64		$	(42	)	$	5,964
		Amortized		Unrealized			Unrealized			Fair
	2013	cost		gains			losses			value
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	516	$	14		$	—		$	529
	U.S. Treasury	20		—			—			20
	U.S. government sponsored enterprises	306		7			(1		)	312
	Corporate	863		19			(11		)	872
	Total debt securities	1,705		40			(12		)	1,734
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	41		1			(2		)	40
	Federal National Mortgage Association	134		5			—			139
	Federal Home Loan Mortgage Corporation	154		5			—			159
	Collateralized mortgage obligations:
	Federal National Mortgage Association	797		—			(36		)	761
	Federal Home Loan Mortgage Corporation	396		—			(17		)	379
	Non-agency issued	12		1			—			13
	Total collateralized mortgage obligations	1,205		1			(54		)	1,152
Total residential mortgage-backed securities	1,534		12			(56		)	1,490
Commercial mortgage-backed securities, non-agency issued	1,759		74			(2		)	1,831
Total mortgage-backed securities	3,294		85			(58		)	3,321
Collateralized loan obligations, non-agency issued	1,392		40			(2		)	1,431
Asset-backed securities collateralized by:
Student loans	306		6			—			312
Credit cards	73		—			(1		)	73
Auto loans	331		4			—			335
Other	186		1			(1		)	186
Total asset-backed securities	896		11			(2		)	905
Other	33		1			—			33
Total securities available for sale	$	7,319	$	178		$	(74	)	$	7,423
Investment securities held to maturity:
Debt securities, U.S. government agencies	$	5	$	—		$	—		$	5
Residential mortgage-backed securities:
Government National Mortgage Association	17		—			—			17
Federal National Mortgage Association	146		—			(3		)	143
Federal Home Loan Mortgage Corporation	81		—			(1		)	81
Collateralized mortgage obligations:
Government National Mortgage Association	1,713		26			(12		)	1,727
Federal National Mortgage Association	1,074		—			(47		)	1,027
Federal Home Loan Mortgage Corporation	1,007		12			(30		)	989
Total collateralized mortgage obligations	3,793		39			(90		)	3,742
Total residential mortgage-backed securities	4,037		40			(94		)	3,983
Total securities held to maturity	$	4,042	$	40		$	(94	)	$	3,988
The table below details certain information regarding our investment securities that were in an unrealized loss position at the dates indicated by the length of time those securities were in a continuous loss position:
	Less than 12 months								12 months or longer						Total
	Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
31-Dec-14	value		losses			Count			value		losses			Count	value		losses			Count
Investment securities available for sale:
Debt securities:
States and political subdivisions	$	16	$	—		22			$	1	$	—		5	$	17	$	—		27
U.S. Treasury	5		—			1			—		—			—	5		—			1
U.S. government sponsored enterprises	18		—			7			42		—			4	60		—			11
Corporate	176		(7		)	127			102		(5		)	61	278		(12		)	188
Total debt securities	215		(7		)	157			145		(5		)	70	360		(12		)	227
Mortgage-backed securities:
Residential mortgage-backed securities:
Government National Mortgage Association	—		—			—			19		(1		)	5	19		(1		)	5
Collateralized mortgage obligations:
Federal National Mortgage Association	26		—			3			517		(13		)	30	542		(13		)	33
Federal Home Loan Mortgage Corporation	47		—			3			216		(4		)	12	263		(4		)	15
Total collateralized mortgage obligations	73		—			6			733		(18		)	42	806		(18		)	48
Total residential mortgage-backed securities	73		—			6			752		(19		)	47	825		(19		)	53
Commercial mortgage-backed securities, non-agency issued	13		—			3			24		—			3	36		—			6
Total mortgage-backed securities	85		—			9			776		(19		)	50	861		(19		)	59
Collateralized loan obligations, non-agency issued	276		(2		)	32			146		(1		)	15	422		(3		)	47
Asset-backed securities collateralized by:
Student loans	26		—			4			2		—			2	28		—			6
Credit card	8		—			1			—		—			—	8		—			1
Auto loans	3		—			2			—		—			—	3		—			2
Other	—		—			1			52		(1		)	5	52		(1		)	6
Total asset-backed securities	37		—			8			55		(1		)	7	92		(1		)	15
Other	—		—			—			9		—			3	9		—			3
Total securities available for sale in an unrealized loss position	$	614	$	(10	)	206			$	1,130	$	(26	)	145	$	1,744	$	(35	)	351
	Less than 12 months								12 months or longer						Total
	Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
31-Dec-14	value		losses			Count			value		losses			Count	value		losses			Count
Investment securities held to maturity:
Debt securities, U.S. government agencies	$	38	$	—		5			$	—	$	—		—	$	38	$	—		5
Residential mortgage-backed securities:
Government National Mortgage Association	—		—			—			2		—			2	2		—			2
Federal National Mortgage Association	4		—			1			51		(1		)	12	55		(1		)	13
Federal Home Loan Mortgage Corporation	33		—			9			9		—			2	42		—			11
Collateralized mortgage obligations:
Government National Mortgage Association	360		(2		)	48			46		(1		)	12	407		(3		)	60
Federal National Mortgage Association	240		(1		)	18			648		(21		)	36	888		(22		)	54
Federal Home Loan Mortgage Corporation	422		(5		)	27			463		(12		)	28	885		(17		)	55
Total collateralized mortgage obligations	1,022		(8		)	93			1,157		(34		)	76	2,179		(41		)	169
Total residential mortgage-backed securities	1,059		(8		)	103			1,219		(35		)	92	2,278		(42		)	195
Total securities held to maturity in an unrealized loss position	$	1,097	$	(8	)	108			$	1,219	$	(35	)	92	$	2,316	$	(42	)	200
	Less than 12 months								12 months or longer						Total
	Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
31-Dec-13	value		losses			Count			value		losses			Count	value		losses			Count
Investment securities available for sale:
Debt securities:
States and political subdivisions	$	13	$	—		25			$	3	$	—		7	$	16	$	—		32
U.S. government sponsored enterprises	71		(1		)	11			2		—			2	73		(1		)	13
Corporate	232		(8		)	165			74		(2		)	23	306		(11		)	188
Total debt securities	315		(9		)	201			79		(2		)	32	394		(12		)	233
Mortgage-backed securities:
Residential mortgage-backed securities:
Government National Mortgage Association	—		—			—			19		(2		)	6	19		(2		)	6
Federal National Mortgage Association	—		—			3			—		—			3	1		—			6
Collateralized mortgage obligations:
Federal National Mortgage Association	744		(36		)	41			—		—			—	744		(36		)	41
Federal Home Loan Mortgage Corporation	361		(17		)	19			—		—			—	361		(17		)	19
Non-agency issued	1		—			3			—		—			—	1		—			3
Total collateralized mortgage obligations	1,106		(54		)	63			—		—			—	1,106		(54		)	63
Total residential mortgage-backed securities	1,106		(54		)	66			19		(2		)	9	1,125		(56		)	75
Commercial mortgage-backed securities, non-agency issued	158		(2		)	15			12		—			3	170		(2		)	18
Total mortgage-backed securities	1,264		(56		)	81			32		(2		)	12	1,296		(58		)	93
Collateralized loan obligations, non-agency issued	261		(2		)	28			3		—			1	264		(2		)	29
Asset-backed securities collateralized by:
Student loans	67		—			8			—		—			—	67		—			8
Credit card	36		(1		)	4			—		—			—	36		(1		)	4
Auto loans	25		—			5			—		—			—	25		—			5
Other	72		(1		)	11			—		—			—	72		(1		)	11
Total asset-backed securities	200		(2		)	28			—		—			—	200		(2		)	28
Other	14		—			3			8		—			2	22		—			5
Total securities available for sale in an unrealized loss position	$	2,054	$	(69	)	341			$	122	$	(5	)	47	$	2,176	$	(74	)	388
	Less than 12 months								12 months or longer						Total
	Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
31-Dec-13	value		losses			Count			value		losses			Count	value		losses			Count
Investment securities held to maturity:
Debt securities, U.S. government agencies	$	5	$	—		1			$	—	$	—		—	$	5	$	—		1
Residential mortgage-backed securities:
Government National Mortgage Association	11		—			4			—		—			—	11		—			4
Federal National Mortgage Association	119		(3		)	30			—		—			—	119		(3		)	30
Federal Home Loan Mortgage Corporation	59		(1		)	15			—		—			—	59		(1		)	15
Collateralized mortgage obligations:
Government National Mortgage Association	520		(12		)	58			—		—			—	520		(12		)	58
Federal National Mortgage Association	1,011		(47		)	59			—		—			—	1,011		(47		)	59
Federal Home Loan Mortgage Corporation	629		(30		)	35			22		(1		)	1	652		(30		)	36
Total collateralized mortgage obligations	2,160		(89		)	152			22		(1		)	1	2,182		(90		)	153
Total residential mortgage-backed securities	2,348		(94		)	201			22		(1		)	1	2,371		(94		)	202
Total securities held to maturity in an unrealized loss position	$	2,353	$	(94	)	202			$	22	$	(1	)	1	$	2,376	$	(94	)	203
We have assessed our securities that were in an unrealized loss position at December 31, 2014 and 2013 and determined that any decline in fair value below amortized cost was temporary.
The Volcker Rule provisions of the Dodd-Frank Act restrict the ability of affiliates of insured depository institutions to sponsor or invest in private funds or to engage in certain types of proprietary trading. Although the Volcker Rule became effective on July 21, 2012 and the final rules became effective April 1, 2014, in connection with the adoption of the final rules on December 10, 2013 by the responsible agencies, the Federal Reserve issued an order extending the period during which institutions have to conform their activities and investments to the requirements of the Volcker Rule to July 21, 2015. The issuance of the final Volcker Rule restricts our ability to hold debt securities issued by Collateralized Loan Obligations ("CLOs") where our investment in these debt securities is deemed to be an ownership interest in a CLO and the CLO itself does not qualify for an exclusion in the final rule for loan securitizations. On December 18, 2014, the Federal Reserve Board announced it would give banking entities until July 21, 2016 to conform investments in covered funds that were in place prior to December 31, 2013 ("legacy covered funds"). The Board also announced its intention to act next year to grant banking entities an additional one-year extension of the conformance period for legacy covered funds which together would extend until July 21, 2017 the time period for institutions to conform their ownership interests to the stated provisions of the final Volcker Rule.
For our CLOs subject to the Volcker Rule in an unrealized loss position, we believe it is more likely than not that we will be able to hold these securities to recovery, which could be maturity as the Federal Reserve announcement extends the conformance period to July 2017 and we believe that other structural remedies are available to us to allow us to continue holding the bonds after the conformance period.
In making the determination that the declines in fair value below amortized cost for the remainder of the portfolio were temporary, we considered some or all of the following factors: the period of time the securities were in an unrealized loss position, the percentage decline in comparison to the securities’ amortized cost, credit rating, the financial condition of the issuer and guarantor, where applicable, the delinquency or default rates of underlying collateral, projected collateral losses, projected cash flows and credit enhancement. If the level of credit enhancement is sufficient based on our expectations of future collateral losses, we conclude that we will receive all of the originally scheduled cash flows. If the present value of the cash flows indicates that we should not expect to recover the amortized cost basis of the security, we would consider the security to be other than temporarily impaired and write down the credit component of the unrealized loss through a charge to current period earnings. We do not intend to sell these securities in an unrealized loss position and it is not more likely than not that we will be required to sell these securities before the recovery of their amortized cost bases, which may be at maturity.
Scheduled contractual maturities of our investment securities were as follows at December 31, 2014:
	Amortized cost		Fair value
Debt securities:
Within one year	$	106	$	107
After one year through five years	795		814
After five years through ten years	619		616
After ten years	15		15
Total debt securities	1,536		1,552
Mortgage-backed securities	8,623		8,690
Collateralized loan obligations	1,001		1,016
Asset-backed securities	591		599
Other	22		22
	$	11,772	$	11,879
While the contractual maturities of our mortgage-backed securities, collateralized loan obligations, asset-backed securities, and other securities generally exceed ten years, we expect the effective lives to be significantly shorter due to prepayments of the underlying loans and the nature of these securities. The duration of our investment securities portfolio was 3.7 years at December 31, 2014, compared to 3.5 years at December 31, 2013.
On March 29, 2013, we transferred $3 billion of residential mortgage-backed securities from available for sale to held to maturity. The amortized cost, unrealized gains and losses, and fair value of these transferred investment securities immediately prior to the transfer were as follows:
	Amortized		Unrealized			Unrealized			Fair
	cost		gains			losses			value
Residential mortgage-backed securities:
Government National Mortgage Association	$	15	$	1		$	—		$	15
Federal National Mortgage Association	173		12			—			185
Federal Home Loan Mortgage Corporation	96		5			—			102
Collateralized mortgage obligations:
Government National Mortgage Association	885		26			—			910
Federal National Mortgage Association	1,019		9			(3		)	1,026
Federal Home Loan Mortgage Corporation	758		7			(2		)	763
Total collateralized mortgage obligations	2,662		42			(4		)	2,699
Total residential mortgage-backed securities	$	2,946	$	59		$	(4	)	$	3,001
At December 31, 2014 and 2013, $6.1 billion and $5.6 billion, respectively, of our investment securities were pledged to secure borrowings and lines of credit from the FHLB and Federal Reserve Bank (“FRB”), as well as repurchase agreements, certain deposits, and derivative instruments. At December 31, 2014, our investment portfolio included securities issued by the Federal Home Loan Mortgage Corporation, Federal National Mortgage Association, and Government National Mortgage Association with a fair value of $2.5 billion, $2.9 billion, and $1.8 billion, respectively. We had no other investments in securities of a single issuer that exceeded 10% of our stockholders’ equity.
Our investment in FHLB stock consists of $256 million and $25 million of FHLB of New York common stock and FHLB of Boston common stock, respectively, at December 31, 2014 and of $231 million and $102 million of FHLB of New York common stock and FHLB of Boston common stock, respectively, at December 31, 2013.
Our investment in FRB stock amounted to $131 million and $136 million at December 31, 2014 and 2013, respectively.

Loans_and_Leases

Loans and Leases	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans and Leases	Note 3. Loans and Leases
	Overall Portfolio
	Our loan portfolio is made up of two segments, commercial loans and consumer loans. Those segments are further segregated between our loans initially accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired (referred to as “acquired” loans). Our commercial loan portfolio segment includes both business and commercial real estate loans. Our consumer portfolio segment includes residential real estate, home equity, indirect auto, credit cards, and other consumer loans.
	Our loans and leases receivable consisted of the following at December 31:
		2014										2013
		Originated			Acquired			Total				Originated			Acquired			Total
	Commercial:
	Real estate	$	6,181		$	1,050		$	7,231			$	5,527		$	1,387		$	6,914
	Construction	973			1			973				828			36			864
	Business	5,430			345			5,775				4,876			414			5,290
	Total commercial	12,584			1,395			13,979				11,231			1,838			13,068
	Consumer:
	Residential real estate	2,096			1,257			3,353				1,902			1,546			3,448
	Home equity	1,847			1,089			2,936				1,618			1,134			2,752
	Indirect auto	2,166			—			2,166				1,544			—			1,544
	Credit cards	324			—			324				325			—			325
	Other consumer	278			—			278				302			—			302
	Total consumer	6,711			2,347			9,058				5,691			2,680			8,371
	Total loans and leases	19,296			3,742			23,037				16,922			4,517			21,440
	Allowance for loan losses	(228		)	(6		)	(234		)		(205		)	(4		)	(209		)
	Total loans and leases, net	$	19,067		$	3,736		$	22,803			$	16,717		$	4,514		$	21,230
	As of December 31, 2014 and 2013, we had a liability for unfunded loan commitments of $16 million and $13 million, respectively. For 2014 and 2013, we recognized provision for credit losses related to our unfunded loan commitments of $3 million and $2 million, respectively.
	Of the $2.9 billion and $2.8 billion home equity portfolio at December 31, 2014 and 2013, respectively, $1.1 billion and $1.0 billion were in a first lien position at each period end, respectively. We hold or service the first lien loan for approximately 10% of the remainder of the home equity portfolio that was in a second lien position as of December 31, 2014 and 2013.
	Acquired loan portfolios
	We have acquired loans in four acquisitions since January 1, 2009. All acquired loans were initially measured at fair value and subsequently accounted for under either Accounting Standards Codification Topic (“ASC”) 310-30 (Loans and Debt Securities Acquired with Deteriorated Credit Quality) or ASC 310-20 (Nonrefundable Fees and Other Costs.)
	The outstanding principal balance and the related carrying amount of our acquired loans included in our Consolidated Statements of Condition were as follows at December 31:
		2014			2013
	Credit impaired acquired loans evaluated individually for future credit losses
	Outstanding principal balance	$	10		$	18
	Carrying amount	6			12
	Acquired loans evaluated collectively for future credit losses
	Outstanding principal balance	2,549			3,301
	Carrying amount	2,496			3,233
	Other acquired loans
	Outstanding principal balance	1,274			1,321
	Carrying amount	1,240			1,273
	Total acquired loans
	Outstanding principal balance	3,832			4,640
	Carrying amount	3,742			4,517
	The following table presents changes in the accretable yield, which includes income recognized from contractual interest cash flows, for the dates indicated. Acquired lines of credit accounted for under ASC 310-20 are not included in this table.
	Balance at January 1, 2013	$	(1,057	)
	Net reclassifications from nonaccretable yield	(15		)
	Accretion	199
	Other (1)	22
	Balance at December 31, 2013	(851		)
	Reclassifications from nonaccretable yield	(5		)
	Accretion	138
	Other (1)	55
	Balance at December 31, 2014	$	(663	)
	-1	Includes changes in expected cash flows from changes in interest rate and prepayment assumptions.
	During the first quarter of 2014 and 2013, we reduced our estimate of future cash flows on acquired loans to reflect our current outlook for prepayment speeds on these balances.  The increase in prepayment speed assumptions reduced our accretable discount by $55 million and $22 million, respectively.  This change did not materially impact our interest income or net interest margin.
	Allowance for loan losses
	As further discussed in Note 1, Summary of Significant Accounting Policies, we establish our allowance for loan losses through a provision for credit losses. The level of the allowance for loan losses is based on our evaluation of the overall credit quality of our total loan portfolio. We segregate our loans between loans we originated which are accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired (referred to as “acquired” loans), as acquired loans were originally recorded at fair value, which included an estimate of lifetime credit losses, resulting in no carryover of the related allowance for loan losses. We continue to monitor and modify the level of our allowance for loan losses to ensure it is adequate to cover losses inherent in our loan portfolio.
	We determined our allowance for loan losses by portfolio segment as defined above. For our originated loans, the allowance for loan losses is comprised of two components. The first component covers pools of loans for which there are incurred losses that are not yet individually identifiable. The allowance for pools of loans is based on net historical loan loss experience for similar loans with similar inherent risk characteristics and performance trends adjusted, as appropriate, for quantitative and qualitative risk factors specific to respective loan types. The second component covers loans that have been identified as impaired or are nonperforming as well as troubled debt restructurings (“TDRs”.)
	We also maintain an allowance for loan losses on acquired loans when: (i) for loans accounted for under ASC 310-30, there is deterioration in credit quality subsequent to acquisition, and (ii) for loans accounted for under ASC 310-20, the inherent losses in the loans exceed the remaining credit discount recorded at the time of acquisition.
	Beginning in the second quarter of 2014, we raised our threshold for evaluating commercial loans individually for impairment from $200 thousand to $1 million. Impaired loans to commercial borrowers with outstandings less than $1 million are pooled and measured for impairment collectively. Additionally, all loans modified in a troubled debt restructuring ("TDR"), regardless of dollar size, are considered impaired. The impact of this change to our allowance for loan losses was not significant. This change is being implemented on a prospective basis, accordingly, prior period financial disclosures have not been revised.
	The following table presents the activity in our allowance for loan losses on originated loans and related recorded investment of the associated loans in our originated loan portfolio segment for the years ended December 31:
		Commercial							Consumer
	Originated loans	Real estate			Business				Residential			Home equity			Indirect auto			Credit cards			Other			Total
																					consumer
	2014
	Allowance for loan losses:
	Balance at beginning of year	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
	Provision for loan losses	23			30				1			4			11			10			6			85
Charge-offs	(10		)	(30		)		(1		)	(4		)	(9		)	(13		)	(8		)	(75		)
Recoveries	4			3				—			1			1			2			1			13
Balance at end of year	$	65		$	122			$	2		$	8		$	14		$	12		$	5		$	228
Allowance for loan losses:
Individually evaluated for impairment	$	2		$	2			$	1		$	1		$	—		$	—		$	—		$	6
Collectively evaluated for impairment	63			120				1			7			14			12			5			222
Total	$	65		$	122			$	2		$	8		$	14		$	12		$	5		$	228
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	64		$	61			$	20		$	7		$	2		$	—		$	2		$	156
Collectively evaluated for impairment	7,089			5,370				2,076			1,840			2,164			324			276			19,139
Total	$	7,154		$	5,430			$	2,096		$	1,847		$	2,166		$	324		$	278		$	19,296
2013
Allowance for loan losses:
Balance at beginning of year	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
Provision for loan losses	17			48				(1		)	6			9			11			8			96
Charge-offs	(10		)	(31		)		(2		)	(3		)	(3		)	(6		)	(8		)	(63		)
Recoveries	4			3				1			—			1			1			2			11
Balance at end of year	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
Allowance for loan losses:
Individually evaluated for impairment	$	4		$	2			$	1		$	3		$	—		$	—		$	—		$	9
Collectively evaluated for impairment	44			117				1			4			10			13			6			196
Total	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	72		$	59			$	20		$	8		$	1		$	—		$	3		$	163
Collectively evaluated for impairment	6,282			4,818				1,882			1,610			1,543			325			299			16,759
Total	$	6,354		$	4,876			$	1,902		$	1,618		$	1,544		$	325		$	302		$	16,922
	Commercial							Consumer
Originated loans	Real estate			Business				Residential			Home Equity			Indirect auto			Credit cards			Other			Total
																				Consumer
2012
Allowance for loan losses:
Balance at beginning of year	$	50		$	57			$	4		$	4		$	—		$	—		$	2		$	118
Provision for loan losses	(7		)	67				3			4			4			8			5			84
Charge-offs	(7		)	(27		)		(3		)	(4		)	(1		)	(1		)	(4		)	(46		)
Recoveries	1			2				—			—			—			—			1			6
Allowance related to loans sold	—			—				—			—			—			—			—			(1		)
Balance at end of year	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
Allowance for loan losses:
Individually evaluated for impairment	$	3		$	5			$	3		$	1		$	—		$	—		$	—		$	11
Collectively evaluated for impairment	35			94				1			4			3			7			5			150
Total	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	67		$	58			$	20		$	5		$	—		$	—		$	2		$	152
Collectively evaluated for impairment	4,977			4,228				1,705			1,281			601			215			214			13,221
Total	$	5,044		$	4,286			$	1,724		$	1,286		$	601		$	215		$	215		$	13,372
The following table presents the activity in our allowance for loan losses and related recorded investment of the associated loans in our acquired loan portfolio for the years ended December 31:
	Commercial							Consumer
Acquired loans	Real estate			Business				Residential			Home equity			Credit cards			Other			Total
																	consumer
2014
Allowance for loan losses:
Balance at beginning of year	$	—		$	—			$	1		$	3		$	—		$	—		$	4
Provision for loan losses	3			1				1			3			—			—			8
Charge-offs	(2		)	—				—			(4		)	—			—			(6		)
Recoveries	—			—				—			—			—			—			—
Balance at end of year	$	1		$	1			$	2		$	2		$	—		$	—		$	6
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	1			1				2			2			—			—			6
Total	$	1		$	1			$	2		$	2		$	—		$	—		$	6
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	—		$	3			$	—		$	4		$	—		$	—		$	7
Collectively evaluated for impairment	—			269				—			964			—			—			1,233
Loans acquired with deteriorated credit quality	1,050			73				1,257			122			—			—			2,502
Total	$	1,050		$	345			$	1,257		$	1,089		$	—		$	—		$	3,742
2013
Allowance for loan losses:
Balance at beginning of year	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Provision for loan losses	4			—				1			3			—			(1		)	7
Charge-offs	(4		)	—				—			—			—			(1		)	(5		)
Recoveries	—			—				—			—			—			—			—
Balance at end of year	$	—		$	—			$	1		$	3		$	—		$	—		$	4
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	—			—				1			3			—			—			4
Total	$	—		$	—			$	1		$	3		$	—		$	—		$	4
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	1		$	7			$	—		$	1		$	—		$	—		$	10
Collectively evaluated for impairment	—			305				—			960			—			—			1,264
Loans acquired with deteriorated credit quality	1,423			102				1,546			173			—			—			3,244
Total	$	1,423		$	414			$	1,546		$	1,134		$	—		$	—		$	4,517
	Commercial							Consumer
Acquired loans	Real estate			Business				Residential			Home equity			Credit cards			Other			Total
																	consumer
2012
Allowance for loan losses:
Balance at beginning of year	$	—		$	—			$	—		$	—		$	—		$	2		$	2
Provision for loan losses	6			—				—			—			—			1			7
Charge-offs	(7		)	—				—			—			—			(2		)	(9		)
Recoveries	1			—				—			—			—			—			1
Balance at end of year	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	—			—				—			—			—			1			2
Total	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	1		$	7			$	—		$	2		$	—		$	—		$	10
Collectively evaluated for impairment	—			427				—			1,045			100			42			1,614
Loans acquired with deteriorated credit quality	2,048			233				2,037			319			—			76			4,713
Total	$	2,049		$	667			$	2,037		$	1,366		$	100		$	118		$	6,338
Credit Quality
We monitor credit quality as indicated by various factors and utilize such information in our evaluation of the adequacy of the allowance for loan losses. The following sections discuss the various credit quality indicators that we consider.
Nonperforming loans
Our nonperforming loans consisted of the following at December 31:
	2014										2013
	Originated			Acquired			Total				Originated			Acquired			Total
Commercial:
Real estate	$	53		$	—		$	53			$	53		$	1		$	54
Business	45			7			53				42			9			51
Total commercial	98			7			106				95			10			105
Consumer:
Residential real estate	34			—			34				31			—			31
Home equity	24			23			47				18			20			39
Indirect auto	13			—			13				6			—			6
Other consumer	5			—			5				6			—			6
Total consumer	75			23			98				62			20			82
Total	$	174		$	30		$	204			$	157		$	30		$	188
The table below provides information about the interest income that would have been recognized if our nonperforming loans had performed in accordance with terms for the years ending December 31:
	2014			2013			2012
Additional interest income that would have been recorded if nonperforming loans had performed in accordance with original terms	$	8		$	7		$	7
Impaired loans
The following table provides information about our impaired originated loans including ending recorded investment, principal balance, and related allowance amount at December 31. Loans with no related allowance for loan losses have adequate collateral securing their carrying value and in some circumstances have been charged down to their current carrying value based on the fair value of the collateral. The carrying value of our impaired loans, less any related allowance for loan losses, was 70% and 69% of the loans’ contractual principal balance at December 31, 2014 and 2013, respectively.
	2014										2013
Originated loans	Recorded			Unpaid			Related				Recorded			Unpaid			Related
	investment			principal			allowance				investment			principal			allowance
				balance										balance
With no related allowance recorded:
Commercial:
Real estate	$	40		$	59		$	—			$	48		$	63		$	—
Business	29			51			—				55			84			—
Total commercial	69			110			—				103			146			—
Consumer:
Residential real estate	8			9			—				12			12			—
Home equity	3			4			—				4			5			—
Indirect auto	2			3			—				1			1			—
Other consumer	2			2			—				1			1			—
Total consumer	16			18			—				18			20			—
Total	$	85		$	128		$	—			$	121		$	166		$	—
With a related allowance recorded:
Commercial:
Real estate	$	24		$	27		$	2			$	24		$	35		$	4
Business	32			43			2				4			6			2
Total commercial	56			70			4				28			41			5
Consumer:
Residential real estate	11			13			1				8			9			1
Home equity	4			4			1				4			5			3
Indirect auto	—			—			—				1			1			—
Other consumer	—			—			—				1			1			—
Total consumer	16			17			2				14			16			4
Total	$	71		$	87		$	6			$	42		$	57		$	9
Total
Commercial:
Real estate	$	64		$	86		$	2			$	72		$	97		$	4
Business	61			93			2				59			90			2
Total commercial	125			179			4				131			187			5
Consumer:
Residential real estate	20			22			1				20			21			1
Home equity	7			8			1				8			10			3
Indirect auto	2			3			—				1			2			—
Other consumer	2			2			—				3			3			—
Total consumer	31			36			2				32			36			4
Total	$	156		$	215		$	6			$	163		$	222		$	9
The following table provides information about our impaired acquired loans with no related allowance at December 31. The remaining credit mark is considered adequate to cover any loss on these balances.
	2014										2013
Acquired loans	Recorded			Unpaid principal balance			Related				Recorded			Unpaid principal balance			Related
	investment						allowance				investment						allowance
Commercial:
Real estate	$	—		$	—		$	—			$	1		$	4		$	—
Business	3			3			—				7			8			—
Total commercial	3			3			—				8			12			—
Consumer:
Residential real estate	—			—			—				—			—			—
Home equity	4			6			—				1			2			—
Other consumer	—			—			—				—			—			—
Total consumer	4			6			—				1			2			—
Total(1)	$	7		$	9		$	—			$	10		$	14		$	—
-1	Includes nonaccrual purchased credit impaired loans.
The following table provides information about our impaired originated loans including the average recorded investment and interest income recognized on impaired loans for the years ended December 31:
	2014							2013							2012
Originated loans	Average			Interest				Average			Interest				Average			Interest
	recorded			income				recorded			income				recorded			income
	investment			recognized				investment			recognized				investment			recognized
Commercial:
Real estate	$	69		$	1			$	80		$	1			$	72		$	1
Business	53			1				63			1				63			1
Total commercial	122			3				142			2				135			2
Consumer:
Residential real estate	21			—				20			—				20			—
Home equity	5			—				5			—				4			—
Indirect auto	3			—				1			—				—			—
Other consumer	3			—				3			—				2			—
Total consumer	31			—				29			1				26			—
Total	$	153		$	3			$	172		$	3			$	161		$	3
The following table provides information about our impaired acquired loans including the average recorded investment and interest income recognized on impaired loans for the years ended December 31.
	2014							2013							2012
Acquired loans	Average			Interest				Average			Interest				Average			Interest
	recorded			income				recorded			income				recorded			income
	investment			recognized				investment			recognized				investment			recognized
Commercial:
Real estate	$	—		$	—			$	1		$	—			$	1		$	—
Business	2			—				7			—				8			—
Total commercial	2			—				8			—				9			—
Consumer:
Residential real estate	—			—				—			—				—			—
Home equity	1			—				—			—				1			—
Other consumer	—			—				—			—				—			—
Total consumer	1			—				—			—				1			—
Total(1)	$	3		$	—			$	9		$	—			$	10		$	—
-1	Includes nonaccrual purchased credit impaired loans.
Period end nonaccrual loans differed from the amount of total impaired loans as certain TDRs, which are considered impaired loans, were accruing interest because the borrower demonstrated its ability to satisfy the terms of the restructured loan for at least six consecutive payments. Also contributing to the difference are nonaccrual commercial loans less than $1 million and nonaccrual consumer loans, which are not considered impaired unless they have been modified in a TDR as they are evaluated collectively when determining the allowance for loan losses.
The following table is a reconciliation between nonaccrual loans and impaired loans at December 31:
	2014										2013
	Commercial			Consumer			Total				Commercial			Consumer			Total
Nonaccrual loans	$	106		$	98		$	204			$	105		$	82		$	188
Plus: Accruing TDRs	59			8			67				45			8			52
Less: Smaller balance nonaccrual loans evaluated collectively when determining the allowance for loan losses	(36		)	(71		)	(108		)		(11		)	(57		)	(67		)
Total impaired loans(1)	$	128		$	35		$	163			$	139		$	33		$	172
(1)	Included nonaccrual purchased credit impaired loans.
Credit Quality Indicators
The primary indicators of credit quality are delinquency status and our internal loan gradings for our commercial loan portfolio segment and delinquency status and current FICO scores for our consumer loan portfolio segment.
The following table contains an aging analysis of our loans by class at December 31:
	30-59 days			60-89 days			Greater than			Total			Current			Total loans			Greater than
	past due			past due			90 days			past due						receivable			90 days
							past due												and accruing (1)
2014
Originated loans
Commercial:
Real estate	$	7		$	2		$	31		$	40		$	7,113		$	7,154		$	—
Business	5			7			17			28			5,402			5,430			—
Total commercial	11			9			49			69			12,515			12,584			—
Consumer:
Residential real estate	4			2			21			27			2,069			2,096			—
Home equity	3			1			15			19			1,828			1,847			—
Indirect auto	17			4			5			27			2,139			2,166			—
Credit cards	2			2			2			6			318			324			2
Other consumer	3			1			3			7			271			278			—
Total consumer	29			10			46			85			6,626			6,711			2
Total	$	41		$	19		$	95		$	154		$	19,141		$	19,296		$	2
Acquired loans
Commercial:
Real estate	$	3		$	3		$	26		$	31		$	1,019		$	1,050		$	26
Business	—			—			7			7			338			345			4
Total commercial	3			3			33			38			1,357			1,395			30
Consumer:
Residential real estate	11			5			56			72			1,186			1,257			56
Home equity	6			2			21			29			1,060			1,089			6
Total consumer	17			7			77			101			2,246			2,347			62
Total	$	21		$	9		$	109		$	139		$	3,603		$	3,742		$	91
2013
Originated loans
Commercial:
Real estate	$	5		$	2		$	27		$	34		$	6,321		$	6,354		$	—
Business	4			3			20			28			4,849			4,876			—
Total commercial	9			5			47			61			11,169			11,231			—
Consumer:
Residential real estate	6			2			21			30			1,872			1,902			—
Home equity	3			2			12			17			1,601			1,618			—
Indirect auto	12			2			3			18			1,526			1,544			—
Credit cards	2			1			3			6			319			325			3
Other consumer	3			1			3			7			295			302			—
Total consumer	27			9			43			79			5,613			5,691			3
Total	$	36		$	15		$	90		$	140		$	16,782		$	16,922		$	3
Acquired loans
Commercial:
Real estate	$	8		$	8		$	37		$	52		$	1,371		$	1,423		$	36
Business	2			1			8			11			403			414			5
Total commercial	10			8			45			63			1,774			1,838			41
Consumer:
Residential real estate	19			11			64			94			1,452			1,546			64
Home equity	7			4			20			31			1,103			1,134			5
Total consumer	26			15			84			125			2,555			2,680			70
Total	$	35		$	23		$	130		$	188		$	4,330		$	4,517		$	110
(1)	Includes credit card loans, loans that have matured and are in the process of collection, and acquired loans that were originally recorded at fair value upon acquisition. Acquired loans are considered to be accruing as we can reasonably estimate future cash flows on these acquired loans and we expect to fully collect the carrying value of these loans net of the allowance for acquired loan losses. Therefore, we are accreting the difference between the carrying value of these loans and their expected cash flows into interest income.
Our internal loan risk assessment provides information about the financial health of our commercial borrowers and our risk of potential loss. The following tables present information about the credit quality of our commercial loan portfolio at December 31:
	Real estate			Business			Total			Percent of total
2014
Originated loans:
Pass	$	6,791		$	5,067		$	11,858		94.2	%
Criticized:(1)
Accrual	310			318			628			5	%
Nonaccrual	53			45			98			0.8	%
Total criticized	363			363			726			5.8	%
Total	$	7,154		$	5,430		$	12,584		100	%
Acquired loans:
Pass	$	948		$	294		$	1,243		89.1	%
Criticized:(1)
Accrual	102			43			145			10.4	%
Nonaccrual	—			7			7			0.5	%
Total criticized	102			51			153			10.9	%
Total	$	1,050		$	345		$	1,395		100	%
2013
Originated loans:
Pass	$	6,028		$	4,590		$	10,618		94.6	%
Criticized:(1)
Accrual	273			244			517			4.6	%
Nonaccrual	53			42			95			0.8	%
Total criticized	327			286			612			5.4	%
Total	$	6,354		$	4,876		$	11,231		100	%
Acquired loans:
Pass	$	1,260		$	359		$	1,619		88.2	%
Criticized:(1)
Accrual	162			46			208			11.3	%
Nonaccrual	1			9			10			0.5	%
Total criticized	163			55			218			11.8	%
Total	$	1,423		$	414		$	1,838		100	%
(1)	Includes special mention, substandard, doubtful, and loss, which are consistent with regulatory definitions, and as described in Part I, Item 1, “Business,” under the heading “Asset Quality Review.”
Borrower FICO scores provide information about the credit quality of our consumer loan portfolio as they provide an indication as to the likelihood that a debtor will repay their debts. The scores are obtained from a nationally recognized consumer rating agency and are presented in the table below at December 31:
	Residential			Home equity			Indirect Auto			Credit cards			Other			Total			Percent of
	real estate												consumer						total
2014
Originated loans by refreshed FICO score:
Over 700	$	1,841		$	1,529		$	1,533		$	226		$	167		$	5,296		78.9	%
660-700	124			182			347			53			46			752			11.2
620-660	62			71			159			24			24			339			5
580-620	28			31			64			11			13			148			2.2
Less than 580	32			32			63			8			12			146			2.2
No score(1)	9			1			—			3			17			31			0.5
Total	$	2,096		$	1,847		$	2,166		$	324		$	278		$	6,711		100	%
Acquired loans by refreshed FICO score:
Over 700	$	872		$	851		$	—		$	—		$	—		$	1,723		73.4	%
660-700	87			93			—			—			—			180			7.7
620-660	61			52			—			—			—			113			4.8
580-620	49			40			—			—			—			88			3.8
Less than 580	57			34			—			—			—			91			3.9
No score(1)	131			20			—			—			—			151			6.4
Total	$	1,257		$	1,089		$	—		$	—		$	—		$	2,347		100	%
2013
Originated loans by refreshed FICO score:
Over 700	$	1,609		$	1,327		$	993		$	223		$	173		$	4,324		76	%
660-700	128			158			304			53			53			696			12.2
620-660	56			69			149			25			28			328			5.8
580-620	32			30			55			12			14			142			2.5
Less than 580	38			30			43			8			15			135			2.4
No score(1)	39			3			—			4			20			66			1.1
Total	$	1,902		$	1,618		$	1,544		$	325		$	302		$	5,691		100	%
Acquired loans by refreshed FICO score:
Over 700	$	1,074		$	874		$	—		$	—		$	—		$	1,948		72.7	%
660-700	115			103			—			—			—			218			8.1
620-660	61			57			—			—			—			119			4.4
580-620	57			39			—			—			—			95			3.6
Less than 580	75			40			—			—			—			114			4.3
No score(1)	164			21			—			—			—			185			6.9
Total	$	1,546		$	1,134		$	—		$	—		$	—		$	2,680		100	%
(1)	Primarily includes loans that are serviced by others for which refreshed FICO scores were not available as of the date indicated.
Troubled Debt Restructures
The following table details additional information about our TDRs at December 31:
	2014			2013			2012
Aggregate recorded investment of impaired loans with terms modified through a troubled debt restructuring:
Accruing interest	$	67		$	52		$	46
Nonaccrual	53			56			42
Total troubled debt restructurings(1)	$	120		$	108		$	89
(1)	Includes 87 and 40 acquired loans that were restructured with a recorded investment of $4 million and $1 million at December 31, 2014 and 2013, respectively.
The modifications made to loans classified as TDRs typically consist of an extension of the payment terms, providing for a period with interest-only payments with deferred principal payments, rate reduction, or loans restructured in a Chapter 7 bankruptcy. We generally do not forgive principal when restructuring loans.
The financial effects of our modifications are as follows for the years ended December 31:
Type of Concession	Count		Postmodification			Premodification			Postmodification
			recorded			allowance for			allowance for
			investment(1)			loan losses			loan losses
2014
Commercial:
Commercial real estate
Extension of term	10		$	20		$	1		$	—
Rate reduction	1		3			—			1
Extension of term and rate reduction	3		1			—			—
Commercial business
Extension of term	15		32			6			1
Extension of term and rate reduction	2		—			—			—
Total commercial	31		56			8			2
Consumer:
Residential real estate
Extension of term	6		1			—			—
Rate reduction	2		—			—			—
Deferral of principal and extension of term	7		1			—			—
Extension of term and rate reduction	14		2			—			—
Chapter 7 Bankruptcy	14		1			—			—
Other	3		—			—			—
Home equity
Extension of term	3		—			—			—
Deferral of principal and extension of term	2		—			—			—
Extension of term and rate reduction	10		—			—			—
Chapter 7 Bankruptcy	79		3			—			—
Other	18		1			—			—
Indirect auto
Chapter 7 Bankruptcy	273		5			—			—
Type of Concession	Count		Postmodification			Premodification			Postmodification
			recorded			allowance for			allowance for
			investment(1)			loan losses			loan losses
Other consumer
Extension of term	1		$	—		$	—		$	—
Chapter 7 Bankruptcy	33		—			—			—
Total consumer	465		14			—			—
Total	496		$	70		$	8		$	2
2013
Commercial:
Commercial real estate
Extension of term	5		$	9		$	1		$	1
Deferral of principal	1		8			—			—
Extension of term and rate reduction	8		17			1			—
Commercial business
Extension of term	10		10			2			—
Extension of term and rate reduction	7		1			—			—
Total commercial	31		46			4			1
Consumer:
Residential real estate
Extension of term	2		—			—			—
Rate reduction	3		—			—			—
Deferral of principal and extension of term	5		—			—			—
Extension of term and rate reduction	11		2			—			—
Chapter 7 Bankruptcy	15		1			—			—
Home equity
Deferral of principal and extension of term	3		—			—			—
Rate reduction	2		—			—			—
Extension of term and rate reduction	3		—			—			—
Chapter 7 Bankruptcy	61		2			—			—
Indirect auto
Chapter 7 Bankruptcy	74		1			—			—
Other consumer
Extension of term	1		—			—			—
Rate reduction	1		—			—			—
Extension of term and rate reduction	1		—			—			—
Chapter 7 Bankruptcy	54		1			—			—
Total consumer	236		9			—			—
Total	267		$	55		$	4		$	2
(1)	Postmodification balances approximate premodification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant.
The recorded investment in loans modified as TDRs within 12 months of the balance sheet date and for which there was a payment default was not significant during the years ended December 31, 2014 and 2013.
Residential Mortgage Banking
The following table provides information about our residential mortgage banking activities at December 31:
	2014			2013			2012
Loans classified as held for sale	$	40		$	50		$	155
Loans sold during the year	663			1,400			1,444
Gains on sale of loans, net	5			12			9
Mortgages serviced for others	3,841			3,665			2,909
Mortgage servicing asset recorded for loans serviced for others, net	37			35			26

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Premises and equipment	Premises and Equipment
	The following table presents the composition of our premises and equipment at December 31:
		2014			2013
	Land	$	29		$	29
	Buildings and leasehold improvements	290			287
	Furniture and equipment	339			307
	Total	658			623
	Accumulated depreciation	(251		)	(205		)
	Premises and equipment, net	$	407		$	418
	Our rent expense, which is included in occupancy and equipment in our Consolidated Statements of Income, was $32 million, $33 million, and $28 million, for 2014, 2013, and 2012, respectively.

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill and Other Intangible Assets
	Goodwill
	The following table shows information regarding our goodwill for the periods indicated:
		Banking			Financial			Consolidated
					services			total
	Balances at January 1, 2013	$	2,416		$	68		$	2,484
	Purchase accounting adjustments(1)	(35		)	—			(35		)
	Balances at December 31, 2013	2,381			68			2,449
	Acquisitions	—			1			1
	Impairment	(1,100		)	—			(1,100		)
	Balances at December 31, 2014	$	1,281		$	69		$	1,350
	(1)	Establishment of deferred tax assets in connection with the HSBC Branch Acquisition and our National City Bank branch acquisition.
	We perform our annual impairment test of goodwill on November 1st of each year or more often if events or circumstances have changed significantly from the annual test date.
	For the quarter ended September 30, 2014, we concluded it was more likely than not that the fair value of our Banking reporting unit was less than its carrying value including goodwill, given our current expectations regarding the macroeconomic and industry environment, including our view of future interest rates and our current stock price range. Accordingly, we performed a Step 1 review for possible goodwill impairment in advance of our annual impairment testing date.
	Under Step 1 of the goodwill impairment review, we calculated the fair value of the Banking reporting unit using a market approach, and compared the fair value to carrying value to identify potential impairment. Under Step 1, we determined that the carrying value of our Banking reporting unit exceeded its fair value. For Step 2, we compared the implied fair value of the Banking reporting unit's goodwill with the carrying amount of the goodwill for the Banking reporting unit.
	Based on our assessments under both Steps 1 and 2, we have recorded an impairment of our Banking reporting unit goodwill of $1.1 billion during the quarter ended September 30, 2014. When we performed our annual goodwill impairment assessment as of November 1, 2014, we concluded that our goodwill balance was not impaired. There was no goodwill impairment in 2013.
	At March 16, 2015, the market value of a share of our common stock was $9.11, as compared to the $7.37 market value of our common stock utilized in our third quarter 2014 impairment computation.
	Other Intangible Assets
	The following table provides information regarding our amortizing intangible assets at December 31:
		2014			2013
	Core deposit intangible	$	191		$	191
	Accumulated amortization	(158		)	(139		)
	Net carrying amount	33			52
	Customer lists	100			95
	Accumulated amortization	(66		)	(53		)
	Net carrying amount	34			42
	Total amortizing intangible assets, net	$	67		$	94
	The estimated future amortization expense for our amortizing intangible assets is as follows at December 31, 2014:
		First quarter			Second quarter			Third quarter			Fourth quarter		Total
	2015	$	6		$	5		$	4		$	4	$	19
	2016	4			3			3			3		13
	2017	3			3			3			3		12
	2018	3			2			2			2		9
	2019	2			1			1			1		5
	Thereafter												10

Deposits

Deposits	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Deposits	Deposits
	Our deposits consisted of the following at December 31:
		2014				2013
		Balance		Weighted		Balance		Weighted
				average				average
				rate				rate
	Core deposits:
	Savings	$	3,452	0.09	%	$	3,667	0.1	%
	Interest-bearing checking	5,084		0.03		4,744		0.04
	Money market deposits	9,962		0.22		9,740		0.21
	Noninterest-bearing	5,407		—		4,866		—
	Total core deposits	23,906		0.11		23,016		0.12
	Certificates	3,876		0.69		3,649		0.68
	Total deposits	$	27,781	0.19	%	$	26,665	0.2	%
	Included in total deposits are municipal deposits totaling $3.3 billion and $2.9 billion at December 31, 2014 and 2013, respectively. Additionally, Included in total deposits are brokered money market deposits of $412 million and $336 million at December 31, 2014 and 2013, respectively, and brokered certificates of deposit of $1.2 billion and $739 million at December 31, 2014 and 2013, respectively.
	Interest expense on our deposits is summarized as follows for the years ended December 31:
		2014		2013		2012
	Certificates	$	27	$	26	$	33
	Money market deposits	22		21		26
	Savings	3		4		5
	Interest-bearing checking	2		2		2
	Total interest expense	$	53	$	53	$	67
	Interest rates on our certificates range from 0.05% to 4.50% at December 31, 2014. Certificates of deposit that we issued in amounts over $100 thousand amounted to $938 million, $928 million, and $1.7 billion at December 31, 2014, 2013, and 2012, respectively. Interest expense on certificates of deposit over $100 thousand totaled $10 million, $11 million, and $11 million in 2014, 2013, and 2012, respectively. Included in certificates of deposit issued in amounts over $100 thousand at December 31, 2014, 2013 and 2012 are $1.2 billion, $739 million and $635 million, respectively, of brokered deposits.

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Borrowings	Borrowings
	Our outstanding borrowings are summarized as follows at December 31:
		2014			2013
	Short-term borrowings:
	FHLB advances	$	5,049		$	4,304
	Repurchase agreements	423			518
	Total short-term borrowings	5,472			4,822
	Long-term borrowings:
	Senior notes (maturing in 2020)	298			298
	Subordinated notes (maturing in 2021)	298			298
	Junior subordinated debentures (maturing between 2030 and 2037)	114			113
	Other (maturing between 2015 and 2032)	23			25
	Total long-term borrowings	734			734
	Total borrowings	$	6,206		$	5,556
	Our FHLB advances bear interest rates ranging from 0.40% to 0.67% and had a weighted average rate of 0.48% at December 31, 2014 and 0.46% at December 31, 2013. Our repurchase agreements bear interest rates ranging from 0.02% to 0.15% and had a weighted average rate of 0.14% at December 31, 2014 and 0.18% at December 31, 2013. Our senior notes and subordinated notes bear interest at annual rates of 6.75% and 7.25%, respectively. Our junior subordinated debentures bear interest rates ranging from 1.16% to 10.88% and have a weighted average interest rate of 2.57% at December 31, 2014.
	Interest expense on our borrowings is summarized as follows for the years ended December 31:
		2014			2013		2012
	FHLB advances	$	19		$	14	$	19
	Repurchase agreements	1			1		17
	Senior notes	21			21		21
	Subordinated notes	23			23		23
	Junior subordinated debentures	5			5		6
	Total interest expense	$	69		$	64	$	86
	Our Bank has borrowing facilities with the FHLB, FRB, and commercial banks that serve as secondary funding sources for lending, liquidity, and asset and liability management. At December 31, 2014 and 2013, the FHLB facility totaled $5.7 billion and $4.5 billion, respectively, of which $5.1 billion and $4.2 billion was utilized and secured by approximately $4.3 billion and $3.9 billion, respectively, of our commercial real estate, residential real estate, and multifamily loans. Investment securities used to secure the FHLB facility totaled $1.4 billion at December 31, 2014 and $584 million investment securities were used to secure the FHLB facility at December 31, 2013. As of December 31, 2014 and 2013, our borrowing capacity totaled $867 million and $777 million, respectively with the FRB, and $250 million and $200 million at December 31, 2014 and 2013, respectively, with commercial banks, neither of which was utilized at December 31, 2014 and 2013. Our lines of credit with commercial banks include a committed line of credit agreement, which contains a negative pledge against our First Niagara Bank, N.A. stock and the maintenance of certain standard financial covenants. The interest rate on outstanding borrowings under this line of credit is, at our election, equal to London Interbank Offered Rate (“LIBOR”) plus 185 basis points, resetting every 30 or 90 days. Interest on the other lines of credit with commercial banks is payable at the overnight federal funds rate.
	At times we may enter into repurchase agreements with various broker-dealers, whereby certain of our securities available for sale and certain of our securities held to maturity were pledged to collateralize the borrowings. We treat these repurchase agreements as financing transactions and our obligation to repurchase is reflected as a borrowing in our Consolidated Statements of Condition. The dollar amount of our securities underlying the agreements is included in our securities available for sale and securities held to maturity in our Consolidated Statements of Condition. These securities however, are delivered to the dealer with whom we execute each transaction. The dealers may sell, loan or otherwise dispose of these securities to other parties in the normal course of their business, but they agree to resell to us the same securities at the maturity of the agreements. We also retain the right of substitution of collateral throughout the terms of the agreements. During 2014 and 2013, we did not enter into any repurchase agreements with broker-dealers and therefore, none of our investment securities were pledged to collateralize these borrowings.
	Our junior subordinated debentures include amounts related to our First Niagara Financial Group Statutory Trust I as well as junior subordinated debentures associated with six statutory trust affiliates that were acquired from our merger with Harleysville and three statutory trusts acquired from NewAlliance (the “Trusts”). The Trusts qualify as variable interest entities and were formed to issue mandatorily redeemable trust preferred securities to investors and loan the proceeds to us for general corporate purposes. We own all of the common securities of the Trusts and have accordingly recorded $4 million in equity method investments classified as other assets in our Consolidated Statement of Condition at December 31, 2014. As the shareholders of the trust preferred securities are the primary beneficiaries of these trusts, the Trusts are not consolidated in our financial statements. Our junior subordinated debentures are redeemable prior to the maturity date at our option upon each trust’s stated option repurchase dates, and from time to time thereafter. These debentures are also redeemable in whole at any time upon the occurrence of specific events defined within the trust indenture. Our obligations under the debentures and related documents, taken together, constitute a full and unconditional guarantee by the Company of the issuers’ obligations under the trust preferred securities.
	The Trusts hold, as their sole assets, junior subordinated debentures of the Company with face amounts totaling $142 million at December 31, 2014.
	The following table summarizes our junior subordinated debentures at December 31, 2014:
	Trust Preferred Subordinated Debentures	Maturity	Interest rate		Principal amount of subordinated debentures		Principal amount of trust preferred securities
					(dollars in millions)
	HNC Statutory Trust III	2035	3 month LIBOR +	1.40%	$	26	$	25
	Willow Grove Statutory Trust I	2036	3 month LIBOR +	1.31%	26		25
	HNC Statutory Trust IV	2037	3 month LIBOR +	1.28%	23		23
	HNC Statutory Trust II	2034	3 month LIBOR +	2.70%	21		20
	First Niagara Financial Group Statutory Trust I	2034	3 month LIBOR +	2.70%	12		12
	Westbank Capital Trust II	2034	3 month LIBOR +	2.19%	9		9
	Westbank Capital Trust III	2034	3 month LIBOR +	2.19%	9		9
	East Penn Statutory Trust I	2033	3 month LIBOR +	3.10%	8		8
	Harleysville Statutory Trust I	2031		10.20%	5		5
	Alliance Capital Trust II	2030		10.88%	4		4
	Total				$	142	$	138
	The carrying value of the trust preferred junior subordinated debentures, net of the unamortized purchase accounting fair value adjustment of approximately $28 million, is $114 million.
	The aggregate maturities of our long-term borrowings are as follows at December 31, 2014 (by year of maturity):
	2015	$	2
	2016	2
	2017	2
	2018	2
	2019	2
	Thereafter	724
	Total	$	734

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments
	We are a party to derivative financial instruments in the normal course of business to manage our own exposure to fluctuations in interest rates and to meet the needs of our customers. These financial instruments have been limited to interest rate swap agreements, which are entered into with counterparties that meet established credit standards and, where appropriate, contain master netting and collateral provisions protecting the party at risk. We believe that the credit risk inherent in all of our derivative contracts is minimal based on our credit standards and the netting and collateral provisions of the interest rate swap agreements.
	Our derivative positions include both instruments that are designated as hedging instruments and instruments that are customer related and not designated in hedging relationships. The following table presents information regarding our derivative financial instruments, at December 31:
		Asset derivatives							Liability derivatives
		Notional			Fair value (1)				Notional			Fair value (2)
		amount							amount
	2014
	Derivatives designated as hedging instruments:
	Interest rate swap agreements	$	4		$	—			$	30		$	2
	Derivatives not designated as hedging instruments:
	Interest rate swap agreements	3,629			96				3,649			96
	Total derivatives	$	3,633		$	96			$	3,679		$	97
	2013
	Derivatives designated as hedging instruments:
	Interest rate swap agreements	$	22		$	—			$	13		$	1
	Derivatives not designated as hedging instruments:
	Interest rate swap agreements	3,092			76				3,094			76
	Total derivatives	$	3,114		$	76			$	3,107		$	77
	-1	Represents gross amounts, included in Other Assets in our Consolidated Statements of Condition.
	-2	Represents gross amounts, included in Other Liabilities in our Consolidated Statements of Condition.
	Some of our interest rate swaps for which we had master netting arrangements with the counterparty were in a net liability position of $93 million and $49 million at December 31, 2014 and 2013, respectively. We offset $96 million and $76 million of liabilities with $3 million and $27 million of assets in our Consolidated Statements of Financial Condition at December 31, 2014 and 2013, respectively, related to these interest rate swaps and we did not include any cash collateral in the netting. We posted collateral for liability positions with a fair value of $130 million and $43 million at December 31, 2014 and 2013, respectively.
	Derivatives designated in hedging relationships
	We designate interest rate swap agreements used to manage changes in the fair value of loans due to interest rate changes as fair value hedges. We have designated the risk of changes in the fair value of loans attributable to changes in the benchmark rate as the hedged risk. Accordingly, changes to the fair value of the hedged items or derivatives attributable to a change in credit risk are excluded from our assessment of hedge effectiveness. The change in fair value of the derivatives, including both the effective and ineffective portions, is recognized in earnings and, so long as our fair value hedging relationships remain highly effective, such change is offset by the gain or loss due to the change in fair value of the loans. The net impact of the fair value hedging relationships on net income was not significant during 2014 and 2013.
	Historically, we have also entered into interest rate swaps to offset the variability in the interest cash outflows of LIBOR based borrowings. These derivative instruments have been designated as cash flow hedges. At December 31, 2014, we did not have any derivatives classified as cash flow hedges. At December 31, 2014, there was a $5 million loss recognized in accumulated other comprehensive income related to borrowings that were previously hedged using interest rate swaps that were classified as cash flow hedges. This amount will be reclassified out of accumulated other comprehensive income and into earnings over the remaining life of the hedged borrowings as an adjustment of yield.
	The following table presents information about amounts recognized for our derivative financial instruments designated in cash flow hedging relationships for the years ended December 31:
	Cash Flow Hedges	2014				2013				2012
	Interest rate swap agreements:
	Amount of gain on derivatives recognized in other comprehensive income, net of tax	$	1			$	1			$	7
	Amount of (loss) on derivatives reclassified from other comprehensive income to income	(1		)	(1)	(1		)	(1)	(15		)	(2)
	-1	Recognized in interest expense on borrowings in our Consolidated Statements of Income.
	-2	Of this amount, $12 million was recognized in merger and acquisition integration expenses when the associated borrowings were repaid in connection with the HSBC Branch Acquisition and $4 million was recognized in interest expense on borrowings in our Consolidated Statements of Income.
	Derivatives not designated in hedging relationships
	In addition to our derivatives designated in hedge relationships, we act as an interest rate swap counterparty for certain commercial borrowers in the normal course of servicing our customers, which are accounted for at fair value. We manage our exposure to such interest rate swaps by entering into corresponding and offsetting interest rate swaps with third parties that mirror the terms of the interest rate swaps we have with the commercial borrowers. These positions (referred to as “customer swaps”) directly offset each other and our exposure is the positive fair value of the derivatives due to changes in credit risk of our commercial borrowers and third parties. We recognized revenue for this service that we provide our customers of $13 million and $18 million for the years ended December 31, 2014 and 2013, respectively, included in Capital Markets income in our Consolidated Statements of Income.
	In the second quarter of 2012, we sold $3.1 billion of investment securities to a third party (“purchaser”) at a certain price as of the date of the sale. Under the sales agreement, the purchaser subsequently sold all of the investment securities over a set period of time and we received a portion of the additional net profits received in excess of the floor price. The agreement qualified as a free standing derivative and was accounted for at fair value. During 2012, we recorded a total gain of $5 million for the increase in the fair value of the derivative. The agreement concluded with the sale of all of the investment securities.

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities
	Loan Commitments
	In the ordinary course of business, we extend commitments to originate commercial and residential mortgages, commercial loans, and consumer loans. Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established under the contract. Our commitments generally have fixed expiration dates or other termination clauses, and may require our customer to pay us a fee. Since we do not expect all of our commitments to be funded, the total commitment amounts do not necessarily represent our future cash requirements. We evaluate each customer’s creditworthiness on a case-by-case basis. We may obtain collateral based upon our assessment of the customer’s creditworthiness. We may write a commitment on a fixed rate basis exposing us to interest rate risk given the possibility that market rates may change between the commitment date and the actual extension of credit. We also extend credit to our retail and commercial customers, up to a specified amount, through lines of credit. The borrowers are able to draw on these lines as needed, making our funding requirements for these products generally more difficult to predict.
	In addition to the commitments discussed above, we issue standby letters of credit to third parties that guarantee payments on behalf of our commercial customers in the event our customer fails to perform under the terms of the contract between our customer and the third party. Since the majority of our unused commercial lines of credit and our outstanding standby letters of credit expire without being funded, our actual funding requirements may be substantially less than the amounts that we report. We anticipate that we will have sufficient funds available to meet our current loan commitments and other obligations through our normal business operations. The credit risk involved in our issuance of these commitments is essentially the same as that involved in extending loans to customers and is limited to the contractual notional amount of these instruments.
	We had a liability for unfunded commitments of $16 million and $13 million as of December 31, 2014 and 2013, respectively. For 2014, and 2013, we recognized provision for credit losses related to our unfunded commitments of $3 million and $2 million, respectively.
	Information pertaining to our loan commitments is as follows at December 31:
		2014		2013
	Outstanding commitments to originate loans:
	Fixed rate	$	265	$	217
	Variable rate	1,522		964
	Total commitments outstanding	$	1,787	$	1,181
	Unused lines of credit	$	9,319	$	8,400
	Standby letters of credit	266		297
	Commitments to sell residential mortgages	137		168
	Given the current interest rate environment and current customer preference for long-term fixed rate mortgages, coupled with our desire to not hold these assets in our portfolio, we generally sell newly originated fixed rate conventional, 15 to 30 year and most FHA and VA loans in the secondary market to government sponsored enterprises such as FNMA and FHLMC or to wholesale lenders. We generally retain the servicing rights on residential mortgage loans sold which results in the recognition of a mortgage service asset upon sale and monthly service fee income, thereafter, net of servicing asset amortization.
	Lease Obligations
	Our future minimum rental commitments for premises and equipment under non-cancelable operating leases and capital lease obligations are as follows at December 31:
		Operating leases			Capital leases
	2015	$	34		$	3
	2016	32			3
	2017	25			3
	2018	21			3
	2019	18			3
	Thereafter	62		(1)	16		(2)
	-1	Thereafter through 2041.
	(2)	Thereafter through 2032.
	Contingent Liabilities
	In the ordinary course of our business there are various threatened and pending legal proceedings against us. Based on our review and consultation with our outside legal counsel, we believe that the aggregate liability, if any, arising from such litigation would not have a material adverse effect on our Consolidated Financial Statements at December 31, 2014.

Capital

Capital	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Capital	Capital
	First Niagara Financial Group, Inc. and our bank subsidiary, First Niagara Bank, N.A. are subject to regulatory capital requirements administered by the Board of Governors of the Federal Reserve System (the “Federal Reserve”) and the Office of the Comptroller of Currency (the “OCC”), respectively. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on our financial statements.
	Under capital adequacy guidelines and the regulatory framework for prompt corrective action, we must meet specific capital guidelines that involve quantitative measures of our assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. Such quantitative measures are also subject to qualitative judgment of the regulators regarding components, risk weightings, and other factors.
	The actual capital amounts, ratios, and requirements for First Niagara Financial Group, Inc. and First Niagara Bank, N.A. are as follows at December 31:
						For capital adequacy				Minimum amount to be
		Actual				purposes				well-capitalized
		Amount		Ratio		Amount		Ratio		Amount		Ratio
	First Niagara Financial Group, Inc.:
	2014
	Leverage ratio	$	2,764	7.5	%	$	1,474	4	%	$	1,843	5	%
	Tier 1 risk-based capital	2,764		9.81		1,127		4		1,691		6
	Total risk-based capital	3,313		11.75		2,256		8		2,819		10
	Tier 1 common capital	2,312		8.2		N/A		N/A		N/A		N/A
	2013
	Leverage ratio	$	2,526	7.26	%	$	1,392	4	%	$	1,739	5	%
	Tier 1 risk-based capital	2,526		9.56		1,057		4		1,585		6
	Total risk-based capital	3,046		11.53		2,114		8		2,642		10
	Tier 1 common capital	2,075		7.86		N/A		N/A		N/A		N/A
	First Niagara Bank, N.A.:
	2014
	Leverage ratio	$	2,949	8.01	%	$	1,473	4	%	$	1,841	5	%
	Tier 1 risk-based capital	2,949		10.48		1,126		4		1,688		6
	Total risk-based capital	3,199		11.37		2,251		8		2,814		10
	2013
	Leverage ratio	$	2,675	7.7	%	$	1,390	4	%	$	1,737	5	%
	Tier 1 risk-based capital	2,675		10.15		1,054		4		1,581		6
	Total risk-based capital	2,898		10.99		2,109		8		2,637		10
	As of December 31, 2014, we met all capital adequacy requirements to which we were subject and both First Niagara Financial Group, Inc. and First Niagara Bank, N.A. were considered well-capitalized under the Federal Reserve’s Regulation Y (in the case of First Niagara Financial Group, Inc.) and the OCC’s prompt corrective action regulations (in the case of First Niagara Bank, N.A.). We are unaware of any conditions or events since the latest notification from federal regulators that have changed our capital adequacy categories.
	The Company had less than $15 billion in assets as of December 31, 2009. Accordingly, and based on Federal Reserve Board interpretations of our acquisitions, the trust preferred securities classified as long-term debt on our balance sheet, in the amount of $114 million at December 31, 2014, will be included as Tier 1 capital while they are outstanding, unless we complete an acquisition of a depository institution holding company after January 1, 2014, at which time they would be subject to the stated phase-out requirements of the New Capital Rules, as described in this report in Part I, Item 1, "Business, Supervision and Regulation," and would be included as Tier 2 capital.
	Our ability to pay dividends to our stockholders is substantially dependent upon the Bank’s ability to pay dividends to the Company. Subject to the Bank meeting or exceeding regulatory capital requirements, the prior approval of the OCC is required if the total of all dividends declared by the Bank in any calendar year would exceed the sum of the Bank’s net profits for that year and its retained net profits for the preceding two calendar years, less any required transfers to surplus. In addition, Federal Reserve guidance sets forth the supervisory expectation that bank holding companies will inform and consult with Federal Reserve staff in advance of issuing a dividend that exceeds earnings for the quarter and should not pay dividends in a rolling four quarter period in an amount that exceeds net income for that period.  Federal law also prohibits the Bank from paying dividends that would be greater than its undivided profits after deducting statutory bad debt in excess of its allowance for loan losses.
	While the size of the goodwill charge does not adversely impact our capital ratios, it does impact our regulatory dividend capacity formula. Even though the non-cash goodwill charge does not impact cash flow for dividends, the size of the charge does require that we get regulatory approval from the OCC to make distributions or other returns of capital from the Bank to the Company and obtain a no objection from the Federal Reserve to pay the Company dividend to our common and preferred stockholders in the future. We have received approval from the OCC and no objection from the Federal Reserve to pay dividends this quarter, which were declared on January 28, 2015.
	Based on current estimates, we expect to need quarterly approval from the OCC until the first quarter of 2017 based on their calculation formula and to seek no objection from the Federal Reserve until the fourth quarter of 2015 based on their calculation formula. While we cannot be assured that the OCC will approve and the Federal Reserve will not object to our quarterly dividend requests going forward, based on conversations with the regulators and barring any unforeseen future developments that would materially impact our profitability, we believe that we can maintain our holding company common and preferred dividend payments at their current levels.
	The Bank paid $80 million and $175 million in dividends to the Company in 2014 and 2013, respectively. Additionally, the Bank made an $85 million capital distribution to the Company during 2014.
	Common Stock Repurchases
	We did not repurchase shares of our common stock during 2014 under stock repurchase plans approved by our Board of Directors. However, we did repurchase 2 million of unallocated ESOP shares in connection with the termination of this plan. As of December 31, 2014, we are authorized to repurchase up to 12 million shares of our common stock.
	Preferred Stock
	Our preferred stock pays dividends quarterly when, as and if declared by our board of directors, at a rate of 8.625% per year until February 15, 2017, whereby the dividends are then paid at a floating rate equal to three month LIBOR plus 7.327% per year. Additionally, the preferred stock has no maturity date. We may redeem the preferred stock, in whole or in part, from time to time, on any dividend payment date on or after February 15, 2017, at a redemption price of $25 per share, plus any declared and unpaid dividends.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The components of our income tax expense are as follows for the years ended December 31:
		2014			2013			2012
	Current:
	Federal	$	36		$	119		$	36
	State	4			4			1
		41			123			37
	Deferred (benefit) taxes:
	Federal	(136		)	3			31
	State	(14		)	1			3
		(150		)	5			34
	Total income tax (benefit) expense	$	(109	)	$	128		$	71
	Our effective tax rate benefit for 2014 was 13.3%. Our effective tax rates for 2013 and 2012 were 30.2% and 29.6%, respectively. Our income tax expense differs from our expected tax expense (computed by applying the Federal corporate tax rate of 35% to income before income taxes) as follows for the years ended December 31:
		2014			2013			2012
	Tax (benefit) expense at statutory rate	$	(289	)	$	148		$	84
	Increase (decrease) attributable to:
	State income taxes, net of Federal benefit	(11		)	4			2
	Bank owned life insurance income	(5		)	(6		)	(5		)
	Tax exempt interest	(13		)	(11		)	(10		)
	Credits	(29		)	(13		)	(2		)
	Goodwill impairment	259			—			—
	Subsidiary reorganization	(27		)	—			—
	Other	5			6			2
	Income tax (benefit)	$	(109	)	$	128		$	71
	The tax effects of our temporary differences that give rise to significant portions of our deferred tax assets and deferred tax liabilities are as follows at December 31:
		2014			2013
	Deferred tax assets:
	Net operating loss and other carryforwards	$	56		$	58
	Capital loss carryforward	44			—
	Financial statement allowance for credit losses	112			111
	Securitizations	2			2
	Partnerships	9			—
	Deferred compensation	13			13
	Stock-based compensation	15			14
	Other accrued expenses not currently deductible	20			21
	Acquired intangibles	88			—
	Post-retirement benefit obligation	5			4
	Nonperforming loan interest	14			12
	Other	34			28
	Total gross deferred tax assets	413			264
	Valuation allowance	(44		)	—
	Deferred tax liabilities:
	Unrealized gain on investment securities available for sale	(40		)	(52		)
	Partnerships	—			(3		)
	Leases	(32		)	(27		)
	Acquired intangibles	—			(33		)
	Premises and equipment	(5		)	(19		)
	Mortgage servicing rights	(14		)	(13		)
	Pension benefits	(22		)	(37		)
	Other	(2		)	(2		)
	Total gross deferred tax liabilities	(114		)	(187		)
	Net deferred tax asset	$	255		$	77
	In assessing the realizability of our deferred tax assets, we consider whether it is more likely than not that we will not realize some portion or all of our deferred tax assets. Our ultimate realization of our deferred tax assets is dependent upon our generation of future taxable income during the periods in which those temporary differences become deductible. We consider the scheduled reversal of our deferred tax liabilities, availability of operating loss carrybacks, our projected future taxable income, and our tax planning strategies in making this assessment. Based upon the level of our available historical taxable income, the opportunity for our net operating loss carrybacks, and projections for our future taxable income over the periods which our deferred tax assets are realizable, we believe it is more likely than not that we will realize the benefits of these deductible differences at December 31, 2014, except for the deferred taxes for which a valuation allowance has been established. We had a valuation allowance of $44 million and $0.2 million, at December 31, 2014 and 2013, respectively.
	We may carry net operating losses back to the preceding two taxable years for Federal income tax purposes and forward to the succeeding 20 taxable years for Federal and State income tax purposes, subject to certain limitations. At December 31, 2014, we had net operating loss carryforwards of $121 million for Federal income tax purposes, which will begin to expire in 2020. These losses, subject to an annual limitation, were obtained through our acquisitions of Great Lakes Bancorp, Inc. and Harleysville. State net operating loss carryforwards at December 31, 2014 were $57 million and are expected to expire by 2030. As of December 31, 2014, there is no valuation allowance for net operating loss carryover that is not expected to be utilized by then end of the carryover period.
	We generated approximately $45 million in Federal and State tax credits in 2014 associated with investment tax credits that arose in 2014. We have Federal alternative minimum tax credits of approximately $7 million that have an unlimited carryforward period.
	In March 2014, the New York State Fiscal Year 2014-2015 Budget legislation was signed into law. Two of the provisions of the New York State Fiscal Year 2014-2015 Budget changed the way banks apportion receipts and changed the applicable tax rates.  As a result of the change in apportionment and tax rates, we were required to make adjustments to deferred tax asset balances, resulting in a $5 million charge to income tax expense in 2014.
	At December 31, 2014, our Bank’s Federal pre-1988 reserve, for which no Federal income tax provision has been made, was approximately $92 million. Under current Federal law, these reserves are subject to recapture into taxable income should our Bank make nondividend distributions, make distributions in excess of earnings and profits retained, as defined, or cease to maintain a banking type charter. A deferred tax liability is not recognized for the base year amount unless it becomes apparent that those temporary differences will reverse into taxable income in the foreseeable future. No deferred tax liability has been established as these two events are not expected to occur in the foreseeable future.
	A reconciliation of our unrecognized tax benefits is as follows for the years ended December 31:
		2014			2013			2012
	Balance at beginning of year	$	6		$	3		$	3
	Additions based on tax positions related to the current year	2			1			1
	Additions for tax positions of prior years	1			3			—
	Reductions related to settlements with taxing authorities	—			(1		)	(2		)
	Balance at end of year	$	9		$	6		$	3
The entire balance of unrecognized tax benefits, if recognized, would favorably affect our effective income tax rate. We recognize penalties and accrued interest related to unrecognized tax benefits in tax expense. Accrued penalties and interest amounted to $0.9 million and $0.3 million at December 31, 2014 and 2013, respectively. The change in accrued penalties and interest for the current year impacted Consolidated Statements of Income as a component of provision for income taxes. We anticipate that approximately $2 million in unrecognized tax benefits will reverse in 2015.
As a large taxpayer, we are under continuous audit by the IRS and other taxing authorities. Although we do not anticipate that a significant impact to our unrecognized tax benefit balance will occur during the next 12 months as a result of these audits, it remains possible that the amount of our liability for unrecognized tax benefits could change over that time period. With few exceptions, we are no longer subject to Federal and State income tax examinations by tax authorities for years before 2011. There are no indications of any material adjustments relating to any examination currently being conducted by any taxing authority.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share
	The following table is a computation of our basic and diluted earnings per share using the two-class method for the years ended December 31:
		2014			2013			2012
	Net (loss) income available to common stockholders	$	(745	)	$	265		$	141
	Less income allocable to unvested restricted stock awards	1			1			—
	Net (loss) income allocable to common stockholders	$	(746	)	$	264		$	140
	Weighted average common shares outstanding:
	Total shares issued	366			366			366
	Unallocated employee stock ownership plan shares	(2		)	(2		)	(2		)
	Unvested restricted stock awards	(3		)	(2		)	(1		)
	Treasury shares	(11		)	(12		)	(14		)
	Total basic weighted average common shares outstanding	350			350			349
	Effect of dilutive stock-based awards	—			1			—
	Total diluted weighted average common shares outstanding	350			350			349
	Basic (loss) earnings per common share	$	(2.13	)	$	0.75		$	0.4
	Diluted (loss) earnings per common share	$	(2.13	)	$	0.75		$	0.4
	Anti-dilutive stock-based awards excluded from the diluted weighted average common share calculations	11			11			12

Other_Comprehensive_Income

Other Comprehensive Income	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Other Comprehensive Income	Other Comprehensive Income
	The following table presents the activity in our other comprehensive income for the years ended December 31:
		Pretax			Income taxes			Net
	2014
	Securities available for sale:
	Net unrealized holding losses arising during the year	$	(19	)	$	(7	)	$	(12	)
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Amortization of net unrealized holding gains to income during the year	(13		)	(5		)	(8		)	(1)
	Interest rate swaps designated as cash flow hedges:
	Reclassification adjustment for realized losses included in net income	1			1			1			(2)
	Pension and post-retirement actuarial losses	(51		)	(16		)	(34		)
	Total other comprehensive loss	$	(81	)	$	(27	)	$	(53	)
	2013
	Securities available for sale:
	Net unrealized holding losses arising during the year	$	(177	)	$	(68	)	$	(109	)
	Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity	(55		)	(21		)	(34		)
	Net unrealized losses on securities available for sale	(232		)	(89		)	(143		)
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Net unrealized holding gains transferred during the year	55			21			34
	Amortization of net unrealized holding gains to income during the year	(20		)	(7		)	(12		)	(1)
	Net unrealized holding gains on securities transferred during the year	35			14			22
	Interest rate swaps designated as cash flow hedges:
	Reclassification adjustment for realized losses included in net income	1			1			1			(2)
	Pension and post-retirement actuarial gains	40			15			25
	Total other comprehensive loss	$	(154	)	$	(59	)	$	(95	)
	2012
	Securities available for sale:
	Net unrealized holding gains arising during the year	$	177		$	68		$	109
	Reclassification adjustment for realized gains included in net income	(16		)	(6		)	(10		)
	Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity	4			2			2
	Net unrealized gains on securities available for sale	165			64			101
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Net unrealized holding gains transferred during the year	(4		)	(2		)	(2		)
	Less: amortization of net unrealized holding gains to income during the year	(3		)	(1		)	(2		)	(1)
	Net unrealized holding gains on securities transferred during the year	(7		)	(3		)	(4		)
	Interest rate swaps designated as cash flow hedges:
	Net unrealized losses arising during the year	(1		)	2			(3		)
	Reclassification adjustment for realized losses included in net income	15			6			10			(2)
	Net unrealized losses on interest rate swaps designated as cash flow hedges	15			8			7
	Pension and post-retirement actuarial losses	(24		)	(10		)	(14		)
	Total other comprehensive income	$	149		$	59		$	89
	(1)	Included in Interest income on investment securities and other in our Consolidated Statement of Income.
	(2)	Included in Interest expense on borrowings in our Consolidated Statement of Income.
	The following table presents the activity in our accumulated other comprehensive income for the periods indicated:
		Net unrealized gains (losses) on securities available for sale			Net unrealized gains (losses) on			Unrealized loss on			Pension and postretirement plans			Total
					securities transferred from			interest rate
					available for sale to			swaps designated as
					held to maturity			cash flow hedges
	Balance, January 1, 2012	$	105		$	3		$	(13	)	$	(27	)	$	68
	Period change, net of tax	101			(4		)	7			(14		)	89
	Balance, December 31, 2012	207			(2		)	(6		)	(41		)	157
	Period change, net of tax	(143		)	22			1			25			(95		)
	Balance, December 31, 2013	64			20			(6		)	(16		)	62
	Period change, net of tax	(12		)	(8		)	1			(34		)	(53		)
	Balance, December 31, 2014	$	52		$	12		$	(5	)	$	(51	)	$	9
	During the next twelve months, we expect to reclassify $1 million of pre-tax net loss on previous cash flow hedges from accumulated other comprehensive income to earnings.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation
	We offer several stock-based incentive awards under one equity based incentive plan, the First Niagara Financial Group, Inc. 2012 Equity Incentive Plan (the "2012 Plan"), which expires in 2022 and authorizes us to issue up to 17 million shares of common stock for grants of stock options, stock appreciation rights, accelerated ownership option rights, restricted stock awards or restricted stock units, or performance unit awards. At December 31, 2014, we had approximately 12 million shares available for grant under the 2012 plan.
	Stock-based compensation expense for 2014, 2013, and 2012 totaled $11 million, $10 million, and $11 million, respectively, which is included in salaries and benefits in our Consolidated Statements of Income.
	Stock Options
	During 2014, we granted stock options under the 2012 Plan. We have two stock-based compensation plans under which we grant options to our directors and key employees. We grant stock options with an exercise price equal to the market price of our stock on the date of grant. All options have a ten year term and become fully vested and exercisable over a period of three years from the grant date. When option recipients exercise their options, we issue shares from treasury stock and record the proceeds as additions to capital.
	Restricted Stock Awards and Units
	During 2014, we granted time-based restricted stock units to key employees and restricted stock awards and restricted stock units to non-employee directors. Restricted stock grants to non-employee directors vest over one year while grants to key employees generally vest over three years from the grant date. When restricted stock grants are forfeited before they vest, we reacquire the shares into treasury stock, and hold them to use for new awards.
	During 2014, we granted approximately 339 thousand performance-based restricted stock units to key employees under the 2012 Plan. Performance-based restricted stock units vest at the conclusion of a three year performance period and distributes based on our total shareholder return performance relative to an industry index.
	At December 31, 2014, we held approximately 13 million shares of our stock as treasury shares, which is adequate to meet the share requirements of our current stock-based compensation plans. During 2014, we issued 1 million shares from treasury stock in connection with grants of restricted stock.
	Stock Options
	The following is a summary of our stock option activity for the year ended December 31, 2014:
		Number of		Weighted average			Weighted average remaining	Aggregate intrinsic
		shares (in thousands)		exercise price			contractual term	value(1)
	Outstanding at January 1, 2014	11,186		$	13.23
	Granted	505		9.27
	Forfeited	(185	)	9.13
	Expired	(626	)	16.92
	Outstanding at December 31, 2014	10,879		$	12.9		2.0 years	$	—
	Exercisable at December 31, 2014	10,132		$	13.17		1.5 years	$	—
	(1)	Intrinsic value is the difference between the fair value of our stock at December 31, 2014 and the exercise price of the stock award. Due to the price of our stock at December 31, 2014, the outstanding and exercisable options had no intrinsic value.
	The following is a summary of our nonvested stock option activity for the year ended December 31, 2014:
		Number of		Weighted			Weighted average
		shares (in thousands)		average			grant date
				exercise price			fair value
	Nonvested at January 1, 2014	653		$	9.45		$	2.52
	Granted	505		9.27			2.59
	Vested	(225	)	10.11			2.67
	Forfeited	(185	)	9.13			2.48
	Nonvested at December 31, 2014	748		$	9.21		$	2.54
	The following is a summary of our stock options outstanding at December 31:
	Exercise price	Options outstanding (in thousands)		Weighted average exercise price			Weighted average remaining life (years)	Options exercisable (in thousands)		Weighted average exercise price
	2014
	$8.86 – $12.00	2,135		$	10.12		6.3	1,388		$	10.61
	$12.01 – $13.50	7,628		13.05			0.6	7,628		13.05
	$13.51 – $15.50	965		14.31			3	965		14.31
	$15.51 – $51.78	151		35.38			1	151		35.38
	Total	10,879		12.9			2	10,132		13.17
	2013
	$8.86 – $12.00	1,835		$	10.25		6.8	1,225		$	10.8
	$12.01 – $15.00	9,099		13.2			1.9	9,056		13.19
	$15.01 – $18.00	42		15.25			0.5	42		15.25
	$18.01 – $57.75	210		40.07			1.5	210		40.07
	Total	11,186		13.23			2.7	10,533		13.46
	2012
	$9.71 – $13.00	2,693		$	11.58		5.6	2,165		$	12
	$13.01 – $16.00	8,168		13.3			2.9	7,896		13.28
	$16.01 – $20.00	19		16.27			0.6	19		16.27
	$20.01 – $57.75	295		41.96			2	295		41.96
	Total	11,175		13.65			3.5	10,375		13.83
	No stock options were exercised during 2014 and the intrinsic value of stock options exercised during 2013 was less than $100 thousand. As of December 31, 2014, we have $1 million of unrecognized compensation cost related to unvested options that we have granted. We expect this cost to be recognized over a weighted average period of 1.2 years.
	We use the Black-Scholes valuation method to estimate the fair value of our stock option awards. This method is dependent upon certain assumptions. The following is a summary of our stock options granted for the years ended December 31, as well as the weighted average assumptions that we utilized to compute the fair value of the options:
		2014			2013			2012
	Options granted (in thousands)	505			434			528
	Grant date weighted average fair value per stock option	$	2.59		$	2.36		$	2.73
	Grant date weighted average share price	$	9.27		$	8.86		$	9.84
	Dividend yield	3.45		%	3.61		%	3.25		%
	Risk-free interest rate	2.05		%	0.99		%	1.26		%
	Expected volatility factor	38.59		%	40.7		%	40.36		%
	Expected life (in years)	6.6			5.7			5.6
	In the table above, the risk-free interest rate is the zero coupon U.S. Treasury rate commensurate with the expected life of options on the date of their grant. We based the volatility of our stock on historical volatility over a span of time equal to the expected life of the options.
	Time-Vested Restricted Stock Awards and Restricted Stock Units
	We expense the grant date fair value of our restricted stock awards and restricted stock units over their respective vesting periods. At December 31, 2014 we had $14 million of unrecognized compensation cost related to unvested restricted stock awards and units and we expect this cost to be recognized over a weighted average period of 1.8 years.
	The following is a summary of our restricted stock and restricted stock unit activity for 2014:
		Number of		Weighted average grant date fair value
shares (in thousands)
Unvested at January 1, 2014	2,103		$	9.65
Awarded	1,860		8.93
Vested	(707	)	10.04
Forfeited	(555	)	9.12
Unvested at December 31, 2014	2,701		$	9.14
The fair value of restricted stock awards and restricted stock units that vested during 2014, 2013, and 2012 was $6 million, $5 million, and $3 million, respectively.
Restricted stock units granted to certain members of our Board of Directors vested on December 31, 2014 and 2013 but are not released until the board member retires. Dividend equivalent units earned during 2014 and 2013 on these restricted stock units totaled 5,295 and 4,495, respectively.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Information regarding our pension plans	Note 15. Benefit Plans
	We account for our pension and postretirement plans by recognizing in our financial statements an asset for a plan’s overfunded status or a liability for a plan’s underfunded status. We report changes in the funded status of our pension and postretirement plan as a component of other comprehensive income, net of applicable taxes, in the year in which changes occur.
	Pension Plans
	We maintain a legacy employer sponsored defined benefit pension plan (the “First Niagara Plan”) for which participation and benefit accruals have been frozen since 2002. Additionally, any pension plans acquired in connection with previous whole-bank acquisitions, and subsequently merged into the First Niagara Plan were frozen prior to or shortly after completion of the transactions. Upon our merger with NewAlliance, we acquired the Employees’ Retirement Plan of NewAlliance Bank (the “NewAlliance Plan”), an employer sponsored defined benefit pension plan. The NewAlliance Plan was frozen prior to completion of the merger and has not been merged into the First Niagara Plan.
	Accordingly, no employees are permitted to commence participation in the First Niagara Plan or the NewAlliance Plan (collectively, the “Plans”) and future salary increases and years of credited service are not considered when computing an employee’s benefits under the Plans. As of December 31, 2014, we have met all minimum ERISA funding requirements.
	We also have unfunded supplemental executive retirement plans (“SERPs”) for which we have recorded an accumulated other comprehensive loss of $6 million and $3 million at December 31, 2014 and 2013, respectively. We had assumed these plans in connection with the NewAlliance and other previous acquisitions, therefore no employees are eligible to commence participation in the SERPs. The projected benefit obligation and accumulated benefit obligation for these SERPs was $23 million and $21 million, respectively, at December 31, 2014 and 2013.
	Information regarding our pension plans is as follows at December 31:
		2014			2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	214		$	243
	Service cost	1			1
	Interest cost	10			10
	Actuarial loss (gain)	49			(26		)
	Benefits paid	(15		)	(13		)
	Projected benefit obligation at end of year	260			214
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year	290			276
	Employer contributions	2			2
	Actual return on plan assets	19			25
	Benefits paid	(14		)	(13		)
	Fair value of plan assets at end of year	296			290
	Overfunded status at year end	$	36		$	76
	Net pension cost is comprised of the following for the years ended December 31:
		2014			2013			2012
	Service cost	$	1		$	1		$	1
	Interest cost	10			10			11
	Expected return on plan assets	(17		)	(16		)	(14		)
	Amortization of unrecognized loss	1			3			2
	Net periodic pension (gain)	$	(5	)	$	(2	)	$	(2	)
	Changes in plan assets and benefit obligations recognized in other comprehensive income are as follows for the years ended December 31:
		2014			2013
	Net loss (gain)	$	46		$	(38	)
	Total loss (gain) loss recognized in other comprehensive income	46			(38		)
	Total recognized in net periodic pension cost and other comprehensive income	$	42		$	(40	)
	The principal actuarial assumptions we used were as follows for the years ended December 31:
		2014		2013		2012
	Projected benefit obligation:
	Discount rate	3.99	%	5.02	%	4.04	%
	Net periodic pension cost:
	Discount rate	5.01	%	4.07	%	5.16	%
	Expected long-term rate of return on plan assets	5.89	%	5.89	%	5.86	%
	For the 2014 pension plan valuations, we utilized the RP-2014 Healthy Annuitant/Employee Mortality table with Projection Scale MP-2014. The discount rate that we used in the measurement of our pension obligation is determined by modeling the pension plan expected future retirement payment cash flows to the Milliman Bond Matching Model as of the measurement date. The expected long-term rate of return on plan assets reflects long-term earnings expectations on existing plan assets and those contributions expected to be received during the current plan year. In estimating that rate, we gave appropriate consideration to historical returns earned by plan assets in the fund and the rates of return expected to be available for reinvestment. We adjusted rates of return to reflect current capital market assumptions and changes in investment allocations.
	Our overall investment strategy with respect to the assets of the Retirement Plan of the First Niagara Financial Group, Inc. is primarily for preservation of capital and to provide regular dividend and interest payments. The Plan’s target asset allocation for 2014 was 74% fixed income securities, 21% equity securities and 5% cash. The fixed income portion of the Plan assets is to be managed as a high-grade intermediate term fixed income account. Equity securities primarily include investments in large cap value and growth stocks as well as mid and small cap companies. Starting in 2015, the Plan's target asset allocation will be 57% fixed income securities, 38% equity securities, and 5% cash. We assumed equity securities to earn a return in the range of 7.5% to 8.5% and fixed income securities to earn a return in the range of 2.5% to 3.5%. The long-term inflation rate was estimated to be 2.5%. When these overall return expectations are applied to our Plan's target allocation, we expect the rate of return to be approximately 5.5%.
	Our overall investment strategy with respect to the assets of the Employees' Retirement Plan of NewAlliance Bank is primarily for preservation of capital and to provide regular dividend and interest payments. The Plan’s target asset allocation for 2014 was 30% fixed income securities, 65% equity securities and 5% cash. The fixed income portion of the Plan assets is to be managed as a high-grade intermediate term fixed income account. Equity securities primarily include investments in large cap value and growth stocks as well as mid and small cap companies. Starting in 2015, the Plan's target asset allocation will be 57% fixed income securities, 38% equity securities, and 5% cash. We assumed equity securities to earn a return in the range of 7.5% to 8.5% and fixed income securities to earn a return in the range of 2.5% to 3.5%. The long-term inflation rate was estimated to be 2.5%. When these overall return expectations are applied to our Plan’s target allocation, we expect the rate of return to be approximately 5.5%.
	The fair values of the Plans’ assets by asset category and level within the fair value hierarchy are as follows at December 31:
	Asset Category	Total			Level 1			Level 2			Level 3
	2014
	Cash	$	14		$	14		$	—		$	—
	Equity securities:
	First Niagara Financial Group, Inc. common stock	1			1			—			—
	Fixed income securities:
	Corporate bonds	3			—			3			—
	Exchange traded funds:
	Large cap growth	23			23			—			—
	Foreign large cap value and blend	4			4			—			—
	High yield bond fund	7			7			—			—
	Inflation protected bond fund	43			43			—			—
	Intermediate term bond fund	91			91			—			—
	Diversified emerging markets	1			1			—			—
	Real estate	5			5			—			—
	Mortgage-backed securities	7			7			—			—
	Small and mid cap blend	5			5			—			—
	World bond	18			18			—			—
	Mutual fund investments:
Foreign large value and blend	5			5			—			—
Small and midcap growth, value, and blend	3			3			—			—
Large cap growth, value, and blend	60			60			—			—
Real estate	4			4			—			—
Diversified emerging markets	2			2			—			—
	$	296		$	294		$	3		$	—
Asset Category	Total			Level 1			Level 2			Level 3
2013
Cash	$	43		$	43		$	—		$	—
Equity securities:
First Niagara Financial Group, Inc. common stock	1			1			—			—
U.S. companies	32			32			—			—
International companies	2			2			—			—
Fixed income securities:
Corporate bonds	4			—			4			—
Exchange traded funds:
Large cap growth	15			15			—			—
Large cap value	9			9			—			—
Foreign large cap blend	3			3			—			—
Small and mid cap blend	2			2			—			—
Mutual fund investments:
Foreign large value and blend	14			14			—			—
Small and midcap growth and blend	11			11			—			—
Mortgage-backed securities	7			7			—			—
Large blend	26			26			—			—
Total return investment grade securities	41			41			—			—
Real estate	3			3			—			—
Diversified emerging markets	5			5			—			—
High yield bond	9			9			—			—
World bond	4			4			—			—
Intermediate term bond	58			58			—			—
	$	290		$	286		$	4		$	—
The Plans did not hold any assets classified as Level 3 during 2014 or 2013.
Estimated benefit payments under our pension plans over the next ten years are as follow at December 31, 2014:
2015	$	14
2016	13
2017	14
2018	14
2019	14
2020-2024	74
Other Post-Retirement Benefits
We have an unfunded post-retirement medical plan which we have modified so that participation is closed to those employees who did not meet the retirement eligibility requirements by December 31, 2001. We also acquired three unfunded post-retirement employee benefit plans from our merger with NewAlliance which are also frozen. Information regarding these post-retirement plans is as follows at December 31:
	2014			2013
Change in accumulated post-retirement benefit obligation:
Accumulated post-retirement benefit obligation at beginning of year	$	10		$	13
Interest cost	1			1
Actuarial loss (gain)	4			(3		)
Benefits paid	(1		)	(1		)
Accumulated post-retirement benefit obligation at end of year	$	14		$	10
Unfunded status at year end	$	(14	)	$	(10	)
The components of net periodic post-retirement benefit cost are as follows for the years ended December 31:
	2014			2013			2012
Interest cost	$	1		$	1		$	1
Total periodic post-retirement cost	$	1		$	—		$	1
Changes in plan benefit obligations recognized in other comprehensive income are as follows for the years ended December 31:
	2014			2013
Net loss (gain)	$	4		$	(3	)
Total loss (gain) recognized in other comprehensive income	$	4		$	(3	)
Total recognized in net periodic post-retirement cost and other comprehensive income	$	5		$	(2	)
The principal actuarial assumptions used were as follows for the years ended December 31:
	2014		2013		2012
Accumulated post-retirement benefit obligation:
Discount rate	3.9	%	4.87	%	3.89	%
Total periodic cost:
Discount rate	4.87	%	3.89	%	5.19	%
For the 2014 unfunded post-retirement medical plan valuations, we utilized the RP-2014 Healthy Annuitant/Employee Mortality table with Projection Scale MP-2014. The assumed health care cost trend rate used in measuring the accumulated post-retirement benefit obligation was 6.4% for 2014, and gradually decreased to 5.6% by 2018. This assumption can have a significant effect on the amounts reported. If the rate were increased one percent, our accumulated post-retirement benefit obligation as of December 31, 2014 and our total periodic cost for 2014 would have increased by 7% and 6%, respectively. If the rate were decreased one percent, our accumulated post-retirement benefit obligation as of December 31, 2014 and our total periodic cost would have decreased by 6% and 5%, respectively. We do not anticipate making any contributions to the post-retirement plan in 2015, except to continue funding benefit payments as they come due.
Estimated benefit payments under the post-retirement plan over the next ten years are as follows at December 31, 2014:
2015	$	1
2016	1
2017	1
2018	1
2019	1
2020-2024	4
Amounts recognized in our Consolidated Statements of Condition related to our pension and post-retirement plans are as follows for the years ended December 31:
	2014			2013
Other assets:
Fair value of plan assets in excess of projected benefit obligation	$	36		$	76
Other liabilities:
Accumulated post-retirement benefit obligation	$	14		$	10
Accumulated other comprehensive loss (income), net of taxes:
Pension plans	$	50		$	19
Post-retirement benefit plan	1			(2		)
	$	51		$	16
401(k) Plan
Our employees that meet certain age and service requirements are eligible to participate in our employer sponsored 401(k) plan. Under the plan, participants may make contributions, in the form of salary deferrals, up to the maximum Internal Revenue Code limit. We contribute to the plan an amount equal to 100% of the first 4% of employee contributions plus 50% of employee contributions between 5% and 6%. These matching contributions are 100% vested. Our total contributions to the 401(k) plan amounted to $14 million, $13 million, and $11 million for 2014, 2013, and 2012, respectively.
Employee Stock Ownership Plan (“ESOP”)
In 2014, the Board of Directors approved the termination of our ESOP as of December 31, 2014.  All participants in the ESOP on the termination date will become 100% vested.  We applied to the Internal Revenue Service ("IRS") for a determination letter in the first quarter of 2015.  After the IRS issues a determination letter, we will notify ESOP participants of the available options for receiving their ESOP distributions.  The distribution options include an in-kind distribution to a qualified retirement plan, a direct in-kind distribution, a cash distribution to a qualified retirement plan, or a direct lump sum cash distribution. We recorded additional compensation expense of $1 million related to the additional shares released as a result of the termination.
Our employees that met certain age and service requirements were eligible to participate in our ESOP. Our ESOP held shares of First Niagara Financial Group, Inc. common stock that were purchased in our 1998 initial public offering and in the open market. The purchased shares were funded by loans in 1998 and 2003 from the Company to the Bank payable in equal annual installments over 30 years bearing a fixed interest rate. Loan payments were funded by cash contributions from the Bank and dividends on allocated and unallocated First Niagara Financial Group, Inc. stock held by the ESOP. Upon the termination of the ESOP, the loans were prepaid without penalty. As the loan was internally leveraged, the loan receivable from the Bank to the Company was not reported as an asset nor was the debt of the Bank shown as a liability in the Company’s financial statements.
Shares purchased by the ESOP were maintained in a suspense account and held for allocation among the participants. As annual loan payments were made, shares were released and allocated to employee accounts. We recognized compensation expense in an amount equal to the average market price of the shares released during the respective periods in which they were committed to be released. Compensation expense of $2 million, $1 million, and $2 million was recognized for 2014, 2013, and 2012, respectively, in connection with 297 thousand shares allocated to participants during 2014 and 178 thousand shares allocated to participants during both 2013 and 2012. The amount of allocated shares was 2 million at December 31, 2014. Due to the termination of the ESOP during 2014, there were no unallocated shares at December 31, 2014. The amounts of unallocated and allocated shares held by the ESOP were both 2 million at December 31, 2013. The fair value of unallocated ESOP shares was $21 million at December 31, 2013.
Other Plans
We also sponsor various nonqualified compensation plans for officers and employees. Awards are payable if certain earnings and performance objectives are met. Expenses under these plans amounted to $25 million, $27 million and $18 million for 2014, 2013, and 2012, respectively.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Current accounting guidance establishes a fair value hierarchy based on the transparency of inputs participants use to price an asset or liability. The fair value hierarchy prioritizes these inputs into the following three levels:
	Level 1 Inputs—Unadjusted quoted prices in active markets for identical assets or liabilities that are available at the measurement date.
	Level 2 Inputs—Inputs, other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.), or inputs that are derived principally from or corroborated by market data through correlation or other means.
	Level 3 Inputs—Unobservable inputs for determining the fair value of the asset or liability and are based on the entity’s own estimates about the assumptions that market participants would use to price the asset or liability.
	A financial instrument’s categorization within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement. A description of the valuation methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below.
	Our valuation methodologies may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. While we believe our valuation methodologies are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	Securities Available for Sale
	The fair value estimates of available for sale securities are based on quoted market prices of identical securities, where available (Level 1). However, as quoted prices of identical securities are not often available, the fair value estimate for almost our entire investment portfolio is based on quoted market prices of similar securities, adjusted for differences between the securities (Level 2). Adjustments may include amounts to reflect differences in underlying collateral, interest rates, estimated prepayment speeds, and counterparty credit quality. Where sufficient information is not available from the pricing services to produce a reliable valuation, we estimate fair value based on either broker quotes or internally developed models. We determine the fair value using third party pricing services, including brokers. As of December 31, 2014, none of our investment securities were priced utilizing broker quotes. See Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations," "Critical Accounting Policies and Estimates," for details regarding our pricing process and sources.
	Loans held for sale
	We have elected the fair value option for certain residential real estate loans held for sale as we believe the fair value measurement of such loans reduces certain timing differences in our Statement of Operations and better aligns with our management of the portfolio from a business perspective. This election is made at the time of origination, on a loan by loan basis, and is irrevocable. The secondary market for securities backed by similar loan types is actively traded, which provides readily observable market pricing to be used as input for the estimate for the fair value of our loans. Accordingly, we have classified this fair value measurement as Level 2. Interest income on these loans is recognized in Interest Income—Loans and Leases in our Consolidated Statements of Operations.
	The table below presents information about our loans held for sale for which we elected the fair value option at December 31:
		2014		2013
	Fair value carrying amount	$	35	$	50
	Aggregate unpaid principal balance	34		49
	Fair value carrying amount less aggregate unpaid principal balance	$	1	$	1
	Derivatives
	We obtain fair value measurements of our interest rate swaps from a third party. The fair value measurements are determined using a market standard methodology of netting discounted future fixed cash receipts (or payments) and the discounted expected variable cash payments (or receipts). Variable cash payments (or receipts) are based on an expectation of future interest rates derived from observable market interest rate curves. Credit valuation adjustments are incorporated to appropriately reflect our nonperformance risk as well as the counterparty’s nonperformance risk. The impact of netting and any applicable credit enhancements, such as bilateral collateral postings, thresholds, mutual puts, and guarantees are also considered in the fair value measurement.
	The fair value of our interest rate swaps was estimated using primarily Level 2 inputs. However, Level 3 inputs were used to determine credit valuation adjustments, such as estimates of current credit spreads to evaluate the likelihood of default. We have determined that the impact of these credit valuation adjustments was not significant to the overall valuation of our interest rate swaps. Therefore, we have classified the entire fair value of our interest rate swaps in Level 2 of the fair value hierarchy.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The following tables summarize our assets and liabilities measured at fair value on a recurring basis at December 31:
		Fair Value Measurements
		Total		Level 1			Level 2			Level 3
	2014
	Assets:
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	453	$	—		$	453		$	—
	U.S. Treasury	25		25			—			—
	U.S. government sponsored enterprises	191		—			191			—
	Corporate	823		—			818			4
	Total debt securities	1,492		25			1,463			4
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	34		—			34			—
	Federal National Mortgage Association	100		—			100			—
	Federal Home Loan Mortgage Corporation	120		—			120			—
	Collateralized mortgage obligations:
	Federal National Mortgage Association	682		—			682			—
	Federal Home Loan Mortgage Corporation	350		—			350			—
	Total collateralized mortgage obligations	1,032		—			1,032			—
	Total residential mortgage-backed securities	1,286		—			1,286			—
	Commercial mortgage-backed securities, non-agency issued	1,500		—			1,500			—
	Total mortgage-backed securities	2,786		—			2,786			—
	Collateralized loan obligations, non-agency issued	1,016		—			1,016			—
	Asset-backed securities collateralized by:
	Student loans	235		—			235			—
	Credit cards	42		—			42			—
	Auto loans	194		—			194			—
	Other	127		—			127			—
	Total asset-backed securities	599		—			599			—
	Other	22		21			1			—
	Total securities available for sale	5,915		47			5,865			4
	Loans held for sale (1)	35		—			35			—
	Derivatives	93		—			93			—
	Total assets	$	6,043	$	47		$	5,993		$	4
	Liabilities:
	Derivatives	$	94	$	—		$	94		$	—
	(1)	Represents loans for which we have elected the fair value option.
		Fair Value Measurements
		Total		Level 1			Level 2			Level 3
	2013
	Assets:
Investment securities available for sale:
Debt securities:
States and political subdivisions	$	529	$	—		$	529		$	—
U.S. Treasury	20		20			—			—
U.S. government sponsored enterprises	312		—			312			—
Corporate	872		—			868			4
Total debt securities	1,734		20			1,709			4
Mortgage-backed securities:
Residential mortgage-backed securities:
Government National Mortgage Association	40		—			40			—
Federal National Mortgage Association	139		—			139			—
Federal Home Loan Mortgage Corporation	159		—			159			—
Collateralized mortgage obligations:
Federal National Mortgage Association	761		—			761			—
Federal Home Loan Mortgage Corporation	379		—			379			—
Non-agency issued	13		—			13			—
Total collateralized mortgage obligations	1,152		—			1,152			—
Total residential mortgage-backed securities	1,490		—			1,490			—
Commercial mortgage-backed securities, non-agency issued	1,831		—			1,831			—
Total mortgage-backed securities	3,321		—			3,321			—
Collateralized loan obligations, non-agency issued	1,431		—			1,431			—
Asset-backed securities collateralized by:
Student loans	312		—			312			—
Credit cards	73		—			73			—
Auto loans	335		—			335			—
Other	186		—			186			—
Total asset-backed securities	905		—			905			—
Other	33		22			10			—
Total securities available for sale	7,423		43			7,376			4
Loans held for sale (1)	50		—			50			—
Derivatives	49		—			49			—
Total assets	$	7,522	$	43		$	7,476		$	4
Liabilities:
Derivatives	$	50	$	—		$	50		$	—
(1)	Represents loans for which we have elected the fair value option.
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
The following table summarizes our assets and liabilities measured at fair value on a nonrecurring basis for the years ended December 31:
	Fair Value Measurements												Total gains
	Total		Level 1			Level 2			Level 3				(losses)
2014
Collateral dependent impaired loans	$	10	$	—		$	10		$	—			$	—
2013
Collateral dependent impaired loans	$	32	$	—		$	20		$	12			$	(2	)
Collateral Dependent Impaired Loans
We record nonrecurring fair value adjustments to the carrying value of collateral dependent impaired loans when establishing the allowance for loan losses. Such amounts are generally based on the fair value of the underlying collateral supporting the loan less estimated costs to sell the collateral. When the fair value of such collateral, less costs to sell, is less than the carrying value of the loan, a specific allowance or charge off is recorded through a provision for credit losses. Real estate collateral is typically valued using independent appraisals that we review for acceptability, or other indications of value based on recent comparable sales of similar properties or assumptions generally observable in the marketplace and the related nonrecurring fair value measurements have been classified as Level 2. Under certain circumstances significant adjustments may be made to the appraised value due to the lack of direct marketplace information. Such adjustments are made as determined necessary in the judgment of our experienced senior credit officers to reflect current market conditions and current operating results for the specific collateral. When the fair value of collateral dependent impaired loans is based on appraisals containing significant adjustments, such collateral dependent impaired loans are classified as Level 3. We obtain new appraisals from an approved appraiser, in accordance with Interagency Appraisal and Evaluation Guidelines and internal policy. Appraisals or evaluations for assets securing substandard rated loans are usually completed within 90 days of the downgrade. An appraisal may be obtained more frequently when volatile or unusual market conditions exist that could affect the ultimate realization of the value of the real estate collateral.
During 2014, we recorded a decrease of $0.1 million to our specific allowance as a result of adjusting the fair value of the collateral for certain collateral dependent impaired loans to $10 million at December 31, 2014, which is included in our provision for credit losses. During 2013, we recorded an increase of $2 million to our specific allowance as a result of adjusting the fair value of the collateral for certain collateral dependent impaired loans to $32 million at December 31, 2013, which is included in our provision for credit losses.
Level 3 Assets
The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis were as follows for the years ended December 31:
	2014			2013
	Trust			Trust			Collateralized			Total
	preferred			preferred			loan obligations
	securities			securities
Balance at beginning of period	$	4		$	14		$	1,545		$	1,559
Transfers between level 2 and level 3(1)	—			—			(1,545		)	(1,545		)
Settlements	—			(10		)	—			(10		)
Gains included in other comprehensive income	—			1			—			1
Losses included in earnings	—			(1		)	—			(1		)
Balance at end of period	$	4		$	4		$	—		$	4
-1	Our policy is to recognize the transfer at the beginning of the period.
Due to the lack of observable market data, we have classified our trust preferred securities, which are included in corporate debt securities, in Level 3 of the fair value hierarchy.
Our CLOs are securitized products where payments from multiple middle sized and large business loans are pooled together and passed on to different classes of owners in various tranches. In 2013, the markets for such securities were generally characterized by low trading volumes and wide bid-ask spreads, all driven by more limited market participants. Although estimated prices were generally obtained for such securities, the level of market observable assumptions used was limited in the valuation. Specifically, market assumptions regarding credit adjusted cash flows and liquidity influences on discount rates were difficult to observe at the individual bond level. During 2013, we transferred our collateralized loan obligations ("CLOs") from level 3 to level 2 of the fair value hierarchy based on increased trading activity and price transparency.
As of December 31, 2014 and 2013, the fair values of our trust preferred securities were based upon third party pricing without adjustment.
Fair Value of Financial Instruments
The carrying value and estimated fair value of our financial instruments, including those that are not measured and reported at fair value on a recurring basis or nonrecurring basis, are as follows at December 31:
	2014								2013
	Carrying value		Estimated fair			Fair value			Carrying value			Estimated fair			Fair value
			value			level						value			level
Financial assets:
Cash and cash equivalents	$	420	$	420		1			$	463		$	463		1
Investment securities available for sale	5,915		5,915			1,2,3		(1)	7,423			7,423			1,2,3	(1)
Investment securities held to maturity	5,942		5,964			2			4,042			3,988			2
Federal Home Loan Bank and Federal Reserve Bank common stock	412		412			2			469			469			2
Loans held for sale	40		40			2			50			50			2
Loans and leases, net	22,803		23,037			2,3		(2)	21,230			21,774			2,3	(2)
Derivatives	93		93			2			49			49			2
Accrued interest receivable	101		101			2			103			103			2
Financial liabilities:
Deposits	$	27,781	$	27,793		2			$	26,665		$	26,695		2
Borrowings	6,206		6,215			2			5,556			5,599			2
Derivatives	94		94			2			50			50			2
Accrued interest payable	11		11			2			10			10			2
(1)	For a detailed breakout of our investment securities available for sale, refer to our table of recurring fair value measurements.
-2	Loans and leases classified as level 2 are made up of $10 million and $20 million of collateral dependent impaired loans without significant adjustments made to appraised values at December 31, 2014 and 2013, respectively. All other loans and leases are classified as level 3.
Our fair value estimates are based on our existing on and off balance sheet financial instruments without attempting to estimate the value of any anticipated future business and the value of assets and liabilities that are not considered financial instruments. In addition, the tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on our fair value estimates and have not been considered in these estimates.
Our fair value estimates are made as of the dates indicated, based on relevant market information and information about the financial instruments, including our judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in our assumptions could significantly affect the estimates. Our fair value estimates, methods, and assumptions are set forth below for each type of financial instrument. The method of estimating the fair value of the financial instruments disclosed in the table above does not necessarily incorporate the exit price concept used to record financial instruments at fair value in our Consolidated Statements of Condition.
Cash and Cash Equivalents
The carrying value of our cash and cash equivalents approximates fair value because these instruments have original maturities of three months or less.
Investment Securities
The fair value estimates of securities are based on quoted market prices of identical securities, where available. However, as quoted prices of identical securities are not often available, the fair value estimate for almost our entire investment portfolio is based on quoted market prices of similar securities, adjusted for differences between the securities. Adjustments may include amounts to reflect differences in underlying collateral, interest rates, estimated prepayment speeds, and counterparty credit quality.
Federal Home Loan Bank and Federal Reserve Bank Common Stock
The carrying value of our Federal Home Loan Bank and Federal Reserve Bank common stock, which are non-marketable equity investments, approximates fair value.
Loans and Leases
Our variable rate loans reprice as the associated rate index changes. The calculation of fair value for our variable rate loans is driven by the comparison between the loan’s margin and the prevailing margin observed in the market at the time of the valuation. Any caps and floors embedded in the loan’s pricing structure are also incorporated into the fair value. We calculated the fair value of our fixed-rate loans and leases by discounting scheduled cash flows through the estimated maturity using credit adjusted period end origination rates. Our estimate of maturity is based on the contractual cash flows adjusted for prepayment estimates based on current economic and lending conditions.
Accrued Interest Receivable and Accrued Interest Payable
The carrying value of accrued interest receivable and accrued interest payable approximates fair value.
Deposits
The fair value of our deposits with no stated maturity, such as savings and checking, as well as mortgagors’ payments held in escrow, is equal to the amount payable on demand. The fair value of our certificates of deposit is based on the discounted value of contractual cash flows, using the period end rates offered for deposits of similar remaining maturities.
Borrowings
The fair value of our borrowings is calculated by discounting scheduled cash flows through the estimated maturity using period end market rates for borrowings of similar remaining maturities.
Commitments
The fair value of our commitments to extend credit, standby letters of credit, and financial guarantees are not included in the above table as the carrying value generally approximates fair value. These instruments generate fees that approximate those currently charged to originate similar commitments.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	Segment Information
	We have two business segments: banking and financial services. The banking segment includes all of our retail and commercial banking operations. The financial services segment includes our insurance operations. Substantially all of our assets relate to the banking segment. Transactions between our banking and financial services segments are eliminated in consolidation.
	Selected financial information for our segments follows for the years ended December 31:
		Banking			Financial		Consolidated
					services		total
	2014
	Net interest income	$	1,086		$	—	$	1,086
	Provision for credit losses	96			—		96
	Net interest income after provision for credit losses	990			—		990
	Noninterest income	244			66		310
	Amortization of intangibles	24			3		27
	Goodwill impairment	1,100			—		1,100
	Other noninterest expense	940			57		997
	(Loss) income before income taxes	(831		)	7		(824		)
	Income tax (benefit) expense	(112		)	3		(109		)
	Net (loss) income	$	(719	)	$	4	$	(715	)
	2013
	Net interest income	$	1,093		$	—	$	1,093
	Provision for credit losses	105			—		105
	Net interest income after provision for credit losses	988			—		988
	Noninterest income	298			67		366
	Amortization of intangibles	37			3		40
	Other noninterest expense	839			52		891
	Income before income taxes	411			12		423
	Income tax expense	123			5		128
	Net income	$	288		$	7	$	295
	2012
	Net interest income	$	1,023		$	—	$	1,023
	Provision for credit losses	92			—		92
	Net interest income after provision for credit losses	931			—		931
	Noninterest income	291			68		360
	Amortization of intangibles	41			4		45
	Other noninterest expense	955			51		1,006
	Income before income taxes	227			13		239
	Income tax expense	66			5		71
	Net income	$	161		$	8	$	168

Condensed_Parent_Company_Only_

Condensed Parent Company Only Financial Statements (Notes)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Parent Company Only Financial Statements	Note 18. Condensed Parent Company Only Financial Statements
	The following condensed statements of condition of the Company at December 31, 2014 and 2013 and the related condensed statements of operations and cash flows for the years ended December 31, 2014, 2013, and 2012 should be read in conjunction with our Consolidated Financial Statements and related notes:
	Condensed Statements of Condition	2014			2013
	Assets:
	Cash and cash equivalents	$	383		$	390
	Investment securities available for sale	—			3
	Loan receivable from ESOP	—			21
	Investment in subsidiary	4,388			5,255
	Deferred taxes	32			34
	Other assets	13			13
	Total assets	$	4,815		$	5,715
	Liabilities and Stockholders’ Equity:
	Accounts payable and other liabilities	$	12		$	13
	Borrowings	710			709
	Stockholders’ equity	4,093			4,993
	Total liabilities and stockholders’ equity	$	4,815		$	5,715
	Condensed Statements of Operations	2014			2013			2012
	Interest income	$	1		$	2		$	7
	Dividends received from subsidiary	80			175			45
	Total interest and dividend income	81			177			52
	Interest expense	48			49			50
	Net interest income	33			128			3
	Noninterest income	3			2			3
	Noninterest expense	27			30			27
	Income before income taxes and undisbursed income of subsidiary	9			100			(21		)
	Income tax benefit	(28		)	(29		)	(24		)
	Income before undisbursed income of subsidiary	36			129			3
	Undisbursed (loss) income of subsidiary	(751		)	167			166
	Net (loss) income	(715		)	295			168
	Preferred stock dividend	30			30			28
	Net (loss) income available to common stockholders	$	(745	)	$	265		$	141
	Net (loss) income	$	(715	)	$	295		$	168
	Other comprehensive (loss) income(1)	(53		)	(95		)	89
	Total comprehensive (loss) income	$	(768	)	$	200		$	258
	(1)	See Consolidated Statements of Comprehensive Income for other comprehensive income detail.
	Condensed Statements of Cash Flows	2014			2013			2012
	Cash flows from operating activities:
	Net (loss) income	$	(715	)	$	295		$	168
	Adjustments to reconcile net (loss) income to net cash provided by operating activities:
	Undisbursed loss (income) of subsidiaries	751			(167		)	(166		)
	Stock-based compensation expense	11			9			11
	Deferred income tax expense (benefit)	2			(18		)	7
	(Increase) decrease in other assets	(2		)	7			35
	Decrease in other liabilities	(1		)	(9		)	(18		)
	Net cash provided by operating activities	46			118			38
	Cash flows from investing activities:
	Proceeds from maturities of securities available for sale	3			—			—
	Principal payments received on securities available for sale	—			1			2
	Purchases of securities available for sale	—			(2		)	—
	Capital contributed to subsidiary	—			—			(215		)
	Repayments from subsidiary	—			—			215
	Repayment of ESOP loan receivable	15			1			1
	Other, net	1			(1		)	—
	Net cash provided by investing activities	19			—			3
	Cash flows from financing activities:
	Return of capital from subsidiary	85			—			—
	Repurchase of shares upon ESOP termination	(14		)	—			—
	Dividends paid on preferred stock	(30		)	(30		)	(28		)
	Dividends paid on common stock	(113		)	(112		)	(112		)
	Net cash used in financing activities	(72		)	(143		)	(140		)
	Net decrease in cash and cash equivalents	(7		)	(25		)	(99		)
	Cash and cash equivalents at beginning of period	390			415			514
	Cash and cash equivalents at end of period	$	383		$	390		$	415

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation
	Our Consolidated Financial Statements include the accounts of the Company and its subsidiaries. We have eliminated all significant intercompany balances in consolidation.
Subsequent Events	Subsequent Events
	We reviewed subsequent events and determined that no further disclosures or measurements were required.
Cash and Cash Equivalents	Cash and Cash Equivalents
	For purposes of our Consolidated Statement of Cash Flows, cash and cash equivalents include cash and due from banks, money market investments, and federal funds sold which have an original term of less than three months.
Investment Securities	Investment Securities
	We have classified our investments in debt and equity securities as held to maturity or available for sale. We classify investment securities as held to maturity if we have the positive intent and ability to hold them to maturity. Held to maturity securities are reported at amortized cost. We classify investment securities not classified as held to maturity as available for sale, and report them at fair value with unrealized gains and losses, net of deferred taxes, reported in other comprehensive income as a separate component of stockholders’ equity.
	We are required to maintain an investment in common stock of the Federal Home Loan Bank (“FHLB”) of New York and Boston as well as the Federal Reserve Bank because our Bank is a member of the FHLB and the Federal Reserve System. We consider these stocks to be nonmarketable equity securities and carry them at cost.
	We conduct a quarterly review and evaluation of our investment securities portfolio to determine if any declines in fair value below amortized cost are other than temporary. In making this determination, we consider some or all of the following factors: the period of time the securities have been in an unrealized loss position, the percentage decline in fair value in comparison to the securities’ amortized cost, credit rating, the financial condition of the issuer and guarantor, where applicable, the delinquency or default rates of underlying collateral, credit enhancement, projected losses, level of credit loss, and projected cash flows. If we intend to sell a security with a fair value below amortized cost or if it is more likely than not that we will be required to sell such a security before recovery, we record an other than temporary impairment charge through current period earnings for the full decline in fair value below amortized cost. For debt securities that we do not intend to sell or it is more likely than not that we will not be required to sell before recovery, we record an other than temporary impairment charge through current period earnings for the amount of the valuation decline below amortized cost that is attributable to credit losses. The remaining difference between the debt security’s fair value and amortized cost (that is, decline in fair value not attributable to credit losses) is recognized in other comprehensive income.
	Our investment securities portfolio includes residential mortgage-backed securities and collateralized mortgage obligations. As the underlying collateral of each of these securities is comprised of a large number of similar residential mortgage loans for which prepayments are probable and the timing and amount of such prepayments can be reasonably estimated, we consider estimates of future principal prepayments of these underlying residential mortgage loans in the calculation of the constant effective yield used to apply the interest method for income recognition, with retroactive adjustments made as warranted.
	Purchases and sales of investment securities are recorded on trade date, with realized gains and losses on sales included in our Consolidated Statements of Income using the specific identification method. We amortize premiums and accrete discounts on our investment securities to interest income utilizing the interest method.
Loans and Leases	Originated Loans and Leases
	Loans we originate and intend to hold in our portfolio are stated at the principal amount outstanding, adjusted for unamortized deferred fees and costs which we amortize to interest income over the expected life of the loan using the interest method. We discontinue accrual of interest on originated loans after payments become more than 90 days past due, or earlier if we do not expect the full collection of principal or interest, with the exception of credit cards. Credit cards are placed on nonaccrual status at 180 days past due. The delinquency status is based upon the contractual terms of the loans. We reverse all uncollected interest income that we previously recognized on nonaccrual loans. When we have doubt as to the collectibility of a loan’s principal, we apply interest payments to principal. With the exception of residential mortgage loans that are well secured and in the process of collection, cash receipts received on nonperforming impaired loans are first applied to the loan’s principal. Once the remaining principal balance has been collected in full, cash receipts are then applied as recoveries of any partially charged-off amount on the loan. Once a loan’s principal balance, including any previously charged-off amounts are collected in full, cash receipts are recorded as interest income. For residential mortgage loans, where the loan is both well secured and in the process of collection, we recognize interest income on a cash basis. Interest income on performing troubled debt restructurings, which are considered impaired loans, are applied in accordance with the terms of the modified loan.
	We return loans to accrual status when principal and interest payments are current, we expect full collectibility of principal and interest, and a consistent repayment record, generally six consecutive payments, has been demonstrated.
	We charge loans off against our allowance for loan losses when it becomes evident that we will not fully collect the balance of the loan. For business and commercial real estate loans, we record a charge off when it is determined that the collection of all or a portion of a loan may not be collected and the amount of that loss is reasonably estimable. For our consumer loans secured by real estate, including our residential mortgages, home equity loans and home equity lines of credit, we order broker price opinions (“BPOs”) at 90 days past due and record partial or full charge-offs based upon the results of such valuations by no later than 180 days past due. All other closed end consumer loans are charged off at 120 days past due and all other open ended consumer lines, including credit card loans, are charged off at 180 days past due.
	We consider a loan impaired when, based on current information, it is probable that we will be unable to collect all amounts of principal and interest due under the original terms of the agreement. Beginning in the second quarter of 2014, we raised the threshold for evaluating commercial loans individually for impairment from $200 thousand to $1 million. Additionally, all loans modified in a troubled debt restructuring (“TDR”), regardless of size, are considered impaired. The impact of this change to our allowance for loan losses was not significant. This change was implemented on a prospective basis, accordingly, prior period financial disclosures were not revised. We measure the impairment in these loans based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical alternative, the loan’s observable market price or the fair value of the underlying collateral, if the loan is collateral dependent.
	At origination, a determination is made whether a loan will be held in our portfolio or is intended for sale in the secondary market. Loans that will be held in our portfolio are carried at amortized cost. Beginning in the second quarter of 2011, we elected the fair value option for substantially all residential mortgage loans held for sale as we believe the fair value measurement of such loans reduces certain timing differences in our Statement of Income and better aligns with our management of the portfolio from a business perspective. This loan by loan election is made at the time of origination and is irrevocable. Residential mortgage loans held for sale for which the fair value option has not been elected, are recorded at the lower of the aggregate cost or market value (“LOCOM”). For residential mortgage loans held for sale where we have elected the fair value option any change in fair value subsequent to origination is recognized immediately in earnings in mortgage banking income. For residential mortgage loans held for sale that are recorded at LOCOM, we recognize any subsequent decreases in fair value in a valuation allowance through a charge to earnings at the time the decline in value occurs. We include gains and losses occurring during the holding period as well as those resulting from sales of our loans held for sale in mortgage banking income.
Acquired Loans	Acquired Loans
	Loans that we acquired in acquisitions subsequent to January 1, 2009 were recorded at fair value with no carryover of the related allowance for loan losses at the time of acquisition. Determining the fair value of the loans involved estimating the amount and timing of principal and interest cash flows expected to be collected on the loans and discounting those cash flows at a market rate of interest.
	We have acquired loans in four separate acquisitions between January 2009 and May 2012. For each acquisition, we reviewed all loans greater than $1 million and considered the following factors as indicators that such an acquired loan had evidence of deterioration in credit quality and was therefore in the scope of Accounting Standards Codification (“ASC”) 310-30 (Loans and Debt Securities Acquired with Deteriorated Credit Quality):
	•	Loans that were 90 days or more past due;
	•	Loans that had an internal risk rating of substandard or worse. Substandard is consistent with regulatory definitions and is defined as having a well defined weakness that jeopardizes liquidation of the loan;
	•	Loans that were classified as nonaccrual by the acquired bank at the time of acquisition; or
	•	Loans that had been previously modified in a troubled debt restructuring.
	Individual acquired loans determined to have evidence of deterioration in credit quality are accounted for individually in accordance with ASC 310-30. Any acquired loans that were not individually in the scope of ASC 310-30 because they did not meet the criteria above were either (i) pooled into groups of similar loans based on the borrower type, loan purpose, and collateral type and accounted for under ASC 310-30 by analogy or (ii) accounted for under ASC 310-20 (Nonrefundable Fees and Other Costs.)
	Based on the guidance included in the December 18, 2009 letter from the AICPA Depository Institutions Panel to the Office of the Chief Accountant of the SEC, we have made an accounting policy election to apply ASC 310-30 by analogy to qualifying acquired pools of loans that (i) were acquired in a business combination or asset purchase, (ii) resulted in recognition of a discount attributable, at least in part, to credit quality; and (iii) were not subsequently accounted for at fair value.
	Acquired loans accounted for under ASC 310-30
	The excess of expected cash flows from acquired loans over the estimated fair value of acquired loans at acquisition is referred to as the accretable discount and is recognized into interest income over the remaining life of the acquired loans using the interest method. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition is referred to as the nonaccretable discount. The nonaccretable discount represents estimated future credit losses expected to be incurred over the life of the acquired loans. Subsequent decreases to the expected cash flows require us to evaluate the need for an addition to the allowance for loan losses. Subsequent improvements in expected cash flows result in the reversal of a corresponding amount of the nonaccretable discount which we then reclassify as accretable discount that is recognized into interest income over the remaining life of the loan using the interest method. Our evaluation of the amount of future cash flows that we expect to collect takes into account actual credit performance of the acquired loans to date and our best estimates for the expected lifetime credit performance of the loans using currently available information. Charge-offs on acquired loans would be first applied to the nonaccretable discount portion of the fair value adjustment. To the extent that we experience a deterioration in credit quality in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loans.
	In accordance with ASC 310-30, recognition of income is dependent on having a reasonable expectation about the timing and amount of cash flows expected to be collected.  We perform such an evaluation on a quarterly basis on both our acquired loans individually accounted for under ASC 310-30 and those in pools accounted for under ASC 310-30 by analogy.
	Cash flows for acquired loans individually accounted for under ASC 310-30 are estimated on a quarterly basis.  Based on this evaluation, a determination is made as to whether or not we have a reasonable expectation about the timing and amount of cash flows.  Such an expectation includes cash flows from normal customer repayment, foreclosure or other collection efforts.  Cash flows for acquired loans accounted for on a pooled basis under ASC 310-30 by analogy are also estimated on a quarterly basis.  For residential real estate, home equity and other consumer loans, cash flow loss estimates are calculated by a vintage and FICO based model which incorporates a projected forward loss curve.  For commercial loans, lifetime loss rates are assigned to each pool with consideration given for pool make-up, including risk rating profile.  Lifetime loss rates are developed from internally generated loss data and are applied to each pool.
	To the extent that we cannot reasonably estimate cash flows, interest income recognition is discontinued.  The unit of account for loans in pools accounted for under ASC 310-30 by analogy is the pool of loans.  Accordingly, as long as we can reasonably estimate cash flows for the pool as a whole, accretable yield on the pool is recognized and all individual loans within the pool - even those more than 90 days past due - would be considered to be accruing interest in our financial statement disclosures, regardless of whether or not we expected to collect any principal or interest cash flows on an individual loan 90 days or more past due.
Allowance for Loan Losses	Allowance for Loan Losses
	We establish our allowance for loan losses through a provision for credit losses. The level of the allowance for loan losses is based on our evaluation of the overall credit quality of our total loan portfolio. We segregate our loans between loans we originated which are accounted for under the amortized cost method (referred to as “originated” loans) and loans acquired (referred to as “acquired” loans), as acquired loans were originally recorded at fair value, which included an estimate of lifetime credit losses, resulting in no carryover of the related allowance for loan losses. We continue to monitor and modify the level of our allowance for loan losses to ensure it is adequate to cover losses inherent in our loan portfolio.
	Originated loans
	We determine our allowance for loan losses by portfolio segment, which consists of commercial loans and consumer loans. Our commercial loan portfolio includes both business and commercial real estate loans. Our consumer loan portfolio includes residential real estate, home equity, indirect auto, credit card and other consumer loans. The allowance for loan losses is comprised of two components. The first component covers pools of loans for which there are incurred losses that are not yet individually identifiable. The allowance for pools of loans is based on net historical loan loss experience for similar loans with similar inherent risk characteristics and performance trends adjusted, as appropriate, for quantitative and qualitative risk factors specific to respective loan types. The second component covers loans that have been identified as impaired or are nonperforming as well as troubled debt restructurings (“TDRs”.)
	Commercial loan portfolio
	Commercial loans are initially evaluated using quantitative models whereby loans are grouped into pools based on similar risk characteristics such as loan type and grade to determine the historical loss rate. By loan type, the historical loss experience over an established loss emergence and look back period for each loan pool is used to calculate historical loss rates that are used as the primary driver of the quantitative historical allowance estimate. The loss emergence and historical loss look-back periods may vary based on a variety of factors. For example, a relatively long look-back may be the appropriate measure during times of economic stability; however, during a period of significant or rapid economic expansion or contraction, a shorter measurement period may be more appropriate. The loss emergence and look back periods may vary by loan pool and are considered in the determination of the historical loss rates for each pool.
	Once the quantitative historical loss rates are established they may be adjusted for qualitative factors to reflect portfolio characteristics, credit concentrations and model imprecision conditions that are not captured in the historical loss rates, recent trends in loan volume and mix, delinquency, local and national economic factors, changes to the Bank’s lending policies and procedures, experience of lending staff, industrial and geographic factors, competition and legal or regulatory requirements. In addition, historical loss rates are modified when loan growth patterns or other trends indicate that the historical loss factors would not accurately reflect losses inherent in the current portfolio. Final adjustments to the historical loss rate calculation are made for known portfolio characteristics such as 100% cash secured loans and SBA guaranteed loans not captured in the modeling approach. Simulation techniques such as Monte Carlo modeling, using varying levels of confidence, are used to make such qualitative adjustments. These simulations help estimate the impact of concentrations such as large loan risk aspects within a loan portfolio and ensure that a reasonable amount of tail risk is captured. The Monte Carlo output may be adjusted for changes in loss severity based on recent trends that would affect charge-off levels. All qualitative adjustments are supported with trend (or other relevant data), which are documented in the quarterly allowance for loan loss analysis. Combining the quantitative and qualitative measurements, the Commercial loan component of our allowance for loan losses is recorded.
	Consumer loan portfolio
	We estimate the allowance for loan losses for our consumer loan portfolio by estimating the amount of loans that will eventually default based on their current delinquency severity. We then apply a loss rate to the amount of loans that we predict will default based on our historical net loss experience. This amount is then adjusted, as necessary, for qualitative considerations to reflect changes in underwriting, market or industry conditions or based on changes in trends in the composition of the portfolio, including risk composition, seasoning, and underlying collateral. We obtain and review refreshed FICO scores on a quarterly basis, and trends are evaluated for consideration as a qualitative adjustment to the allowance. Other qualitative considerations include, but are not limited to, the evaluation of trends in property values, building permits and unemployment.
	Impaired loans
	We consider a commercial loan impaired, when, based on current information, it is probable that we will be unable to collect all amounts of principal and interest due under the original terms of the agreement. Beginning in the second quarter of 2014, we raised the threshold for evaluating commercial loans individually for impairment from $200 thousand to $1 million. Additionally, all loans (commercial and consumer) modified in a troubled debt restructuring (“TDR”), regardless of size, are considered impaired. The impact of this change to our allowance for loan losses was not significant. This change was implemented on a prospective basis, accordingly, prior period financial disclosures were not revised. The need for specific valuation allowances are determined for impaired loans and recorded as necessary. We measure the impairment in these loans based on the present value of expected future cash flows discounted at the loan’s effective interest rate or, as a practical alternative, the loan’s observable market price or the fair value of the underlying collateral, if the loan is collateral dependent. We then factor any related allowance for loan losses for these loans. Confirmed losses are charged off immediately. We typically would obtain an appraisal to use as the basis for the fair value of the underlying collateral.
	Acquired Loans
	Acquired loans accounted for under ASC 310-30 (including those accounted for under ASC 310-30 by analogy)
	For our acquired loans accounted for under ASC 310-30 for which subsequent decreases to the expected cash flows requires us to evaluate the need for an addition to the allowance for loan losses, our modeling techniques are similar to those we utilize for our originated loans. To the extent that we experience a deterioration in borrower credit quality resulting in a decrease in our expected cash flows subsequent to the acquisition of the loans, an allowance for loan losses would be established based on our estimate of future credit losses over the remaining life of the loans.
	Acquired loans accounted for under ASC 310-20
	We establish our allowance for loan losses through a provision for credit losses based upon an evaluation process that is similar to our evaluation process used for originated loans. This evaluation, which includes a review of loans on which full collectability may not be reasonably assured, considers, among other matters, the estimated fair value of the underlying collateral, economic conditions, historical net loan loss experience, carrying value of the loans, which includes the remaining net purchase discount or premium, and other factors that warrant recognition in determining our allowance for loan losses.
Premises and Equipment	Premises and Equipment
	Our premises and equipment are carried at cost, net of accumulated depreciation and amortization. We compute depreciation on the straight-line method over the estimated useful lives of the assets. We amortize our leasehold improvements on the straight-line method over the lesser of the life of the improvements or the lease term. We generally depreciate buildings over a period of 20 to 39 years, furniture and equipment over a period of 3 to 10 years, and capital leases over the lesser of the useful life or the respective lease term.
Goodwill and Intangible Assets	Goodwill and Intangible Assets
	We record the excess of the cost of acquired entities over the fair value of identifiable tangible and intangible assets acquired less the fair value of liabilities assumed as goodwill. We amortize our acquired identifiable intangible assets with definite useful economic lives over their useful economic life utilizing an accelerated amortization method. On a periodic basis, we assess whether events or changes in circumstances indicate that the carrying amounts of our core deposit and other intangible assets may be impaired. We do not amortize goodwill or any acquired identifiable intangible assets with an indefinite useful economic life, but we review them for impairment on an annual basis, or when events or changes in circumstances indicate that the carrying amounts may be impaired. Goodwill is reviewed for impairment at the reporting unit level. We define a reporting unit as a distinct, separately identifiable component of one of our operating segments for which complete, discrete financial information is available and reviewed regularly by that segment’s management.
	We have the option to first assess qualitative factors to determine whether there are events or circumstances that exist that make it more likely than not that the fair value of the reporting unit is less than its carrying amount (Step 0). If it is more likely than not that the fair value of the reporting unit is less than its carrying amount, or if we choose to bypass the qualitative assessment, we proceed to compare each reporting unit's fair value to carrying value to identify potential impairment (Step 1). If the estimated fair value of a reporting unit exceeds its carrying amount, goodwill of the reporting unit is not considered impaired. However, if the carrying amount of the reporting unit were to exceed its estimated fair value, a second step (Step 2) would be performed that would compare the implied fair value of the reporting unit's goodwill with the carrying amount of the goodwill for the reporting unit. The implied fair value of goodwill is determined in the same manner as goodwill that is recognized in a business combination. Significant judgment and estimates are involved in estimating the fair value of the assets and liabilities of the reporting units.
	We perform our annual impairment review of goodwill on November 1 of each year utilizing valuation methods we believe appropriate, given the availability and applicability of market-based inputs for those methods.
Derivative Instruments	Derivative Instruments
	We use interest rate swaps to manage our interest rate risk. We also act as an interest rate swap counterparty for certain commercial customers, and manage the interest rate risk of these positions by entering into offsetting interest rate swap agreements with third parties. Interest rate swaps are recorded on our Consolidated Statements of Condition as either an asset or liability at estimated fair value and recognition of the changes in fair value in the income statement depends upon whether the interest rate swaps are in a designated hedging relationship. The change in the fair value of interest rate swaps designated as fair value hedges, including both the effective and ineffective portions, is recognized in earnings. These amounts are offset by the change in fair value of the hedged item, which is also recognized in earnings. The gain or loss associated with the effective portion of our cash flow hedges is recognized in other comprehensive income and is subsequently reclassified into earnings in the period during which the hedged forecasted transactions affects earnings. The gain or loss associated with the ineffective portion of our cash flow hedges is recognized immediately in earnings. We formally document our risk management objectives, strategy, and the relationship between the hedging instrument and the hedged items. We evaluate the effectiveness of the hedge relationship both at inception of the hedge and on an ongoing basis. If the interest rate swap is not designated in a hedge relationship, gains or losses reflecting changes in fair value are recorded in earnings.
Employee Benefits	Employee Benefits
	We maintain an employer sponsored 401(k) plan where participants may make contributions in the form of salary deferrals and we provide matching contributions in accordance with the terms of the plan. Contributions due under the terms of our defined contribution plans are accrued as earned by employees.
	We also maintain noncontributory, qualified, defined benefit pension plans for certain employees who meet age and service requirements. We provide post-retirement benefits, principally health care and group life insurance, to employees who meet certain age and service requirements. We have frozen all benefit participation in our pension and post-retirement plans. Pension plans that we acquired in connection with our previous whole-bank acquisitions were frozen prior to or shortly after the completion of the transactions. The actuarially determined pension benefit in the form of a life annuity is based on the employee’s combined years of service, age, and compensation. The cost of our pension plan is based on actuarial estimates of current and future benefits for employees and is charged to current operating expenses.
	We recognize an asset for a plan’s overfunded status or a liability for a plan’s underfunded status in our financial statements. We report changes in the funded status of our pension and postretirement plans as a component of other comprehensive income, net of applicable taxes, in the year in which changes occur.
	We measure our plans’ assets and obligations that determine its future funded status as of December 31st each year.
Stock-Based Compensation	Stock-Based Compensation
	We maintain various long-term incentive stock benefit plans under which we grant stock options, restricted stock awards, and restricted stock units to certain key employees and directors. We recognize compensation expense in our income statement over the requisite service period, based on the grant-date fair value of the award. The fair values of stock options are estimated using the Black-Scholes option pricing model. For restricted stock awards and units, we recognize compensation expense on a straight-line basis over the vesting period for the fair value of the award, measured at the grant date.
Income Taxes	Income Taxes
	We account for income taxes under the asset and liability method. Our deferred tax assets and liabilities are reflected at currently enacted income tax rates applicable to the periods in which we expect the deferred tax assets or liabilities to be realized or settled. Deferred tax assets are recognized only to the extent that it is probable that sufficient taxable profit will be available against which those unused tax losses, unused tax credits or deductible temporary differences can be utilized. As changes in tax laws or rates are enacted, we adjust our deferred tax assets and liabilities through income tax expense. We recognize penalties and accrued interest related to unrecognized tax benefits in income tax expense. Federal and State tax credits are accounted for as a reduction of income tax expense.
Earnings per Share	Earnings per Share
	We compute earnings per common share (“EPS”) in accordance with the two-class method, which requires that our unvested restricted stock awards that contain nonforfeitable rights to dividends be treated as participating securities in the computation of EPS pursuant to the two-class method. The two-class method is an earnings allocation that determines EPS for each class of common stock and participating security. Our basic EPS is computed by dividing net income allocable to common stockholders by the weighted average number of our common shares outstanding for the period. Our diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock or resulted in the issuance of common stock that then shared in our earnings. Unallocated common shares held by the Employee Stock Ownership Plan (“ESOP”) are not included in the weighted-average number of common shares outstanding for either basic or diluted earnings per share calculations.
Investment and Fiduciary Services	Investment and Fiduciary Services
	Assets that we hold in a fiduciary or agency capacity for our customers are not included in our accompanying Consolidated Statements of Condition, since these assets are not our assets and we are not the primary beneficiary. We recognize fee income from the management of these assets using the accrual method.
Use of Estimates	Use of Estimates
	We have made a number of estimates and assumptions relating to the reporting of assets and liabilities and disclosure of contingent assets and liabilities in order to prepare these financial statements in conformity with GAAP. The estimates and assumptions that we deem to be critical involve our accounting policies relating to our valuation of our investment securities, prepayment assumptions on our collateralized mortgage obligations and mortgage-backed securities, the accounting treatment and valuation of our acquired loans, adequacy of our allowance for loan losses, and the analysis of the carrying value of goodwill for impairment. These estimates and assumptions are based on management’s best estimates and judgment and we evaluate them on an ongoing basis using historical experience and other factors, including the current economic environment. We adjust our estimates and assumptions when facts and circumstances dictate. As future events cannot be determined with precision, actual results could differ significantly from our estimates.
Accounting Standards Adopted in 2014	Accounting Standards Adopted in 2014
	In February 2013, the FASB issued guidance for the recognition, measurement, and disclosure of obligations resulting from joint and several liability arrangements for which the total amount of the obligation is fixed at the reporting date. Examples of obligations within the scope of the guidance include debt arrangements, other contractual obligations, and settled litigation and judicial rulings. The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
	In June 2013, the FASB released amended guidance to improve the accounting for determining whether an entity is an investment company.  The amendments change the approach to assessing investment company status and provide two required fundamental characteristics and five typical characteristics for determining whether an entity is an investment company.  The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
	In July 2013, the FASB issued guidance to reduce diversity in practice related to the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists.  Some entities present the unrecognized tax benefit as a liability and other entities present the unrecognized tax benefit as a reduction to a deferred tax asset.  The guidance requires an unrecognized tax benefit to be presented in the financial statements as a reduction to a deferred tax asset. The guidance became effective for us on January 1, 2014 and did not have a significant impact on our financial statements.
	In November 2014, the FASB issued guidance that allows, through an option, an acquired entity to apply pushdown accounting in its separate financial statements upon occurrence of an event in which an acquirer obtains control of the acquired entity. The guidance became effective in November 2014 on a prospective basis to future change-in-control events.
Accounting Standards Not Adopted as of December 31, 2014	Accounting Standards Not Yet Required to be Adopted as of December 31, 2014
	In January 2014, the FASB issued guidance on accounting for investments by a reporting entity in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for the low-income housing tax credit.  The low-income housing tax credit program is designed to encourage private capital investment in the construction and rehabilitation of low-income housing.  The guidance becomes effective for us on January 1, 2015 with early adoption permitted.  We have not early adopted this guidance and we do not expect this to have a significant impact on our financial statements.
	In January 2014, the FASB issued guidance on when a creditor should reclassify a collateralized mortgage loan such that the loan should be derecognized and the collateral asset recognized.  The objective of the guidance is to reduce diversity by clarifying when an in substance repossession or foreclosure occurs, that is, when a creditor should be considered to have received physical possession of residential real estate property collateralizing a consumer mortgage loan such that the loan receivable should be derecognized and the real estate property recognized.  The guidance becomes effective for us on January 1, 2015 with early adoption permitted.  We have not early adopted this guidance and we do not expect this to have a significant impact on our financial statements.
	In April 2014, the FASB issued guidance that will change the requirements for reporting discontinued operations.  The new guidance will require that a disposal of an entity or a group of components of an entity be reported in discontinued operations if the disposal represents a strategic shift that has (or will have) a major effect on an entity’s operations and financial results.  The guidance becomes effective for us on January 1, 2015 and we do not expect this to have a significant impact on our financial statements.
	In May 2014, the FASB issued guidance that improves the revenue recognition requirements for contracts with customers. The core principle is that an entity 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 guidance becomes effective for us on January 1, 2017, and we are currently evaluating the impact on our financial statements.
	In June 2014, the FASB issued guidance that clarifies the accounting for share-based payments granted to employees in which the terms of the award provide that a performance target, that affects vesting, could be achieved after the requisite service period. The amendments require that those performance targets should be treated as performance conditions. The guidance becomes effective for us on January 1, 2016, with early adoption permitted, and we are currently evaluating the impact on our financial statements.
	In August 2014, the FASB issued guidance that requires a mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the following conditions are met: (1) the loan has a government guarantee that is not separable from the loan before foreclosure; (2) at the time of foreclosure, the creditor has the intent to convey the real estate property to the guarantor and make a claim on the guarantee, and the creditor has the ability to recover under that claim; and (3) at the time of foreclosure, any amount of the claim that is determined on the basis of the fair value of the real estate is fixed. Upon foreclosure, the separate other receivable should be measured based on the amount of the loan balance (principal plus interest) expected to be recovered from the guarantor. The guidance becomes effective for us on January 1, 2015, and we do not expect this to have a significant impact on our financial statements.
	In August 2014, the FASB issued guidance on determining when and how to disclose going-concern uncertainties in the financial statements. The new standard requires management to perform interim and annual assessments of an entity’s ability to continue as a going concern within one year of the date the financial statements are issued. An entity must provide certain disclosures if “conditions or events raise substantial doubt about the entity’s ability to continue as a going concern.” The guidance applies to all entities and is effective for us for annual periods ending after December 15, 2016, and interim periods thereafter, with early adoption permitted, and we do not expect this to have a significant impact on our financial statements.
	In November 2014, the FASB issued guidance for determining whether the nature of the host contract within a hybrid instrument is more akin to debt or equity. The guidance requires evaluating the nature of the host contract by considering the economic characteristics and risks of the entire hybrid, including the embedded feature that is being evaluated for separation. The guidance becomes effective for us on January 1, 2016, and we do not expect this to have a significant impact on our financial statements.
	In January 2015, the FASB issued guidance that eliminates the concept of extraordinary items from GAAP. The guidance becomes effective for us on January 1, 2016 and may be applied on either a prospective or retrospective basis and we do not expect this to have a significant impact on our financial statements.
Pending Accounting Standards	Pending FASB Rule Proposals
	The FASB currently has two projects underway that could have a meaningful impact on bank financial statements, capital levels and regulatory capital ratios. The first project, which addresses the amount and timing of loss recognition for loans and investment securities, would generally result in an increase in overall allowance levels and lower capital levels. This project has been exposed for public comment three times since 2010. The most recent exposure draft did not contain an effective date, and the FASB has not indicated when they expect to issue a final standard or the final effective date.
	The second project relates to leases and requires an operating lease to be recognized on the balance sheet as a "right to use" asset and as a corresponding liability representing the obligation to pay rent. This project would result in an increase to assets and liabilities recognized and therefore increase risk-weighted assets for regulatory capital purposes. This project has been exposed for public comment twice since 2010. The most recent exposure draft did not contain an effective date, and the FASB has not indicated when they expect to issue a final standard or the final effective date.
	We are evaluating the projects as proposed and the possible range of impacts and will determine any impact of these projects to capital or future earnings once the final rules are issued.

Investment_Securities_Tables

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
The amortized cost, gross unrealized gains and losses, and approximate fair value of investment securities	The amortized cost, gross unrealized gains and losses, and fair value of our investment securities are as follows at December 31:
		Amortized		Unrealized			Unrealized			Fair
	2014	cost		gains			losses			value
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	444	$	10		$	—		$	453
	U.S. Treasury	25		—			—			25
	U.S. government sponsored enterprises	187		5			—			191
	Corporate	820		15			(12		)	823
	Total debt securities	1,476		29			(12		)	1,492
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	34		1			(1		)	34
	Federal National Mortgage Association	96		5			—			100
	Federal Home Loan Mortgage Corporation	115		5			—			120
	Collateralized mortgage obligations:
	Federal National Mortgage Association	694		2			(13		)	682
	Federal Home Loan Mortgage Corporation	353		1			(4		)	350
	Total collateralized mortgage obligations	1,047		3			(18		)	1,032
	Total residential mortgage-backed securities	1,291		13			(19		)	1,286
	Commercial mortgage-backed securities, non-agency issued	1,450		51			—			1,500
	Total mortgage-backed securities	2,741		64			(19		)	2,786
	Collateralized loan obligations, non-agency issued	1,001		18			(3		)	1,016
	Asset-backed securities collateralized by:
	Student loans	228		7			—			235
	Credit cards	42		—			—			42
	Auto loans	193		1			—			194
	Other	127		1			(1		)	127
	Total asset-backed securities	591		9			(1		)	599
	Other	22		—			—			22
	Total securities available for sale	$	5,830	$	121		$	(35	)	$	5,915
	Investment securities held to maturity:
	Debt securities, U.S. government agencies	$	60	$	—		$	—		$	60
	Residential mortgage-backed securities:
	Government National Mortgage Association	12		—			—			12
	Federal National Mortgage Association	118		1			(1		)	118
	Federal Home Loan Mortgage Corporation	65		1			—			65
	Collateralized mortgage obligations:
	Government National Mortgage Association	1,755		27			(3		)	1,779
	Federal National Mortgage Association	1,965		11			(22		)	1,954
	Federal Home Loan Mortgage Corporation	1,967		25			(17		)	1,976
	Total collateralized mortgage obligations	5,687		63			(41		)	5,709
	Total residential mortgage-backed securities	5,882		64			(42		)	5,904
	Total securities held to maturity	$	5,942	$	64		$	(42	)	$	5,964
		Amortized		Unrealized			Unrealized			Fair
	2013	cost		gains			losses			value
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	516	$	14		$	—		$	529
	U.S. Treasury	20		—			—			20
	U.S. government sponsored enterprises	306		7			(1		)	312
	Corporate	863		19			(11		)	872
	Total debt securities	1,705		40			(12		)	1,734
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	41		1			(2		)	40
	Federal National Mortgage Association	134		5			—			139
	Federal Home Loan Mortgage Corporation	154		5			—			159
	Collateralized mortgage obligations:
	Federal National Mortgage Association	797		—			(36		)	761
	Federal Home Loan Mortgage Corporation	396		—			(17		)	379
	Non-agency issued	12		1			—			13
	Total collateralized mortgage obligations	1,205		1			(54		)	1,152
	Total residential mortgage-backed securities	1,534		12			(56		)	1,490
Commercial mortgage-backed securities, non-agency issued	1,759		74			(2		)	1,831
Total mortgage-backed securities	3,294		85			(58		)	3,321
Collateralized loan obligations, non-agency issued	1,392		40			(2		)	1,431
Asset-backed securities collateralized by:
Student loans	306		6			—			312
Credit cards	73		—			(1		)	73
Auto loans	331		4			—			335
Other	186		1			(1		)	186
Total asset-backed securities	896		11			(2		)	905
Other	33		1			—			33
Total securities available for sale	$	7,319	$	178		$	(74	)	$	7,423
Investment securities held to maturity:
Debt securities, U.S. government agencies	$	5	$	—		$	—		$	5
Residential mortgage-backed securities:
Government National Mortgage Association	17		—			—			17
Federal National Mortgage Association	146		—			(3		)	143
Federal Home Loan Mortgage Corporation	81		—			(1		)	81
Collateralized mortgage obligations:
Government National Mortgage Association	1,713		26			(12		)	1,727
Federal National Mortgage Association	1,074		—			(47		)	1,027
Federal Home Loan Mortgage Corporation	1,007		12			(30		)	989
Total collateralized mortgage obligations	3,793		39			(90		)	3,742
Total residential mortgage-backed securities	4,037		40			(94		)	3,983
Total securities held to maturity	$	4,042	$	40		$	(94	)	$	3,988
Available for Sale Securities and Held to Maturity Securities Continuous Unrealized Loss Position	The table below details certain information regarding our investment securities that were in an unrealized loss position at the dates indicated by the length of time those securities were in a continuous loss position:
		Less than 12 months								12 months or longer						Total
		Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
	31-Dec-14	value		losses			Count			value		losses			Count	value		losses			Count
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	16	$	—		22			$	1	$	—		5	$	17	$	—		27
	U.S. Treasury	5		—			1			—		—			—	5		—			1
	U.S. government sponsored enterprises	18		—			7			42		—			4	60		—			11
	Corporate	176		(7		)	127			102		(5		)	61	278		(12		)	188
	Total debt securities	215		(7		)	157			145		(5		)	70	360		(12		)	227
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	—		—			—			19		(1		)	5	19		(1		)	5
	Collateralized mortgage obligations:
	Federal National Mortgage Association	26		—			3			517		(13		)	30	542		(13		)	33
	Federal Home Loan Mortgage Corporation	47		—			3			216		(4		)	12	263		(4		)	15
	Total collateralized mortgage obligations	73		—			6			733		(18		)	42	806		(18		)	48
	Total residential mortgage-backed securities	73		—			6			752		(19		)	47	825		(19		)	53
	Commercial mortgage-backed securities, non-agency issued	13		—			3			24		—			3	36		—			6
	Total mortgage-backed securities	85		—			9			776		(19		)	50	861		(19		)	59
	Collateralized loan obligations, non-agency issued	276		(2		)	32			146		(1		)	15	422		(3		)	47
	Asset-backed securities collateralized by:
	Student loans	26		—			4			2		—			2	28		—			6
	Credit card	8		—			1			—		—			—	8		—			1
	Auto loans	3		—			2			—		—			—	3		—			2
	Other	—		—			1			52		(1		)	5	52		(1		)	6
	Total asset-backed securities	37		—			8			55		(1		)	7	92		(1		)	15
	Other	—		—			—			9		—			3	9		—			3
	Total securities available for sale in an unrealized loss position	$	614	$	(10	)	206			$	1,130	$	(26	)	145	$	1,744	$	(35	)	351
		Less than 12 months								12 months or longer						Total
		Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
	31-Dec-14	value		losses			Count			value		losses			Count	value		losses			Count
	Investment securities held to maturity:
	Debt securities, U.S. government agencies	$	38	$	—		5			$	—	$	—		—	$	38	$	—		5
	Residential mortgage-backed securities:
	Government National Mortgage Association	—		—			—			2		—			2	2		—			2
	Federal National Mortgage Association	4		—			1			51		(1		)	12	55		(1		)	13
	Federal Home Loan Mortgage Corporation	33		—			9			9		—			2	42		—			11
	Collateralized mortgage obligations:
	Government National Mortgage Association	360		(2		)	48			46		(1		)	12	407		(3		)	60
	Federal National Mortgage Association	240		(1		)	18			648		(21		)	36	888		(22		)	54
	Federal Home Loan Mortgage Corporation	422		(5		)	27			463		(12		)	28	885		(17		)	55
	Total collateralized mortgage obligations	1,022		(8		)	93			1,157		(34		)	76	2,179		(41		)	169
	Total residential mortgage-backed securities	1,059		(8		)	103			1,219		(35		)	92	2,278		(42		)	195
	Total securities held to maturity in an unrealized loss position	$	1,097	$	(8	)	108			$	1,219	$	(35	)	92	$	2,316	$	(42	)	200
		Less than 12 months								12 months or longer						Total
		Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
	31-Dec-13	value		losses			Count			value		losses			Count	value		losses			Count
	Investment securities available for sale:
	Debt securities:
	States and political subdivisions	$	13	$	—		25			$	3	$	—		7	$	16	$	—		32
	U.S. government sponsored enterprises	71		(1		)	11			2		—			2	73		(1		)	13
	Corporate	232		(8		)	165			74		(2		)	23	306		(11		)	188
	Total debt securities	315		(9		)	201			79		(2		)	32	394		(12		)	233
	Mortgage-backed securities:
	Residential mortgage-backed securities:
	Government National Mortgage Association	—		—			—			19		(2		)	6	19		(2		)	6
	Federal National Mortgage Association	—		—			3			—		—			3	1		—			6
	Collateralized mortgage obligations:
	Federal National Mortgage Association	744		(36		)	41			—		—			—	744		(36		)	41
	Federal Home Loan Mortgage Corporation	361		(17		)	19			—		—			—	361		(17		)	19
	Non-agency issued	1		—			3			—		—			—	1		—			3
	Total collateralized mortgage obligations	1,106		(54		)	63			—		—			—	1,106		(54		)	63
Total residential mortgage-backed securities	1,106		(54		)	66			19		(2		)	9	1,125		(56		)	75
Commercial mortgage-backed securities, non-agency issued	158		(2		)	15			12		—			3	170		(2		)	18
Total mortgage-backed securities	1,264		(56		)	81			32		(2		)	12	1,296		(58		)	93
Collateralized loan obligations, non-agency issued	261		(2		)	28			3		—			1	264		(2		)	29
Asset-backed securities collateralized by:
Student loans	67		—			8			—		—			—	67		—			8
Credit card	36		(1		)	4			—		—			—	36		(1		)	4
Auto loans	25		—			5			—		—			—	25		—			5
Other	72		(1		)	11			—		—			—	72		(1		)	11
Total asset-backed securities	200		(2		)	28			—		—			—	200		(2		)	28
Other	14		—			3			8		—			2	22		—			5
Total securities available for sale in an unrealized loss position	$	2,054	$	(69	)	341			$	122	$	(5	)	47	$	2,176	$	(74	)	388
	Less than 12 months								12 months or longer						Total
	Fair		Unrealized						Fair		Unrealized				Fair		Unrealized
31-Dec-13	value		losses			Count			value		losses			Count	value		losses			Count
Investment securities held to maturity:
Debt securities, U.S. government agencies	$	5	$	—		1			$	—	$	—		—	$	5	$	—		1
Residential mortgage-backed securities:
Government National Mortgage Association	11		—			4			—		—			—	11		—			4
Federal National Mortgage Association	119		(3		)	30			—		—			—	119		(3		)	30
Federal Home Loan Mortgage Corporation	59		(1		)	15			—		—			—	59		(1		)	15
Collateralized mortgage obligations:
Government National Mortgage Association	520		(12		)	58			—		—			—	520		(12		)	58
Federal National Mortgage Association	1,011		(47		)	59			—		—			—	1,011		(47		)	59
Federal Home Loan Mortgage Corporation	629		(30		)	35			22		(1		)	1	652		(30		)	36
Total collateralized mortgage obligations	2,160		(89		)	152			22		(1		)	1	2,182		(90		)	153
Total residential mortgage-backed securities	2,348		(94		)	201			22		(1		)	1	2,371		(94		)	202
Total securities held to maturity in an unrealized loss position	$	2,353	$	(94	)	202			$	22	$	(1	)	1	$	2,376	$	(94	)	203
Scheduled contractual maturities of investment securities	Scheduled contractual maturities of our investment securities were as follows at December 31, 2014:
		Amortized cost		Fair value
	Debt securities:
	Within one year	$	106	$	107
	After one year through five years	795		814
	After five years through ten years	619		616
	After ten years	15		15
	Total debt securities	1,536		1,552
	Mortgage-backed securities	8,623		8,690
	Collateralized loan obligations	1,001		1,016
	Asset-backed securities	591		599
	Other	22		22
		$	11,772	$	11,879
Available for sale securities transferred to held to maturity securities	On March 29, 2013, we transferred $3 billion of residential mortgage-backed securities from available for sale to held to maturity. The amortized cost, unrealized gains and losses, and fair value of these transferred investment securities immediately prior to the transfer were as follows:
		Amortized		Unrealized			Unrealized			Fair
		cost		gains			losses			value
	Residential mortgage-backed securities:
	Government National Mortgage Association	$	15	$	1		$	—		$	15
	Federal National Mortgage Association	173		12			—			185
	Federal Home Loan Mortgage Corporation	96		5			—			102
	Collateralized mortgage obligations:
	Government National Mortgage Association	885		26			—			910
	Federal National Mortgage Association	1,019		9			(3		)	1,026
	Federal Home Loan Mortgage Corporation	758		7			(2		)	763
	Total collateralized mortgage obligations	2,662		42			(4		)	2,699
	Total residential mortgage-backed securities	$	2,946	$	59		$	(4	)	$	3,001

Loans_and_Leases_Tables

Loans and Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Summary of loans and leases	Our loans and leases receivable consisted of the following at December 31:
		2014										2013
		Originated			Acquired			Total				Originated			Acquired			Total
	Commercial:
	Real estate	$	6,181		$	1,050		$	7,231			$	5,527		$	1,387		$	6,914
	Construction	973			1			973				828			36			864
	Business	5,430			345			5,775				4,876			414			5,290
	Total commercial	12,584			1,395			13,979				11,231			1,838			13,068
	Consumer:
	Residential real estate	2,096			1,257			3,353				1,902			1,546			3,448
	Home equity	1,847			1,089			2,936				1,618			1,134			2,752
	Indirect auto	2,166			—			2,166				1,544			—			1,544
	Credit cards	324			—			324				325			—			325
	Other consumer	278			—			278				302			—			302
	Total consumer	6,711			2,347			9,058				5,691			2,680			8,371
	Total loans and leases	19,296			3,742			23,037				16,922			4,517			21,440
	Allowance for loan losses	(228		)	(6		)	(234		)		(205		)	(4		)	(209		)
	Total loans and leases, net	$	19,067		$	3,736		$	22,803			$	16,717		$	4,514		$	21,230
The outstanding principal balance and the related carrying amount of acquired loans	The outstanding principal balance and the related carrying amount of our acquired loans included in our Consolidated Statements of Condition were as follows at December 31:
		2014			2013
	Credit impaired acquired loans evaluated individually for future credit losses
	Outstanding principal balance	$	10		$	18
	Carrying amount	6			12
	Acquired loans evaluated collectively for future credit losses
	Outstanding principal balance	2,549			3,301
	Carrying amount	2,496			3,233
	Other acquired loans
	Outstanding principal balance	1,274			1,321
	Carrying amount	1,240			1,273
	Total acquired loans
	Outstanding principal balance	3,832			4,640
	Carrying amount	3,742			4,517
Changes in the accretable discount on loans acquired	The following table presents changes in the accretable yield, which includes income recognized from contractual interest cash flows, for the dates indicated. Acquired lines of credit accounted for under ASC 310-20 are not included in this table.
	Balance at January 1, 2013	$	(1,057	)
	Net reclassifications from nonaccretable yield	(15		)
	Accretion	199
	Other (1)	22
	Balance at December 31, 2013	(851		)
	Reclassifications from nonaccretable yield	(5		)
	Accretion	138
	Other (1)	55
	Balance at December 31, 2014	$	(663	)
Activity in the allowance for credit losses for the years ended	The following table presents the activity in our allowance for loan losses on originated loans and related recorded investment of the associated loans in our originated loan portfolio segment for the years ended December 31:
		Commercial							Consumer
	Originated loans	Real estate			Business				Residential			Home equity			Indirect auto			Credit cards			Other			Total
																					consumer
	2014
	Allowance for loan losses:
	Balance at beginning of year	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
	Provision for loan losses	23			30				1			4			11			10			6			85
	Charge-offs	(10		)	(30		)		(1		)	(4		)	(9		)	(13		)	(8		)	(75		)
	Recoveries	4			3				—			1			1			2			1			13
	Balance at end of year	$	65		$	122			$	2		$	8		$	14		$	12		$	5		$	228
	Allowance for loan losses:
	Individually evaluated for impairment	$	2		$	2			$	1		$	1		$	—		$	—		$	—		$	6
	Collectively evaluated for impairment	63			120				1			7			14			12			5			222
	Total	$	65		$	122			$	2		$	8		$	14		$	12		$	5		$	228
	Loans receivable:
	Balance at end of year
	Individually evaluated for impairment	$	64		$	61			$	20		$	7		$	2		$	—		$	2		$	156
	Collectively evaluated for impairment	7,089			5,370				2,076			1,840			2,164			324			276			19,139
	Total	$	7,154		$	5,430			$	2,096		$	1,847		$	2,166		$	324		$	278		$	19,296
	2013
	Allowance for loan losses:
	Balance at beginning of year	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
	Provision for loan losses	17			48				(1		)	6			9			11			8			96
	Charge-offs	(10		)	(31		)		(2		)	(3		)	(3		)	(6		)	(8		)	(63		)
	Recoveries	4			3				1			—			1			1			2			11
	Balance at end of year	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
	Allowance for loan losses:
	Individually evaluated for impairment	$	4		$	2			$	1		$	3		$	—		$	—		$	—		$	9
	Collectively evaluated for impairment	44			117				1			4			10			13			6			196
	Total	$	48		$	119			$	2		$	7		$	10		$	13		$	6		$	205
	Loans receivable:
	Balance at end of year
	Individually evaluated for impairment	$	72		$	59			$	20		$	8		$	1		$	—		$	3		$	163
	Collectively evaluated for impairment	6,282			4,818				1,882			1,610			1,543			325			299			16,759
	Total	$	6,354		$	4,876			$	1,902		$	1,618		$	1,544		$	325		$	302		$	16,922
		Commercial							Consumer
	Originated loans	Real estate			Business				Residential			Home Equity			Indirect auto			Credit cards			Other			Total
																					Consumer
	2012
	Allowance for loan losses:
	Balance at beginning of year	$	50		$	57			$	4		$	4		$	—		$	—		$	2		$	118
	Provision for loan losses	(7		)	67				3			4			4			8			5			84
	Charge-offs	(7		)	(27		)		(3		)	(4		)	(1		)	(1		)	(4		)	(46		)
	Recoveries	1			2				—			—			—			—			1			6
	Allowance related to loans sold	—			—				—			—			—			—			—			(1		)
	Balance at end of year	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
	Allowance for loan losses:
	Individually evaluated for impairment	$	3		$	5			$	3		$	1		$	—		$	—		$	—		$	11
	Collectively evaluated for impairment	35			94				1			4			3			7			5			150
	Total	$	38		$	99			$	5		$	5		$	3		$	7		$	5		$	161
	Loans receivable:
	Balance at end of year
	Individually evaluated for impairment	$	67		$	58			$	20		$	5		$	—		$	—		$	2		$	152
	Collectively evaluated for impairment	4,977			4,228				1,705			1,281			601			215			214			13,221
	Total	$	5,044		$	4,286			$	1,724		$	1,286		$	601		$	215		$	215		$	13,372
	The following table presents the activity in our allowance for loan losses and related recorded investment of the associated loans in our acquired loan portfolio for the years ended December 31:
		Commercial							Consumer
	Acquired loans	Real estate			Business				Residential			Home equity			Credit cards			Other			Total
																		consumer
	2014
	Allowance for loan losses:
	Balance at beginning of year	$	—		$	—			$	1		$	3		$	—		$	—		$	4
	Provision for loan losses	3			1				1			3			—			—			8
Charge-offs	(2		)	—				—			(4		)	—			—			(6		)
Recoveries	—			—				—			—			—			—			—
Balance at end of year	$	1		$	1			$	2		$	2		$	—		$	—		$	6
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	1			1				2			2			—			—			6
Total	$	1		$	1			$	2		$	2		$	—		$	—		$	6
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	—		$	3			$	—		$	4		$	—		$	—		$	7
Collectively evaluated for impairment	—			269				—			964			—			—			1,233
Loans acquired with deteriorated credit quality	1,050			73				1,257			122			—			—			2,502
Total	$	1,050		$	345			$	1,257		$	1,089		$	—		$	—		$	3,742
2013
Allowance for loan losses:
Balance at beginning of year	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Provision for loan losses	4			—				1			3			—			(1		)	7
Charge-offs	(4		)	—				—			—			—			(1		)	(5		)
Recoveries	—			—				—			—			—			—			—
Balance at end of year	$	—		$	—			$	1		$	3		$	—		$	—		$	4
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	—			—				1			3			—			—			4
Total	$	—		$	—			$	1		$	3		$	—		$	—		$	4
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	1		$	7			$	—		$	1		$	—		$	—		$	10
Collectively evaluated for impairment	—			305				—			960			—			—			1,264
Loans acquired with deteriorated credit quality	1,423			102				1,546			173			—			—			3,244
Total	$	1,423		$	414			$	1,546		$	1,134		$	—		$	—		$	4,517
	Commercial							Consumer
Acquired loans	Real estate			Business				Residential			Home equity			Credit cards			Other			Total
																	consumer
2012
Allowance for loan losses:
Balance at beginning of year	$	—		$	—			$	—		$	—		$	—		$	2		$	2
Provision for loan losses	6			—				—			—			—			1			7
Charge-offs	(7		)	—				—			—			—			(2		)	(9		)
Recoveries	1			—				—			—			—			—			1
Balance at end of year	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Allowance for loan losses:
Individually evaluated for impairment	$	—		$	—			$	—		$	—		$	—		$	—		$	—
Collectively evaluated for impairment	—			—				—			—			—			1			2
Total	$	—		$	—			$	—		$	—		$	—		$	1		$	2
Loans receivable:
Balance at end of year
Individually evaluated for impairment	$	1		$	7			$	—		$	2		$	—		$	—		$	10
Collectively evaluated for impairment	—			427				—			1,045			100			42			1,614
Loans acquired with deteriorated credit quality	2,048			233				2,037			319			—			76			4,713
Total	$	2,049		$	667			$	2,037		$	1,366		$	100		$	118		$	6,338
Summary of nonaccruing loans	Our nonperforming loans consisted of the following at December 31:
		2014										2013
		Originated			Acquired			Total				Originated			Acquired			Total
	Commercial:
	Real estate	$	53		$	—		$	53			$	53		$	1		$	54
	Business	45			7			53				42			9			51
	Total commercial	98			7			106				95			10			105
	Consumer:
	Residential real estate	34			—			34				31			—			31
	Home equity	24			23			47				18			20			39
	Indirect auto	13			—			13				6			—			6
	Other consumer	5			—			5				6			—			6
	Total consumer	75			23			98				62			20			82
	Total	$	174		$	30		$	204			$	157		$	30		$	188
Details of additional information on loans	The table below provides information about the interest income that would have been recognized if our nonperforming loans had performed in accordance with terms for the years ending December 31:
		2014			2013			2012
	Additional interest income that would have been recorded if nonperforming loans had performed in accordance with original terms	$	8		$	7		$	7
Summary of originated impaired loans	The carrying value of our impaired loans, less any related allowance for loan losses, was 70% and 69% of the loans’ contractual principal balance at December 31, 2014 and 2013, respectively.
		2014										2013
	Originated loans	Recorded			Unpaid			Related				Recorded			Unpaid			Related
		investment			principal			allowance				investment			principal			allowance
					balance										balance
	With no related allowance recorded:
	Commercial:
	Real estate	$	40		$	59		$	—			$	48		$	63		$	—
	Business	29			51			—				55			84			—
	Total commercial	69			110			—				103			146			—
	Consumer:
	Residential real estate	8			9			—				12			12			—
	Home equity	3			4			—				4			5			—
	Indirect auto	2			3			—				1			1			—
	Other consumer	2			2			—				1			1			—
	Total consumer	16			18			—				18			20			—
	Total	$	85		$	128		$	—			$	121		$	166		$	—
	With a related allowance recorded:
	Commercial:
	Real estate	$	24		$	27		$	2			$	24		$	35		$	4
	Business	32			43			2				4			6			2
	Total commercial	56			70			4				28			41			5
	Consumer:
	Residential real estate	11			13			1				8			9			1
	Home equity	4			4			1				4			5			3
	Indirect auto	—			—			—				1			1			—
	Other consumer	—			—			—				1			1			—
	Total consumer	16			17			2				14			16			4
	Total	$	71		$	87		$	6			$	42		$	57		$	9
	Total
	Commercial:
	Real estate	$	64		$	86		$	2			$	72		$	97		$	4
	Business	61			93			2				59			90			2
	Total commercial	125			179			4				131			187			5
	Consumer:
	Residential real estate	20			22			1				20			21			1
	Home equity	7			8			1				8			10			3
	Indirect auto	2			3			—				1			2			—
	Other consumer	2			2			—				3			3			—
	Total consumer	31			36			2				32			36			4
	Total	$	156		$	215		$	6			$	163		$	222		$	9
	The following table provides information about our impaired acquired loans with no related allowance at December 31. The remaining credit mark is considered adequate to cover any loss on these balances.
		2014										2013
	Acquired loans	Recorded			Unpaid principal balance			Related				Recorded			Unpaid principal balance			Related
		investment						allowance				investment						allowance
	Commercial:
	Real estate	$	—		$	—		$	—			$	1		$	4		$	—
	Business	3			3			—				7			8			—
	Total commercial	3			3			—				8			12			—
	Consumer:
	Residential real estate	—			—			—				—			—			—
	Home equity	4			6			—				1			2			—
	Other consumer	—			—			—				—			—			—
	Total consumer	4			6			—				1			2			—
	Total(1)	$	7		$	9		$	—			$	10		$	14		$	—
	-1	Includes nonaccrual purchased credit impaired loans.
	The following table provides information about our impaired originated loans including the average recorded investment and interest income recognized on impaired loans for the years ended December 31:
		2014							2013							2012
	Originated loans	Average			Interest				Average			Interest				Average			Interest
		recorded			income				recorded			income				recorded			income
		investment			recognized				investment			recognized				investment			recognized
	Commercial:
	Real estate	$	69		$	1			$	80		$	1			$	72		$	1
	Business	53			1				63			1				63			1
Total commercial	122			3				142			2				135			2
Consumer:
Residential real estate	21			—				20			—				20			—
Home equity	5			—				5			—				4			—
Indirect auto	3			—				1			—				—			—
Other consumer	3			—				3			—				2			—
Total consumer	31			—				29			1				26			—
Total	$	153		$	3			$	172		$	3			$	161		$	3
The following table provides information about our impaired acquired loans including the average recorded investment and interest income recognized on impaired loans for the years ended December 31.
	2014							2013							2012
Acquired loans	Average			Interest				Average			Interest				Average			Interest
	recorded			income				recorded			income				recorded			income
	investment			recognized				investment			recognized				investment			recognized
Commercial:
Real estate	$	—		$	—			$	1		$	—			$	1		$	—
Business	2			—				7			—				8			—
Total commercial	2			—				8			—				9			—
Consumer:
Residential real estate	—			—				—			—				—			—
Home equity	1			—				—			—				1			—
Other consumer	—			—				—			—				—			—
Total consumer	1			—				—			—				1			—
Total(1)	$	3		$	—			$	9		$	—			$	10		$	—
-1	Includes nonaccrual purchased credit impaired loans.
Reconciliation between nonaccrual loans and impaired loans	The following table is a reconciliation between nonaccrual loans and impaired loans at December 31:
		2014										2013
		Commercial			Consumer			Total				Commercial			Consumer			Total
	Nonaccrual loans	$	106		$	98		$	204			$	105		$	82		$	188
	Plus: Accruing TDRs	59			8			67				45			8			52
	Less: Smaller balance nonaccrual loans evaluated collectively when determining the allowance for loan losses	(36		)	(71		)	(108		)		(11		)	(57		)	(67		)
	Total impaired loans(1)	$	128		$	35		$	163			$	139		$	33		$	172
	(1)	Included nonaccrual purchased credit impaired loans.
Aging analysis of loans	The following table contains an aging analysis of our loans by class at December 31:
		30-59 days			60-89 days			Greater than			Total			Current			Total loans			Greater than
		past due			past due			90 days			past due						receivable			90 days
								past due												and accruing (1)
	2014
	Originated loans
	Commercial:
	Real estate	$	7		$	2		$	31		$	40		$	7,113		$	7,154		$	—
	Business	5			7			17			28			5,402			5,430			—
	Total commercial	11			9			49			69			12,515			12,584			—
	Consumer:
	Residential real estate	4			2			21			27			2,069			2,096			—
	Home equity	3			1			15			19			1,828			1,847			—
	Indirect auto	17			4			5			27			2,139			2,166			—
	Credit cards	2			2			2			6			318			324			2
	Other consumer	3			1			3			7			271			278			—
	Total consumer	29			10			46			85			6,626			6,711			2
	Total	$	41		$	19		$	95		$	154		$	19,141		$	19,296		$	2
	Acquired loans
	Commercial:
	Real estate	$	3		$	3		$	26		$	31		$	1,019		$	1,050		$	26
	Business	—			—			7			7			338			345			4
	Total commercial	3			3			33			38			1,357			1,395			30
	Consumer:
	Residential real estate	11			5			56			72			1,186			1,257			56
	Home equity	6			2			21			29			1,060			1,089			6
	Total consumer	17			7			77			101			2,246			2,347			62
	Total	$	21		$	9		$	109		$	139		$	3,603		$	3,742		$	91
	2013
	Originated loans
	Commercial:
	Real estate	$	5		$	2		$	27		$	34		$	6,321		$	6,354		$	—
	Business	4			3			20			28			4,849			4,876			—
	Total commercial	9			5			47			61			11,169			11,231			—
	Consumer:
	Residential real estate	6			2			21			30			1,872			1,902			—
	Home equity	3			2			12			17			1,601			1,618			—
	Indirect auto	12			2			3			18			1,526			1,544			—
	Credit cards	2			1			3			6			319			325			3
	Other consumer	3			1			3			7			295			302			—
	Total consumer	27			9			43			79			5,613			5,691			3
	Total	$	36		$	15		$	90		$	140		$	16,782		$	16,922		$	3
	Acquired loans
	Commercial:
	Real estate	$	8		$	8		$	37		$	52		$	1,371		$	1,423		$	36
	Business	2			1			8			11			403			414			5
	Total commercial	10			8			45			63			1,774			1,838			41
	Consumer:
	Residential real estate	19			11			64			94			1,452			1,546			64
	Home equity	7			4			20			31			1,103			1,134			5
	Total consumer	26			15			84			125			2,555			2,680			70
	Total	$	35		$	23		$	130		$	188		$	4,330		$	4,517		$	110
	(1)	Includes credit card loans, loans that have matured and are in the process of collection, and acquired loans that were originally recorded at fair value upon acquisition. Acquired loans are considered to be accruing as we can reasonably estimate future cash flows on these acquired loans and we expect to fully
Information about the credit quality of our commercial loan portfolio	he following tables present information about the credit quality of our commercial loan portfolio at December 31:
		Real estate			Business			Total			Percent of total
	2014
	Originated loans:
	Pass	$	6,791		$	5,067		$	11,858		94.2	%
	Criticized:(1)
	Accrual	310			318			628			5	%
	Nonaccrual	53			45			98			0.8	%
	Total criticized	363			363			726			5.8	%
	Total	$	7,154		$	5,430		$	12,584		100	%
	Acquired loans:
	Pass	$	948		$	294		$	1,243		89.1	%
	Criticized:(1)
	Accrual	102			43			145			10.4	%
	Nonaccrual	—			7			7			0.5	%
	Total criticized	102			51			153			10.9	%
	Total	$	1,050		$	345		$	1,395		100	%
	2013
	Originated loans:
	Pass	$	6,028		$	4,590		$	10,618		94.6	%
	Criticized:(1)
	Accrual	273			244			517			4.6	%
	Nonaccrual	53			42			95			0.8	%
	Total criticized	327			286			612			5.4	%
	Total	$	6,354		$	4,876		$	11,231		100	%
	Acquired loans:
	Pass	$	1,260		$	359		$	1,619		88.2	%
	Criticized:(1)
	Accrual	162			46			208			11.3	%
	Nonaccrual	1			9			10			0.5	%
	Total criticized	163			55			218			11.8	%
	Total	$	1,423		$	414		$	1,838		100	%
	(1)	Includes special mention, substandard, doubtful, and loss, which are consistent with regulatory definitions, and as described in Part I, Item 1, “Business,” under the heading “Asset Quality Review.”
Information about the credit quality of our consumer loan portfolio	The scores are obtained from a nationally recognized consumer rating agency and are presented in the table below at December 31:
		Residential			Home equity			Indirect Auto			Credit cards			Other			Total			Percent of
		real estate												consumer						total
	2014
	Originated loans by refreshed FICO score:
	Over 700	$	1,841		$	1,529		$	1,533		$	226		$	167		$	5,296		78.9	%
	660-700	124			182			347			53			46			752			11.2
	620-660	62			71			159			24			24			339			5
	580-620	28			31			64			11			13			148			2.2
	Less than 580	32			32			63			8			12			146			2.2
	No score(1)	9			1			—			3			17			31			0.5
	Total	$	2,096		$	1,847		$	2,166		$	324		$	278		$	6,711		100	%
	Acquired loans by refreshed FICO score:
	Over 700	$	872		$	851		$	—		$	—		$	—		$	1,723		73.4	%
	660-700	87			93			—			—			—			180			7.7
	620-660	61			52			—			—			—			113			4.8
	580-620	49			40			—			—			—			88			3.8
	Less than 580	57			34			—			—			—			91			3.9
	No score(1)	131			20			—			—			—			151			6.4
	Total	$	1,257		$	1,089		$	—		$	—		$	—		$	2,347		100	%
	2013
	Originated loans by refreshed FICO score:
	Over 700	$	1,609		$	1,327		$	993		$	223		$	173		$	4,324		76	%
	660-700	128			158			304			53			53			696			12.2
	620-660	56			69			149			25			28			328			5.8
	580-620	32			30			55			12			14			142			2.5
	Less than 580	38			30			43			8			15			135			2.4
	No score(1)	39			3			—			4			20			66			1.1
	Total	$	1,902		$	1,618		$	1,544		$	325		$	302		$	5,691		100	%
	Acquired loans by refreshed FICO score:
	Over 700	$	1,074		$	874		$	—		$	—		$	—		$	1,948		72.7	%
	660-700	115			103			—			—			—			218			8.1
	620-660	61			57			—			—			—			119			4.4
	580-620	57			39			—			—			—			95			3.6
	Less than 580	75			40			—			—			—			114			4.3
	No score(1)	164			21			—			—			—			185			6.9
	Total	$	1,546		$	1,134		$	—		$	—		$	—		$	2,680		100	%
	(1)	Primarily includes loans that are serviced by others for which refreshed FICO scores were not available as of the date indicated.
Aggregate recorded investment of impaired loans with terms through troubled debt restructuring	The following table details additional information about our TDRs at December 31:
		2014			2013			2012
	Aggregate recorded investment of impaired loans with terms modified through a troubled debt restructuring:
	Accruing interest	$	67		$	52		$	46
	Nonaccrual	53			56			42
	Total troubled debt restructurings(1)	$	120		$	108		$	89
	(1)	Includes 87 and 40 acquired loans that were restructured with a recorded investment of $4 million and $1 million at December 31, 2014 and 2013, respectively.
Schedule of financial effects of modifications made to restructured loans	The financial effects of our modifications are as follows for the years ended December 31:
	Type of Concession	Count		Postmodification			Premodification			Postmodification
				recorded			allowance for			allowance for
				investment(1)			loan losses			loan losses
	2014
	Commercial:
	Commercial real estate
	Extension of term	10		$	20		$	1		$	—
	Rate reduction	1		3			—			1
	Extension of term and rate reduction	3		1			—			—
	Commercial business
	Extension of term	15		32			6			1
	Extension of term and rate reduction	2		—			—			—
	Total commercial	31		56			8			2
	Consumer:
	Residential real estate
	Extension of term	6		1			—			—
	Rate reduction	2		—			—			—
	Deferral of principal and extension of term	7		1			—			—
	Extension of term and rate reduction	14		2			—			—
	Chapter 7 Bankruptcy	14		1			—			—
	Other	3		—			—			—
	Home equity
	Extension of term	3		—			—			—
	Deferral of principal and extension of term	2		—			—			—
	Extension of term and rate reduction	10		—			—			—
	Chapter 7 Bankruptcy	79		3			—			—
	Other	18		1			—			—
	Indirect auto
	Chapter 7 Bankruptcy	273		5			—			—
	Type of Concession	Count		Postmodification			Premodification			Postmodification
				recorded			allowance for			allowance for
				investment(1)			loan losses			loan losses
	Other consumer
	Extension of term	1		$	—		$	—		$	—
	Chapter 7 Bankruptcy	33		—			—			—
	Total consumer	465		14			—			—
	Total	496		$	70		$	8		$	2
	2013
	Commercial:
	Commercial real estate
	Extension of term	5		$	9		$	1		$	1
	Deferral of principal	1		8			—			—
	Extension of term and rate reduction	8		17			1			—
	Commercial business
	Extension of term	10		10			2			—
	Extension of term and rate reduction	7		1			—			—
	Total commercial	31		46			4			1
	Consumer:
	Residential real estate
	Extension of term	2		—			—			—
	Rate reduction	3		—			—			—
	Deferral of principal and extension of term	5		—			—			—
	Extension of term and rate reduction	11		2			—			—
	Chapter 7 Bankruptcy	15		1			—			—
	Home equity
	Deferral of principal and extension of term	3		—			—			—
	Rate reduction	2		—			—			—
	Extension of term and rate reduction	3		—			—			—
	Chapter 7 Bankruptcy	61		2			—			—
	Indirect auto
	Chapter 7 Bankruptcy	74		1			—			—
	Other consumer
	Extension of term	1		—			—			—
Rate reduction	1		—			—			—
Extension of term and rate reduction	1		—			—			—
Chapter 7 Bankruptcy	54		1			—			—
Total consumer	236		9			—			—
Total	267		$	55		$	4		$	2
(1)	Postmodification balances approximate premodification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant.
Information about residential mortgage loans	The following table provides information about our residential mortgage banking activities at December 31:
		2014			2013			2012
	Loans classified as held for sale	$	40		$	50		$	155
	Loans sold during the year	663			1,400			1,444
	Gains on sale of loans, net	5			12			9
	Mortgages serviced for others	3,841			3,665			2,909
	Mortgage servicing asset recorded for loans serviced for others, net	37			35			26

Premises_and_Equipment_Tables

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
A summary of our premises and equipment	premises and equipment at December 31:
		2014			2013
	Land	$	29		$	29
	Buildings and leasehold improvements	290			287
	Furniture and equipment	339			307
	Total	658			623
	Accumulated depreciation	(251		)	(205		)
	Premises and equipment, net	$	407		$	418

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Information regarding our goodwill	The following table shows information regarding our goodwill for the periods indicated:
		Banking			Financial			Consolidated
					services			total
	Balances at January 1, 2013	$	2,416		$	68		$	2,484
	Purchase accounting adjustments(1)	(35		)	—			(35		)
	Balances at December 31, 2013	2,381			68			2,449
	Acquisitions	—			1			1
	Impairment	(1,100		)	—			(1,100		)
	Balances at December 31, 2014	$	1,281		$	69		$	1,350
	(1)	Establishment of deferred tax assets in connection with the HSBC Branch Acquisition and our National City Bank branch acquisition.
Information regarding our amortizing intangible assets	The following table provides information regarding our amortizing intangible assets at December 31:
		2014			2013
	Core deposit intangible	$	191		$	191
	Accumulated amortization	(158		)	(139		)
	Net carrying amount	33			52
	Customer lists	100			95
	Accumulated amortization	(66		)	(53		)
	Net carrying amount	34			42
	Total amortizing intangible assets, net	$	67		$	94
Estimated future amortization expense for our amortizing intangible assets	The estimated future amortization expense for our amortizing intangible assets is as follows at December 31, 2014:
		First quarter			Second quarter			Third quarter			Fourth quarter		Total
	2015	$	6		$	5		$	4		$	4	$	19
	2016	4			3			3			3		13
	2017	3			3			3			3		12
	2018	3			2			2			2		9
	2019	2			1			1			1		5
	Thereafter												10

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Deposits	Our deposits consisted of the following at December 31:
		2014				2013
		Balance		Weighted		Balance		Weighted
				average				average
				rate				rate
	Core deposits:
	Savings	$	3,452	0.09	%	$	3,667	0.1	%
	Interest-bearing checking	5,084		0.03		4,744		0.04
	Money market deposits	9,962		0.22		9,740		0.21
	Noninterest-bearing	5,407		—		4,866		—
	Total core deposits	23,906		0.11		23,016		0.12
	Certificates	3,876		0.69		3,649		0.68
	Total deposits	$	27,781	0.19	%	$	26,665	0.2	%
Interest expense on deposits	Interest expense on our deposits is summarized as follows for the years ended December 31:
		2014		2013		2012
	Certificates	$	27	$	26	$	33
	Money market deposits	22		21		26
	Savings	3		4		5
	Interest-bearing checking	2		2		2
	Total interest expense	$	53	$	53	$	67

Borrowings_Tables

Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of outstanding borrowings	Our outstanding borrowings are summarized as follows at December 31:
		2014			2013
	Short-term borrowings:
	FHLB advances	$	5,049		$	4,304
	Repurchase agreements	423			518
	Total short-term borrowings	5,472			4,822
	Long-term borrowings:
	Senior notes (maturing in 2020)	298			298
	Subordinated notes (maturing in 2021)	298			298
	Junior subordinated debentures (maturing between 2030 and 2037)	114			113
	Other (maturing between 2015 and 2032)	23			25
	Total long-term borrowings	734			734
	Total borrowings	$	6,206		$	5,556
Interest expense on borrowings	Interest expense on our borrowings is summarized as follows for the years ended December 31:
		2014			2013		2012
	FHLB advances	$	19		$	14	$	19
	Repurchase agreements	1			1		17
	Senior notes	21			21		21
	Subordinated notes	23			23		23
	Junior subordinated debentures	5			5		6
	Total interest expense	$	69		$	64	$	86
Junior subordinated debentures
	Trust Preferred Subordinated Debentures	Maturity	Interest rate		Principal amount of subordinated debentures		Principal amount of trust preferred securities
					(dollars in millions)
	HNC Statutory Trust III	2035	3 month LIBOR +	1.40%	$	26	$	25
	Willow Grove Statutory Trust I	2036	3 month LIBOR +	1.31%	26		25
	HNC Statutory Trust IV	2037	3 month LIBOR +	1.28%	23		23
	HNC Statutory Trust II	2034	3 month LIBOR +	2.70%	21		20
	First Niagara Financial Group Statutory Trust I	2034	3 month LIBOR +	2.70%	12		12
	Westbank Capital Trust II	2034	3 month LIBOR +	2.19%	9		9
	Westbank Capital Trust III	2034	3 month LIBOR +	2.19%	9		9
	East Penn Statutory Trust I	2033	3 month LIBOR +	3.10%	8		8
	Harleysville Statutory Trust I	2031		10.20%	5		5
	Alliance Capital Trust II	2030		10.88%	4		4
	Total				$	142	$	138
Aggregate maturities of our long term borrowings	The aggregate maturities of our long-term borrowings are as follows at December 31, 2014 (by year of maturity):
	2015	$	2
	2016	2
	2017	2
	2018	2
	2019	2
	Thereafter	724
	Total	$	734

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative financial instruments	Our derivative positions include both instruments that are designated as hedging instruments and instruments that are customer related and not designated in hedging relationships. The following table presents information regarding our derivative financial instruments, at December 31:
		Asset derivatives							Liability derivatives
		Notional			Fair value (1)				Notional			Fair value (2)
		amount							amount
	2014
	Derivatives designated as hedging instruments:
	Interest rate swap agreements	$	4		$	—			$	30		$	2
	Derivatives not designated as hedging instruments:
	Interest rate swap agreements	3,629			96				3,649			96
	Total derivatives	$	3,633		$	96			$	3,679		$	97
	2013
	Derivatives designated as hedging instruments:
	Interest rate swap agreements	$	22		$	—			$	13		$	1
	Derivatives not designated as hedging instruments:
	Interest rate swap agreements	3,092			76				3,094			76
	Total derivatives	$	3,114		$	76			$	3,107		$	77
	-1	Represents gross amounts, included in Other Assets in our Consolidated Statements of Condition.
	-2	Represents gross amounts, included in Other Liabilities in our Consolidated Statements of Condition.
Amounts recognized for derivative financial instruments	The following table presents information about amounts recognized for our derivative financial instruments designated in cash flow hedging relationships for the years ended December 31:
	Cash Flow Hedges	2014				2013				2012
	Interest rate swap agreements:
	Amount of gain on derivatives recognized in other comprehensive income, net of tax	$	1			$	1			$	7
	Amount of (loss) on derivatives reclassified from other comprehensive income to income	(1		)	(1)	(1		)	(1)	(15		)	(2)
	-1	Recognized in interest expense on borrowings in our Consolidated Statements of Income.
	-2	Of this amount, $12 million was recognized in merger and acquisition integration expenses when the associated borrowings were repaid in connection with the HSBC Branch Acquisition and $4 million was recognized in interest expense on borrowings in our Consolidated Statements of Income.

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Loan commitments	Information pertaining to our loan commitments is as follows at December 31:
		2014		2013
	Outstanding commitments to originate loans:
	Fixed rate	$	265	$	217
	Variable rate	1,522		964
	Total commitments outstanding	$	1,787	$	1,181
	Unused lines of credit	$	9,319	$	8,400
	Standby letters of credit	266		297
	Commitments to sell residential mortgages	137		168
Future minimum lease payments	Our future minimum rental commitments for premises and equipment under non-cancelable operating leases and capital lease obligations are as follows at December 31:
		Operating leases			Capital leases
	2015	$	34		$	3
	2016	32			3
	2017	25			3
	2018	21			3
	2019	18			3
	Thereafter	62		(1)	16		(2)
	-1	Thereafter through 2041.
	(2)	Thereafter through 2032.

Capital_Tables

Capital (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Actual capital amounts ratios and requirements	The actual capital amounts, ratios, and requirements for First Niagara Financial Group, Inc. and First Niagara Bank, N.A. are as follows at December 31:
						For capital adequacy				Minimum amount to be
		Actual				purposes				well-capitalized
		Amount		Ratio		Amount		Ratio		Amount		Ratio
	First Niagara Financial Group, Inc.:
	2014
	Leverage ratio	$	2,764	7.5	%	$	1,474	4	%	$	1,843	5	%
	Tier 1 risk-based capital	2,764		9.81		1,127		4		1,691		6
	Total risk-based capital	3,313		11.75		2,256		8		2,819		10
	Tier 1 common capital	2,312		8.2		N/A		N/A		N/A		N/A
	2013
	Leverage ratio	$	2,526	7.26	%	$	1,392	4	%	$	1,739	5	%
	Tier 1 risk-based capital	2,526		9.56		1,057		4		1,585		6
	Total risk-based capital	3,046		11.53		2,114		8		2,642		10
	Tier 1 common capital	2,075		7.86		N/A		N/A		N/A		N/A
	First Niagara Bank, N.A.:
	2014
	Leverage ratio	$	2,949	8.01	%	$	1,473	4	%	$	1,841	5	%
	Tier 1 risk-based capital	2,949		10.48		1,126		4		1,688		6
	Total risk-based capital	3,199		11.37		2,251		8		2,814		10
	2013
	Leverage ratio	$	2,675	7.7	%	$	1,390	4	%	$	1,737	5	%
	Tier 1 risk-based capital	2,675		10.15		1,054		4		1,581		6
	Total risk-based capital	2,898		10.99		2,109		8		2,637		10

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Components of our income tax	The components of our income tax expense are as follows for the years ended December 31:
		2014			2013			2012
	Current:
	Federal	$	36		$	119		$	36
	State	4			4			1
		41			123			37
	Deferred (benefit) taxes:
	Federal	(136		)	3			31
	State	(14		)	1			3
		(150		)	5			34
	Total income tax (benefit) expense	$	(109	)	$	128		$	71
Summary Income tax expense	Our income tax expense differs from our expected tax expense (computed by applying the Federal corporate tax rate of 35% to income before income taxes) as follows for the years ended December 31:
		2014			2013			2012
	Tax (benefit) expense at statutory rate	$	(289	)	$	148		$	84
	Increase (decrease) attributable to:
	State income taxes, net of Federal benefit	(11		)	4			2
	Bank owned life insurance income	(5		)	(6		)	(5		)
	Tax exempt interest	(13		)	(11		)	(10		)
	Credits	(29		)	(13		)	(2		)
	Goodwill impairment	259			—			—
	Subsidiary reorganization	(27		)	—			—
	Other	5			6			2
	Income tax (benefit)	$	(109	)	$	128		$	71
Significant portions of deferred tax assets and deferred tax liabilities	The tax effects of our temporary differences that give rise to significant portions of our deferred tax assets and deferred tax liabilities are as follows at December 31:
		2014			2013
	Deferred tax assets:
	Net operating loss and other carryforwards	$	56		$	58
	Capital loss carryforward	44			—
	Financial statement allowance for credit losses	112			111
	Securitizations	2			2
	Partnerships	9			—
	Deferred compensation	13			13
	Stock-based compensation	15			14
	Other accrued expenses not currently deductible	20			21
	Acquired intangibles	88			—
	Post-retirement benefit obligation	5			4
	Nonperforming loan interest	14			12
	Other	34			28
	Total gross deferred tax assets	413			264
	Valuation allowance	(44		)	—
	Deferred tax liabilities:
	Unrealized gain on investment securities available for sale	(40		)	(52		)
	Partnerships	—			(3		)
	Leases	(32		)	(27		)
	Acquired intangibles	—			(33		)
	Premises and equipment	(5		)	(19		)
	Mortgage servicing rights	(14		)	(13		)
	Pension benefits	(22		)	(37		)
	Other	(2		)	(2		)
	Total gross deferred tax liabilities	(114		)	(187		)
	Net deferred tax asset	$	255		$	77
Reconciliation of unrecognized tax benefits	A reconciliation of our unrecognized tax benefits is as follows for the years ended December 31:
		2014			2013			2012
	Balance at beginning of year	$	6		$	3		$	3
	Additions based on tax positions related to the current year	2			1			1
	Additions for tax positions of prior years	1			3			—
	Reductions related to settlements with taxing authorities	—			(1		)	(2		)
	Balance at end of year	$	9		$	6		$	3

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per share using two-class method	The following table is a computation of our basic and diluted earnings per share using the two-class method for the years ended December 31:
		2014			2013			2012
	Net (loss) income available to common stockholders	$	(745	)	$	265		$	141
	Less income allocable to unvested restricted stock awards	1			1			—
	Net (loss) income allocable to common stockholders	$	(746	)	$	264		$	140
	Weighted average common shares outstanding:
	Total shares issued	366			366			366
	Unallocated employee stock ownership plan shares	(2		)	(2		)	(2		)
	Unvested restricted stock awards	(3		)	(2		)	(1		)
	Treasury shares	(11		)	(12		)	(14		)
	Total basic weighted average common shares outstanding	350			350			349
	Effect of dilutive stock-based awards	—			1			—
	Total diluted weighted average common shares outstanding	350			350			349
	Basic (loss) earnings per common share	$	(2.13	)	$	0.75		$	0.4
	Diluted (loss) earnings per common share	$	(2.13	)	$	0.75		$	0.4
	Anti-dilutive stock-based awards excluded from the diluted weighted average common share calculations	11			11			12

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Schedule of Comprehensive Income (Loss)	The following table presents the activity in our other comprehensive income for the years ended December 31:
		Pretax			Income taxes			Net
	2014
	Securities available for sale:
	Net unrealized holding losses arising during the year	$	(19	)	$	(7	)	$	(12	)
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Amortization of net unrealized holding gains to income during the year	(13		)	(5		)	(8		)	(1)
	Interest rate swaps designated as cash flow hedges:
	Reclassification adjustment for realized losses included in net income	1			1			1			(2)
	Pension and post-retirement actuarial losses	(51		)	(16		)	(34		)
	Total other comprehensive loss	$	(81	)	$	(27	)	$	(53	)
	2013
	Securities available for sale:
	Net unrealized holding losses arising during the year	$	(177	)	$	(68	)	$	(109	)
	Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity	(55		)	(21		)	(34		)
	Net unrealized losses on securities available for sale	(232		)	(89		)	(143		)
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Net unrealized holding gains transferred during the year	55			21			34
	Amortization of net unrealized holding gains to income during the year	(20		)	(7		)	(12		)	(1)
	Net unrealized holding gains on securities transferred during the year	35			14			22
	Interest rate swaps designated as cash flow hedges:
	Reclassification adjustment for realized losses included in net income	1			1			1			(2)
	Pension and post-retirement actuarial gains	40			15			25
	Total other comprehensive loss	$	(154	)	$	(59	)	$	(95	)
	2012
	Securities available for sale:
	Net unrealized holding gains arising during the year	$	177		$	68		$	109
	Reclassification adjustment for realized gains included in net income	(16		)	(6		)	(10		)
	Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity	4			2			2
	Net unrealized gains on securities available for sale	165			64			101
	Net unrealized holding gains on securities transferred between available for sale and held to maturity:
	Net unrealized holding gains transferred during the year	(4		)	(2		)	(2		)
	Less: amortization of net unrealized holding gains to income during the year	(3		)	(1		)	(2		)	(1)
	Net unrealized holding gains on securities transferred during the year	(7		)	(3		)	(4		)
	Interest rate swaps designated as cash flow hedges:
	Net unrealized losses arising during the year	(1		)	2			(3		)
	Reclassification adjustment for realized losses included in net income	15			6			10			(2)
	Net unrealized losses on interest rate swaps designated as cash flow hedges	15			8			7
	Pension and post-retirement actuarial losses	(24		)	(10		)	(14		)
	Total other comprehensive income	$	149		$	59		$	89
	(1)	Included in Interest income on investment securities and other in our Consolidated Statement of Income.
	(2)	Included in Interest expense on borrowings in our Consolidated Statement of Income.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents the activity in our accumulated other comprehensive income for the periods indicated:
		Net unrealized gains (losses) on securities available for sale			Net unrealized gains (losses) on			Unrealized loss on			Pension and postretirement plans			Total
					securities transferred from			interest rate
					available for sale to			swaps designated as
					held to maturity			cash flow hedges
	Balance, January 1, 2012	$	105		$	3		$	(13	)	$	(27	)	$	68
	Period change, net of tax	101			(4		)	7			(14		)	89
	Balance, December 31, 2012	207			(2		)	(6		)	(41		)	157
	Period change, net of tax	(143		)	22			1			25			(95		)
	Balance, December 31, 2013	64			20			(6		)	(16		)	62
	Period change, net of tax	(12		)	(8		)	1			(34		)	(53		)
	Balance, December 31, 2014	$	52		$	12		$	(5	)	$	(51	)	$	9

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Option Activity	The following is a summary of our stock option activity for the year ended December 31, 2014:
		Number of		Weighted average			Weighted average remaining	Aggregate intrinsic
		shares (in thousands)		exercise price			contractual term	value(1)
	Outstanding at January 1, 2014	11,186		$	13.23
	Granted	505		9.27
	Forfeited	(185	)	9.13
	Expired	(626	)	16.92
	Outstanding at December 31, 2014	10,879		$	12.9		2.0 years	$	—
	Exercisable at December 31, 2014	10,132		$	13.17		1.5 years	$	—
	(1)	Intrinsic value is the difference between the fair value of our stock at December 31, 2014 and the exercise price of the stock award.
Nonvested Stock Option	The following is a summary of our nonvested stock option activity for the year ended December 31, 2014:
		Number of		Weighted			Weighted average
		shares (in thousands)		average			grant date
				exercise price			fair value
	Nonvested at January 1, 2014	653		$	9.45		$	2.52
	Granted	505		9.27			2.59
	Vested	(225	)	10.11			2.67
	Forfeited	(185	)	9.13			2.48
	Nonvested at December 31, 2014	748		$	9.21		$	2.54
Summary of Stock Option Outstanding	The following is a summary of our stock options outstanding at December 31:
	Exercise price	Options outstanding (in thousands)		Weighted average exercise price			Weighted average remaining life (years)	Options exercisable (in thousands)		Weighted average exercise price
	2014
	$8.86 – $12.00	2,135		$	10.12		6.3	1,388		$	10.61
	$12.01 – $13.50	7,628		13.05			0.6	7,628		13.05
	$13.51 – $15.50	965		14.31			3	965		14.31
	$15.51 – $51.78	151		35.38			1	151		35.38
	Total	10,879		12.9			2	10,132		13.17
	2013
	$8.86 – $12.00	1,835		$	10.25		6.8	1,225		$	10.8
	$12.01 – $15.00	9,099		13.2			1.9	9,056		13.19
	$15.01 – $18.00	42		15.25			0.5	42		15.25
	$18.01 – $57.75	210		40.07			1.5	210		40.07
	Total	11,186		13.23			2.7	10,533		13.46
	2012
	$9.71 – $13.00	2,693		$	11.58		5.6	2,165		$	12
	$13.01 – $16.00	8,168		13.3			2.9	7,896		13.28
	$16.01 – $20.00	19		16.27			0.6	19		16.27
	$20.01 – $57.75	295		41.96			2	295		41.96
	Total	11,175		13.65			3.5	10,375		13.83
Summary of Stock Option Granted and Weighted Average Assumption to Compute Fair Value of Options	The following is a summary of our stock options granted for the years ended December 31, as well as the weighted average assumptions that we utilized to compute the fair value of the options:
		2014			2013			2012
	Options granted (in thousands)	505			434			528
	Grant date weighted average fair value per stock option	$	2.59		$	2.36		$	2.73
	Grant date weighted average share price	$	9.27		$	8.86		$	9.84
	Dividend yield	3.45		%	3.61		%	3.25		%
	Risk-free interest rate	2.05		%	0.99		%	1.26		%
	Expected volatility factor	38.59		%	40.7		%	40.36		%
	Expected life (in years)	6.6			5.7			5.6
Summary of Restricted Stock Activity	The following is a summary of our restricted stock and restricted stock unit activity for 2014:
		Number of		Weighted average grant date fair value
		shares (in thousands)
	Unvested at January 1, 2014	2,103		$	9.65
	Awarded	1,860		8.93
	Vested	(707	)	10.04
	Forfeited	(555	)	9.12
	Unvested at December 31, 2014	2,701		$	9.14

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Change in projected benefit obligation
		2014			2013
	Change in projected benefit obligation:
	Projected benefit obligation at beginning of year	$	214		$	243
	Service cost	1			1
	Interest cost	10			10
	Actuarial loss (gain)	49			(26		)
	Benefits paid	(15		)	(13		)
	Projected benefit obligation at end of year	260			214
	Change in fair value of plan assets:
	Fair value of plan assets at beginning of year	290			276
	Employer contributions	2			2
	Actual return on plan assets	19			25
	Benefits paid	(14		)	(13		)
	Fair value of plan assets at end of year	296			290
	Overfunded status at year end	$	36		$	76
Net pension cost	Net pension cost is comprised of the following for the years ended December 31:
		2014			2013			2012
	Service cost	$	1		$	1		$	1
	Interest cost	10			10			11
	Expected return on plan assets	(17		)	(16		)	(14		)
	Amortization of unrecognized loss	1			3			2
	Net periodic pension (gain)	$	(5	)	$	(2	)	$	(2	)
Change in plan assets and benefit obligation recognized in other comprehensive income	Changes in plan assets and benefit obligations recognized in other comprehensive income are as follows for the years ended December 31:
		2014			2013
	Net loss (gain)	$	46		$	(38	)
	Total loss (gain) loss recognized in other comprehensive income	46			(38		)
	Total recognized in net periodic pension cost and other comprehensive income	$	42		$	(40	)
Principal actuarial assumption	The principal actuarial assumptions we used were as follows for the years ended December 31:
		2014		2013		2012
	Projected benefit obligation:
	Discount rate	3.99	%	5.02	%	4.04	%
	Net periodic pension cost:
	Discount rate	5.01	%	4.07	%	5.16	%
	Expected long-term rate of return on plan assets	5.89	%	5.89	%	5.86	%
Fair value of the plan's assets by assets category and level within the faire value hierarchy	The fair values of the Plans’ assets by asset category and level within the fair value hierarchy are as follows at December 31:
	Asset Category	Total			Level 1			Level 2			Level 3
	2014
	Cash	$	14		$	14		$	—		$	—
	Equity securities:
	First Niagara Financial Group, Inc. common stock	1			1			—			—
	Fixed income securities:
	Corporate bonds	3			—			3			—
	Exchange traded funds:
	Large cap growth	23			23			—			—
	Foreign large cap value and blend	4			4			—			—
	High yield bond fund	7			7			—			—
	Inflation protected bond fund	43			43			—			—
	Intermediate term bond fund	91			91			—			—
	Diversified emerging markets	1			1			—			—
	Real estate	5			5			—			—
	Mortgage-backed securities	7			7			—			—
	Small and mid cap blend	5			5			—			—
	World bond	18			18			—			—
	Mutual fund investments:
	Foreign large value and blend	5			5			—			—
	Small and midcap growth, value, and blend	3			3			—			—
	Large cap growth, value, and blend	60			60			—			—
	Real estate	4			4			—			—
	Diversified emerging markets	2			2			—			—
		$	296		$	294		$	3		$	—
	Asset Category	Total			Level 1			Level 2			Level 3
	2013
	Cash	$	43		$	43		$	—		$	—
	Equity securities:
	First Niagara Financial Group, Inc. common stock	1			1			—			—
	U.S. companies	32			32			—			—
	International companies	2			2			—			—
	Fixed income securities:
	Corporate bonds	4			—			4			—
	Exchange traded funds:
	Large cap growth	15			15			—			—
	Large cap value	9			9			—			—
	Foreign large cap blend	3			3			—			—
	Small and mid cap blend	2			2			—			—
	Mutual fund investments:
	Foreign large value and blend	14			14			—			—
	Small and midcap growth and blend	11			11			—			—
	Mortgage-backed securities	7			7			—			—
	Large blend	26			26			—			—
	Total return investment grade securities	41			41			—			—
	Real estate	3			3			—			—
	Diversified emerging markets	5			5			—			—
	High yield bond	9			9			—			—
	World bond	4			4			—			—
	Intermediate term bond	58			58			—			—
		$	290		$	286		$	4		$	—
Estimated benefit payment under pension plan	Estimated benefit payments under our pension plans over the next ten years are as follow at December 31, 2014:
	2015	$	14
	2016	13
	2017	14
	2018	14
	2019	14
	2020-2024	74
Information regarding post-retirement plan	Information regarding these post-retirement plans is as follows at December 31:
		2014			2013
	Change in accumulated post-retirement benefit obligation:
	Accumulated post-retirement benefit obligation at beginning of year	$	10		$	13
	Interest cost	1			1
	Actuarial loss (gain)	4			(3		)
	Benefits paid	(1		)	(1		)
	Accumulated post-retirement benefit obligation at end of year	$	14		$	10
	Unfunded status at year end	$	(14	)	$	(10	)
Components of net periodic post-retirement benefit cost	The components of net periodic post-retirement benefit cost are as follows for the years ended December 31:
		2014			2013			2012
	Interest cost	$	1		$	1		$	1
	Total periodic post-retirement cost	$	1		$	—		$	1
Change in plan benefit obligation recognized in other comprehensive income	Changes in plan benefit obligations recognized in other comprehensive income are as follows for the years ended December 31:
		2014			2013
	Net loss (gain)	$	4		$	(3	)
	Total loss (gain) recognized in other comprehensive income	$	4		$	(3	)
	Total recognized in net periodic post-retirement cost and other comprehensive income	$	5		$	(2	)
Principal actuarial assumptions related to other post retirement benefit	The principal actuarial assumptions used were as follows for the years ended December 31:
		2014		2013		2012
	Accumulated post-retirement benefit obligation:
	Discount rate	3.9	%	4.87	%	3.89	%
	Total periodic cost:
	Discount rate	4.87	%	3.89	%	5.19	%
Estimated benefit payments under the post-retirement plan over the next ten years	Estimated benefit payments under the post-retirement plan over the next ten years are as follows at December 31, 2014:
	2015	$	1
	2016	1
	2017	1
	2018	1
	2019	1
	2020-2024	4
Amount recognized in consolidated statements of condition related to pension and post retirement plans	Amounts recognized in our Consolidated Statements of Condition related to our pension and post-retirement plans are as follows for the years ended December 31:
		2014			2013
	Other assets:
	Fair value of plan assets in excess of projected benefit obligation	$	36		$	76
	Other liabilities:
	Accumulated post-retirement benefit obligation	$	14		$	10
	Accumulated other comprehensive loss (income), net of taxes:
	Pension plans	$	50		$	19
	Post-retirement benefit plan	1			(2		)
		$	51		$	16

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014																	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Fair value option quantitative disclosures
		2014		2013
	Fair value carrying amount	$	35	$	50
	Aggregate unpaid principal balance	34		49
	Fair value carrying amount less aggregate unpaid principal balance	$	1	$	1
Summary of assets and liabilities measured at fair value on a recurring basis	The following tables summarize our assets and liabilities measured at fair value on a recurring basis at December 31:
																			Fair Value Measurements
		Fair Value Measurements																	Total		Level 1		Level 2		Level 3
		Total		Level 1			Level 2			Level 3								2013
	2014																	Assets:
	Assets:																	Investment securities available for sale:
	Investment securities available for sale:																	Debt securities:
	Debt securities:																	States and political subdivisions	$	529	$	—	$	529	$	—
	States and political subdivisions	$	453	$	—		$	453		$	—
																		U.S. Treasury	20		20		—		—
	U.S. Treasury	25		25			—			—
																		U.S. government sponsored enterprises	312		—		312		—
	U.S. government sponsored enterprises	191		—			191			—
																		Corporate	872		—		868		4
	Corporate	823		—			818			4
																		Total debt securities	1,734		20		1,709		4
	Total debt securities	1,492		25			1,463			4
																		Mortgage-backed securities:
	Mortgage-backed securities:																	Residential mortgage-backed securities:
	Residential mortgage-backed securities:																	Government National Mortgage Association	40		—		40		—
	Government National Mortgage Association	34		—			34			—
																		Federal National Mortgage Association	139		—		139		—
	Federal National Mortgage Association	100		—			100			—
																		Federal Home Loan Mortgage Corporation	159		—		159		—
	Federal Home Loan Mortgage Corporation	120		—			120			—
																		Collateralized mortgage obligations:
	Collateralized mortgage obligations:																	Federal National Mortgage Association	761		—		761		—
	Federal National Mortgage Association	682		—			682			—
																		Federal Home Loan Mortgage Corporation	379		—		379		—
	Federal Home Loan Mortgage Corporation	350		—			350			—
																		Non-agency issued	13		—		13		—
	Total collateralized mortgage obligations	1,032		—			1,032			—
																		Total collateralized mortgage obligations	1,152		—		1,152		—
	Total residential mortgage-backed securities	1,286		—			1,286			—
																		Total residential mortgage-backed securities	1,490		—		1,490		—
	Commercial mortgage-backed securities, non-agency issued	1,500		—			1,500			—
																		Commercial mortgage-backed securities, non-agency issued	1,831		—		1,831		—
	Total mortgage-backed securities	2,786		—			2,786			—
																		Total mortgage-backed securities	3,321		—		3,321		—
	Collateralized loan obligations, non-agency issued	1,016		—			1,016			—
																		Collateralized loan obligations, non-agency issued	1,431		—		1,431		—
	Asset-backed securities collateralized by:
	Student loans	235		—			235			—								Asset-backed securities collateralized by:
																		Student loans	312		—		312		—
	Credit cards	42		—			42			—
																		Credit cards	73		—		73		—
	Auto loans	194		—			194			—
																		Auto loans	335		—		335		—
	Other	127		—			127			—
																		Other	186		—		186		—
	Total asset-backed securities	599		—			599			—
																		Total asset-backed securities	905		—		905		—
	Other	22		21			1			—
																		Other	33		22		10		—
	Total securities available for sale	5,915		47			5,865			4
																		Total securities available for sale	7,423		43		7,376		4
	Loans held for sale (1)	35		—			35			—
																		Loans held for sale (1)	50		—		50		—
	Derivatives	93		—			93			—
																		Derivatives	49		—		49		—
	Total assets	$	6,043	$	47		$	5,993		$	4
																		Total assets	$	7,522	$	43	$	7,476	$	4
	Liabilities:
	Derivatives	$	94	$	—		$	94		$	—							Liabilities:
																	Derivatives	$	50	$	—	$	50	$	—
(1)	Represents loans for which we have elected the fair value option.
																	(1)	Represents loans for which we have elected the fair value option.
Summary of assets and liabilities measured at fair value on a nonrecurring basis	he following table summarizes our assets and liabilities measured at fair value on a nonrecurring basis for the years ended December 31:
		Fair Value Measurements												Total gains
		Total		Level 1			Level 2			Level 3				(losses)
	2014
	Collateral dependent impaired loans	$	10	$	—		$	10		$	—			$	—
	2013
	Collateral dependent impaired loans	$	32	$	—		$	20		$	12			$	(2	)
Changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis	The changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis were as follows for the years ended December 31:
		2014			2013
		Trust			Trust			Collateralized			Total
		preferred			preferred			loan obligations
		securities			securities
	Balance at beginning of period	$	4		$	14		$	1,545		$	1,559
	Transfers between level 2 and level 3(1)	—			—			(1,545		)	(1,545		)
	Settlements	—			(10		)	—			(10		)
	Gains included in other comprehensive income	—			1			—			1
	Losses included in earnings	—			(1		)	—			(1		)
	Balance at end of period	$	4		$	4		$	—		$	4
	-1	Our policy is to recognize the transfer at the beginning of the period.
Carrying value and estimated fair value of financial instruments	The carrying value and estimated fair value of our financial instruments, including those that are not measured and reported at fair value on a recurring basis or nonrecurring basis, are as follows at December 31:
		2014								2013
		Carrying value		Estimated fair			Fair value			Carrying value			Estimated fair			Fair value
				value			level						value			level
	Financial assets:
	Cash and cash equivalents	$	420	$	420		1			$	463		$	463		1
	Investment securities available for sale	5,915		5,915			1,2,3		(1)	7,423			7,423			1,2,3	(1)
	Investment securities held to maturity	5,942		5,964			2			4,042			3,988			2
	Federal Home Loan Bank and Federal Reserve Bank common stock	412		412			2			469			469			2
	Loans held for sale	40		40			2			50			50			2
	Loans and leases, net	22,803		23,037			2,3		(2)	21,230			21,774			2,3	(2)
	Derivatives	93		93			2			49			49			2
	Accrued interest receivable	101		101			2			103			103			2
	Financial liabilities:
	Deposits	$	27,781	$	27,793		2			$	26,665		$	26,695		2
	Borrowings	6,206		6,215			2			5,556			5,599			2
	Derivatives	94		94			2			50			50			2
	Accrued interest payable	11		11			2			10			10			2
	(1)	For a detailed breakout of our investment securities available for sale, refer to our table of recurring fair value measurements.
	-2	Loans and leases classified as level 2 are made up of $10 million and $20 million of collateral dependent impaired loans without significant adjustments made to appraised values at December 31, 2014 and 2013, respectively. All other loans and leases are classified as level 3.

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Financial information of business segments	Selected financial information for our segments follows for the years ended December 31:
		Banking			Financial		Consolidated
					services		total
	2014
	Net interest income	$	1,086		$	—	$	1,086
	Provision for credit losses	96			—		96
	Net interest income after provision for credit losses	990			—		990
	Noninterest income	244			66		310
	Amortization of intangibles	24			3		27
	Goodwill impairment	1,100			—		1,100
	Other noninterest expense	940			57		997
	(Loss) income before income taxes	(831		)	7		(824		)
	Income tax (benefit) expense	(112		)	3		(109		)
	Net (loss) income	$	(719	)	$	4	$	(715	)
	2013
	Net interest income	$	1,093		$	—	$	1,093
	Provision for credit losses	105			—		105
	Net interest income after provision for credit losses	988			—		988
	Noninterest income	298			67		366
	Amortization of intangibles	37			3		40
	Other noninterest expense	839			52		891
	Income before income taxes	411			12		423
	Income tax expense	123			5		128
	Net income	$	288		$	7	$	295
	2012
	Net interest income	$	1,023		$	—	$	1,023
	Provision for credit losses	92			—		92
	Net interest income after provision for credit losses	931			—		931
	Noninterest income	291			68		360
	Amortization of intangibles	41			4		45
	Other noninterest expense	955			51		1,006
	Income before income taxes	227			13		239
	Income tax expense	66			5		71
	Net income	$	161		$	8	$	168

Condensed_Parent_Company_Only_1

Condensed Parent Company Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheet
	Condensed Statements of Condition	2014			2013
	Assets:
	Cash and cash equivalents	$	383		$	390
	Investment securities available for sale	—			3
	Loan receivable from ESOP	—			21
	Investment in subsidiary	4,388			5,255
	Deferred taxes	32			34
	Other assets	13			13
	Total assets	$	4,815		$	5,715
	Liabilities and Stockholders’ Equity:
	Accounts payable and other liabilities	$	12		$	13
	Borrowings	710			709
	Stockholders’ equity	4,093			4,993
	Total liabilities and stockholders’ equity	$	4,815		$	5,715
Schedule of Condensed Income Statement
	Condensed Statements of Operations	2014			2013			2012
	Interest income	$	1		$	2		$	7
	Dividends received from subsidiary	80			175			45
	Total interest and dividend income	81			177			52
	Interest expense	48			49			50
	Net interest income	33			128			3
	Noninterest income	3			2			3
	Noninterest expense	27			30			27
	Income before income taxes and undisbursed income of subsidiary	9			100			(21		)
	Income tax benefit	(28		)	(29		)	(24		)
	Income before undisbursed income of subsidiary	36			129			3
	Undisbursed (loss) income of subsidiary	(751		)	167			166
	Net (loss) income	(715		)	295			168
	Preferred stock dividend	30			30			28
	Net (loss) income available to common stockholders	$	(745	)	$	265		$	141
	Net (loss) income	$	(715	)	$	295		$	168
	Other comprehensive (loss) income(1)	(53		)	(95		)	89
	Total comprehensive (loss) income	$	(768	)	$	200		$	258
	(1)	See Consolidated Statements of Comprehensive Income for other comprehensive income detail.
Schedule of Condensed Cash Flow Statement
	Condensed Statements of Cash Flows	2014			2013			2012
	Cash flows from operating activities:
	Net (loss) income	$	(715	)	$	295		$	168
	Adjustments to reconcile net (loss) income to net cash provided by operating activities:
	Undisbursed loss (income) of subsidiaries	751			(167		)	(166		)
	Stock-based compensation expense	11			9			11
	Deferred income tax expense (benefit)	2			(18		)	7
	(Increase) decrease in other assets	(2		)	7			35
	Decrease in other liabilities	(1		)	(9		)	(18		)
	Net cash provided by operating activities	46			118			38
	Cash flows from investing activities:
	Proceeds from maturities of securities available for sale	3			—			—
	Principal payments received on securities available for sale	—			1			2
	Purchases of securities available for sale	—			(2		)	—
	Capital contributed to subsidiary	—			—			(215		)
	Repayments from subsidiary	—			—			215
	Repayment of ESOP loan receivable	15			1			1
	Other, net	1			(1		)	—
	Net cash provided by investing activities	19			—			3
	Cash flows from financing activities:
	Return of capital from subsidiary	85			—			—
	Repurchase of shares upon ESOP termination	(14		)	—			—
	Dividends paid on preferred stock	(30		)	(30		)	(28		)
	Dividends paid on common stock	(113		)	(112		)	(112		)
	Net cash used in financing activities	(72		)	(143		)	(140		)
	Net decrease in cash and cash equivalents	(7		)	(25		)	(99		)
	Cash and cash equivalents at beginning of period	390			415			514
	Cash and cash equivalents at end of period	$	383		$	390		$	415

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	6 Months Ended		12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2014
			payment
			acquisition
Maturity period of cash and cash equivalents			3 months
Number of consecutive payments of principal and interest for repayment of real estate loans			6
Number of days consumer loans secured by real estate are past due when we order broker price opinions and record partial or full charge-offs			90 days
Number of days past due for residential mortgage and home equity loans and home equity lines of credit are charged off			180 days
Number of days past due for other consumer loans are charged off for closed end loans			120 days
Number of days past due for other consumer loans are charged off for open ended loans			180 days
Minimum amount of nonaccrual business and commercial real estate loans evaluated individually for impairment	$1,000,000	$200,000
Amount of allowance for credit losses related to acquired loans		$0
Number of separate acquisitions			4
Loans that reviewed for each acquisition			greater than $1 million
Building [Member] | Minimum [Member]
Useful life			20 years
Building [Member] | Maximum [Member]
Useful life			39 years
Furniture and equipment | Minimum [Member]
Useful life			3 years
Furniture and equipment | Maximum [Member]
Useful life			10 years
Loans receivable [Member]
Minimum number of days past due for estimate future cash flows on acquired loans expect to fully collect			90 days
Credit card receivable [Member]
Minimum number of days past due for estimate future cash flows on acquired loans expect to fully collect			180 days
Originated loans [Member] | Loans receivable [Member]
Minimum Number of Days Originated Loans are Past Due Prior to Deterioration in Credit Quality			90 days

Investment_Securities_Availabl

Investment Securities - Available for Sale and Held to Maturity Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	$5,830	$7,319
Securities available for sale, unrealized gains	121	178
Securities available for sale, unrealized losses	-35	-74
Securities available for sale, fair value	5,915	7,423
Securities held to maturity, amortized cost	5,942	4,042
Securities held to maturity, unrealized gains	64	40
Securities held to maturity, unrealized losses	-42	-94
Investment securities held to maturity	5,964	3,988
Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	5,882	4,037
Securities held to maturity, unrealized gains	64	40
Securities held to maturity, unrealized losses	-42	-94
Investment securities held to maturity	5,904	3,983
Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	5,687	3,793
Securities held to maturity, unrealized gains	63	39
Securities held to maturity, unrealized losses	-41	-90
Investment securities held to maturity	5,709	3,742
Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	12	17
Securities held to maturity, unrealized gains	0	0
Securities held to maturity, unrealized losses	0	0
Investment securities held to maturity	12	17
Government National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	1,755	1,713
Securities held to maturity, unrealized gains	27	26
Securities held to maturity, unrealized losses	-3	-12
Investment securities held to maturity	1,779	1,727
Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	118	146
Securities held to maturity, unrealized gains	1	0
Securities held to maturity, unrealized losses	-1	-3
Investment securities held to maturity	118	143
Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	1,965	1,074
Securities held to maturity, unrealized gains	11	0
Securities held to maturity, unrealized losses	-22	-47
Investment securities held to maturity	1,954	1,027
Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	65	81
Securities held to maturity, unrealized gains	1	0
Securities held to maturity, unrealized losses	0	-1
Investment securities held to maturity	65	81
Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	1,967	1,007
Securities held to maturity, unrealized gains	25	12
Securities held to maturity, unrealized losses	-17	-30
Investment securities held to maturity	1,976	989
U.S. government agencies debt securities [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Securities held to maturity, amortized cost	60	5
Securities held to maturity, unrealized gains	0	0
Securities held to maturity, unrealized losses	0	0
Investment securities held to maturity	60	5
Debt securities [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	1,476	1,705
Securities available for sale, unrealized gains	29	40
Securities available for sale, unrealized losses	-12	-12
Securities available for sale, fair value	1,492	1,734
Debt securities [Member] | States and political subdivisions [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	444	516
Securities available for sale, unrealized gains	10	14
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	453	529
Debt securities [Member] | U.S. Treasury [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	25	20
Securities available for sale, unrealized gains	0	0
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	25	20
Debt securities [Member] | U.S. government sponsored enterprises [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	187	306
Securities available for sale, unrealized gains	5	7
Securities available for sale, unrealized losses	0	-1
Securities available for sale, fair value	191	312
Debt securities [Member] | Corporate [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	820	863
Securities available for sale, unrealized gains	15	19
Securities available for sale, unrealized losses	-12	-11
Securities available for sale, fair value	823	872
Mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	2,741	3,294
Securities available for sale, unrealized gains	64	85
Securities available for sale, unrealized losses	-19	-58
Securities available for sale, fair value	2,786	3,321
Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	1,291	1,534
Securities available for sale, unrealized gains	13	12
Securities available for sale, unrealized losses	-19	-56
Securities available for sale, fair value	1,286	1,490
Residential mortgage-backed securities [Member] | Government National Mortgage Association [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	34	41
Securities available for sale, unrealized gains	1	1
Securities available for sale, unrealized losses	-1	-2
Securities available for sale, fair value	34	40
Residential mortgage-backed securities [Member] | Federal National Mortgage Association [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	96	134
Securities available for sale, unrealized gains	5	5
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	100	139
Residential mortgage-backed securities [Member] | Federal Home Loan Mortgage Corporation [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	115	154
Securities available for sale, unrealized gains	5	5
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	120	159
Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	1,047	1,205
Securities available for sale, unrealized gains	3	1
Securities available for sale, unrealized losses	-18	-54
Securities available for sale, fair value	1,032	1,152
Collateralized mortgage obligations [Member] | Federal National Mortgage Association [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	694	797
Securities available for sale, unrealized gains	2	0
Securities available for sale, unrealized losses	-13	-36
Securities available for sale, fair value	682	761
Collateralized mortgage obligations [Member] | Federal Home Loan Mortgage Corporation [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	353	396
Securities available for sale, unrealized gains	1	0
Securities available for sale, unrealized losses	-4	-17
Securities available for sale, fair value	350	379
Collateralized mortgage obligations [Member] | Non-agency issued [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale		12
Securities available for sale, unrealized gains		1
Securities available for sale, unrealized losses		0
Securities available for sale, fair value		13
Commercial mortgage-backed securities, non-agency issued [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	1,450	1,759
Securities available for sale, unrealized gains	51	74
Securities available for sale, unrealized losses	0	-2
Securities available for sale, fair value	1,500	1,831
Collateralized loan obligations, non-agency issued [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	1,001	1,392
Securities available for sale, unrealized gains	18	40
Securities available for sale, unrealized losses	-3	-2
Securities available for sale, fair value	1,016	1,431
Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	591	896
Securities available for sale, unrealized gains	9	11
Securities available for sale, unrealized losses	-1	-2
Securities available for sale, fair value	599	905
Asset-backed securities [Member] | Student loans [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	228	306
Securities available for sale, unrealized gains	7	6
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	235	312
Asset-backed securities [Member] | Credit cards [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	42	73
Securities available for sale, unrealized gains	0	0
Securities available for sale, unrealized losses	0	-1
Securities available for sale, fair value	42	73
Asset-backed securities [Member] | Auto loans [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	193	331
Securities available for sale, unrealized gains	1	4
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	194	335
Asset-backed securities [Member] | Other [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	127	186
Securities available for sale, unrealized gains	1	1
Securities available for sale, unrealized losses	-1	-1
Securities available for sale, fair value	127	186
Other securities [Member]
Schedule of available for sale securities [Line Items]
Amortized cost for securities available for sale	22	33
Securities available for sale, unrealized gains	0	1
Securities available for sale, unrealized losses	0	0
Securities available for sale, fair value	$22	$33

Investment_Securities_Availabl1

Investment Securities - Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Security	Security
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	$614	$2,054
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-10	-69
Available-for-sale securities in unrealized loss position less than 12 months, count	206	341
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	1,130	122
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-26	-5
Available-for-sale securities in unrealized loss position 12 months or longer, count	145	47
Total fair value available-for-sale securities	1,744	2,176
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-35	-74
Available for sale securities in unrealized loss position, count	351	388
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	1,097	2,353
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-8	-94
Held-to-maturity securities in unrealized loss position less than 12 months, count	108	202
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	1,219	22
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-35	-1
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	92	1
Total fair value of held-to-maturity securities	2,316	2,376
Total unrealized losses of held to maturity securities	-42	-94
Held-to-maturity securities in unrealized loss position, count	200	203
Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	1,059	2,348
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-8	-94
Held-to-maturity securities in unrealized loss position less than 12 months, count	103	201
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	1,219	22
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-35	-1
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	92	1
Total fair value of held-to-maturity securities	2,278	2,371
Total unrealized losses of held to maturity securities	-42	-94
Held-to-maturity securities in unrealized loss position, count	195	202
Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	1,022	2,160
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-8	-89
Held-to-maturity securities in unrealized loss position less than 12 months, count	93	152
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	1,157	22
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-34	-1
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	76	1
Total fair value of held-to-maturity securities	2,179	2,182
Total unrealized losses of held to maturity securities	-41	-90
Held-to-maturity securities in unrealized loss position, count	169	153
Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	0	11
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	0	0
Held-to-maturity securities in unrealized loss position less than 12 months, count	0	4
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	2	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	0	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	2	0
Total fair value of held-to-maturity securities	2	11
Total unrealized losses of held to maturity securities	0	0
Held-to-maturity securities in unrealized loss position, count	2	4
Government National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	360	520
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-2	-12
Held-to-maturity securities in unrealized loss position less than 12 months, count	48	58
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	46	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-1	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	12	0
Total fair value of held-to-maturity securities	407	520
Total unrealized losses of held to maturity securities	-3	-12
Held-to-maturity securities in unrealized loss position, count	60	58
Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	4	119
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	0	-3
Held-to-maturity securities in unrealized loss position less than 12 months, count	1	30
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	51	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-1	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	12	0
Total fair value of held-to-maturity securities	55	119
Total unrealized losses of held to maturity securities	-1	-3
Held-to-maturity securities in unrealized loss position, count	13	30
Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	240	1,011
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-1	-47
Held-to-maturity securities in unrealized loss position less than 12 months, count	18	59
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	648	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-21	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	36	0
Total fair value of held-to-maturity securities	888	1,011
Total unrealized losses of held to maturity securities	-22	-47
Held-to-maturity securities in unrealized loss position, count	54	59
Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	33	59
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	0	-1
Held-to-maturity securities in unrealized loss position less than 12 months, count	9	15
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	9	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	0	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	2	0
Total fair value of held-to-maturity securities	42	59
Total unrealized losses of held to maturity securities	0	-1
Held-to-maturity securities in unrealized loss position, count	11	15
Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	422	629
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	-5	-30
Held-to-maturity securities in unrealized loss position less than 12 months, count	27	35
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	463	22
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	-12	-1
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	28	1
Total fair value of held-to-maturity securities	885	652
Total unrealized losses of held to maturity securities	-17	-30
Held-to-maturity securities in unrealized loss position, count	55	36
Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	215	315
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-7	-9
Available-for-sale securities in unrealized loss position less than 12 months, count	157	201
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	145	79
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-5	-2
Available-for-sale securities in unrealized loss position 12 months or longer, count	70	32
Total fair value available-for-sale securities	360	394
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-12	-12
Available for sale securities in unrealized loss position, count	227	233
Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	73	1,106
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-54
Available-for-sale securities in unrealized loss position less than 12 months, count	6	63
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	733	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-18	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	42	0
Total fair value available-for-sale securities	806	1,106
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-18	-54
Available for sale securities in unrealized loss position, count	48	63
Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	73	1,106
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-54
Available-for-sale securities in unrealized loss position less than 12 months, count	6	66
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	752	19
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-19	-2
Available-for-sale securities in unrealized loss position 12 months or longer, count	47	9
Total fair value available-for-sale securities	825	1,125
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-19	-56
Available for sale securities in unrealized loss position, count	53	75
Commercial mortgage-backed securities, non-agency issued [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	13	158
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-2
Available-for-sale securities in unrealized loss position less than 12 months, count	3	15
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	24	12
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	3	3
Total fair value available-for-sale securities	36	170
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-2
Available for sale securities in unrealized loss position, count	6	18
Mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	85	1,264
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-56
Available-for-sale securities in unrealized loss position less than 12 months, count	9	81
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	776	32
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-19	-2
Available-for-sale securities in unrealized loss position 12 months or longer, count	50	12
Total fair value available-for-sale securities	861	1,296
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-19	-58
Available for sale securities in unrealized loss position, count	59	93
Collateralized loan obligations, non-agency issued [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	276	261
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-2	-2
Available-for-sale securities in unrealized loss position less than 12 months, count	32	28
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	146	3
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-1	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	15	1
Total fair value available-for-sale securities	422	264
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-3	-2
Available for sale securities in unrealized loss position, count	47	29
Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	37	200
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-2
Available-for-sale securities in unrealized loss position less than 12 months, count	8	28
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	55	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-1	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	7	0
Total fair value available-for-sale securities	92	200
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-1	-2
Available for sale securities in unrealized loss position, count	15	28
Other securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	0	14
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available-for-sale securities in unrealized loss position less than 12 months, count	0	3
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	9	8
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	3	2
Total fair value available-for-sale securities	9	22
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available for sale securities in unrealized loss position, count	3	5
Student loans [Member] | Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	26	67
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available-for-sale securities in unrealized loss position less than 12 months, count	4	8
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	2	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	2	0
Total fair value available-for-sale securities	28	67
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available for sale securities in unrealized loss position, count	6	8
Credit cards [Member] | Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	8	36
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-1
Available-for-sale securities in unrealized loss position less than 12 months, count	1	4
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	0	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	0	0
Total fair value available-for-sale securities	8	36
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-1
Available for sale securities in unrealized loss position, count	1	4
Auto loans [Member] | Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	3	25
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available-for-sale securities in unrealized loss position less than 12 months, count	2	5
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	0	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	0	0
Total fair value available-for-sale securities	3	25
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available for sale securities in unrealized loss position, count	2	5
Other [Member] | Asset-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	0	72
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-1
Available-for-sale securities in unrealized loss position less than 12 months, count	1	11
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	52	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-1	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	5	0
Total fair value available-for-sale securities	52	72
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-1	-1
Available for sale securities in unrealized loss position, count	6	11
States and political subdivisions [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	16	13
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available-for-sale securities in unrealized loss position less than 12 months, count	22	25
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	1	3
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	5	7
Total fair value available-for-sale securities	17	16
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available for sale securities in unrealized loss position, count	27	32
U.S. Treasury [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	5
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0
Available-for-sale securities in unrealized loss position less than 12 months, count	1
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	0
Total fair value available-for-sale securities	5
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0
Available for sale securities in unrealized loss position, count	1
U.S. government agencies debt securities [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of held-to-maturity securities in unrealized loss position less than 12 months	38	5
Unrealized losses of held to maturity securities in unrealized loss position less than 12 months	0	0
Held-to-maturity securities in unrealized loss position less than 12 months, count	5	1
Fair value held-to-maturity securities in unrealized loss position 12 months or longer	0	0
Unrealized losses of held to maturity securities in unrealized loss position 12 months or longer	0	0
Held-to-maturiy securities in unrealized loss position longer than 12 months, count	0	0
Total fair value of held-to-maturity securities	38	5
Total unrealized losses of held to maturity securities	0	0
Held-to-maturity securities in unrealized loss position, count	5	1
U.S. government sponsored enterprises [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	18	71
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-1
Available-for-sale securities in unrealized loss position less than 12 months, count	7	11
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	42	2
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	0	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	4	2
Total fair value available-for-sale securities	60	73
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-1
Available for sale securities in unrealized loss position, count	11	13
Corporate [Member] | Debt securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	176	232
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-7	-8
Available-for-sale securities in unrealized loss position less than 12 months, count	127	165
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	102	74
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-5	-2
Available-for-sale securities in unrealized loss position 12 months or longer, count	61	23
Total fair value available-for-sale securities	278	306
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-12	-11
Available for sale securities in unrealized loss position, count	188	188
Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	0	0
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	0
Available-for-sale securities in unrealized loss position less than 12 months, count	0	0
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	19	19
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-1	-2
Available-for-sale securities in unrealized loss position 12 months or longer, count	5	6
Total fair value available-for-sale securities	19	19
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-1	-2
Available for sale securities in unrealized loss position, count	5	6
Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	26	744
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-36
Available-for-sale securities in unrealized loss position less than 12 months, count	3	41
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	517	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-13	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	30	0
Total fair value available-for-sale securities	542	744
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-13	-36
Available for sale securities in unrealized loss position, count	33	41
Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months		0
Available for sale securities in unrealized loss position less than 12 months, unrealized losses		0
Available-for-sale securities in unrealized loss position less than 12 months, count		3
Fair value of available-for-sale securities in unrealized loss position 12 months or longer		0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses		0
Available-for-sale securities in unrealized loss position 12 months or longer, count		3
Total fair value available-for-sale securities		1
Available for sale securities in unrealized loss position less than 12 months, unrealized losses		0
Available for sale securities in unrealized loss position, count		6
Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months	47	361
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	0	-17
Available-for-sale securities in unrealized loss position less than 12 months, count	3	19
Fair value of available-for-sale securities in unrealized loss position 12 months or longer	216	0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses	-4	0
Available-for-sale securities in unrealized loss position 12 months or longer, count	12	0
Total fair value available-for-sale securities	263	361
Available for sale securities in unrealized loss position less than 12 months, unrealized losses	-4	-17
Available for sale securities in unrealized loss position, count	15	19
Non-agency issued [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Fair value of available-for-sale securities in unrealized loss position less than 12 months		1
Available for sale securities in unrealized loss position less than 12 months, unrealized losses		0
Available-for-sale securities in unrealized loss position less than 12 months, count		3
Fair value of available-for-sale securities in unrealized loss position 12 months or longer		0
Available for sale securities in unrealized loss position 12 months or longer, unrealized losses		0
Available-for-sale securities in unrealized loss position 12 months or longer, count		0
Total fair value available-for-sale securities		1
Available for sale securities in unrealized loss position less than 12 months, unrealized losses		$0
Available for sale securities in unrealized loss position, count		3

Investment_Securities_Maturiti

Investment Securities - Maturities of Available for Sale and Held to Maturity Debt Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Scheduled contractual maturities of investment securities [Line Items]
Debt securities, amortized cost within one year	$106
Debt securities, fair value within one year	107
Debt securities, amortized cost after one year through five years	795
Debt securities, fair value after one year through five years	814
Debt securities, amortized cost after five years through ten years	619
Debt securities, fair value after five years through ten years	616
Debt securities, amortized cost after ten years	15
Debt securities, fair value after ten years	15
Debt securities, amortized cost	1,536
Debt securities, fair value	1,552
Mortgage-backed securities, amortized cost	8,623
Mortgage-backed securities, fair value	8,690
Amortized cost for securities available for sale	5,830	7,319
Securities available for sale, fair value	5,915	7,423
Total available for sale and held to maturity securities, amortized cost	11,772
Total available for sale and held to maturity, fair value	11,879
Collateralized loan obligations, non-agency issued [Member]
Scheduled contractual maturities of investment securities [Line Items]
Amortized cost for securities available for sale	1,001	1,392
Securities available for sale, fair value	1,016	1,431
Asset-backed securities [Member]
Scheduled contractual maturities of investment securities [Line Items]
Amortized cost for securities available for sale	591	896
Securities available for sale, fair value	599	905
Other securities [Member]
Scheduled contractual maturities of investment securities [Line Items]
Amortized cost for securities available for sale	22	33
Securities available for sale, fair value	$22	$33

Investment_Securities_Investme

Investment Securities Investment Securities - Schedule of Available for Sale Securities Transferred to Held to Maturity Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			$2,946
Available for sale securities, transferred to held to maturity, unrealized gains			59
Available for sale securities transferred to held to maturity, unrealized losses			-4
Securities transferred from available for sale to held to maturity, fair value	0	3,001	3,001	0
Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			2,662
Available for sale securities, transferred to held to maturity, unrealized gains			42
Available for sale securities transferred to held to maturity, unrealized losses			-4
Securities transferred from available for sale to held to maturity, fair value			2,699
Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			15
Available for sale securities, transferred to held to maturity, unrealized gains			1
Available for sale securities transferred to held to maturity, unrealized losses			0
Securities transferred from available for sale to held to maturity, fair value			15
Government National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			885
Available for sale securities, transferred to held to maturity, unrealized gains			26
Available for sale securities transferred to held to maturity, unrealized losses			0
Securities transferred from available for sale to held to maturity, fair value			910
Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			173
Available for sale securities, transferred to held to maturity, unrealized gains			12
Available for sale securities transferred to held to maturity, unrealized losses			0
Securities transferred from available for sale to held to maturity, fair value			185
Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			1,019
Available for sale securities, transferred to held to maturity, unrealized gains			9
Available for sale securities transferred to held to maturity, unrealized losses			-3
Securities transferred from available for sale to held to maturity, fair value			1,026
Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			96
Available for sale securities, transferred to held to maturity, unrealized gains			5
Available for sale securities transferred to held to maturity, unrealized losses			0
Securities transferred from available for sale to held to maturity, fair value			102
Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Schedule of available for sale securities [Line Items]
Available for sale securities transferred to Hhld to maturity, amortized cost			758
Available for sale securities, transferred to held to maturity, unrealized gains			7
Available for sale securities transferred to held to maturity, unrealized losses			-2
Securities transferred from available for sale to held to maturity, fair value			$763

Investment_Securities_Details_

Investment Securities (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Investment Securities (Textual) [Abstract]
Contractual maturity period of securities (in years)	10 years
Weighted average duration investment securities portfolio (in years)	3 years 8 months	3 years 6 months
Securities transferred from available for sale to held to maturity (at fair value)	$0	$3,001,000,000	$3,001,000,000	$0
Investment securities pledged as collateral	6,100,000,000	5,600,000,000
Fair value of securities issued, FHLMC	2,500,000,000
Fair value of securities issued, FNMA	2,900,000,000
Fair value of securities issued, GNMA	1,800,000,000
Maximum percentage of our stockholders equity invested in securities of single issuer	10.00%
Federal Reserve Bank Stock	131,000,000	136,000,000
New York common stock [Member]
Investment Securities (Textual) [Abstract]
Investment related to FHLB stock	256,000,000	231,000,000
Boston common stock [Member]
Investment Securities (Textual) [Abstract]
Investment related to FHLB stock	$25,000,000	$102,000,000

Loans_and_Leases_Composition_D

Loans and Leases - Composition (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Summary of loans and leases
Loans receivable	$23,037	$21,440
Allowance for loan losses	-234	-209
Total loans and leases, net	22,803	21,230
Total commercial [Member]
Summary of loans and leases
Loans receivable	13,979	13,068
Total commercial [Member] | Commercial real estate [Member]
Summary of loans and leases
Loans receivable	7,231	6,914
Total commercial [Member] | Construction [Member]
Summary of loans and leases
Loans receivable	973	864
Total commercial [Member] | Business [Member]
Summary of loans and leases
Loans receivable	5,775	5,290
Total consumer [Member]
Summary of loans and leases
Loans receivable	9,058	8,371
Total consumer [Member] | Residential real estate [Member]
Summary of loans and leases
Loans receivable	3,353	3,448
Total consumer [Member] | Home equity [Member]
Summary of loans and leases
Loans receivable	2,936	2,752
Total consumer [Member] | Indirect auto [Member]
Summary of loans and leases
Loans receivable	2,166	1,544
Total consumer [Member] | Credit cards [Member]
Summary of loans and leases
Loans receivable	324	325
Total consumer [Member] | Other consumer [Member]
Summary of loans and leases
Loans receivable	278	302
Originated loans [Member]
Summary of loans and leases
Loans receivable	19,296	16,922	13,372
Allowance for loan losses	-228	-205
Total loans and leases, net	19,067	16,717
Originated loans [Member] | Total commercial [Member]
Summary of loans and leases
Loans receivable	12,584	11,231
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of loans and leases
Loans receivable	6,181	5,527
Originated loans [Member] | Total commercial [Member] | Construction [Member]
Summary of loans and leases
Loans receivable	973	828
Originated loans [Member] | Total commercial [Member] | Business [Member]
Summary of loans and leases
Loans receivable	5,430	4,876	4,286
Originated loans [Member] | Total consumer [Member]
Summary of loans and leases
Loans receivable	6,711	5,691
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of loans and leases
Loans receivable	2,096	1,902	1,724
Originated loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of loans and leases
Loans receivable	1,847	1,618	1,286
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member]
Summary of loans and leases
Loans receivable	2,166	1,544	601
Originated loans [Member] | Total consumer [Member] | Credit cards [Member]
Summary of loans and leases
Loans receivable	324	325
Originated loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of loans and leases
Loans receivable	278	302
Acquired loans [Member]
Summary of loans and leases
Loans receivable	3,742	4,517	6,338
Allowance for loan losses	-6	-4
Total loans and leases, net	3,736	4,514
Acquired loans [Member] | Total commercial [Member]
Summary of loans and leases
Loans receivable	1,395	1,838
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of loans and leases
Loans receivable	1,050	1,387
Acquired loans [Member] | Total commercial [Member] | Construction [Member]
Summary of loans and leases
Loans receivable	1	36
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Summary of loans and leases
Loans receivable	345	414	667
Acquired loans [Member] | Total consumer [Member]
Summary of loans and leases
Loans receivable	2,347	2,680
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of loans and leases
Loans receivable	1,257	1,546	2,037
Acquired loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of loans and leases
Loans receivable	1,089	1,134	1,366
Acquired loans [Member] | Total consumer [Member] | Indirect auto [Member]
Summary of loans and leases
Loans receivable	0	0
Acquired loans [Member] | Total consumer [Member] | Credit cards [Member]
Summary of loans and leases
Loans receivable	0	0
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of loans and leases
Loans receivable	$0	$0

Loans_and_Leases_Acquired_Loan

Loans and Leases - Acquired Loans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
The outstanding principal balance and the related carrying amount of the acquired loans
Outstanding principal balance	$3,832	$4,640
Carrying amount	3,742	4,517
Credit impaired acquired loans evaluated individually for future credit losses [Member]
The outstanding principal balance and the related carrying amount of the acquired loans
Outstanding principal balance	10	18
Carrying amount	6	12
Credit impaired acquired loans evaluated collectively for future credit losses [Member]
The outstanding principal balance and the related carrying amount of the acquired loans
Outstanding principal balance	2,549	3,301
Carrying amount	2,496	3,233
Other acquired loans [Member]
The outstanding principal balance and the related carrying amount of the acquired loans
Outstanding principal balance	1,274	1,321
Carrying amount	$1,240	$1,273

Loans_and_Leases_Accretable_Yi

Loans and Leases - Accretable Yield Rollforward (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Changes in the accretable discount on loans acquired
Beginning Balance	($851)		($1,057)
Net reclassifications from nonaccretable yield	-5		-15
Accretion	138		199
Other changes in accretable yield	55	[1]	22	[1]
Ending Balance	($663)		($851)
[1]	Includes changes in expected cash flows from changes in interest rate and prepayment assumptions.

Loans_and_Leases_Allowance_for

Loans and Leases - Allowance for Loan Loss Rollforward (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Activity in the allowance for credit losses for the years ended
Total	$23,037	$21,440
Total commercial [Member]
Activity in the allowance for credit losses for the years ended
Total	13,979	13,068
Total commercial [Member] | Business [Member]
Activity in the allowance for credit losses for the years ended
Total	5,775	5,290
Total consumer [Member]
Activity in the allowance for credit losses for the years ended
Total	9,058	8,371
Total consumer [Member] | Residential real estate [Member]
Activity in the allowance for credit losses for the years ended
Total	3,353	3,448
Total consumer [Member] | Home equity [Member]
Activity in the allowance for credit losses for the years ended
Total	2,936	2,752
Total consumer [Member] | Indirect auto [Member]
Activity in the allowance for credit losses for the years ended
Total	2,166	1,544
Originated loans [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	205	161	118
Provision for loan losses	85	96	84
Charge-offs	-75	-63	-46
Recoveries	13	11	6
Allowance related to loans sold			-1
Balance at end of year	228	205	161
Allowance for loan losses, individually evaluated for impairment	6	9	11
Allowance for loan losses, collectively evaluated for impairment	222	196	150
Total	228	205	161
Loans receivables, individually evaluated for impairment	156	163	152
Loans receivables, collectively evaluated for impairment	19,139	16,759	13,221
Total	19,296	16,922	13,372
Originated loans [Member] | Total commercial [Member]
Activity in the allowance for credit losses for the years ended
Total	12,584	11,231
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	48	38	50
Provision for loan losses	23	17	-7
Charge-offs	-10	-10	-7
Recoveries	4	4	1
Allowance related to loans sold			0
Balance at end of year	65	48	38
Allowance for loan losses, individually evaluated for impairment	2	4	3
Allowance for loan losses, collectively evaluated for impairment	63	44	35
Total	65	48	38
Loans receivables, individually evaluated for impairment	64	72	67
Loans receivables, collectively evaluated for impairment	7,089	6,282	4,977
Total	7,154	6,354	5,044
Originated loans [Member] | Total commercial [Member] | Business [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	119	99	57
Provision for loan losses	30	48	67
Charge-offs	-30	-31	-27
Recoveries	3	3	2
Allowance related to loans sold			0
Balance at end of year	122	119	99
Allowance for loan losses, individually evaluated for impairment	2	2	5
Allowance for loan losses, collectively evaluated for impairment	120	117	94
Total	122	119	99
Loans receivables, individually evaluated for impairment	61	59	58
Loans receivables, collectively evaluated for impairment	5,370	4,818	4,228
Total	5,430	4,876	4,286
Originated loans [Member] | Total consumer [Member]
Activity in the allowance for credit losses for the years ended
Total	6,711	5,691
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	2	5	4
Provision for loan losses	1	-1	3
Charge-offs	-1	-2	-3
Recoveries	0	1	0
Allowance related to loans sold			0
Balance at end of year	2	2	5
Allowance for loan losses, individually evaluated for impairment	1	1	3
Allowance for loan losses, collectively evaluated for impairment	1	1	1
Total	2	2	5
Loans receivables, individually evaluated for impairment	20	20	20
Loans receivables, collectively evaluated for impairment	2,076	1,882	1,705
Total	2,096	1,902	1,724
Originated loans [Member] | Total consumer [Member] | Home equity [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	7	5	4
Provision for loan losses	4	6	4
Charge-offs	-4	-3	-4
Recoveries	1	0	0
Allowance related to loans sold			0
Balance at end of year	8	7	5
Allowance for loan losses, individually evaluated for impairment	1	3	1
Allowance for loan losses, collectively evaluated for impairment	7	4	4
Total	8	7	5
Loans receivables, individually evaluated for impairment	7	8	5
Loans receivables, collectively evaluated for impairment	1,840	1,610	1,281
Total	1,847	1,618	1,286
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	10	3	0
Provision for loan losses	11	9	4
Charge-offs	-9	-3	-1
Recoveries	1	1	0
Allowance related to loans sold			0
Balance at end of year	14	10	3
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	14	10	3
Total	14	10	3
Loans receivables, individually evaluated for impairment	2	1	0
Loans receivables, collectively evaluated for impairment	2,164	1,543	601
Total	2,166	1,544	601
Originated loans [Member] | Total consumer [Member] | Credit Cards [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	13	7	0
Provision for loan losses	10	11	8
Charge-offs	-13	-6	-1
Recoveries	2	1	0
Allowance related to loans sold			0
Balance at end of year	12	13	7
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	12	13	7
Total	12	13	7
Loans receivables, individually evaluated for impairment	0	0	0
Loans receivables, collectively evaluated for impairment	324	325	215
Total	324	325	215
Originated loans [Member] | Total consumer [Member] | Other consumer [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	6	5	2
Provision for loan losses	6	8	5
Charge-offs	-8	-8	-4
Recoveries	1	2	1
Allowance related to loans sold			0
Balance at end of year	5	6	5
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	5	6	5
Total	5	6	5
Loans receivables, individually evaluated for impairment	2	3	2
Loans receivables, collectively evaluated for impairment	276	299	214
Total	278	302	215
Acquired loans [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	4	2	2
Provision for loan losses	8	7	7
Charge-offs	-6	-5	-9
Recoveries	0	0	1
Balance at end of year	6	4	2
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	6	4	2
Total	6	4	2
Loans receivables, individually evaluated for impairment	7	10	10
Loans receivables, collectively evaluated for impairment	1,233	1,264	1,614
Loans acquired with deteriorated credit quality	2,502	3,244	4,713
Total	3,742	4,517	6,338
Acquired loans [Member] | Total commercial [Member]
Activity in the allowance for credit losses for the years ended
Total	1,395	1,838
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	0	0	0
Provision for loan losses	3	4	6
Charge-offs	-2	-4	-7
Recoveries	0	0	1
Balance at end of year	1	0	0
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	1	0	0
Total	1	0	0
Loans receivables, individually evaluated for impairment	0	1	1
Loans receivables, collectively evaluated for impairment	0	0	0
Loans acquired with deteriorated credit quality	1,050	1,423	2,048
Total	1,050	1,423	2,049
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	0	0	0
Provision for loan losses	1	0	0
Charge-offs	0	0	0
Recoveries	0	0	0
Balance at end of year	1	0	0
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	1	0	0
Total	1	0	0
Loans receivables, individually evaluated for impairment	3	7	7
Loans receivables, collectively evaluated for impairment	269	305	427
Loans acquired with deteriorated credit quality	73	102	233
Total	345	414	667
Acquired loans [Member] | Total consumer [Member]
Activity in the allowance for credit losses for the years ended
Total	2,347	2,680
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	1	0	0
Provision for loan losses	1	1	0
Charge-offs	0	0	0
Recoveries	0	0	0
Balance at end of year	2	1	0
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	2	1	0
Total	2	1	0
Loans receivables, individually evaluated for impairment	0	0	0
Loans receivables, collectively evaluated for impairment	0	0	0
Loans acquired with deteriorated credit quality	1,257	1,546	2,037
Total	1,257	1,546	2,037
Acquired loans [Member] | Total consumer [Member] | Home equity [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	3	0	0
Provision for loan losses	3	3	0
Charge-offs	-4	0	0
Recoveries	0	0	0
Balance at end of year	2	3	0
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	2	3	0
Total	2	3	0
Loans receivables, individually evaluated for impairment	4	1	2
Loans receivables, collectively evaluated for impairment	964	960	1,045
Loans acquired with deteriorated credit quality	122	173	319
Total	1,089	1,134	1,366
Acquired loans [Member] | Total consumer [Member] | Indirect auto [Member]
Activity in the allowance for credit losses for the years ended
Total	0	0
Acquired loans [Member] | Total consumer [Member] | Credit Cards [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	0	0	0
Provision for loan losses	0	0	0
Charge-offs	0	0	0
Recoveries	0	0	0
Balance at end of year	0	0	0
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	0	0	0
Total	0	0	0
Loans receivables, individually evaluated for impairment	0	0	0
Loans receivables, collectively evaluated for impairment	0	0	100
Loans acquired with deteriorated credit quality	0	0	0
Total	0	0	100
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member]
Activity in the allowance for credit losses for the years ended
Balance at beginning of year	0	1	2
Provision for loan losses	0	-1	1
Charge-offs	0	-1	-2
Recoveries	0	0	0
Balance at end of year	0	0	1
Allowance for loan losses, individually evaluated for impairment	0	0	0
Allowance for loan losses, collectively evaluated for impairment	0	0	1
Total	0	0	1
Loans receivables, individually evaluated for impairment	0	0	0
Loans receivables, collectively evaluated for impairment	0	0	42
Loans acquired with deteriorated credit quality	0	0	76
Total	$0	$0	$118

Loans_and_Leases_Nonperforming

Loans and Leases - Nonperforming Loans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Summary of nonaccruing loans
Nonaccruing loans	$204	$188
Total commercial [Member]
Summary of nonaccruing loans
Nonaccruing loans	106	105
Total commercial [Member] | Commercial real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	53	54
Total commercial [Member] | Business [Member]
Summary of nonaccruing loans
Nonaccruing loans	53	51
Total consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	98	82
Total consumer [Member] | Residential real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	34	31
Total consumer [Member] | Home equity [Member]
Summary of nonaccruing loans
Nonaccruing loans	47	39
Total consumer [Member] | Indirect auto [Member]
Summary of nonaccruing loans
Nonaccruing loans	13	6
Total consumer [Member] | Other consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	5	6
Originated loans [Member]
Summary of nonaccruing loans
Nonaccruing loans	174	157
Originated loans [Member] | Total commercial [Member]
Summary of nonaccruing loans
Nonaccruing loans	98	95
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	53	53
Originated loans [Member] | Total commercial [Member] | Business [Member]
Summary of nonaccruing loans
Nonaccruing loans	45	42
Originated loans [Member] | Total consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	75	62
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	34	31
Originated loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of nonaccruing loans
Nonaccruing loans	24	18
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member]
Summary of nonaccruing loans
Nonaccruing loans	13	6
Originated loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	5	6
Acquired loans [Member]
Summary of nonaccruing loans
Nonaccruing loans	30	30
Acquired loans [Member] | Total commercial [Member]
Summary of nonaccruing loans
Nonaccruing loans	7	10
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	0	1
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Summary of nonaccruing loans
Nonaccruing loans	7	9
Acquired loans [Member] | Total consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	23	20
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of nonaccruing loans
Nonaccruing loans	0	0
Acquired loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of nonaccruing loans
Nonaccruing loans	23	20
Acquired loans [Member] | Total consumer [Member] | Indirect auto [Member]
Summary of nonaccruing loans
Nonaccruing loans	0	0
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of nonaccruing loans
Nonaccruing loans	$0	$0

Loans_and_Leases_Interest_Inco

Loans and Leases - Interest Income Foregone (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Details of additional information on loans
Additional interest income that would have been recorded if nonperforming loans had performed in accordance with original terms	$8	$7	$7

Loans_and_Leases_Impaired_Loan

Loans and Leases - Impaired Loans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Summary of impaired loans
Recorded investment	$163	[1]	$172	[1]
Total commercial [Member]
Summary of impaired loans
Recorded investment	128	[1]	139	[1]
Total commercial [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	69		103
Unpaid principal balance	110		146
Related allowance	0		0
Total commercial [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	56		28
Unpaid principal balance	70		41
Related allowance	4		5
Total consumer [Member]
Summary of impaired loans
Recorded investment	35	[1]	33	[1]
Total consumer [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	16		18
Unpaid principal balance	18		20
Related allowance	0		0
Total consumer [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	16		14
Unpaid principal balance	17		16
Related allowance	2		4
Originated loans [Member]
Summary of impaired loans
Recorded investment	156		163
Unpaid principal balance	215		222
Related allowance	6		9
Average recorded investment	153		172		161
Interest income recognized	3		3		3
Originated loans [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	85		121
Unpaid principal balance	128		166
Related allowance	0		0
Originated loans [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	71		42
Unpaid principal balance	87		57
Related allowance	6		9
Originated loans [Member] | Total commercial [Member]
Summary of impaired loans
Recorded investment	125		131
Unpaid principal balance	179		187
Related allowance	4		5
Average recorded investment	122		142		135
Interest income recognized	3		2		2
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of impaired loans
Recorded investment	64		72
Unpaid principal balance	86		97
Related allowance	2		4
Average recorded investment	69		80		72
Interest income recognized	1		1		1
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	40		48
Unpaid principal balance	59		63
Related allowance	0		0
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	24		24
Unpaid principal balance	27		35
Related allowance	2		4
Originated loans [Member] | Total commercial [Member] | Business [Member]
Summary of impaired loans
Recorded investment	61		59
Unpaid principal balance	93		90
Related allowance	2		2
Average recorded investment	53		63		63
Interest income recognized	1		1		1
Originated loans [Member] | Total commercial [Member] | Business [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	29		55
Unpaid principal balance	51		84
Related allowance	0		0
Originated loans [Member] | Total commercial [Member] | Business [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	32		4
Unpaid principal balance	43		6
Related allowance	2		2
Originated loans [Member] | Total consumer [Member]
Summary of impaired loans
Recorded investment	31		32
Unpaid principal balance	36		36
Related allowance	2		4
Average recorded investment	31		29		26
Interest income recognized	0		1		0
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of impaired loans
Recorded investment	20		20
Unpaid principal balance	22		21
Related allowance	1		1
Average recorded investment	21		20		20
Interest income recognized	0		0		0
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	8		12
Unpaid principal balance	9		12
Related allowance	0		0
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	11		8
Unpaid principal balance	13		9
Related allowance	1		1
Originated loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of impaired loans
Recorded investment	7		8
Unpaid principal balance	8		10
Related allowance	1		3
Average recorded investment	5		5		4
Interest income recognized	0		0		0
Originated loans [Member] | Total consumer [Member] | Home equity [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	3		4
Unpaid principal balance	4		5
Related allowance	0		0
Originated loans [Member] | Total consumer [Member] | Home equity [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	4		4
Unpaid principal balance	4		5
Related allowance	1		3
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member]
Summary of impaired loans
Recorded investment	2		1
Unpaid principal balance	3		2
Related allowance	0		0
Average recorded investment	3		1		0
Interest income recognized	0		0		0
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	2		1
Unpaid principal balance	3		1
Related allowance	0		0
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	0		1
Unpaid principal balance	0		1
Related allowance	0		0
Originated loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of impaired loans
Recorded investment	2		3
Unpaid principal balance	2		3
Related allowance	0		0
Average recorded investment	3		3		2
Interest income recognized	0		0		0
Originated loans [Member] | Total consumer [Member] | Other consumer [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	2		1
Unpaid principal balance	2		1
Related allowance	0		0
Originated loans [Member] | Total consumer [Member] | Other consumer [Member] | With a related allowance recorded
Summary of impaired loans
Recorded investment	0		1
Unpaid principal balance	0		1
Related allowance	0		0
Acquired loans [Member]
Summary of impaired loans
Average recorded investment	3	[1]	9	[1]	10	[1]
Interest income recognized	0	[1]	0	[1]	0	[1]
Acquired loans [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	7	[1]	10	[1]
Unpaid principal balance	9	[1]	14	[1]
Related allowance	0	[1]	0	[1]
Acquired loans [Member] | Total commercial [Member]
Summary of impaired loans
Average recorded investment	2		8		9
Interest income recognized	0		0		0
Acquired loans [Member] | Total commercial [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	3		8
Unpaid principal balance	3		12
Related allowance	0		0
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Summary of impaired loans
Average recorded investment	0		1		1
Interest income recognized	0		0		0
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	0		1
Unpaid principal balance	0		4
Related allowance	0		0
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Summary of impaired loans
Average recorded investment	2		7		8
Interest income recognized	0		0		0
Acquired loans [Member] | Total commercial [Member] | Business [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	3		7
Unpaid principal balance	3		8
Related allowance	0		0
Acquired loans [Member] | Total consumer [Member]
Summary of impaired loans
Average recorded investment	1		0		1
Interest income recognized	0		0		0
Acquired loans [Member] | Total consumer [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	4		1
Unpaid principal balance	6		2
Related allowance	0		0
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member]
Summary of impaired loans
Average recorded investment	0		0		0
Interest income recognized	0		0		0
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	0		0
Acquired loans [Member] | Total consumer [Member] | Home equity [Member]
Summary of impaired loans
Average recorded investment	1		0		1
Interest income recognized	0		0		0
Acquired loans [Member] | Total consumer [Member] | Home equity [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	4		1
Unpaid principal balance	6		2
Related allowance	0		0
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member]
Summary of impaired loans
Average recorded investment	0		0		0
Interest income recognized	0		0		0
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member] | With no related allowance recorded
Summary of impaired loans
Recorded investment	0		0
Unpaid principal balance	0		0
Related allowance	$0		$0
[1]	Includes nonaccrual purchased credit impaired loans.

Loans_and_Leases_Reconciliatio

Loans and Leases - Reconciliation of Nonperforming Loans to Impaired Loans (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccruing loans	$204		$188
Plus: Accruing TDRs	67		52		46
Less : Smaller balance nonaccrual loans evaluated collectively when determining the allowance for loan losses	-108		-67
Total impaired loans	163	[1]	172	[1]
Total commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccruing loans	106		105
Plus: Accruing TDRs	59		45
Less : Smaller balance nonaccrual loans evaluated collectively when determining the allowance for loan losses	-36		-11
Total impaired loans	128	[1]	139	[1]
Total consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccruing loans	98		82
Plus: Accruing TDRs	8		8
Less : Smaller balance nonaccrual loans evaluated collectively when determining the allowance for loan losses	-71		-57
Total impaired loans	$35	[1]	$33	[1]
[1]	Includes nonaccrual purchased credit impaired loans.

Loans_and_Leases_Past_Due_Agin

Loans and Leases - Past Due Aging Analysis (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Aging analysis of loans
Total	$23,037		$21,440
Total commercial [Member]
Aging analysis of loans
Total	13,979		13,068
Total commercial [Member] | Business [Member]
Aging analysis of loans
Total	5,775		5,290
Total consumer [Member]
Aging analysis of loans
Total	9,058		8,371
Total consumer [Member] | Residential real estate [Member]
Aging analysis of loans
Total	3,353		3,448
Total consumer [Member] | Home equity [Member]
Aging analysis of loans
Total	2,936		2,752
Total consumer [Member] | Indirect auto [Member]
Aging analysis of loans
Total	2,166		1,544
Originated loans [Member]
Aging analysis of loans
30-59 days past due	41		36
60-89 days past due	19		15
Greater than 90 days past due	95		90
Total past due	154		140
Current	19,141		16,782
Total	19,296		16,922		13,372
Greater than 90 days and accruing	2	[1]	3	[1]
Originated loans [Member] | Total commercial [Member]
Aging analysis of loans
30-59 days past due	11		9
60-89 days past due	9		5
Greater than 90 days past due	49		47
Total past due	69		61
Current	12,515		11,169
Total	12,584		11,231
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Aging analysis of loans
30-59 days past due	7		5
60-89 days past due	2		2
Greater than 90 days past due	31		27
Total past due	40		34
Current	7,113		6,321
Total	7,154		6,354		5,044
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total commercial [Member] | Business [Member]
Aging analysis of loans
30-59 days past due	5		4
60-89 days past due	7		3
Greater than 90 days past due	17		20
Total past due	28		28
Current	5,402		4,849
Total	5,430		4,876		4,286
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total consumer [Member]
Aging analysis of loans
30-59 days past due	29		27
60-89 days past due	10		9
Greater than 90 days past due	46		43
Total past due	85		79
Current	6,626		5,613
Total	6,711		5,691
Greater than 90 days and accruing	2	[1]	3	[1]
Originated loans [Member] | Total consumer [Member] | Residential real estate [Member]
Aging analysis of loans
30-59 days past due	4		6
60-89 days past due	2		2
Greater than 90 days past due	21		21
Total past due	27		30
Current	2,069		1,872
Total	2,096		1,902		1,724
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total consumer [Member] | Home equity [Member]
Aging analysis of loans
30-59 days past due	3		3
60-89 days past due	1		2
Greater than 90 days past due	15		12
Total past due	19		17
Current	1,828		1,601
Total	1,847		1,618		1,286
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total consumer [Member] | Indirect auto [Member]
Aging analysis of loans
30-59 days past due	17		12
60-89 days past due	4		2
Greater than 90 days past due	5		3
Total past due	27		18
Current	2,139		1,526
Total	2,166		1,544		601
Greater than 90 days and accruing	0	[1]	0	[1]
Originated loans [Member] | Total consumer [Member] | Credit Cards [Member]
Aging analysis of loans
30-59 days past due	2		2
60-89 days past due	2		1
Greater than 90 days past due	2		3
Total past due	6		6
Current	318		319
Total	324		325		215
Greater than 90 days and accruing	2	[1]	3	[1]
Originated loans [Member] | Total consumer [Member] | Other consumer [Member]
Aging analysis of loans
30-59 days past due	3		3
60-89 days past due	1		1
Greater than 90 days past due	3		3
Total past due	7		7
Current	271		295
Total	278		302		215
Greater than 90 days and accruing	0	[1]	0	[1]
Acquired loans [Member]
Aging analysis of loans
30-59 days past due	21		35
60-89 days past due	9		23
Greater than 90 days past due	109		130
Total past due	139		188
Current	3,603		4,330
Total	3,742		4,517		6,338
Greater than 90 days and accruing	91	[1]	110	[1]
Acquired loans [Member] | Total commercial [Member]
Aging analysis of loans
30-59 days past due	3		10
60-89 days past due	3		8
Greater than 90 days past due	33		45
Total past due	38		63
Current	1,357		1,774
Total	1,395		1,838
Greater than 90 days and accruing	30	[1]	41	[1]
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Aging analysis of loans
30-59 days past due	3		8
60-89 days past due	3		8
Greater than 90 days past due	26		37
Total past due	31		52
Current	1,019		1,371
Total	1,050		1,423		2,049
Greater than 90 days and accruing	26	[1]	36	[1]
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Aging analysis of loans
30-59 days past due	0		2
60-89 days past due	0		1
Greater than 90 days past due	7		8
Total past due	7		11
Current	338		403
Total	345		414		667
Greater than 90 days and accruing	4	[1]	5	[1]
Acquired loans [Member] | Total consumer [Member]
Aging analysis of loans
30-59 days past due	17		26
60-89 days past due	7		15
Greater than 90 days past due	77		84
Total past due	101		125
Current	2,246		2,555
Total	2,347		2,680
Greater than 90 days and accruing	62	[1]	70	[1]
Acquired loans [Member] | Total consumer [Member] | Residential real estate [Member]
Aging analysis of loans
30-59 days past due	11		19
60-89 days past due	5		11
Greater than 90 days past due	56		64
Total past due	72		94
Current	1,186		1,452
Total	1,257		1,546		2,037
Greater than 90 days and accruing	56	[1]	64	[1]
Acquired loans [Member] | Total consumer [Member] | Home equity [Member]
Aging analysis of loans
30-59 days past due	6		7
60-89 days past due	2		4
Greater than 90 days past due	21		20
Total past due	29		31
Current	1,060		1,103
Total	1,089		1,134		1,366
Greater than 90 days and accruing	6	[1]	5	[1]
Acquired loans [Member] | Total consumer [Member] | Indirect auto [Member]
Aging analysis of loans
Total	0		0
Acquired loans [Member] | Total consumer [Member] | Credit Cards [Member]
Aging analysis of loans
Total	0		0		100
Acquired loans [Member] | Total consumer [Member] | Other consumer [Member]
Aging analysis of loans
Total	$0		$0		$118
[1]	Includes credit card loans, loans that have matured and are in the process of collection, and acquired loans that were originally recorded at fair value upon acquisition. Acquired loans are considered to be accruing as we can reasonably estimate future cash flows on these acquired loans and we expect to fully collect the carrying value of these loans net of the allowance for acquired loan losses. Therefore, we are accreting the difference between the carrying value of these loans and their expected cash flows into interest income.

Loans_and_Leases_Commercial_Cr

Loans and Leases - Commercial Credit Quality Indicators (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Information about the credit quality of our commercial loan portfolio
Loans receivable	$23,037		$21,440
Total commercial [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	13,979		13,068
Total commercial [Member] | Business [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	5,775		5,290
Originated Loans
Information about the credit quality of our commercial loan portfolio
Loans receivable	19,296		16,922		13,372
Originated Loans | Total commercial [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	12,584		11,231
Percent of total	100.00%		100.00%
Originated Loans | Total commercial [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	726	[1]	612	[1]
Percent of total	5.80%	[1]	5.40%	[1]
Originated Loans | Total commercial [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	628	[1]	517	[1]
Percent of total	5.00%	[1]	4.60%	[1]
Originated Loans | Total commercial [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	98	[1]	95	[1]
Percent of total	0.80%	[1]	0.80%	[1]
Originated Loans | Total commercial [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	11,858		10,618
Percent of total	94.20%		94.60%
Originated Loans | Total commercial [Member] | Business [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	5,430		4,876		4,286
Originated Loans | Total commercial [Member] | Business [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	363	[1]	286	[1]
Originated Loans | Total commercial [Member] | Business [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	318	[1]	244	[1]
Originated Loans | Total commercial [Member] | Business [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	45	[1]	42	[1]
Originated Loans | Total commercial [Member] | Business [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	5,067		4,590
Originated Loans | Total commercial [Member] | Commercial real estate [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	7,154		6,354		5,044
Originated Loans | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	363	[1]	327	[1]
Originated Loans | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	310	[1]	273	[1]
Originated Loans | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	53	[1]	53	[1]
Originated Loans | Total commercial [Member] | Commercial real estate [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	6,791		6,028
Acquired loans [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	3,742		4,517		6,338
Acquired loans [Member] | Total commercial [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	1,395		1,838
Percent of total	100.00%		100.00%
Acquired loans [Member] | Total commercial [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	153	[1]	218	[1]
Percent of total	10.90%	[1]	11.80%	[1]
Acquired loans [Member] | Total commercial [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	145	[1]	208	[1]
Percent of total	10.40%	[1]	11.30%	[1]
Acquired loans [Member] | Total commercial [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	7	[1]	10	[1]
Percent of total	0.50%	[1]	0.50%	[1]
Acquired loans [Member] | Total commercial [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	1,243		1,619
Percent of total	89.10%		88.20%
Acquired loans [Member] | Total commercial [Member] | Business [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	345		414		667
Acquired loans [Member] | Total commercial [Member] | Business [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	51	[1]	55	[1]
Acquired loans [Member] | Total commercial [Member] | Business [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	43	[1]	46	[1]
Acquired loans [Member] | Total commercial [Member] | Business [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	7	[1]	9	[1]
Acquired loans [Member] | Total commercial [Member] | Business [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	294		359
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	1,050		1,423		2,049
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	102	[1]	163	[1]
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member] | Accrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	102	[1]	162	[1]
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member] | Criticized [Member] | Nonaccrual
Information about the credit quality of our commercial loan portfolio
Loans receivable	0	[1]	1	[1]
Acquired loans [Member] | Total commercial [Member] | Commercial real estate [Member] | Pass [Member]
Information about the credit quality of our commercial loan portfolio
Loans receivable	$948		$1,260
[1]	Includes special mention, substandard, doubtful, and loss, which are consistent with regulatory definitions, and as described in Part I, Item 1, “Business,” under the heading “Asset Quality Review.”

Loans_and_Leases_Consumer_Cred

Loans and Leases - Consumer Credit Quality Indicators - Refreshed FICO (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Information about the credit quality of our consumer loan portfolio
Loans receivable	$23,037		$21,440
Originated loans [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	19,296		16,922		13,372
Acquired loans [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	3,742		4,517		6,338
Total consumer [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	9,058		8,371
Total consumer [Member] | Residential real estate [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	3,353		3,448
Total consumer [Member] | Home equity [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	2,936		2,752
Total consumer [Member] | Indirect auto [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	2,166		1,544
Total consumer [Member] | Originated loans [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	6,711		5,691
Percent of total	100.00%		100.00%
Total consumer [Member] | Originated loans [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	5,296		4,324
Percent of total	78.90%		76.00%
Total consumer [Member] | Originated loans [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	752		696
Percent of total	11.20%		12.20%
Total consumer [Member] | Originated loans [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	339		328
Percent of total	5.00%		5.80%
Total consumer [Member] | Originated loans [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	148		142
Percent of total	2.20%		2.50%
Total consumer [Member] | Originated loans [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	146		135
Percent of total	2.20%		2.40%
Total consumer [Member] | Originated loans [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	31	[1]	66	[1]
Percent of total	0.50%	[1]	1.10%	[1]
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	2,096		1,902		1,724
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,841		1,609
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	124		128
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	62		56
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	28		32
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	32		38
Total consumer [Member] | Originated loans [Member] | Residential real estate [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	9	[1]	39	[1]
Total consumer [Member] | Originated loans [Member] | Home equity [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,847		1,618		1,286
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,529		1,327
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	182		158
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	71		69
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	31		30
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	32		30
Total consumer [Member] | Originated loans [Member] | Home equity [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1	[1]	3	[1]
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	2,166		1,544		601
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,533		993
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	347		304
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	159		149
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	64		55
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	63		43
Total consumer [Member] | Originated loans [Member] | Indirect auto [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0	[1]	0	[1]
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	324		325		215
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	226		223
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	53		53
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	24		25
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	11		12
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	8		8
Total consumer [Member] | Originated loans [Member] | Credit Cards [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	3	[1]	4	[1]
Total consumer [Member] | Originated loans [Member] | Other consumer [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	278		302		215
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	167		173
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	46		53
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	24		28
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	13		14
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	12		15
Total consumer [Member] | Originated loans [Member] | Other consumer [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	17	[1]	20	[1]
Total consumer [Member] | Acquired loans [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	2,347		2,680
Percent of total	100.00%		100.00%
Total consumer [Member] | Acquired loans [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,723		1,948
Percent of total	73.40%		72.70%
Total consumer [Member] | Acquired loans [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	180		218
Percent of total	7.70%		8.10%
Total consumer [Member] | Acquired loans [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	113		119
Percent of total	4.80%		4.40%
Total consumer [Member] | Acquired loans [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	88		95
Percent of total	3.80%		3.60%
Total consumer [Member] | Acquired loans [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	91		114
Percent of total	3.90%		4.30%
Total consumer [Member] | Acquired loans [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	151	[1]	185	[1]
Percent of total	6.40%	[1]	6.90%	[1]
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,257		1,546		2,037
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	872		1,074
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	87		115
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	61		61
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	49		57
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	57		75
Total consumer [Member] | Acquired loans [Member] | Residential real estate [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	131	[1]	164	[1]
Total consumer [Member] | Acquired loans [Member] | Home equity [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	1,089		1,134		1,366
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	851		874
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	93		103
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	52		57
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	40		39
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	34		40
Total consumer [Member] | Acquired loans [Member] | Home equity [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	20	[1]	21	[1]
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Indirect auto [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0	[1]	0	[1]
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0		100
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Credit Cards [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0	[1]	0	[1]
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0		118
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | Over 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | 660 - 700 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | 620-660 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | 580 - 620 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | Less than 580 [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	0		0
Total consumer [Member] | Acquired loans [Member] | Other consumer [Member] | No Score [Member]
Information about the credit quality of our consumer loan portfolio
Loans receivable	$0	[1]	$0	[1]
[1]	Primarily includes loans that are serviced by others for which refreshed FICO scores were not available as of the date indicated.

Loans_and_Leases_Summary_of_Tr

Loans and Leases - Summary of Troubled Debt Restructurings (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Aggregate recorded investment of impaired loans with terms through troubled debt restructuring
Accruing interest	$67		$52		$46
Nonaccrual	53		56		42
Total troubled debt restructurings	$120	[1]	$108	[1]	$89
[1]	Includes 87 and 40 acquired loans that were restructured with a recorded investment of $4 million and $1 million at December 31, 2014 and 2013, respectively.

Loans_and_Leases_Troubled_Debt

Loans and Leases - Troubled Debt Restructuring by Concession Type (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
	Contract		Contract
Financing effects of our modifications
Count	496		267
Postmodification recorded investment	$70	[1]	$55	[1]
Premodification allowance for loan losses	8		4
Postmodification allowance for loan losses	2		2
Total commercial [Member]
Financing effects of our modifications
Count	31		31
Postmodification recorded investment	56	[1]	46	[1]
Premodification allowance for loan losses	8		4
Postmodification allowance for loan losses	2		1
Total commercial [Member] | Commercial real estate [Member] | Extension of term [Member]
Financing effects of our modifications
Count	10		5
Postmodification recorded investment	20	[1]	9	[1]
Premodification allowance for loan losses	1		1
Postmodification allowance for loan losses	0		1
Total commercial [Member] | Commercial real estate [Member] | Deferral of principal [Member]
Financing effects of our modifications
Count			1
Postmodification recorded investment			8	[1]
Premodification allowance for loan losses			0
Postmodification allowance for loan losses			0
Total commercial [Member] | Commercial real estate [Member] | Extension of term and rate reduction [Member]
Financing effects of our modifications
Count	3		8
Postmodification recorded investment	1	[1]	17	[1]
Premodification allowance for loan losses	0		1
Postmodification allowance for loan losses	0		0
Total commercial [Member] | Commercial real estate [Member] | Rate reduction [Member][
Financing effects of our modifications
Count	1
Postmodification recorded investment	3	[1]
Premodification allowance for loan losses	0
Postmodification allowance for loan losses	1
Total commercial [Member] | Business [Member] | Extension of term [Member]
Financing effects of our modifications
Count	15		10
Postmodification recorded investment	32	[1]	10	[1]
Premodification allowance for loan losses	6		2
Postmodification allowance for loan losses	1		0
Total commercial [Member] | Business [Member] | Extension of term and rate reduction [Member]
Financing effects of our modifications
Count	2		7
Postmodification recorded investment	0	[1]	1	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member]
Financing effects of our modifications
Count	465		236
Postmodification recorded investment	14	[1]	9	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Extension of term [Member]
Financing effects of our modifications
Count	6		2
Postmodification recorded investment	1	[1]	0	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Extension of term and rate reduction [Member]
Financing effects of our modifications
Count	14		11
Postmodification recorded investment	2	[1]	2	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Rate reduction [Member][
Financing effects of our modifications
Count	2		3
Postmodification recorded investment	0	[1]	0	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Deferral of principal and extension of term [Member]
Financing effects of our modifications
Count	7		5
Postmodification recorded investment	1	[1]	0	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Chapter 7 bankruptcy [Member]
Financing effects of our modifications
Count	14		15
Postmodification recorded investment	1	[1]	1	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Residential real estate [Member] | Other [Member]
Financing effects of our modifications
Count	3
Postmodification recorded investment	0
Premodification allowance for loan losses	0
Postmodification allowance for loan losses	0
Total consumer [Member] | Home equity [Member] | Extension of term [Member]
Financing effects of our modifications
Count	3
Postmodification recorded investment	0
Premodification allowance for loan losses	0
Postmodification allowance for loan losses	0
Total consumer [Member] | Home equity [Member] | Extension of term and rate reduction [Member]
Financing effects of our modifications
Count	10		3
Postmodification recorded investment	0	[1]	0	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Home equity [Member] | Rate reduction [Member][
Financing effects of our modifications
Count			2
Postmodification recorded investment			0	[1]
Premodification allowance for loan losses			0
Postmodification allowance for loan losses			0
Total consumer [Member] | Home equity [Member] | Deferral of principal and extension of term [Member]
Financing effects of our modifications
Count	2		3
Postmodification recorded investment	0	[1]	0
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Home equity [Member] | Chapter 7 bankruptcy [Member]
Financing effects of our modifications
Count	79		61
Postmodification recorded investment	3	[1]	2	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Home equity [Member] | Other [Member]
Financing effects of our modifications
Count	18
Postmodification recorded investment	1
Premodification allowance for loan losses	0
Postmodification allowance for loan losses	0
Total consumer [Member] | Indirect auto [Member] | Chapter 7 bankruptcy [Member]
Financing effects of our modifications
Count	273		74
Postmodification recorded investment	5	[1]	1	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Other consumer [Member] | Chapter 7 bankruptcy [Member]
Financing effects of our modifications
Count	33		54
Postmodification recorded investment	0	[1]	1	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Other consumer [Member] | Extension of term [Member]
Financing effects of our modifications
Count	1		1
Postmodification recorded investment	0	[1]	0	[1]
Premodification allowance for loan losses	0		0
Postmodification allowance for loan losses	0		0
Total consumer [Member] | Other consumer [Member] | Extension of term and rate reduction [Member]
Financing effects of our modifications
Count			1
Postmodification recorded investment			0	[1]
Premodification allowance for loan losses			0
Postmodification allowance for loan losses			0
Total consumer [Member] | Other consumer [Member] | Rate reduction [Member][
Financing effects of our modifications
Count			1
Postmodification recorded investment			0	[1]
Premodification allowance for loan losses			0
Postmodification allowance for loan losses			$0
[1]	Postmodification balances approximate premodification balances. The aggregate amount of charge-offs as a result of the restructurings was not significant.

Loans_and_Leases_Information_a

Loans and Leases - Information about Residential Mortgage Banking (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Information about residential mortgage loans
Loans classified as held for sale	$40	$50	$155
Loans sold during the year	663	1,400	1,444
Gain on sale of loans, net	5	12	9
Mortgages serviced for others	3,841	3,665	2,909
Mortgage servicing asset recorded for loans serviced for others, net	$37	$35	$26

Loans_and_Leases_Details_Textu

Loans and Leases (Details Textual) (USD $)	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2014	Jun. 30, 2014	Dec. 31, 2014		Dec. 31, 2013
			Contract		Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of segments in portfolio			2
Liability for unfunded commitments			$16,000,000		$13,000,000
Provision for credit losses			3,000,000		2,000,000
Home equity portfolio			2,900,000,000		2,800,000,000
Portion of home equity portfolio in first lien position			1,100,000,000		1,000,000,000
Percentage of home equity portfolio first lien loan hold and service			10.00%
Other changes in accretable yield			55,000,000	[1]	22,000,000	[1]
Carrying value of impaired loans, less related allowance, as percent of principal			70.00%		69.00%
Minimum number of payments of restructured loan			6
Threshold Loans Individually Impaired	200,000	1,000,000	1,000,000
Troubled debt restructures acquired loan portfolio count			87		40
Troubled debt restructures acquired loan portfolio			$4,000,000		$1,000,000
[1]	Includes changes in expected cash flows from changes in interest rate and prepayment assumptions.

Premises_and_Equipment_Details

Premises and Equipment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
A summary of our premises and equipment
Land	$29	$29
Buildings and leasehold improvements	290	287
Furniture and equipment	339	307
Total	658	623
Accumulated depreciation	-251	-205
Premises and equipment, net	407	418
Premises and Equipment (Textual) [Abstract]
Rent expense	$32	$33	$28

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Goodwill (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Information regarding our goodwill
Goodwill, beginning	$2,449,000,000	$2,484,000,000
Acquisitions	1,000,000
Goodwill impairment	-1,100,000,000	0		0
Adjustment		-35,000,000	[1]
Goodwill, ending	1,350,000,000	2,449,000,000		2,484,000,000
Banking [Member]
Information regarding our goodwill
Goodwill, beginning	2,381,000,000	2,416,000,000
Acquisitions	0
Goodwill impairment	-1,100,000,000	0
Adjustment		-35,000,000	[1]
Goodwill, ending	1,281,000,000	2,381,000,000
Financial services [Member]
Information regarding our goodwill
Goodwill, beginning	68,000,000	68,000,000
Acquisitions	1,000,000
Goodwill impairment	0
Adjustment		0	[1]
Goodwill, ending	$69,000,000	$68,000,000
[1]	Establishment of deferred tax assets in connection with the HSBC Branch Acquisition and our National City Bank branch acquisition.

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Amortizing Intangible Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Information regarding our amortizing intangible assets
Net carrying amount	$67	$94
Core deposit intangible [Member]
Information regarding our amortizing intangible assets
Finite-Lived Intangible Asset, Gross	191	191
Accumulated amortization	-158	-139
Net carrying amount	33	52
Other intangibles [Member]
Information regarding our amortizing intangible assets
Finite-Lived Intangible Asset, Gross	100	95
Accumulated amortization	-66	-53
Net carrying amount	$34	$42

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets - Future Amortization Expense (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Goodwill [Line Items]
2015	$19
2016	13
2017	12
2018	9
2019	5
Thereafter	10
First quarter [Member]
Goodwill [Line Items]
2019	2
Second quarter [Member]
Goodwill [Line Items]
2019	1
Third quarter [Member]
Goodwill [Line Items]
2019	1
Fourth quarter [Member]
Goodwill [Line Items]
2019	1
First quarter [Member]
Goodwill [Line Items]
2018	3
Second quarter [Member]
Goodwill [Line Items]
2018	2
Third quarter [Member]
Goodwill [Line Items]
2018	2
Fourth quarter [Member]
Goodwill [Line Items]
2018	2
First quarter [Member]
Goodwill [Line Items]
2017	3
Second quarter [Member]
Goodwill [Line Items]
2017	3
Third quarter [Member]
Goodwill [Line Items]
2017	3
Fourth quarter [Member]
Goodwill [Line Items]
2017	3
First quarter [Member]
Goodwill [Line Items]
2016	4
Second quarter [Member]
Goodwill [Line Items]
2016	3
Third quarter [Member]
Goodwill [Line Items]
2016	3
Fourth quarter [Member]
Goodwill [Line Items]
2016	3
First quarter [Member]
Goodwill [Line Items]
2015	6
Second quarter [Member]
Goodwill [Line Items]
2015	5
Third quarter [Member]
Goodwill [Line Items]
2015	4
Fourth quarter [Member]
Goodwill [Line Items]
2015	$4

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 16, 2015	Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment	$1,100,000,000	$0	$0
Share Price				$9.11	$7.37
Banking [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment	$1,100,000,000	$0

Deposits_Composition_Rates_and

Deposits - Composition, Rates and Interest Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Core deposits:
Savings, balance	$3,452	$3,667
Savings, weighted average rate	0.09%	0.10%
Interest-bearing checking, balance	5,084	4,744
Interest-bearing checking, weighted average rate	0.03%	0.04%
Money market deposits, balance	9,962	9,740
Money market deposits, weighted average rate	0.22%	0.21%
Noninterest-bearing, balance	5,407	4,866
Noninterest-bearing, weighted average rate	0.00%	0.00%
Total core deposits, balance	23,906	23,016
Total core deposits, weighted average rate	0.11%	0.12%
Certificates, balance	3,876	3,649
Certificates, weighted average rate	0.69%	0.68%
Total deposits, balance	27,781	26,665
Total deposits, weighted average rate	0.19%	0.20%
Interest expense on deposits
Certificates	27	26	33
Money market deposits	22	21	26
Savings	3	4	5
Interest bearing checking	2	2	2
Total interest expense	$53	$53	$67

Deposits_Details_Textual

Deposits (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Deposits (Textual) [Abstract]
Municipal deposits	$3,300,000,000	$2,900,000,000
Brokered money market deposits	412,000,000	336,000,000
Brokered certificates of deposit	1,200,000,000	739,000,000	635,000,000
Interest rates on certificates minimum	0.05%
Interest rates on certificates maximum	4.50%
Certificates of Deposits issued over $100 thousand	938,000,000	928,000,000	1,700,000,000
Interest Expense certificates of deposit $100,000 or More	$10,000,000	$11,000,000	$11,000,000

Borrowings_Composition_Outstan

Borrowings - Composition Outstanding (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Short-term borrowings:
FHLB advances	$5,049	$4,304
Repurchase agreements	423	518
Total short-term borrowings	5,472	4,822
Long-term borrowings:
Senior notes (maturing in 2020)	298	298
Subordinated notes (maturing in 2021)	298	298
Junior subordinated debentures (maturing between 2030 and 2037)	114	113
Other (maturing between 2015 and 2032)	23	25
Total long-term borrowings	734	734
Total borrowings	$6,206	$5,556

Borrowings_Interest_Expense_De

Borrowings - Interest Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest expense by debt instrument [Line Items]
Interest expense	$69	$64	$86
FHLB advances
Interest expense by debt instrument [Line Items]
Interest expense	19	14	19
Repurchase agreements
Interest expense by debt instrument [Line Items]
Interest expense	1	1	17
Senior notes
Interest expense by debt instrument [Line Items]
Interest expense	21	21	21
Subordinated notes
Interest expense by debt instrument [Line Items]
Interest expense	23	23	23
Junior subordinated debentures
Interest expense by debt instrument [Line Items]
Interest expense	$5	$5	$6

Borrowings_Borrowings_Junior_S

Borrowings Borrowings - Junior Subordinated Debentures (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	London Interbank Offered Rate (“LIBOR”) plus 185 basis points
Principal amount of subordinated debentures	$142
Principal amount of trust preferred securities	138
HNC Statutory Trust III [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	1.40%
Principal amount of subordinated debentures	26
Principal amount of trust preferred securities	25
Willow Grove Statutory Trust I [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	1.31%
Principal amount of subordinated debentures	26
Principal amount of trust preferred securities	25
HNC Statutory Trust IV [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	1.28%
Principal amount of subordinated debentures	23
Principal amount of trust preferred securities	23
HNC Statutory Trust II [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	2.70%
Principal amount of subordinated debentures	21
Principal amount of trust preferred securities	20
First Niagara Financial Group Statutory Trust I [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	2.70%
Principal amount of subordinated debentures	12
Principal amount of trust preferred securities	12
Westbank Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	2.19%
Principal amount of subordinated debentures	9
Principal amount of trust preferred securities	9
Westbank Capital Trust III [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	2.19%
Principal amount of subordinated debentures	9
Principal amount of trust preferred securities	9
East Penn Statutory Trust I [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debentures with variable interest rate, 3 month LIBOR plus	3 month LIBOR +
Variable interest rate, three month LIBOR spread	3.10%
Principal amount of subordinated debentures	8
Principal amount of trust preferred securities	8
Harleysville Statutory Trust I [Member]
Subordinated Borrowing [Line Items]
Fixed interest rate	10.20%
Principal amount of subordinated debentures	5
Principal amount of trust preferred securities	5
Alliance Capital Trust II [Member]
Subordinated Borrowing [Line Items]
Fixed interest rate	10.88%
Principal amount of subordinated debentures	4
Principal amount of trust preferred securities	$4

Borrowings_Aggregate_Maturitie

Borrowings - Aggregate Maturities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Aggregate Maturities of long term Borrowings
2015	$2
2016	2
2017	2
2018	2
2019	2
Thereafter	724
Total long-term borrowings	$734	$734

Borrowings_Details_Textual

Borrowings (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Debt instrument [Line Items]
FHLB advances fixed interest rates, minimum	0.40%
FHLB advances fixed interest rates, maximum	0.67%
FHLB advances bear fixed interest weighted average rate	0.48%	0.46%
Repurchase agreements fixed interest rates, minimum	0.02%
Repurchase agreements fixed interest rates, maximum	0.15%
Repurchase agreements bear fixed interest weighted average rate	0.14%	0.18%
Rates paid on senior notes	6.75%
Rate paid on subordinated notes	7.25%
Subordinated debenture interest rates, minimum	1.16%
Subordinated debenture interest rates, maximum	10.88%
Subordinated debenture weighted interest rates	2.57%
FHLB facility total	$5,700,000,000	$4,500,000,000
FHLB facility, utilized	5,100,000,000	4,200,000,000
FHLB facility, secured by real estate loans	4,300,000,000	3,900,000,000
FHLB facility, secured by investment securities	1,400,000,000	584,000,000
Federal Reserve Bank facility not utilized	867,000,000	777,000,000
Commercial banks facility, not utilized	250,000,000	200,000,000
Line of credit rate commercial bank	London Interbank Offered Rate (“LIBOR”) plus 185 basis points
Period Change in debt basis spread on variable rate user condition one	30 days
Period change in debt basis spread on variable rate user condition two	90 days
Securities held to maturity were pledged to collateralize the borrowings	0
Junior subordinated debentures	114,000,000	113,000,000
Principal amount of subordinated debentures	142,000,000
First Niagara Financial Group Statutory Trust
Debt instrument [Line Items]
Number of statutory trusts	6
Acquired from Merger with Harleysville, New Alliance and related to First Niagara Statutory Trusts I
Debt instrument [Line Items]
Number of statutory trusts	3
Equity method investments classified as other assets	4,000,000
Junior Subordinated debentures of the Company held by Statutory Trusts | Acquired from Merger with Harleysville, New Alliance and related to First Niagara Statutory Trusts I
Debt instrument [Line Items]
Carrying value of junior subordinated debentures of the Company	114,000,000
Preferred subordinate debentures | Acquired from Merger with Harleysville, New Alliance and related to First Niagara Statutory Trusts I
Debt instrument [Line Items]
Unamortized fair value adjustment related to merger with Harleysville	$28,000,000

Derivative_Financial_Instrumen2

Derivative Financial Instruments - Notional Amount and Fair Value of Derivative Instruments (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified
Derivative financial instruments
Asset Derivatives, Notional Amount	$3,633		$3,114
Asset Derivatives, Fair Value	96	[1]	76	[1]
Liability Derivatives, Notional Amount	3,679		3,107
Liability Derivatives, Fair Value	97	[1]	77	[1]
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member]
Derivative financial instruments
Asset Derivatives, Notional Amount	4		22
Asset Derivatives, Fair Value	0	[1]	0	[1]
Liability Derivatives, Notional Amount	30		13
Liability Derivatives, Fair Value	2	[2]	1	[2]
Interest Rate Swap [Member] | Not Designated as Hedging Instrument [Member]
Derivative financial instruments
Asset Derivatives, Notional Amount	3,629		3,092
Asset Derivatives, Fair Value	96	[1]	76	[1]
Liability Derivatives, Notional Amount	3,649		3,094
Liability Derivatives, Fair Value	$96	[2]	$76	[2]
[1]	Represents gross amounts, included in Other Assets in our Consolidated Statements of Condition.
[2]	Represents gross amounts, included in Other Liabilities in our Consolidated Statements of Condition.

Derivative_Financial_Instrumen3

Derivative Financial Instruments - Amount of Gain/Loss Recognized for Derivative Instruments (Details) (Interest Rate Swap [Member], Cash Flow Hedging [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Interest rate swap agreements:
Amount of gain (loss) on derivatives recognized in other comprehensive income, net of tax	$1		$1		$7
Amount of (loss) on derivatives reclassified from other comprehensive income to income	($1)	[1]	($1)	[2]	($15)	[1]
[1]	Recognized in interest expense on borrowings in our Consolidated Statements of Income.
[2]	Of this amount, $12 million was recognized in merger and acquisition integration expenses when the associated borrowings were repaid in connection with the HSBC Branch Acquisition and $4 million was recognized in interest expense on borrowings in our Consolidated Statements of Income.

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Net liability positions with counterparties		$93,000,000	$49,000,000
Gross amounts of recognized liabilities to be offset with asset		96,000,000	76,000,000
Gross amount of asset offsetting liabilities in the Statement of Condition		3,000,000	27,000,000
Collateral posted for net liability positions		130,000,000	43,000,000
Loss in accumulated other comprehensive income borrowings previously hedged		5,000,000	6,000,000	6,000,000	13,000,000
Sale of investment securities to third party	3,100,000,000
Customer Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Revenue		13,000,000	18,000,000
Securities Sale Agreement [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Security sales derivative gain				5,000,000
Merger and Acquisition expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount recognized in merger and acquisition integration expenses and interest expense				12,000,000
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount recognized in merger and acquisition integration expenses and interest expense				$4,000,000

Commitments_and_Contingent_Lia2

Commitments and Contingent Liabilities - Loan Commitments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Outstanding commitments to originate loans:
Fixed rate	$265	$217
Variable rate	1,522	964
Total commitments outstanding	1,787	1,181
Commitments to sell residential mortgages	137	168
Unused lines of credit
Outstanding commitments to originate loans:
Unused lines of credit	9,319	8,400
Standby letters of credit
Outstanding commitments to originate loans:
Standby letters of credit	$266	$297

Commitments_and_Contingent_Lia3

Commitments and Contingent Liabilities Commitments and Contingent Liabilities - Lease Commitments (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Operating leases, future minimum payments [Abstract]
2015	$34
2016	32
2017	25
2018	21
2019	18
Thereafter through 2041	62	[1]
Capital leases, future minimum payments [Abstract]
2015	3
2016	3
2017	3
2018	3
2019	3
Thereafter through 2032	$16	[2]
[1]	Thereafter through 2041.
[2]	Thereafter through 2032.

Commitments_and_Contingent_Lia4

Commitments and Contingent Liabilities (Details Textual) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
Liability for unfunded commitments	$16	$13
Provision for credit losses for unfunded commitments	$3	$2

Capital_Details

Capital (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
First Niagara Financial Group, Inc.
Actual capital amounts, ratios, and requirements
Leverage ratio amount	$2,764	$2,526
Leverage ratio	7.50%	7.26%
Leverage capital for capital adequacy purposes	1,474	1,392
Leverage ratio for capital adequacy purposes	4.00%	4.00%
Leverage ratio required to be well-capitalized value	1,843	1,739
Leverage ratio required to be well-capitalized	5.00%	5.00%
Tier one risk-based capital	2,764	2,526
Tier one risk-based capital ratio	9.81%	9.56%
Tier one risk-based capital for capital adequacy purposes	1,127	1,057
Tier one risk-based capital ratio for capital adequacy purposes	4.00%	4.00%
Tier one risk-based capital to be well-capitalized	1,691	1,585
Tier one risk-based capital ratio to be well-capitalized	6.00%	6.00%
Tota risk-based capital	3,313	3,046
Total risk-based capital ratio	11.75%	11.53%
Total risk-based capital for capital adequacy purposes	2,256	2,114
Total risk-based capital ratio for capital adequacy purposes	8.00%	8.00%
Total risk-based capital to be well-capitalized	2,819	2,642
Total risk-based capital ratio to be well-capitalized	10.00%	10.00%
Tier 1 common capital	2,312	2,075
Tier 1 common capital ratio	8.20%	7.86%
First Niagara Bank, N.A.
Actual capital amounts, ratios, and requirements
Leverage ratio amount	2,949	2,675
Leverage ratio	8.01%	7.70%
Leverage capital for capital adequacy purposes	1,473	1,390
Leverage ratio for capital adequacy purposes	4.00%	4.00%
Leverage ratio required to be well-capitalized value	1,841	1,737
Leverage ratio required to be well-capitalized	5.00%	5.00%
Tier one risk-based capital	2,949	2,675
Tier one risk-based capital ratio	10.48%	10.15%
Tier one risk-based capital for capital adequacy purposes	1,126	1,054
Tier one risk-based capital ratio for capital adequacy purposes	4.00%	4.00%
Tier one risk-based capital to be well-capitalized	1,688	1,581
Tier one risk-based capital ratio to be well-capitalized	6.00%	6.00%
Tota risk-based capital	3,199	2,898
Total risk-based capital ratio	11.37%	10.99%
Total risk-based capital for capital adequacy purposes	2,251	2,109
Total risk-based capital ratio for capital adequacy purposes	8.00%	8.00%
Total risk-based capital to be well-capitalized	$2,814	$2,637
Total risk-based capital ratio to be well-capitalized	10.00%	10.00%

Capital_Detail_Textual

Capital (Detail Textual) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2009
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
The Company had less than $15 billion in assets at December 31, 2009	$38,551	$37,628	$15,000
Dividends paid	80	175
Return of capital from subsidiary	85
Repurchase of shares upon ESOP termination	1,704,290
Common stock
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Shares authorized to be repurchased	12,000,000
Series B Preferred Stock [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Preferred rate of dividend	8.63%
Dividends paid at floating rate	7.33%
Redemption price per share	$25
Junior Subordinated Debt [Member] | Six Statutory Trust Affiliates [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Carrying value of junior subordinated debentures of the Company	$114

Income_Taxes_Components_of_Exp

Income Taxes - Components of Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal	$36	$119	$36
State	4	4	1
Current income tax expense	41	123	37
Deferred taxes (benefit):
Federal	-136	3	31
State	-14	1	3
Deferred income tax (benefit) expense	-150	5	34
Income tax (benefit)	($109)	$128	$71

Income_Taxes_Actual_Expense_Vs

Income Taxes - Actual Expense Vs Statutory Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax (benefit) expense at statutory rate	($289)	$148	$84
Increase (decrease) attributable to:
State income taxes, net of Federal benefit	-11	4	2
Bank owned life insurance income	-5	-6	-5
Tax exempt interest	-13	-11	-10
Credits	-29	-13	-2
Goodwill impairment	259	0	0
Taxable subsidiary reorganization	-27	0	0
Other	5	6	2
Income tax (benefit)	($109)	$128	$71

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Asset and Liability (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred tax assets:
Net operating loss and other carryforwards acquired	$56	$58
Capital loss carryforward	44	0
Financial statement allowance for credit losses	112	111
Securitizations	2	2
Partnerships	9	0
Deferred compensation	13	13
Stock-based compensation	15	14
Other accrued expenses not currently deductible	20	21
Deferred Tax Assets, Goodwill and Intangible Assets	88	0
Post-retirement benefit obligation	5	4
Nonperforming loan interest	14	12
Other	34	28
Total gross deferred tax assets	413	264
Valuation allowance	-44	-0.2
Deferred tax liabilities:
Unrealized gain on investment securities available for sale	-40	-52
Partnerships	0	-3
Leases	-32	-27
Acquired intangibles	0	-33
Premises and equipment	-5	-19
Mortgage servicing rights	-14	-13
Pension benefits	-22	-37
Other	-2	-2
Total gross deferred tax liabilities	-114	-187
Net deferred tax asset	$255	$77

Income_Taxes_Unrecognized_Tax_

Income Taxes - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of unrecognized tax benefits
Balance at beginning of year	$6	$3	$3
Additions based on tax positions related to the current year	2	1	1
Additions for tax positions of prior years	1	3	0
Reductions related to settlements with taxing authorities	0	-1	-2
Balance at end of year	$9	$6	$3

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Effective income tax rate		-13.30%	30.20%	29.60%
Effective income tax rate reconciliation, at federal statutory income tax rate	35.00%
Valuation allowance for net operating loss carryforwards		$0
Federal and state tax credits		45,000,000
Valuation allowance		44,000,000	200,000
Income tax expense related to change in tax law		5,000,000
Unrecognized tax benefits, income tax penalties and interest accrued		900,000	300,000
Unrecognized tax benefit to reverse in 2015		2,000,000
Federal Alternative Minimum Tax
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount		7,000,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating losses carried to number of preceeding years		2 years
Net operating losses carried to number of succeeding years		20 years
Operating loss carryforwards		121,000,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		57,000,000
Federal Pre Nineteen Eighty Eight Reserve for Which No Federal Income Tax Provision Has Been Made [Member]
Operating Loss Carryforwards [Line Items]
Federal reserve excluding federal income tax provision		$92,000,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Computation of basic and diluted earnings per share using two-class method
Net (loss) income available to common stockholders	($745)	$265	$141
Less income allocable to unvested restricted stock awards	1	1	0
Net (loss) income allocable to common stockholders	($746)	$264	$140
Weighted average common shares outstanding:
Total shares issued	366	366	366
Unallocated employee stock ownership plan shares	-2	-2	-2
Unvested restricted stock awards	-3	-2	-1
Treasury shares	-11	-12	-14
Total basic weighted average common shares outstanding	350	350	349
Effect of dilutive stock-based awards	0	1	0
Total diluted weighted average common shares outstanding	350	350	349
Basic (loss) earnings per common share	($2.13)	$0.75	$0.40
Diluted (loss) earnings per common share	($2.13)	$0.75	$0.40
Anti-dilutive stock options and restricted stock awards excluded from the diluted weighted average common share calculations	11	11	12

Other_Comprehensive_Income_Com

Other Comprehensive Income - Comprehensive Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Securities available for sale:
Net unrealized holding (losses) gains arising during the year, pretax	($19)		($177)		$177
Reclassification adjustment for realized gains included in net income, pretax					-16
Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity, pretax			-55		4
Net unrealized (losses) gains on securities available for sale, pretax			-232		165
Net unrealized holding (losses) gains arising during the year, tax	-7		-68		68
Reclassification adjustment for realized gains included in net income, tax					-6
Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity, tax			-21		2
Net unrealized (losses) gains on securities available for sale, tax			-89		64
Net unrealized (losses) gains arising during the year	-12		-109		109
Reclassification adjustment for realized gains included in net income, net of tax	0		0		-10
Reclassification adjustment for net unrealized holding gains on securities transferred between available for sale and held to maturity, net of tax	0		-34		2
Net unrealized (losses) gains on securities available for sale	-12		-143		101
Net unrealized holding gains on securities transferred between available for sale and held to maturity:
Net unrealized holding gains transferred during the year, pretax			55		-4
Amortization of net unrealized holding gains to income during the year, pretax	-13	[1]	-20	[1]	-3	[1]
Net unrealized holding gains (losses) on securities transferred during the year, pretax			35		-7
Net unrealized holding gains transferred during the year, tax			21		-2
Amortization of net unrealized holding gains to income during the year, tax	-5	[1]	-7	[1]	-1	[1]
Net unrealized holding gains (losses) on securities transferred during the year, tax			14		-3
Net unrealized holding gains transferred during the year, net of tax	0		34		-2
Amortization of net unrealized holding gains to income during the year, net of tax	-8		-12		-2	[1]
Net unrealized holding gains on securities transferred during the year	-8		22		-4
Interest rate swaps designated as cash flow hedges:
Net unrealized gains (losses) arising during the year, pretax					-1
Reclassification adjustment for realized losses included in net income, pretax	1	[2]	1	[2]	15	[2]
Net unrealized losses on interest rate swaps designated as cash flow hedges, pretax					15
Net unrealized gains (losses) arising during the year, tax					2
Reclassification adjustment for realized losses included in net income, tax	1	[2]	1	[2]	6	[2]
Net unrealized losses on interest rate swaps designated as cash flow hedges, tax					8
Net unrealized gains (losses) arising during the year, net of tax					-3
Reclassification adjustment for realized losses included in net income, net of tax	1		1		10
Net unrealized gains (losses) on interest rate swaps designated as cash flow hedges, net of tax	1		1		7
Pension and post-retirement plans:
Pension and post-retirement actuarial losses, pretax	-51		40		-24
Pension and post-retirement actuarial losses, tax	-16		15		-10
Pension and postretirement actuarial losses, net of tax	-34		25		-14
Total other comprehensive (loss) income, pretax	-81		-154		149
Total other comprehensive (loss) income, tax	-27		-59		59
Total other comprehensive (loss) income, net	($53)		($95)		$89
[1]	Included in Interest income on investment securities and other in our Consolidated Statement of Income.
[2]	Included in Interest expense on borrowings in our Consolidated Statement of Income.

Other_Comprehensive_Income_Cha

Other Comprehensive Income - Change in Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Amount expected to be reclassified over next twelve months on previous cash flow hedges from accumulated other comprehensive income to earnings	$1
Accumulated other comprehensive income
Net unrealized gains on securities available for sale, beginning balance	64	207	105
Net unrealized gains (losses) on securities transferred from available for sale to held to maturity, beginning balance	20	-2	3
Unrealized (losses) gains on interest rate swaps designated as cash flow hedges, beginning balance	-6	-6	-13
Pension and postretirement plans, beginning balance	16	-41	-27
Accumulated other comprehensive income, Total, Beginning balance	62	157	68
Net unrealized (losses) gains on securities available for sale, period change, net of tax	-12	-143	101
Net unrealized gains (losses) on securities transferred from available for sale to held to maturity, period change, net of tax	-8	22	-4
Net unrealized gains on interest rate swaps designated as cash flow hedges arising during the year	1	1	7
Pension and postretirement plans, period change, net of tax	-34	25	-14
Other comprehensive (loss) income	-53	-95	89
Net unrealized gains on securities available for sale, ending balance	52	64	207
Net unrealized gains (losses) on securities transferred from available for sale to held to maturity, ending balance	12	20	-2
Unrealized (losses) gains on interest rate swaps designated as cash flow hedges, ending balance	-5	-6	-6
Pension and postretirement plans, ending balance	51	16	-41
Accumulated other comprehensive income, Total, Ending balance	$9	$62	$157

StockBased_Compensation_Stock_

Stock-Based Compensation - Stock Option Activity (Details) (USD $)	12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding, beginning balance	11,186
Granted, number of shares	505		434	528
Forfeited, number of shares	-185
Expired, number of shares	-626
Options outstanding, ending balance	10,879		11,186
Options exercisable, number of shares	10,132
Options outstanding, weighted average exercise price, beginning of period	$13.23
Granted, weighted average exercise price	$9.27		$8.86	$9.84
Forfeited, weighted average exercise price	$9.13
Expired, weighted average exercise price	$16.92
Options outstanding, weighted average exercise price, end of period	$12.90		$13.23
Options exercisable, weighted average exercise price	$13.17
Options outstanding, weighted average remaining contractual term, ending balance	2 years 0 months
Options exercisable weighted average remaining contractual term	1 year 6 months
Options outstanding, aggregate intrinsic value, ending balance	$0	[1]
Options exercisable, aggregate intrinsic value	$0	[1]
[1]	Intrinsic value is the difference between the fair value of our stock at December 31, 2014 and the exercise price of the stock award. Due to the price of our stock at December 31, 2014, the outstanding and exercisable options had no intrinsic value.

StockBased_Compensation_Nonves

Stock-Based Compensation - Nonvested Stock Option Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nonvested stock options
Options outstanding, beginning balance	11,186
Granted, number of shares	505	434	528
Forfeited, number of shares	-185
Options outstanding, ending balance	10,879	11,186
Granted, weighted average exercise price	$9.27	$8.86	$9.84
Forfeited, weighted average exercise price	$9.13
Granted, weighted average grant date fair value	$2.59	$2.36	$2.73
Nonvested stock options
Nonvested stock options
Options outstanding, beginning balance	653
Granted, number of shares	505
Vested, number of shares	-225
Forfeited, number of shares	-185
Options outstanding, ending balance	748
Options outstanding, weighted average exercise price, beginning of period	$9.45
Granted, weighted average exercise price	$9.27
Vested, weighted average exercise price	$10.11
Forfeited, weighted average exercise price	$9.13
Options outstanding, weighted average exercise price, end of period	$9.21
Options outstanding, weighted average grant date fair value, beginning of period	$2.52
Granted, weighted average grant date fair value	$2.59
Vested, weighted average grant date fair value	$2.67
Forfeited, weighted average grant date fair value	$2.48
Options outstanding, weighted average grant date fair value, end of period	$2.54

StockBased_Compensation_Stock_1

Stock-Based Compensation - Stock Options Outstanding (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Stock Options Outstanding
Options Outstanding	10,879	11,186	11,175
Options Outstanding, Weighted Average Exercise Price	$12.90	$13.23	$13.65
Weighted Average Remaining Life (Years)	2 years 0 months	2 years 8 months	3 years 6 months
Options Exercisable	10,132	10,533	10,375
Options Exercisable, Weighted Average Exercise Price	$13.17	$13.46	$13.83
Exercise price range 1
Summary of Stock Options Outstanding
Exercise Price Range, Lower Range Limit	$8.86	$8.86	$9.71
Exercise Price Range, Upper Range Limit	$12	$12	$13
Options Outstanding	2,135	1,835	2,693
Options Outstanding, Weighted Average Exercise Price	$10.12	$10.25	$11.58
Weighted Average Remaining Life (Years)	6 years 4 months	6 years 9 months	5 years 7 months
Options Exercisable	1,388	1,225	2,165
Options Exercisable, Weighted Average Exercise Price	$10.61	$10.80	$12
Exercise price range 2
Summary of Stock Options Outstanding
Exercise Price Range, Lower Range Limit	$12.01	$12.01	$13.01
Exercise Price Range, Upper Range Limit	$13.50	$15	$16
Options Outstanding	7,628	9,099	8,168
Options Outstanding, Weighted Average Exercise Price	$13.05	$13.20	$13.30
Weighted Average Remaining Life (Years)	0 years 7 months	1 year 11 months	2 years 11 months
Options Exercisable	7,628	9,056	7,896
Options Exercisable, Weighted Average Exercise Price	$13.05	$13.19	$13.28
Exercise price range 3
Summary of Stock Options Outstanding
Exercise Price Range, Lower Range Limit	$13.51	$15.01	$16.01
Exercise Price Range, Upper Range Limit	$15.50	$18	$20
Options Outstanding	965	42	19
Options Outstanding, Weighted Average Exercise Price	$14.31	$15.25	$16.27
Weighted Average Remaining Life (Years)	3 years	6 months	7 months
Options Exercisable	965	42	19
Options Exercisable, Weighted Average Exercise Price	$14.31	$15.25	$16.27
Exercise price range 4
Summary of Stock Options Outstanding
Exercise Price Range, Lower Range Limit	$15.51	$18.01	$20.01
Exercise Price Range, Upper Range Limit	$51.78	$57.75	$57.75
Options Outstanding	151	210	295
Options Outstanding, Weighted Average Exercise Price	$35.38	$40.07	$41.96
Weighted Average Remaining Life (Years)	1 year 0 months	1 year 6 months	2 years
Options Exercisable	151	210	295
Options Exercisable, Weighted Average Exercise Price	$35.38	$40.07	$41.96

StockBased_Compensation_Stock_2

Stock-Based Compensation - Stock Option Valuation (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary of Stock Options Granted and Weighted Average Assumptions to Compute the Fair Value of the Options
Options granted	505	434	528
Grant date weighted average fair value per stock option	$2.59	$2.36	$2.73
Grant date weighted average share price	$9.27	$8.86	$9.84
Dividend yield	3.45%	3.61%	3.25%
Risk-free interest rate	2.05%	0.99%	1.26%
Expected volatility factor	38.59%	40.70%	40.36%
Expected life (in years)	6 years 7 months	5 years 8 months	5 years 7 months

StockBased_Compensation_Restri

Stock-Based Compensation - Restricted Stock Awards (Details) (Time-vested restricted stock, USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
Time-vested restricted stock
Summary of Restricted Stock Activity [Abstract]
Unvested, Number of shares, Beginning Balance	2,103
Unvested, Weighted Average Grant Date Fair Value, Beginning Balance	$9.65
Awarded Number of Shares	1,860
Awarded Weighted Average Grant Date Fair Value	$8.93
Vested Number of Shares	-707
Vested weighted average grant date fair value	$10.04
Forfeited Number of Shares	-555
Forfeited Weighted Average Grant Date Fair Value	$9.12
Unvested, Number of shares, Ending Balance	2,701
Unvested, Weighted Average Grant Date Fair Value, Ending Balance	$9.14

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expenses	$11,000,000	$10,000,000	$11,000,000
Stock held as Treasury Shares	12,613,836	12,060,739
Restricted stock activity, shares	1,151,193	1,320,324	786,670
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Term of award	10 years
Vesting period of grants	3 years
No stock options were exercised in 2014 and the intrinsic value of stock options exercised was less than $100,000 in 2013	0	100,000
Unrecognized compensation cost related to unvested	1,000,000
Weighted average period for cost recognition	1 year 2 months
Time-vested restricted stock
Share-based Compensation Arrangement by Share-based Payment Award
Awarded Number of Shares	1,860,000
Unrecognized compensation cost related to unvested	14,000,000
Weighted average period for cost recognition	1 year 10 months
Total fair value of restricted stock awards that vested during the period	$6,000,000	$5,000,000	$3,000,000
2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award
Authorized to issue up to common stock for grants of stock options	17,000,000
Shares available for Grant under the plan	12,000,000
Performance-based restricted stock
Share-based Compensation Arrangement by Share-based Payment Award
Awarded Number of Shares	339,000
Director | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Dividend equivalent units earned restricted stock units	5,295	4,495
Director | Time-vested restricted stock | Time-vested restricted stock
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period of grants	1 year
Employees | Time-vested restricted stock | Time-vested restricted stock
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period of grants	3 years

Benefit_Plans_Pension_Plan_Inf

Benefit Plans - Pension Plan Information (Details) (Pension plans [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$214	$243
Service cost	1	1	1
Interest cost	10	10	11
Actuarial loss (gain)	49	-26
Benefits paid	-15	-13
Projected benefit obligation at end of year	260	214	243
Change in fair value of plan assets:
Fair value of plan assets at beginning of year	290	276
Employer contributions	2	2
Actual return on plan assets	19	25
Benefits paid	-14	-13
Fair value of plan assets at end of year	296	290	276
Overfunded status at year end	$36	$76

Benefit_Plans_Net_Pension_Cost

Benefit Plans - Net Pension Cost (Details) (Pension plans [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension plans [Member]
Net pension cost
Service cost	$1	$1	$1
Interest cost	10	10	11
Expected return on plan assets	-17	-16	-14
Amortization of unrecognized loss	1	3	2
Net periodic pension (gain)	($5)	($2)	($2)

Benefit_Plans_Pension_Change_i

Benefit Plans - Pension Change in Assets and Benefit Obligations OCI (Details) (Pension plans [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension plans [Member]
Change in plan assets and benefit obligation recognized in other comprehensive income
Net loss (gain)	$46	($38)
Total loss (gain) loss recognized in other comprehensive income	46	-38
Total recognized in net periodic pension cost and other comprehensive income	$42	($40)

Benefit_Plans_Pension_Actuaria

Benefit Plans - Pension Actuarial Assumptions (Details) (Pension plans [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension plans [Member]
Projected benefit obligation:
Discount rate	3.99%	5.02%	4.04%
Net periodic pension cost:
Discount rate	5.01%	4.07%	5.16%
Expected long-term rate of return on plan assets	5.89%	5.89%	5.86%

Benefit_Plans_Pension_Fair_Val

Benefit Plans - Pension Fair Value Hierarchy (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	$296	$290	$276
Fair Value, Measurements, Recurring [Member] | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	296	290
Fair Value, Measurements, Recurring [Member] | Cash | Cash | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	14	43
Fair Value, Measurements, Recurring [Member] | Equity Securities | First Niagara Financial Group, Inc. common stock | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	1	1
Fair Value, Measurements, Recurring [Member] | Equity Securities | U.S. Companies | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		32
Fair Value, Measurements, Recurring [Member] | Equity Securities | International companies | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		2
Fair Value, Measurements, Recurring [Member] | Fixed Income Securities | Corporate Bonds | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	3	4
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Large cap growth | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	23	15
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Large cap value | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		9
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Foreign large cap blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		3
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Small and mid cap blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5	2
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Intermediate term bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	91
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Diversified emerging markets | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	1
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Real estate | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Foreign large value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	4
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | High yield bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	7
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | Inflation protected bond fund | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	43
Fair Value, Measurements, Recurring [Member] | Exchange Traded Funds | World bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	18
Fair Value, Measurements, Recurring [Member] | Mortgage Backed Securities, Other [Member] | Diversified emerging markets | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	7
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Intermediate term bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		58
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Diversified emerging markets | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	2	5
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Real estate | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	4	3
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Foreign large value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5	14
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Small and midcap growth and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		11
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Small and midcap, growth, value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	3
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Mortgage-backed securities | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		7
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Large blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	60	26
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | Total return investment grade securities | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		41
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | High yield bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		9
Fair Value, Measurements, Recurring [Member] | Mutual Fund Investments | World bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		4
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	294	286
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Cash | Cash | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	14	43
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Equity Securities | First Niagara Financial Group, Inc. common stock | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	1	1
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Equity Securities | U.S. Companies | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		32
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Equity Securities | International companies | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		2
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Large cap growth | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	23	15
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Large cap value | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		9
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Foreign large cap blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		3
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Small and mid cap blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5	2
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Intermediate term bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	91
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Diversified emerging markets | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	1
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Real estate | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Foreign large value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	4
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | High yield bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	7
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | Inflation protected bond fund | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	43
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Exchange Traded Funds | World bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	18
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mortgage Backed Securities, Other [Member] | Diversified emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	7
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Intermediate term bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		58
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Diversified emerging markets | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	2	5
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Real estate | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	4	3
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Foreign large value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	5	14
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Small and midcap growth and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		11
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Small and midcap, growth, value and blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	3
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Mortgage-backed securities | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		7
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Large blend | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	60	26
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | Total return investment grade securities | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		41
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | High yield bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		9
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Mutual Fund Investments | World bond | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category		4
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	3	4
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Fixed Income Securities | Corporate Bonds | Pension plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of the plan's assets by assets category	$3	$4

Benefit_Plans_Pension_Estimate

Benefit Plans - Pension Estimated Benefit Payments(Details) (Pension plans [Member], USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Pension plans [Member]
Estimated benefit payment under pension plan
2015	$14
2016	13
2017	14
2018	14
2019	14
2020-2024	$74

Benefit_Plans_OPEB_Change_in_B

Benefit Plans - OPEB Change in Benefit Obligation (Details) (Other Post-retirement Benefits, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Post-retirement Benefits
Change in accumulated post-retirement benefit obligation [Roll Forward]
Projected benefit obligation at beginning of year	$10	$13
Interest cost	1	1	1
Actuarial loss (gain)	4	-3
Benefits paid	-1	-1
Projected benefit obligation at end of year	14	10	13
Unfunded status at year end	($14)	($10)

Benefit_Plans_OPEB_Benefit_Cos

Benefit Plans - OPEB Benefit Cost (Details) (Other Post-retirement Benefits, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Post-retirement Benefits
Components of net periodic post-retirement benefit cost
Interest cost	$1	$1	$1
Total periodic post-retirement cost	$1	$0	$1

Benefit_Plans_OPEB_OCI_Details

Benefit Plans - OPEB OCI (Details) (Other Post-retirement Benefits, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Post-retirement Benefits
Change in plan benefit obligation recognized in other comprehensive income
Net loss (gain)	$4	($3)
Total loss (gain) recognized in other comprehensive income	4	-3
Total recognized in net periodic pension cost and other comprehensive income	$5	($2)

Benefit_Plans_OPEB_Actuarial_A

Benefit Plans - OPEB Actuarial Assumptions (Details) (Other Post-retirement Benefits)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Post-retirement Benefits
Accumulated Post Retirement Benefit Obligation
Discount rate	3.90%	4.87%	3.89%
Total Periodic Cost
Discount rate	4.87%	3.89%	5.19%

Benefit_Plans_OPEB_Estimated_B

Benefit Plans - OPEB Estimated Benefit Payments (Details) (Other Post-retirement Benefits, USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Other Post-retirement Benefits
Estimated benefit payment under pension plan
2015	$1
2016	1
2017	1
2018	1
2019	1
2020-2024	$4

Benefit_Plans_Pension_and_OPEB

Benefit Plans - Pension and OPEB Statement of Condition (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Accumulated other comprehensive loss (income), net of taxes:
Accumulated other comprehensive income, pension and Post-retirement benefit plan	$51	$16	($41)	($27)
Pension plans
Other Assets:
Fair value of plan assets in excess of projected benefit obligation	36	76
Accumulated other comprehensive loss (income), net of taxes:
Accumulated other comprehensive income, pension and Post-retirement benefit plan	50	19
Other Post-retirement Benefits
Other Liabilities:
Accumulated post-retirement benefit obligation	14	10
Accumulated other comprehensive loss (income), net of taxes:
Accumulated other comprehensive income, pension and Post-retirement benefit plan	$1	($2)

Benefit_Plans_Details_Textual

Benefit Plans (Details Textual) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2015	Dec. 31, 2011
Benefit Plans (Textual) [Abstract]
Accumulated other comprehensive income, pension and Post-retirement benefit plan	$51	$16	-41		($27)
Pension plans
Benefit Plans (Textual) [Abstract]
Accumulated other comprehensive income, pension and Post-retirement benefit plan	50	19
Expected rate of return on Plan's target allocation	5.89%	5.89%	5.86%
SERPs
Benefit Plans (Textual) [Abstract]
Accumulated other comprehensive income, pension and Post-retirement benefit plan	6	3
Projected benefit obligation and accumulated benefit obligation	23	21
First Niagara Plan
Benefit Plans (Textual) [Abstract]
Long term inflation rate	2.50%
Expected rate of return on Plan's target allocation	5.50%
New Alliance Plan
Benefit Plans (Textual) [Abstract]
Long term inflation rate	2.50%
Expected rate of return on Plan's target allocation	5.50%
Other Post-retirement Benefits
Benefit Plans (Textual) [Abstract]
Accumulated other comprehensive income, pension and Post-retirement benefit plan	1	-2
Assumed health care cost trend rate in 2014	6.40%
Assumed health care cost trend rate by 2018	5.60%
Year that Rate Reaches Ultimate Trend Rate	2018
Effect of one percentage point increase on accumulated postretirement benefit obligation percentage	7.00%
Effect of one percentage point Increase on service and interest cost components percentage	6.00%
Effect of one percentage point decrease on accumulated postretirement benefit obligation percentage	6.00%
Effect of one percentage point decrease on service and interest cost components percentage	5.00%
Plan 401 k
Benefit Plans (Textual) [Abstract]
Percentage of employer contribution of first 4% of employee contribution	100.00%
Percentage of employee contribution for initial employer contribution	4.00%
Additional percentage of employer contribution of employee contribution between 5% and 6%	50.00%
Vested matching contribution	100.00%
Contribution to 401(k) plan	14	13	11
Plan 401 k | Minimum [Member]
Benefit Plans (Textual) [Abstract]
Percentage of employee contribution for additional employer contribution	5.00%
Plan 401 k | Maximum [Member]
Benefit Plans (Textual) [Abstract]
Percentage of employee contribution for additional employer contribution	6.00%
Fixed Income Securities | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities	74.00%
Fixed Income Securities | First Niagara Plan | Minimum [Member]
Benefit Plans (Textual) [Abstract]
Return on fixed income securities	2.50%
Fixed Income Securities | First Niagara Plan | Maximum [Member]
Benefit Plans (Textual) [Abstract]
Return on fixed income securities	3.50%
Fixed Income Securities | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities	30.00%
Fixed Income Securities | New Alliance Plan | Minimum [Member]
Benefit Plans (Textual) [Abstract]
Return on fixed income securities	2.50%
Fixed Income Securities | New Alliance Plan | Maximum [Member]
Benefit Plans (Textual) [Abstract]
Return on fixed income securities	3.50%
Equity Securities | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities	21.00%
Equity Securities | First Niagara Plan | Minimum [Member]
Benefit Plans (Textual) [Abstract]
Return on Equity Securities	7.50%
Equity Securities | First Niagara Plan | Maximum [Member]
Benefit Plans (Textual) [Abstract]
Return on Equity Securities	8.50%
Equity Securities | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities	65.00%
Equity Securities | New Alliance Plan | Minimum [Member]
Benefit Plans (Textual) [Abstract]
Return on Equity Securities	7.50%
Equity Securities | New Alliance Plan | Maximum [Member]
Benefit Plans (Textual) [Abstract]
Return on Equity Securities	8.50%
Cash | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, cash	5.00%
Cash | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, cash	5.00%
Other benefit plan [Member]
Benefit Plans (Textual) [Abstract]
Expense under these plans	$25	$27	18
Plan target asset allocation for 2015 [Member] | Fixed Income Securities | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities				57.00%
Plan target asset allocation for 2015 [Member] | Fixed Income Securities | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities				57.00%
Plan target asset allocation for 2015 [Member] | Equity Securities | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities				38.00%
Plan target asset allocation for 2015 [Member] | Equity Securities | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, fixed income securities				38.00%
Plan target asset allocation for 2015 [Member] | Cash | First Niagara Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, cash				5.00%
Plan target asset allocation for 2015 [Member] | Cash | New Alliance Plan
Benefit Plans (Textual) [Abstract]
Plan's Target Allocation Percentage, cash				5.00%

Benefit_Plans_Details_Textual_

Benefit Plans (Details Textual 1) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Benefit Plans (Textual) [Abstract]
Amount of unallocated shares held by ESOP	0	2,001,373
Employee Stock Ownership Plan (ESOP)
Benefit Plans (Textual) [Abstract]
Annual loan payable installments years	30 years
Compensation expense	$2,000,000	$1,000,000	$2,000,000
Shares allocated to participants	297,000	178,000	178,000
Amount of unallocated shares held by ESOP		2,000,000
Amount of allocated shares held by ESOP	2,000,000	2,000,000
Fair value of unallocated ESOP shares	$0	$21,000,000

Fair_Value_Measurements_Fair_V

Fair Value Measurements - Fair Value Option on Loans Held for Sale (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Loans held for sale
Fair value carrying amount	$35	$50
Aggregate unpaid principal balance	34	49
Fair value carrying amount less aggregate unpaid principal balance	$1	$1

Fair_Value_Measurements_Fair_V1

Fair Value Measurements - Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets:
Securities available for sale, fair value	$5,915	$7,423
Loans held for sale	35	50
Debt securities [Member]
Assets:
Securities available for sale, fair value	1,492	1,734
Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	1,286	1,490
Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	1,032	1,152
Commercial mortgage-backed securities, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,500	1,831
Mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	2,786	3,321
Collateralized loan obligations, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,016	1,431
States and political subdivisions [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	453	529
U.S. Treasury [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	25	20
U.S. government sponsored enterprises [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	191	312
Corporate [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	823	872
Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	34	40
Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	100	139
Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	682	761
Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	120	159
Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	350	379
Non-agency issued [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value		13
Fair Value, Measurements, Recurring [Member]
Assets:
Securities available for sale, fair value	5,915	7,423
Loans held for sale	35	50
Derivatives	93	49
Total assets	6,043	7,522
Liabilities:
Derivatives	94	50
Fair Value, Measurements, Recurring [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	1,492	1,734
Fair Value, Measurements, Recurring [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	1,286	1,490
Fair Value, Measurements, Recurring [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	1,032	1,152
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	2,786	3,321
Fair Value, Measurements, Recurring [Member] | Collateralized loan obligations, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,016	1,431
Fair Value, Measurements, Recurring [Member] | States and political subdivisions [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	453	529
Fair Value, Measurements, Recurring [Member] | U.S. Treasury [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	25	20
Fair Value, Measurements, Recurring [Member] | U.S. government sponsored enterprises [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	191	312
Fair Value, Measurements, Recurring [Member] | Corporate [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	823	872
Fair Value, Measurements, Recurring [Member] | Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	34	40
Fair Value, Measurements, Recurring [Member] | Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	100	139
Fair Value, Measurements, Recurring [Member] | Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	682	761
Fair Value, Measurements, Recurring [Member] | Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	120	159
Fair Value, Measurements, Recurring [Member] | Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	350	379
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations, non-agency issued [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value		13
Fair Value, Measurements, Recurring [Member] | Non-agency issued [Member] | Commercial mortgage-backed securities, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,500	1,831
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]
Assets:
Securities available for sale, fair value	599	905
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Student loans [Member]
Assets:
Securities available for sale, fair value	235	312
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Credit cards [Member]
Assets:
Securities available for sale, fair value	42	73
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Auto loans [Member]
Assets:
Securities available for sale, fair value	194	335
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Other Loans [Member]
Assets:
Securities available for sale, fair value	127	186
Fair Value, Measurements, Recurring [Member] | Other securities [Member]
Assets:
Securities available for sale, fair value	22	33
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Securities available for sale, fair value	47	43
Total assets	47	43
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	25	20
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Treasury [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	25	20
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other securities [Member]
Assets:
Securities available for sale, fair value	21	22
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Securities available for sale, fair value	5,865	7,376
Loans held for sale	35	50
Derivatives	93	49
Total assets	5,993	7,476
Liabilities:
Derivatives	94	50
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	1,463	1,709
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	1,286	1,490
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	1,032	1,152
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	2,786	3,321
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Collateralized loan obligations, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,016	1,431
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | States and political subdivisions [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	453	529
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. government sponsored enterprises [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	191	312
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	818	868
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Government National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	34	40
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Federal National Mortgage Association [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	100	139
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Federal National Mortgage Association [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	682	761
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Federal Home Loan Mortgage Corporation [Member] | Residential mortgage-backed securities [Member]
Assets:
Securities available for sale, fair value	120	159
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Federal Home Loan Mortgage Corporation [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value	350	379
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Collateralized Mortgage Obligations, non-agency issued [Member] | Collateralized mortgage obligations [Member]
Assets:
Securities available for sale, fair value		13
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Non-agency issued [Member] | Commercial mortgage-backed securities, non-agency issued [Member]
Assets:
Securities available for sale, fair value	1,500	1,831
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member]
Assets:
Securities available for sale, fair value	599	905
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member] | Student loans [Member]
Assets:
Securities available for sale, fair value	235	312
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member] | Credit cards [Member]
Assets:
Securities available for sale, fair value	42	73
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member] | Auto loans [Member]
Assets:
Securities available for sale, fair value	194	335
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed securities [Member] | Other Loans [Member]
Assets:
Securities available for sale, fair value	127	186
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other securities [Member]
Assets:
Securities available for sale, fair value	1	10
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets:
Securities available for sale, fair value	4	4
Total assets	4	4
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	4	4
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate [Member] | Debt securities [Member]
Assets:
Securities available for sale, fair value	$4	$4

Fair_Value_Measurements_Fair_V2

Fair Value Measurements - Fair Value, Assets and Liabilities Measured on Nonrecurring Basis (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary of assets and liabilities measured at fair value on a nonrecurring basis
Collateral dependent impaired loans	$10	$32
Level 1 [Member]
Summary of assets and liabilities measured at fair value on a nonrecurring basis
Collateral dependent impaired loans	0	0
Level 2 [Member]
Summary of assets and liabilities measured at fair value on a nonrecurring basis
Collateral dependent impaired loans	10	20
Level 3 [Member]
Summary of assets and liabilities measured at fair value on a nonrecurring basis
Collateral dependent impaired loans	0	12
Collateral Dependent Impaired Loans [Member]
Summary of assets and liabilities measured at fair value on a nonrecurring basis
Total gains (losses)	$0	($2)

Fair_Value_Measurements_Change

Fair Value Measurements - Change in Level 3 Assets Measured on Recurring Basis (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis [Roll Forward]
Balance at beginning of period			$1,559
Transfers between level 2 and level 3			-1,545	[1]
Settlements			-10
Gains included in other comprehensive income			1
Losses included in earnings			-1
Balance at end of period			4
Trust preferred securities [Member]
Changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis [Roll Forward]
Balance at beginning of period	4		14
Transfers between level 2 and level 3	0	[1]	0	[1]
Settlements	0		-10
Gains included in other comprehensive income	0		1
Losses included in earnings	0		-1
Balance at end of period	4		4
Collateralized loan obligations [Member]
Changes in Level 3 assets and liabilities measured at estimated fair value on a recurring basis [Roll Forward]
Balance at beginning of period			1,545
Transfers between level 2 and level 3			-1,545	[1]
Settlements			0
Gains included in other comprehensive income			0
Losses included in earnings			0
Balance at end of period			$0
[1]	Our policy is to recognize the transfer at the beginning of the period.

Fair_Value_Measurements_Fair_V3

Fair Value Measurements - Fair Value of Financial Instruments by Balance Sheet Grouping (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Financial assets:
Cash and cash equivalents	$420		$463		$431	$837
Securities available for sale, fair value	5,915		7,423
Securities held to maturity, fair value	5,942		4,042
Investment securities held to maturity	5,964		3,988
Federal Home Loan Bank and Federal Reserve Bank common stock	412		469
Loans held for sale	40		50		155
Derivatives	96	[1]	76	[1]
Financial liabilities:
Deposits	27,781		26,665
Derivatives	97	[1]	77	[1]
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Level 1 [Member]
Financial assets:
Cash and cash equivalents	420		463
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair value inputs level 1, 2, 3 [Member]
Financial assets:
Securities available for sale, fair value	5,915		7,423
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Level 2 [Member]
Financial assets:
Securities held to maturity, fair value	5,942		4,042
Federal Home Loan Bank and Federal Reserve Bank common stock	412		469
Loans held for sale	40		50
Derivatives	93		49
Accrued interest receivable	101		103
Financial liabilities:
Deposits	27,781		26,665
Borrowings	6,206		5,556
Derivatives	94		50
Accrued interest payable	11		10
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair value inputs level 2, 3 [Member]
Financial assets:
Loans and leases, net	22,803		21,230
Estimate of Fair Value, Fair Value Disclosure [Member] | Level 1 [Member]
Financial assets:
Cash and and cash equivalents, fair value	420		463
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair value inputs level 1, 2, 3 [Member]
Financial assets:
Securities available for sale, fair value	5,915		7,423
Estimate of Fair Value, Fair Value Disclosure [Member] | Level 2 [Member]
Financial assets:
Investment securities held to maturity	5,964		3,988
Federal Home Loan Bank and Federal Reserve Bank common stock	412		469
Loans held for sale	40		50
Derivatives	93		49
Accrued interest receivable	101		103
Financial liabilities:
Deposits	27,793		26,695
Borrowings	6,215		5,599
Derivatives	94		50
Accrued interest payable	11		10
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair value inputs level 2, 3 [Member]
Financial assets:
Loans and leases, net	$23,037		$21,774
[1]	Represents gross amounts, included in Other Assets in our Consolidated Statements of Condition.

Fair_Value_Measurements_Detail

Fair Value Measurements (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities price at broker quotes	$0
Maximum days for completion of appraisals or evaluations for assets	90 days
Original maturity period for cash and cash equivalents (3 months or less)	3 months
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans fair value disclosure	10,000,000	32,000,000
Fair Value, Measurements, Nonrecurring [Member] | Collateral Dependent Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net increase in allowance for credit losses	100,000	2,000,000
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent impaired loans fair value disclosure	$10,000,000	$20,000,000

Segment_Information_Details

Segment Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Segment
Segment Reporting Information [Line Items]
Number of Reportable Segments	2
Financial information of business segments
Net interest income	$1,086,000,000	$1,093,000,000	$1,023,000,000
Provision for credit losses	96,000,000	105,000,000	92,000,000
Net interest income after provision for credit losses	990,000,000	988,000,000	931,000,000
Noninterest income	310,000,000	366,000,000	360,000,000
Amortization of intangibles	27,000,000	40,000,000	45,000,000
Goodwill impairment	1,100,000,000	0	0
Other noninterest expense	997,000,000	891,000,000	1,006,000,000
(Loss) income before income taxes	-824,000,000	423,000,000	239,000,000
Income tax (benefit)	-109,000,000	128,000,000	71,000,000
Net (loss) income	-715,000,000	295,000,000	168,000,000
Banking [Member]
Financial information of business segments
Net interest income	1,086,000,000	1,093,000,000	1,023,000,000
Provision for credit losses	96,000,000	105,000,000	92,000,000
Net interest income after provision for credit losses	990,000,000	988,000,000	931,000,000
Noninterest income	244,000,000	298,000,000	291,000,000
Amortization of intangibles	24,000,000	37,000,000	41,000,000
Goodwill impairment	1,100,000,000	0
Other noninterest expense	940,000,000	839,000,000	955,000,000
(Loss) income before income taxes	-831,000,000	411,000,000	227,000,000
Income tax (benefit)	-112,000,000	123,000,000	66,000,000
Net (loss) income	-719,000,000	288,000,000	161,000,000
Financial services [Member]
Financial information of business segments
Net interest income	0	0	0
Provision for credit losses	0	0	0
Net interest income after provision for credit losses	0	0	0
Noninterest income	66,000,000	67,000,000	68,000,000
Amortization of intangibles	3,000,000	3,000,000	4,000,000
Goodwill impairment	0
Other noninterest expense	57,000,000	52,000,000	51,000,000
(Loss) income before income taxes	7,000,000	12,000,000	13,000,000
Income tax (benefit)	3,000,000	5,000,000	5,000,000
Net (loss) income	$4,000,000	$7,000,000	$8,000,000

Condensed_Parent_Company_Only_2

Condensed Parent Company Only Balance Sheet (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2009
In Millions, unless otherwise specified
ASSETS
Cash and cash equivalents	$420	$463	$431	$837
Securities available for sale, fair value	5,915	7,423
Deferred taxes	255	77
Other assets	769	574
Total assets	38,551	37,628			15,000
LIABILITIES AND STOCKHOLDERS’ EQUITY
Stockholders equity	4,093	4,993	4,927	4,798
Total liabilities and stockholders’ equity	38,551	37,628
Parent Company
ASSETS
Cash and cash equivalents	383	390	415	514
Securities available for sale, fair value	0	3
Loan receivable from ESOP	0	21
Investment in subsidiary	4,388	5,255
Deferred taxes	32	34
Other assets	13	13
Total assets	4,815	5,715
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable and other liabilities	12	13
Borrowings	710	709
Stockholders equity	4,093	4,993
Total liabilities and stockholders’ equity	$4,815	$5,715

Condensed_Parent_Company_Only_3

Condensed Parent Company Only Income Statement (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Condensed Statements of Income
Total interest income	$1,207		$1,210		$1,176
Interest expense	122		117		153
Net interest income	1,086		1,093		1,023
Noninterest income	310		366		360
Noninterest expense	2,124		931		1,051
(Loss) income before income taxes	-824		423		239
Income tax benefit	-109		128		71
Net (loss) income	-715		295		168
Preferred stock dividend	30		30		28
Net (loss) income available to common stockholders	-745		265		141
Other comprehensive (loss) income	-53		-95		89
Total comprehensive (loss) income	-768		200		258
Parent Company
Condensed Statements of Income
Interest income	1		2		7
Dividends received from subsidiary	80		175		45
Total interest income	81		177		52
Interest expense	48		49		50
Net interest income	33		128		3
Noninterest income	3		2		3
Noninterest expense	27		30		27
(Loss) income before income taxes	9		100		-21
Income tax benefit	-28		-29		-24
Income before undisbursed income of subsidiary	36		129		3
Undisbursed (loss) income of subsidiary	-751		167		166
Net (loss) income	-715		295		168
Preferred stock dividend	30		30		28
Net (loss) income available to common stockholders	-745		265		141
Other comprehensive (loss) income	-53	[1]	-95	[1]	89	[1]
Total comprehensive (loss) income	($768)		$200		$258
[1]	See Consolidated Statements of Comprehensive Income for other comprehensive income detail.

Condensed_Parent_Company_Only_4

Condensed Parent Company Only Cash Flow (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net (loss) income	($715)	$295	$168
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Stock-based compensation expense	11	10	11
Deferred income tax expense (benefit)	-150	5	34
Net cash provided by operating activities	484	716	159
Cash flows from investing activities:
Proceeds from maturities of securities available for sale	371	196	242
Principal payments received on securities available for sale	952	1,124	2,108
Purchases of securities available for sale	-162	-1,497	-6,273
Proceeds from sales of securities available for sale	331	485	3,239
Acquisitions, net of cash and cash equivalents	0	0	7,703
Other, net	-68	-32	53
Net cash (used in) provided by investing activities	-2,136	-1,375	5,574
Cash flows from financing activities:
Return of capital from subsidiary	85
Dividends paid on preferred stock	-30	-30	-28
Dividends paid on common stock	-113	-112	-112
Proceeds from (Payments for) Other Financing Activities	-1	-1	-1
Net cash provided by (used in) financing activities	1,610	692	-6,138
Net decrease in cash and cash equivalents	-43	32	-406
Cash and cash equivalents at beginning of period	463	431	837
Cash and cash equivalents at end of period	420	463	431
Parent Company
Cash flows from operating activities:
Net (loss) income	-715	295	168
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Undisbursed loss (income) of subsidiaries	751	-167	-166
Stock-based compensation expense	11	9	11
Deferred income tax expense (benefit)	2	-18	7
(Increase) decrease in other assets	-2	7	35
Decrease in other liabilities	-1	-9	-18
Net cash provided by operating activities	46	118	38
Cash flows from investing activities:
Proceeds from maturities of securities available for sale	3	0	0
Principal payments received on securities available for sale	0	1	2
Purchases of securities available for sale	0	-2	0
Capital contributed to subsidiary	0	0	-215
Repayments from subsidiary	0	0	215
Repayment of ESOP loan receivable	15	1	1
Other, net	1	-1	0
Net cash (used in) provided by investing activities	19	0	3
Cash flows from financing activities:
Return of capital from subsidiary	85	0	0
Repurchase of shares upon ESOP termination	-14	0	0
Dividends paid on preferred stock	-30	-30	-28
Dividends paid on common stock	-113	-112	-112
Net cash provided by (used in) financing activities	-72	-143	-140
Net decrease in cash and cash equivalents	-7	-25	-99
Cash and cash equivalents at beginning of period	390	415	514
Cash and cash equivalents at end of period	$383	$390	$415