MUFG Americas (UB) 10-K 2 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015
Document And Entity Information
Entity Registrant Name	MUFG Americas Holdings Corp
Entity Central Index Key	1011659
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Public Float	$0
Entity Common Stock, Shares Outstanding		136,330,831
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	UB

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Interest Income
Loans	$2,805	$2,641	$2,439
Securities	452	469	527
Other	13	13	6
Total interest income	3,270	3,123	2,972
Interest Expense
Deposits	238	248	214
Commercial paper and other short-term borrowings	5	5	9
Long-term debt	165	154	147
Total interest expense	408	407	370
Net Interest Income	2,862	2,716	2,602
(Reversal of) provision for credit losses	6	-29	8
Net interest income after (reversal of) provision for credit losses	2,856	2,745	2,594
Noninterest Income
Service charges on deposit accounts	203	209	209
Trust and investment management fees	104	135	119
Trading account activities	71	61	101
Securities gains, net	18	178	108
Credit facility fees	122	111	105
Merchant banking fees	124	93	89
Brokerage commissions and fees	53	46	39
Card processing fees, net	34	34	32
Fees from affiliates	319	0	0
Other, net	75	9	16
Total noninterest income	1,123	876	818
Noninterest Expense
Salaries and employee benefits	1,785	1,631	1,479
Net occupancy and equipment	296	306	267
Professional and outside services	256	250	228
Regulatory assessments	57	74	65
Intangible asset amortization	52	65	81
Other	453	451	463
Total noninterest expense	2,899	2,777	2,583
Income before income taxes and including noncontrolling interests	1,080	844	829
Income tax expense	274	195	220
Net Income including Noncontrolling Interests	806	649	609
Deduct: Net loss from noncontrolling interests	19	18	19
Net Income attributable to MUAH	$825	$667	$628

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 Income Attributable to MUAH	$825	$667	$628
Other Comprehensive Income (Loss), Net of Tax:
Net change in unrealized gains (losses) on cash flow hedges	5	-8	41
Net change in unrealized gains (losses) on investment securities	183	-487	266
Foreign currency translation adjustment	-7	-4	1
Net change in gains (losses) on pension and other postretirement benefits	-286	389	-13
Total other comprehensive income (loss)	-105	-110	295
Comprehensive Income (Loss) Attributable to MUAH	720	557	923
Comprehensive loss from noncontrolling interests	-19	-18	-19
Total Comprehensive Income (Loss)	$701	$539	$904

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets
Cash and due from banks	$1,759	$1,863
Interest bearing deposits in banks	3,930	4,329
Federal funds sold and securities purchased under resale agreements	62	11
Total cash and cash equivalents	5,751	6,203
Trading account assets (includes $69 at December 31, 2014 and $8 at December 31, 2013 of assets pledged as collateral)	1,114	851
Securities available for sale	13,724	15,817
Securities held to maturity (Fair value $8,412 at December 31, 2014 and $6,439 at December 31, 2013)	8,291	6,509
Loans held for investment	76,804	68,312
Allowance for loan losses	-537	-568
Loans held for investment, net	76,267	67,744
Premises and equipment, net	621	688
Goodwill	3,225	3,228
Other assets	4,685	4,854
Total assets	113,678	105,894
Deposits:
Noninterest bearing	30,534	26,495
Interest bearing	55,470	53,606
Total deposits	86,004	80,101
Commercial paper and other short-term borrowings	2,704	2,563
Long-term debt	6,972	6,547
Trading account liabilities	894	540
Other liabilities	1,889	1,675
Total liabilities	98,463	91,426
Commitments, contingencies and guarantees—See Note 20
MUAH stockholder's equity:
Preferred stock: Authorized 5,000,000 shares; no shares issued or outstanding	0	0
Common stock, par value $1 per share: Authorized 300,000,000 shares, 136,330,831 shares issued and outstanding as of December 31, 2014 and 136,330,830 as of December 31, 2013	136	136
Additional paid-in capital	7,232	7,191
Retained earnings	8,346	7,512
Accumulated other comprehensive loss	-729	-624
Total MUAH stockholder's equity	14,985	14,215
Noncontrolling interests	230	253
Total equity	15,215	14,468
Total liabilities and equity	$113,678	$105,894

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]
Trading account assets pledged as collateral	$69	$8
Fair value of securities held to maturity	$8,412	$6,439
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$1	$1
Common stock, share authorized	300,000,000	300,000,000
Common stock, share issued	136,330,831	136,330,830
Common stock, share outstanding	136,330,831	136,330,830

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholder's Equity (USD $)		Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
In Millions, except Share data
BALANCE, beginning at Dec. 31, 2011		$11,801	$136	$5,989	$6,217	($809)	$268
BALANCE beginning, shares at Dec. 31, 2011			136,330,830
Net income (loss)		609			628		-19
Other comprehensive income (loss), net of tax		295				295
Compensation - restricted stock units		5		5
Other		15					15
Net change		924		5	628	295	-4
BALANCE, ending at Dec. 31, 2012		12,725	136	5,994	6,845	-514	264
BALANCE ending, shares at Dec. 31, 2012			136,330,830
Net income (loss)		649			667		-18
Other comprehensive income (loss), net of tax		-110				-110
Compensation - restricted stock units		-5		-5
Capital Contribution from BTMU	[1]	1,200		1,200
Other		9		2			7
Net change		1,743		1,197	667	-110	-11
BALANCE, ending at Dec. 31, 2013		14,468	136	7,191	7,512	-624	253
BALANCE beginning, shares at Dec. 31, 2013			136,330,830
Net income (loss)		806			825		-19
Other comprehensive income (loss), net of tax		-105				-105
Compensation - restricted stock units		10		10
Capital Contribution from BTMU	[1]	31		31
Capital Contribution from BTMU, shares	[1]		1
Other	[1]	5			9		-4
Net change		747		41	834	-105	-23
Net change, shares			1
BALANCE, ending at Dec. 31, 2014		$15,215	$136	$7,232	$8,346	($729)	$230
BALANCE ending, shares at Dec. 31, 2014			136,330,831
[1]	For additional information on the capital contribution, refer to Note 21 to these consolidated financial statements.

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 income including noncontrolling interests	$806		$649		$609
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
(Reversal of) provision for credit losses	6		-29		8
Depreciation, amortization and accretion, net	324		434		416
Stock-based compensation—restricted stock units	34		21		5
Deferred income taxes	103		61		81
Net gains on sales of securities	-18		-178		-108
Net decrease (increase) in trading account assets	-263		357		-74
Net decrease (increase) in other assets	-71		-312		357
Net increase (decrease) in trading account liabilities	354		-355		-144
Net increase (decrease) in other liabilities	408		363		-531
Loans originated for sale	-841		-622		-211
Net proceeds from sale of loans originated for sale	839		599		148
Pension and other benefits	-80		-262		-26
Other, net	21		-37		-70
Total adjustments	816		40		-149
Net cash provided by (used in) operating activities	1,622		689		460
Cash Flows from Investing Activities:
Proceeds from sales of securities available for sale	1,376		8,340		6,845
Proceeds from paydowns and maturities of securities available for sale	2,373		3,451		7,657
Purchases of securities available for sale	-1,317		-11,106		-9,499
Proceeds from paydowns and maturities of securities held to maturity	1,047		501		238
Purchases of securities held to maturity	-2,845		-1,682		-941
Proceeds from sales of loans	196		254		202
Net decrease (increase) in loans	-8,664		-4,912		-4,100
Net cash acquired from (paid for) acquisitions	0		-3,185		53
Other, net	-686		-192		-65
Net cash provided by (used in) investing activities	-8,520		-8,531		390
Cash Flows from Financing Activities:
Net increase (decrease) in deposits	5,903		5,224		4,230
Net increase (decrease) in commercial paper and other short-term borrowings	141		1,200		-2,670
Proceeds from Contributed Capital	0		1,200		0
Proceeds from issuance of subordinated debt due to BTMU	0		1,050		0
Proceeds from issuance of long-term debt	749		1,999		895
Repayment of long-term debt	-318		-2,103		-2,025
Other, net	-25		-25		1
Change in noncontrolling interests	-4		9		15
Net cash provided by (used in) financing activities	6,446		8,554		446
Net change in cash and cash equivalents	-452		712		1,296
Cash and cash equivalents at beginning of period	6,203		5,491		4,195
Cash and cash equivalents at end of period	5,751		6,203		5,491
Cash Paid During the Period For:
Interest	408		396		404
Income taxes, net	38		15		207
Acquisitions:
Fair value of assets acquired	0		3,487		7,655
Fair value of liabilities assumed	0		573		6,139
Transfer of assets and liabilities from BTMU:
Carrying amount of assets acquired	70	[1]	0	[1]	0	[1]
Carrying amount of liabilities assumed	31	[1]	0	[1]	0	[1]
Supplemental Schedule of Noncash Investing and Financing Activities:
Securities available for sale transferred to securities held to maturity	0		4,386		155
Net transfer of loans held for investment to loans held for sale	196		246		155
Transfer of loans held for investment to OREO	28		49		100
Carrying amount of securities held to maturity immediately prior to transfer to securities available for sale	$0		$0		$1,112
[1]	For additional information on the transfer of assets and liabilities from BTMU, refer to Note 21 to these consolidated financial statements.

Summary_of_Significant_Account

Summary of Significant Accounting Policies and Nature of Operations	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Nature of Operations	duction
	MUFG Americas Holdings Corporation (MUAH) is a financial holding company and a bank holding company whose principal subsidiary is MUFG Union Bank, N.A. (MUB). The Company provides a wide range of financial services to consumers, small businesses, middle-market companies and major corporations nationally and internationally.
	On November 4, 2008, the Company became a privately held company (privatization transaction). All of the Company's issued and outstanding shares of common stock are owned by BTMU.
	Principles of Consolidation and Basis of Financial Statement Presentation
	The consolidated financial statements include the accounts of the Company and other entities in which the Company has a controlling financial interest. The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a VIE. The primary beneficiary of a VIE is the entity that has the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and has the obligation to absorb losses or receive benefits from the VIE that could potentially be significant to the VIE. Results of operations from VIEs are included from the dates that the Company became the primary beneficiary. All intercompany transactions and balances with consolidated entities are eliminated in consolidation.
	The Company accounts for equity investments over which it exerts significant influence using the equity method of accounting. Non-marketable equity investments where the Company does not exert significant influence are accounted for at cost. Investments accounted for under both the equity method and cost method are included in other assets.
	The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States of America (GAAP) The policies that materially affect the determination of financial position, results of operations and cash flows are summarized below.
	The preparation of financial statements in conformity with GAAP also requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Although such estimates contemplate current conditions and management's expectations of how they may change in the future, it is reasonably possible that actual results could differ significantly from those estimates. This could materially affect the Company's results of operations and financial condition in the near term. Significant estimates made by management in the preparation of the Company's financial statements include, but are not limited to, the fair value of assets acquired and liabilities assumed (Note 2), the evaluation of other-than-temporary impairment on investment securities (Note 3), the allowance for credit losses (Note 4), purchased credit-impaired loans (Note 4), goodwill impairment (Note 6), fair value of financial instruments (Note 11), hedge accounting (Note 12), pension accounting (Note 15), and income taxes (Note 17).
	During 2014, the Company identified that certain noncash items related to the amortization and accretion of interest income and expense on loans held for investment, and activities related to loan syndications, had been reported as cash flows from investing activities but should have been presented as cash flows from operating activities.  The loan syndication activities were also incorrectly reported as noncash transfers from loans held for investment to loans held for sale in the supplemental schedule of noncash investing and financing activities. The Company corrected the prior period presentations to conform to the presentation adopted in 2014.  The Company has evaluated the effect of the incorrect presentation and determined that the errors were not material, either individually or in the aggregate, to any of the Company’s previously filed annual or quarterly consolidated financial statements.
	The following tables display the affected line items for 2013 and 2012:
			For the Year Ended December 31, 2013
	(Dollars in millions)		As Previously Reported			Reclassification Amounts			As Revised
	Cash Flows from Operating Activities:
	Depreciation, amortization and accretion, net		$	509		$	(75	)	$	434
	Loans originated for sale		(276		)	(346		)	(622		)
	Net proceeds from sale of loans originated for sale		226			373			599
	Net cash provided by (used in) operating activities		737			(48		)	689
	Cash Flows from Investing Activities:
	Proceeds from sales of loans		627			(373		)	254
	Net decrease (increase) in loans		(5,333		)	421			(4,912		)
	Net cash provided by (used in) investing activities		(8,579		)	48			(8,531		)
	Cash Flows from Financing Activities:
	Net cash provided by (used in) financing activities		8,554			—			8,554
	Net change in cash and cash equivalents		$	712		$	—		$	712
	Supplemental Schedule of Noncash Investing and Financing Activities:
	Net transfer of loans held for investment to loans held for sale		$	592		$	(346	)	$	246
			For the Year Ended December 31, 2012
	(Dollars in millions)		As Previously Reported			Reclassification Amounts			As Revised
	Cash Flows from Operating Activities:
	Depreciation, amortization and accretion, net		$	518		$	(102	)	$	416
	Loans originated for sale		(58		)	(153		)	(211		)
	Net proceeds from sale of loans originated for sale		34			114			148
	Net cash provided by (used in) operating activities		601			(141		)	460
	Cash Flows from Investing Activities:
	Proceeds from sales of loans		316			(114		)	202
	Net decrease (increase) in loans		(4,355		)	255			(4,100		)
	Net cash provided by (used in) investing activities		249			141			390
	Cash Flows from Financing Activities:
	Net cash provided by (used in) financing activities		446			—			446
	Net change in cash and cash equivalents		$	1,296		$	—		$	1,296
	Supplemental Schedule of Noncash Investing and Financing Activities:
	Net transfer of loans held for investment to loans held for sale		$	308		$	(153	)	$	155
	Cash and Cash Equivalents
	Cash and cash equivalents include cash and due from banks, interest bearing deposits in banks, and federal funds sold and securities purchased under resale agreements, which have original maturities less than 90 days.
	Resale and Repurchase Agreements
	Transactions involving purchases of securities under agreements to resell (reverse repurchase agreements or reverse repos) or sales of securities under agreements to repurchase (repurchase agreements or repos) are accounted for as collateralized financings except where the Company does not have an agreement to sell (or purchase) the same or substantially the same securities before maturity at a fixed or determinable price. These agreements accounted for as collateralized financings are recorded at the amounts at which the securities were acquired or sold, plus accrued interest, and are carried at amortized cost. The Company's policy is to obtain possession of collateral with a market value equal to or in excess of the principal amount financed under resale agreements. Collateral is valued daily, and the Company may require counterparties to deposit additional collateral or return collateral pledged, when appropriate.
	Trading Account Assets and Liabilities
	Trading account assets and liabilities are recorded at fair value and include certain securities and derivatives. Securities are classified as trading when management acquires them with the intent to hold for short periods of time in order to take advantage of anticipated changes in fair values or as an accommodation to customers. Substantially all of the securities have a high degree of liquidity and a readily determinable fair value. Interest on securities classified as trading is included in interest income, and realized gains and losses from sale and unrealized fair value adjustments are recognized in noninterest income.
	Derivatives included in trading account assets and liabilities are entered into for trading purposes or as an accommodation to customers. Contracts primarily include interest rate swaps and options, commodity swaps and options, foreign exchange contracts and equity options relating to our market-linked CD product. The Company nets derivative assets and liabilities, and the related cash collateral receivables and payables, when a legally enforceable master netting arrangement exists between the Company and the derivative counterparty. Changes in fair values and realized income or expense for trading asset and liability derivatives are included in noninterest income.
	Securities
	Securities are classified based on management's intent and are recorded on the consolidated balance sheet as of the trade date, when acquired in a regular-way trade. Debt securities for which management has both the positive intent and ability to hold to maturity are classified as held to maturity and are carried at amortized cost. Debt securities and equity securities with readily determinable fair values that are not classified as trading assets or held to maturity are classified as available for sale and are carried at fair value, with the unrealized gains or losses reported net of taxes as a component of AOCI in stockholder's equity until realized.
	Interest income on debt securities classified as either available for sale or held to maturity includes the amortization of premiums and the accretion of discounts using a method that produces a level yield and is included in interest income on securities.
	Debt securities in the available for sale and held to maturity portfolios are subject to impairment testing when their fair value is lower than amortized cost at the end of a reporting period.
	Realized gains and losses on the sale of available for sale securities are included in net interest income. The specific identification method is used to calculate realized gains and losses on sales.
	Securities available for sale that are pledged under an agreement to repurchase and which may be sold or repledged under that agreement are separately identified as pledged as collateral.
	Other-than-Temporary Impairment
	Debt securities available for sale and debt securities held to maturity are subject to impairment testing when a security's fair value is lower than its amortized cost. Debt securities with unrealized losses are considered other-than-temporarily impaired if we intend to sell the debt security, if it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis, or if we do not expect to recover the entire amortized cost basis of the security. If we intend to sell the security, or if it is more likely than not that we will be required to sell the security before recovery, an other-than-temporary impairment write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the debt security. However, even if we do not expect to sell a debt security we must evaluate the expected cash flows to be received and determine if a credit loss exists. In the event of a credit loss, only the amount of impairment associated with the credit loss is recognized in income. Amounts related to factors other than credit losses are recorded in other comprehensive income. For further information on our other-than-temporary impairment analysis, see Note 3 to our Consolidated Financial Statements in this Form  10-K.
	Marketable equity securities are subject to testing for other-than-temporary impairment when there is a severe or sustained decline in market price below the amount recorded for that investment. The Company considers the issuer's financial condition, capital strength, and near-term prospects in assessing whether other-than-temporary impairment exists. An other-than-temporary impairment results in a write-down recognized in earnings equal to the entire difference between the carrying amount and fair value of the equity security.
	Loans Held for Investment, Purchased Credit-Impaired Loans, Other Acquired Loans and Loans Held for Sale
	Loans held for investment are reported at the principal amounts outstanding, net of charge-offs, unamortized nonrefundable loan fees, direct loan origination costs, purchase premiums and discounts, and a historical fair value adjustment related to the Company's privatization transaction. Where loans are held for investment, the net basis adjustment excluding charge-offs on the loan is generally recognized in interest income on an effective yield basis over the contractual loan term.
	Nonaccrual loans are those for which management has discontinued accrual of interest because there exists significant uncertainty as to the full and timely collection of either principal or interest. Loans are generally placed on nonaccrual when such loans have become contractually past due 90 days with respect to principal or interest. Past due status is determined based on the contractual terms of the loan and the number of payment cycles since the last payment date. Interest accruals are continued past 90 days for certain small business loans and consumer installment loans, which are charged off at 120 days. For the commercial loan portfolio segment, interest accruals are also continued for loans that are both well-secured and in the process of collection.
	When a loan is placed on nonaccrual status, all previously accrued but uncollected interest is reversed against current period interest income. When full collection of the outstanding principal balance is in doubt, subsequent payments received are first applied to unpaid principal and then to uncollected interest. A loan may be returned to accrual status at such time as the loan is brought fully current as to both principal and interest, and such loan is considered to be fully collectible on a timely basis. The Company's policy also allows management to continue the recognition of interest income on certain loans placed on nonaccrual status. This portion of the nonaccrual portfolio is referred to as "Cash Basis Nonaccrual" under which the accrual of interest is suspended and interest income is recognized only when collected. This policy applies to consumer portfolio segment loans and commercial portfolio segment loans that are well-secured and in management's judgment are considered to be fully collectible but the timely collection of payments is in doubt.
	A TDR is a restructuring of a loan in which the creditor, for economic or legal reasons related to the borrower's financial difficulties, grants a concession to the borrower that it would not otherwise consider. A loan subject to such a restructuring is accounted for as a TDR. A TDR typically involves a modification of terms such as a reduction of the interest rate below the current market rate for a loan with similar risk characteristics or extending the maturity date of the loan without corresponding compensation or additional support. The Company measures impairment of a TDR using the methodology described for individually impaired loans (see "Allowance for Loan Losses" below). For the consumer portfolio segment, TDRs are initially placed on nonaccrual and typically, a minimum of six consecutive months of sustained performance is required before returning to accrual status. For the commercial portfolio segment, the Company generally determines accrual status for TDRs by performing an individual assessment of each loan, which may include, among other factors, the consideration of demonstrated performance by the borrower under the previous terms.
	Except for certain transactions between entities under common control, loans acquired in a transfer, including business combinations, are recorded at fair value at the acquisition date, factoring in credit losses expected to be incurred over the life of the loan.
For acquired loans where there is evidence of credit deterioration since origination and it is probable at the date of acquisition that the Company will not collect all contractually required principal and interest payments, the loans are accounted for as purchased credit-impaired loans. This guidance requires that the excess of the cash flows initially expected to be collected over the loan's fair value at the acquisition date (i.e., the accretable yield) be accreted into interest income over the loan's estimated remaining life using the effective yield method, provided that the timing and amount of future cash flows is reasonably estimable. Accordingly, such loans are not classified as nonaccrual and are considered to be accruing. The difference between the contractually required payments and the cash flows expected to be collected at acquisition, considering the impact of prepayments, is referred to as the nonaccretable difference. Accordingly, an allowance for loan losses is not carried over or recorded for purchased credit-impaired loans as of the acquisition date. Substantially all of the remaining purchased credit-impaired loans are aggregated within pools based on common risk characteristics, which results in the pool becoming the unit of account.
Subsequent to acquisition of purchased credit-impaired loans, estimates of cash flows expected to be collected are updated each reporting period based on updated assumptions that are reflective of current market conditions. If there is a probable decrease in cash flows expected to be collected (other than due to decreases in interest rate indices or changes in prepayments), the Company charges the provision for credit losses, resulting in an increase to the allowance for loan losses. If there is a probable and significant increase in cash flows expected to be collected, the Company will first reverse any previously established allowance for loan losses and then increase interest income as a prospective yield adjustment over the remaining life of the pool of loans, which also has the effect of reclassifying a portion of the nonaccretable difference to accretable yield. The impact of changes in variable interest rates is recognized prospectively as adjustments to interest income.
Modifications of purchased credit-impaired loans that are accounted for within loan pools do not result in the removal of these loans from the pool even if the modification would otherwise be considered a TDR. Each pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Accordingly, modifications of loans within such pools are not considered TDRs.
For other acquired loans, the purchase premium or discount is accreted to interest income over the remaining contractual life of the loans when the loans are performing, or immediately upon sale or prepayment.
Loans held for sale, which are recorded in other assets, are carried at the lower of cost or fair value and measured on an individual basis for commercial loans and on an aggregate basis for residential mortgage loans. Changes in fair value are recognized in other noninterest income. Nonrefundable fees, direct loan origination costs, and purchase premiums and discounts related to loans held for sale are deferred and recognized as a component of the gain or loss on sale. Contractual interest earned on loans held for sale is recognized in interest income.
The Company primarily offers two types of leases to customers: 1) direct financing leases where the assets leased are acquired without additional financing from other sources, and 2) leveraged leases where a substantial portion of the financing is provided by debt with no recourse to the Company. Direct financing leases and leverage leases are recorded based on the amount of minimum lease payments receivable, unguaranteed residual value accruing to the benefit of the lessor, unamortized initial direct costs, and are reduced for any unearned income. Leveraged leases are also recorded net of any nonrecourse debt.
Allowance for Loan Losses
The Company maintains an allowance for loan losses to absorb losses inherent in the loan portfolio. The allowance is based on ongoing, quarterly assessments of the probable estimated losses inherent in the loan portfolio. The allowance is increased by the provision for loan losses, which is charged against current period operating results and decreased by the amount of charge-offs, net of recoveries. The Company's methodology for assessing the appropriateness of the allowance consists of several key elements, which include the allowance for loans collectively evaluated for impairment, the allowance for loans individually evaluated for impairment, and the unallocated allowance. Management estimates probable losses inherent in the portfolio based on a loss emergence period. The loss emergence period is the estimated average period of time between a material adverse event that affects the creditworthiness of a borrower and the subsequent recognition of a loss. Updates of the loss emergence period are performed when significant events cause management to reexamine data. Management develops and documents its systematic methodology for determining the allowance for loan losses by first dividing its portfolio into segments—the commercial segment, consumer segment and purchased credit-impaired loans. The Company further divides the portfolio segments into classes based on initial measurement attributes, risk characteristics or its method of monitoring and assessing credit risk. The classes for the Company include commercial and industrial, commercial mortgage, construction, residential mortgage, home equity and other consumer loans, and purchased credit-impaired loans. While the Company's methodology attributes portions of the allowance to specific portfolio segments, the entire allowance is available to absorb credit losses inherent in the total loan portfolio.
For the commercial portfolio segment, the allowance for loans collectively evaluated for impairment is calculated by applying loss factors to outstanding loans and most unused commitments, based on the internal risk rating of such loans. Loss factors are based on historical loss experience and may be adjusted for significant qualitative considerations that, in management's judgment, affect the collectability of the portfolio as of the evaluation date. Those qualitative considerations are based upon management's evaluation of certain risks that may be identified from current conditions and developments within the portfolio that are not directly measured in the computation of the loss factors. Loss factors for individually graded credits are derived from a loan migration application that tracks historical losses over an economic cycle, which management believes captures the inherent losses in our loan portfolio.
For the consumer portfolio segment, loans are generally pooled by product type with similar risk characteristics. The Company estimates the allowance for loans collectively evaluated for impairment based on forecasted losses. For the purchased credit-impaired segment, we charge the provision for loan losses, resulting in an increase to the allowance for loan losses when there is a probable decrease in cash flows expected to be collected.
The allowance for loans collectively evaluated for impairment also includes attributions for certain sectors within the commercial and consumer portfolio segments to account for probable losses based on incurred loss events that are currently not reflected in the derived loss factors. Segment attributions are calculated based on migration scenarios for the commercial portfolio and specific attributes applicable to the consumer portfolio. Segment considerations are revised periodically as portfolio and environmental conditions change.
Estimates of cash flows expected to be collected for purchased credit-impaired loans are updated each reporting period. If there is a probable decrease in expected cash flows to be collected after acquisition (other than due to decreases in interest rate indices or changes in voluntary prepayments), the Company charges the provision for loan losses and establishes an allowance for loan losses.
The Company individually evaluates for impairment larger nonaccruing loans within the commercial portfolio. Residential mortgage and consumer loans are not individually evaluated for impairment unless they represent TDRs. Loans are considered impaired when the evaluation of current information regarding the borrower's financial condition, loan collateral, and cash flows indicates that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement, including interest payments. The amount of impairment is measured using the present value of expected future cash flows discounted at the loan's effective rate, the loan's observable market price, or the fair value of the collateral, if the loan is collateral dependent.
The unallocated allowance is composed of attributions that are intended to capture probable losses from adverse changes in credit migration and other inherent losses that are not currently reflected in the allowance for loan losses that are ascribed to our portfolio segments.
Significant risk characteristics considered in estimating the allowance for credit losses include the following:
•	Commercial and industrial—industry specific economic trends and individual borrower financial condition
•	Construction and commercial mortgage loans—type of property (i.e., residential, commercial, industrial), geographic concentrations, and risks and individual borrower financial condition
•	Residential mortgage and consumer—historical and expected future charge-offs, borrower's credit, property collateral, and loan characteristics
Loans are charged-off in whole or in part when they are considered to be uncollectible. Loans in the commercial loan portfolio segment are generally considered uncollectible based on an evaluation of borrower financial condition as well as the value of any collateral. Loans in the consumer portfolio segment are generally considered uncollectible based on past due status or the execution of certain TDR modifications such as discharge through Chapter 7 bankruptcy and the value of any collateral. Recoveries of amounts previously charged off are recorded as a recovery to the allowance for loan losses.
Allowance for Losses on Unfunded Credit Commitments
The Company maintains an allowance for losses on unfunded credit commitments to absorb losses inherent in those commitments upon funding. The Company's methodology for assessing the appropriateness of this allowance is the same as that used for the allowance for loan losses (see "Allowance for Loan Losses" above) and incorporates an assumption based upon historical experience of likely utilization of the commitment. The allowance for losses on unfunded credit commitments is classified as other liabilities and the change in this allowance is recognized in the provision for credit losses. Losses on unfunded credit commitments are identified when exposures committed to customers facing difficulty are drawn upon, and subsequently result in charge-offs.
Premises and Equipment
Premises and equipment are carried at cost, less accumulated depreciation and amortization, impairment, and fair value adjustments related to the Company's privatization transaction. Depreciation and amortization are calculated using the straight-line method over the estimated useful life of each asset. Lives of premises range from ten to fifty years; lives of furniture, fixtures and equipment range from three to eight years. Leasehold improvements are amortized over the term of the respective lease or the estimated useful life of the improvement, whichever is shorter.
Long-lived assets that are held for use are evaluated periodically for impairment when events or changes in circumstances indicate that the carrying amount may not be recoverable. Impairment is determined if the expected undiscounted future cash flows of a long-lived asset or group of assets is lower than its carrying amount. In the event of impairment, the Company recognizes a loss for the difference between the carrying amount and the fair value of the asset. The impairment loss is recognized in noninterest expense. Restoration of a previously recognized impairment loss is prohibited.
Goodwill and Identifiable Intangible Assets
Intangible assets represent purchased assets that lack physical substance and can be separately distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold, exchanged, or licensed. Intangible assets are recorded at fair value at the date of acquisition.
Intangible assets that have indefinite lives are tested for impairment at least annually, and more frequently in certain circumstances. Intangible assets that have finite lives, which include core deposit intangibles, customer relationships, non-compete agreements and trade names, are amortized either using the straight-line method or a method that patterns the manner in which the economic benefit is consumed. Intangible assets are amortized over their estimated periods of benefit, which range from three to forty years. The Company periodically evaluates the recoverability of intangible assets and takes into account events or circumstances that warrant revised estimates of useful lives or that indicate that impairment exists.
Goodwill is assessed for impairment at least annually at the reporting unit level either qualitatively or quantitatively. If the elected qualitative assessment results indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then the quantitative impairment test is required. Various valuation methodologies are applied to carry out the first step of the quantitative impairment test by comparing the fair value of the reporting unit to its carrying amount, including goodwill. If the fair value of the reporting unit is less than its carrying amount, a second step is required to measure the amount of impairment by comparing the implied fair value of the goodwill assigned to the reporting unit with the carrying amount of that goodwill. Goodwill impairment is recognized through a direct write down to its carrying amount and subsequent reversals of goodwill impairment are prohibited.
FDIC Indemnification Asset
In conjunction with the FDIC-assisted acquisitions of Frontier and Tamalpais in 2010, the Company entered into loss share agreements with the FDIC. Under the terms of the purchase and assumption and loss share agreements, the FDIC will reimburse the Company for certain losses on the covered assets, subject to specific compliance, servicing, notification and reporting requirements.
At the date of the acquisitions, the Company recorded an indemnification asset at fair value based on the present value of cash flows expected to be collected from the FDIC under the loss share agreements. Subsequent to acquisition, the indemnification asset is accounted for on the same basis as the related FDIC covered assets and is linked to the losses on those assets. The difference between the carrying amount and the undiscounted cash flows that the Company expects to collect from the FDIC is amortized into noninterest income over the life of the FDIC indemnification asset. Any increases in expected cash flows of covered loans due to decreases in expected credit losses are amortized over the lesser of the contractual term of the FDIC loss share agreement and the remaining life of the indemnified assets. Any decreases in cash flows of the covered loans due to increases in expected credit losses will increase the FDIC indemnification asset and adjust the provision for credit losses. At the date of the acquisitions, the Company also recorded a standalone liability for the FDIC's ability to clawback a portion of the loss share reimbursements paid to the Company. Because such consideration is contingently payable to the FDIC, the Company accounts for this liability as a form of contingent consideration that is recorded at fair value through noninterest expense.
Other Real Estate Owned
OREO represents the collateral acquired through foreclosure in full or partial satisfaction of the related loan. OREO is initially recorded in other assets at the date physical possession is received at the fair value as established by a current appraisal, adjusted for estimated costs to sell the asset. Any write-down on the date of transfer from loan classification is charged to the allowance for loan losses. Subsequently, OREO is measured at the lower of the acquisition date fair value or fair value less estimated costs to sell the asset. OREO values are reviewed on an ongoing basis and subsequent declines in an individual property's fair value are recognized in earnings in the current period or in certain instances as a charge to the allowance for loan losses. The net operating results from these assets are included in the current period in noninterest expense as foreclosed asset expense.
Other Investments
The Company invests in private equity investments, which include direct investments in private companies. These nonmarketable equity investments are initially recorded at cost and are accounted for using the cost or equity method of accounting depending on whether the Company has significant influence over the investee. Under the equity method, the investment is adjusted for the Company's share of the investee's net income or loss for the period. Under the cost method, dividends received are recognized in other noninterest income, and dividends received in excess of the investee's earnings are considered a return of investment and are recorded as a reduction of investment cost. These investments are evaluated for other-than-temporary impairment if events or conditions indicate that it is probable that the carrying amount of the investment will not be fully recovered in the foreseeable future. If an investment is determined to be other-than-temporarily impaired, it is written down to its fair value through earnings. Fair value is estimated based on a company's business model, current and projected financial performance, capital needs and our exit strategy. As a practical expedient, fair value can also be estimated using the net asset value of the fund. All of these investments are included within other assets and any other-than-temporary impairment is recognized in other noninterest income.
The Company invests in limited liability partnerships and other entities operating qualified affordable housing projects. These LIHC investments provide tax benefits to investors in the form of tax deductions from operating losses and tax credits. The unguaranteed LIHC investments are initially recorded at cost, and subsequently accounted for under the equity method of accounting with equity method losses recognized through noninterest expense. These investments are reviewed periodically for impairment.
The Company invests in guaranteed LIHC investments where the availability of tax credits are guaranteed by a creditworthy entity. The investments are initially recorded at cost. When certain criteria are met, the investment is amortized over the period the tax credits are allocated to provide a constant effective yield, as a component of income tax expense. In other instances, the investment is accounted for under the equity method of accounting with equity method losses recorded in noninterest expense. These investments are reviewed periodically for impairment.
The Company also invests in limited liability entities and trusts that operate renewable energy projects, either directly or indirectly. Tax credits, taxable income and distributions associated with these renewable energy projects may be allocated to investors according to the terms of the partnership agreements. These investments are accounted for under the equity method and are reviewed periodically for impairment, considering projected operating results and realizability of tax credits.
Derivative Instruments Used in Hedging Relationships
The Company enters into a variety of derivative contracts as a means of managing the Company's interest rate exposure and designates such derivatives under qualifying hedge relationships. All such derivative instruments are recorded at fair value and are included in other assets or other liabilities. The Company offsets derivative assets and liabilities, and the related cash collateral receivables and payables, when a legally enforceable master netting arrangement exists between the company and the derivative counterparty.
At hedge inception, the Company designates a derivative instrument as a hedge of the fair value of a recognized asset or liability (i.e., fair value hedge), or a hedge of the variability in the expected future cash flows associated with either an existing recognized asset or liability or a probable forecasted transaction (i.e., cash flow hedge).
Where hedge accounting is applied at hedge inception, the Company formally documents its risk management objective and strategy for undertaking the hedge, which includes identification of the hedging instrument, the hedged item or transaction, the nature of the risk being hedged, and how the hedge's effectiveness will be assessed prospectively and retrospectively. Both at the inception of the hedge and on an ongoing basis, the hedging instrument must be highly effective in offsetting changes in fair values or cash flows of the hedged item in order to qualify for hedge accounting.
For fair value hedges, any ineffectiveness is recognized in noninterest expense in the period in which it arises. For cash flow hedges, only ineffectiveness resulting from over-hedging is recorded in earnings as an adjustment to noninterest expense, with other changes in the fair value of the derivative instrument recognized in other comprehensive income. The amount in other comprehensive income is subsequently reclassified to net interest income in the period in which the cash flow from the hedged item is recognized in earnings. If a derivative instrument is no longer determined to be highly effective as a designated hedge, hedge accounting is discontinued and subsequent fair value adjustments of the derivative instrument are recorded in earnings.
Transfers of Financial Assets
Transfers of financial assets in which the Company has surrendered control over the transferred assets are accounted for as sales. Control is generally considered to have been surrendered when the transferred assets have been legally isolated from the Company, the transferee has the right to pledge or exchange the assets without any significant constraints, and the Company has not entered into a repurchase agreement, does not hold significant call options and has not written significant put options on the transferred assets. In assessing whether control has been surrendered, the Company considers whether the transferee would be a consolidated affiliate and the impact of all arrangements or agreements made contemporaneously with, or in contemplation of, the transfer, even if they were not entered into at the time of transfer.
Transfer Pricing
As a result of the business integration initiative, employees of the Company perform management and support services to BTMU in connection with the operation and administration of BTMU’s businesses in the Americas. In consideration for the services provided, BTMU pays the Company fees under a master services agreement, which reflects market-based pricing for those services. The Company recognizes transfer pricing revenue when delivery (performance) has occurred or services have been rendered. Revenue is recognized based on the gross amount billed to BTMU without netting the associated costs to perform those services. Gross presentation is deemed appropriate in these instances as the Company acts as a principal when providing these services directly to BTMU.
Operating Leases
The Company enters into a variety of lease contracts generally for premises and equipment as a lessee. Lease contracts that do not transfer substantially all of the benefits and risks of ownership and do not meet the accounting requirements for capital lease classification are treated as operating leases. The Company accounts for the payments of rent on these contracts on a straight-line basis over the lease term. At inception of the lease term, any periods for which no rents are paid or escalation clauses are stipulated in the lease contract are included in the determination of the rent expense and recognized ratably over the lease term.
The Company records liabilities for legal obligations associated with the future retirement of buildings and leasehold improvements at fair value when incurred. The assets are increased by the related liability and depreciated over the shorter of the estimated useful life of that asset or the lease term.
Income Taxes
The Company files consolidated U.S. federal income tax returns, foreign tax returns and various combined and separate company state income tax returns.
Management evaluates two components of income tax expense: current and deferred. Current income tax expense approximates taxes to be paid or refunded for the current period and includes income tax expense related to the Company's uncertain tax positions. Management determines deferred income taxes using the balance sheet method. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax bases of assets and liabilities, and recognizes enacted changes in tax rates and laws in the period in which they occur. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. Deferred tax assets are recognized subject to management's judgment that realization is more likely than not. A tax position that meets the "more likely than not" recognition threshold is measured to determine the amount of benefit to recognize. The tax position is measured at the largest amount of benefit that is greater than 50% likely of being realized upon settlement. Foreign taxes paid are generally applied as credits to reduce U.S. federal income taxes payable. Interest and penalties are recognized as a component of income tax expense.
Employee Pension and Other Postretirement Benefits
The Company provides a variety of pension and other postretirement benefit plans for eligible employees and retirees. Provisions for the costs of these employee pension and other postretirement benefit plans are accrued and charged to expense when the benefit is earned.
Stock-Based Compensation
The Company grants restricted stock units settled in ADRs representing shares of common stock of the Company's ultimate parent company, MUFG, to employees. Stock-based compensation is measured at fair value on the grant date and is recognized in the Company's results of operations on a straight-line basis over the vesting period. The amortization of stock-based compensation reflects estimated forfeitures adjusted for actual forfeitures experience.
Business Combinations
The Company accounts for all business combinations using the acquisition method of accounting. Except for certain transactions between entities under common control, assets and liabilities acquired are recorded at fair value at the acquisition date, with the excess of purchase price over the fair value of the net assets acquired (including identifiable intangibles) recorded as goodwill. Management may further adjust the acquisition date fair values for a period of up to one year from the date of acquisition. The recognition at the acquisition date of an allowance for loan losses is not carried over or recorded as of acquisition date, as credit-related factors are incorporated directly into the fair value measurement of the loans.
Recently Issued Accounting Pronouncements
Accounting for Investments in Qualified Affordable Housing Projects
In January 2014, the FASB issued ASU 2014-1, Accounting for Investments in Qualified Affordable Housing Projects, which amends guidance on the accounting for investments in qualified affordable housing projects and permits reporting entities to make an accounting policy election to account for investments in qualified affordable housing projects using the proportional amortization method, if certain conditions are met.  Under the proportional amortization method, reporting entities amortize the initial cost of the investment in proportion to tax credits and tax benefits received and recognize the amortization as a component of income tax expense. This guidance is effective for interim and annual periods beginning on January 1, 2015 with early adoption permitted. The guidance is required to be applied retrospectively to all periods presented upon adoption. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure
In January 2014, the FASB issued ASU 2014-4, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure, which provides guidance on when an in-substance repossession or foreclosure of residential real estate has occurred and when a creditor should derecognize the consumer mortgage loan and recognize the residential real estate. The guidance clarifies that an in-substance repossession or foreclosure occurs upon either (1) the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or (2) the borrower conveying all interest in the residential real estate property to the creditor to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. In addition, the standard requires additional interim and annual disclosures. The guidance is effective for interim and annual periods beginning on January 1, 2015, with early adoption permitted. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
Presentation of Financial Statements and Property, Plant and Equipment and Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity
In April 2014, the FASB issued ASU 2014-8, Presentation of Financial Statements and Property, Plant and Equipment and Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, which amends the criteria for reporting discontinued operations and requires additional disclosures for discontinued operations which meet the new criteria. The amendments in ASU 2014-8 limit discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have or will have a major effect on an entity’s operations and financial results. The guidance is effective for interim and annual periods beginning on January 1, 2015 with early adoption permitted. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
Revenue from Contracts with Customers
In May 2014, the FASB issued ASU 2014-9, Revenue from Contracts with Customers, which provides guidance on the core principle 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. This standard applies to all contracts with customers, except financial instruments, guarantees, lease contracts, insurance contracts, and certain non-monetary exchanges. It provides the following five-step revenue recognition model: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the entity satisfies a performance obligation. In addition, the standard requires additional disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The standard is effective for interim and annual periods beginning on January 1, 2017. Management is currently assessing the impact of this guidance on the Company’s financial position and results of operations.
Transfers and Servicing - Amendments to Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosure
In June 2014, the FASB issued ASU 2014-11, Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, which changes the accounting for repurchase-to-maturity transactions and repurchase financing arrangements. The guidance requires that repurchase-to-maturity transactions be accounted for as secured borrowings consistent with the accounting for other repurchase agreements. Additionally, the guidance requires separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. It also requires enhanced disclosures about repurchase agreements and other similar transactions. The guidance is effective on January 1, 2015. Earlier application is prohibited. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period
In June 2014, the FASB issued ASU 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period, which provides guidance that a performance target that affects vesting of a share-based payment and that could be achieved after the completion of the employee’s requisite service period is a performance condition under the accounting guidance for share-based awards. The standard clarifies that the performance target would not be reflected in estimating the fair value of the award at the grant date. Instead, compensation cost for the award would be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or results of operations.
Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure
In August 2014, the FASB issued ASU 2014-14, Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure, which provides guidance on the accounting for the classification of foreclosed loans that are fully-government-guaranteed.  The guidance clarifies that a residential mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the loan has both of the following characteristics: (1) The loan has a government guarantee that is not separable from the loan before foreclosure entitling the creditor to the full unpaid principal balance of the loan, and (2) At the time of foreclosure, the creditor has the intent to make a claim on the guarantee and the ability to recover the full unpaid principal balance of the loan through the guarantee.  The guidance is effective for interim and annual periods beginning on January 1, 2015, with early adoption permitted.  The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity
In November 2014, the FASB issued ASU 2014-16, Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity, which provides guidance on identifying whether the host contract in certain hybrid instruments is in the form of debt or equity. Such identification impacts the analysis of whether an embedded derivative exists in the instrument. The standard requires an entity to determine the nature of the host contract by considering all stated and implied substantive terms and features of the hybrid financial instrument, weighing each term and feature on the basis of the relevant facts and circumstances (commonly referred to as the whole-instrument approach). Under this approach, an entity would determine the nature of the host contract by considering the economic characteristics and risks of the entire hybrid financial instrument, including the embedded derivative feature that is being evaluated for separate accounting from the host contract. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or result of operations.
Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items
In January 2015, the FASB issued ASU 2015-01, Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items, which eliminates the need to determine whether to classify an item as an extraordinary item in the income statement. Under current guidance, a reporting entity is required to separately classify, present and disclose extraordinary events apart from events that are unusual in nature or occur infrequently (but not both). The existing presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be expanded to include items that are both unusual in nature and occur infrequently. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. The guidance may be applied either prospectively or retrospectively. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or results of operations.
Amendments to the Consolidation Analysis
In February 2015, the FASB issued ASU 2015-02, which is intended to improve current GAAP by making changes to targeted areas of the consolidation guidance.  This standard simplifies current GAAP as it reduces the number of consolidation models by eliminating specialized consolidation guidance for certain investment funds that are exempt from applying the VIE model.  The standard also changes the determination of whether limited partnerships and similar entities are VIEs or voting interest entities, the evaluation of the fees paid to decision makers and the application of the related-party guidance in determining whether a controlling financial interest exists.  The guidance is effective for periods beginning on January 1, 2016, with early adoption permitted. The standard may be applied using a modified or full retrospective approach.  Management is currently evaluating the impact to the Company’s financial position and results of operations.

Business_Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Business Combinations	Business Combinations
	Acquisition of PB Capital Corporation
	During the second quarter of 2013, the Company acquired PB Capital Corporation's institutional CRE lending division for $3.7 billion in cash. The acquisition expands the Company's CRE presence in the U.S., and provides geographic and asset class diversification. Excluding the effects of purchase accounting adjustments, the Company acquired approximately $3.5 billion in loans. The final fair value of the assets acquired totaled $3.4 billion, resulting in goodwill of $238 million, which was allocated to the Company's Commercial Banking reporting segment.
	Other Acquisitions
	In November 2013, we completed the acquisition of First Bank Association Bank Services, a unit of First Bank, which provides a full range of banking services to homeowners associations and community management companies. We acquired approximately $570 million in deposits in this transaction.

Securities

Securities	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Securities	Securities
	Securities Available for Sale
	At December 31, 2014 and 2013, the amortized cost, gross unrealized gains, gross unrealized losses, and fair values of securities are presented below.
		31-Dec-14
	(Dollars in millions)	Amortized		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Value
				Gains		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	7,649	$	2	$	91	$	7,560
	Privately issued	166		3		1		168
	Commercial mortgage-backed securities	1,689		15		13		1,691
	Collateralized loan obligations	2,527		4		37		2,494
	Other	8		1		—		9
	Asset Liability Management securities	12,039		25		142		11,922
	Other debt securities:
	Direct bank purchase bonds	1,719		49		27		1,741
	Other	53		—		1		52
	Equity securities	8		2		1		9
	Total securities available for sale	$	13,819	$	76	$	171	$	13,724
		31-Dec-13
	(Dollars in millions)	Amortized		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Value
				Gains		Losses
	Asset Liability Management securities:
	U.S. government-sponsored agencies	$	73	$	—	$	—	$	73
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	9,194		2		296		8,900
	Privately issued	220		4		2		222
	Commercial mortgage-backed securities	1,947		8		85		1,870
	Collateralized loan obligations	2,670		25		22		2,673
	Other	34		1		—		35
	Asset Liability Management securities	14,138		40		405		13,773
	Other debt securities:
	Direct bank purchase bonds	1,968		35		43		1,960
	Other	81		—		5		76
	Equity securities	7		1		—		8
	Total securities available for sale	$	16,194	$	76	$	453	$	15,817
	The Company's securities available for sale with a continuous unrealized loss position at December 31, 2014 and 2013 are shown below, identified for periods less than 12 months and 12 months or more.
		31-Dec-14
		Less than 12 months				12 months or more				Total
	(Dollars in millions)	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
		Value		Losses		Value		Losses		Value		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	611	$	1	$	6,258	$	90	$	6,869	$	91
	Privately issued	9		—		49		1		58		1
	Commercial mortgage-backed securities	143		—		842		13		985		13
	Collateralized loan obligations	657		6		1,481		31		2,138		37
	Other	—		—		1		—		1		—
	Asset Liability Management securities	1,420		7		8,631		135		10,051		142
	Other debt securities:
	Direct bank purchase bonds	75		3		937		24		1,012		27
	Other	—		—		22		1		22		1
	Equity securities	1		1		5		—		6		1
	Total securities available for sale	$	1,496	$	11	$	9,595	$	160	$	11,091	$	171
		31-Dec-13
		Less than 12 months				12 months or more				Total
	(Dollars in millions)	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
		Value		Losses		Value		Losses		Value		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	8,508	$	293	$	147	$	3	$	8,655	$	296
	Privately issued	72		2		18		—		90		2
Commercial mortgage-backed securities	1,274		80		58		5		1,332		85
Collateralized loan obligations	1,879		21		10		1		1,889		22
Other	—		—		1		—		1		—
Asset Liability Management securities	11,733		396		234		9		11,967		405
Other debt securities:
Direct bank purchase bonds	537		18		778		25		1,315		43
Other	15		1		34		4		49		5
Equity Securities	5		—		—		—		5		—
Total securities available for sale	$	12,290	$	415	$	1,046	$	38	$	13,336	$	453
At December 31, 2014, the Company did not have the intent to sell any securities in an unrealized loss position before a recovery of the amortized cost, which may be at maturity. The Company also believes that it is more likely than not that it will not be required to sell the securities prior to recovery of amortized cost.
Agency RMBS consist of securities guaranteed by a U.S. government agency or a government-sponsored agency such as Fannie Mae, Freddie Mac, and Ginnie Mae. These securities are collateralized by residential mortgage loans and may be prepaid at par prior to maturity. The unrealized losses on agency RMBS resulted from changes in interest rates and not from changes in credit quality. At December 31, 2014, the Company expects to recover the entire amortized cost basis of these securities because the Company determined that the strength of the issuers' guarantees through direct obligations or support from the U.S. government is sufficient to protect the Company from losses.
CMBS are collateralized by commercial mortgage loans and are generally subject to prepayment penalties. The unrealized losses on CMBS resulted from higher market yields since purchase. Cash flow analysis of the underlying collateral provides an estimate of other-than-temporary impairment, which is performed quarterly when the fair value of a security is lower than its amortized cost. Based on the analysis performed as of December 31, 2014, the Company expects to recover the entire amortized cost basis of these securities.
The CLOs consist of Cash Flow CLOs. A Cash Flow CLO is a structured finance product that securitizes a diversified pool of loan assets into multiple classes of notes. Cash Flow CLOs pay the note holders through the receipt of interest and principal repayments from the underlying loans unlike other types of CLOs that pay note holders through the trading and sale of underlying collateral. Unrealized losses typically arise from widening credit spreads and deteriorating credit quality of the underlying collateral. Cash flow analysis of the underlying collateral provides an estimate of other-than-temporary impairment, which is performed quarterly when the fair value of a security is lower than its amortized cost. Based on the analysis performed as of December 31, 2014, the Company expects to recover the entire amortized cost basis of these securities.
Other debt securities primarily consist of direct bank purchase bonds, which are not rated by external credit rating agencies. The unrealized losses on these bonds resulted from a higher return on capital expected by the secondary market compared with the return on capital required at the time of origination when the bonds were purchased. The Company estimated the unrealized loss projections for each security by assessing the underlying collateral of each security. The Company estimates the portion of loss attributable to credit based on the expected cash flows of the underlying collateral using estimates of current key assumptions, such as probability of default and loss severity. Cash flow analysis of the underlying obligor or collateral provides an estimate of other-than-temporary impairment, which is performed quarterly when the fair value of a security is lower than its amortized cost and potential impairment is identified. Based on the analysis performed as of December 31, 2014, the Company expects to recover the entire amortized cost basis of these securities.
The fair value of debt securities available for sale by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.
	31-Dec-14
(Dollars in millions)	One Year or		Over One Year		Over Five Years		Over Ten Years		Total Fair
	Less		Through		Through				Value
			Five Years		Ten Years
Asset Liability Management securities:
Residential mortgage-backed securities:
U.S. government agency and government-sponsored agencies	$	—	$	13	$	458	$	7,089	$	7,560
Privately issued	—		4		—		164		168
Commercial mortgage-backed securities	—		—		36		1,655		1,691
Collateralized loan obligations	30		80		572		1,812		2,494
Other	—		2		7		—		9
Asset Liability Management securities	30		99		1,073		10,720		11,922
Other debt securities:
Direct bank purchase bonds	72		547		663		459		1,741
Other	5		12		4		31		52
Total debt securities available for sale	$	107	$	658	$	1,740	$	11,210	$	13,715
The proceeds from sales of securities available for sale and gross realized gains and losses for the years ended December 31, 2014, 2013 and 2012 are shown below. The specific identification method is used to calculate realized gains and losses on sales.
	For the Year Ended December 31,
(Dollars in millions)	2014		2013		2012
Proceeds from sales	$	1,376	$	8,340	$	6,845
Gross realized gains	23		190		113
Gross realized losses	—		3		2
Securities Held to Maturity
The securities held to maturity consist of U.S. Treasury securities and U.S. government-sponsored agency securities. Management has asserted the positive intent and ability to hold these securities to maturity. At December 31, 2014 and 2013, the amortized cost, gross unrealized gains and losses recognized in Other Comprehensive Income (OCI), carrying amount, gross unrealized gains and losses not recognized in OCI, and fair values of securities held to maturity are presented below.
	31-Dec-14
			Recognized in						Not Recognized in
			OCI						OCI
(Dollars in millions)	Amortized		Gross		Gross		Carrying		Gross		Gross		Fair
	Cost		Unrealized		Unrealized		Amount		Unrealized		Unrealized		Value
			Gains		Losses				Gains		Losses
U.S. Treasury	$	486	$	—	$	—	$	486	$	3	$	—	$	489
U.S. government-sponsored agencies	125		—		—		125		—		—		125
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	6,002		6		66		5,942		76		5		6,013
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,820		—		82		1,738		53		6		1,785
Total securities held to maturity	$	8,433	$	6	$	148	$	8,291	$	132	$	11	$	8,412
	31-Dec-13
			Recognized in						Not Recognized in
			OCI						OCI
(Dollars in millions)	Amortized		Gross		Gross		Carrying		Gross		Gross		Fair
	Cost		Unrealized		Unrealized		Amount		Unrealized		Unrealized		Value
			Gains		Losses				Gains		Losses
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	$	5,065	$	7	$	77	$	4,995	$	8	$	69	$	4,934
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,606		—		92		1,514		3		12		1,505
Total securities held to maturity	$	6,671	$	7	$	169	$	6,509	$	11	$	81	$	6,439
For securities held to maturity, the amount recognized in OCI primarily reflects the unrealized gains or losses at date of transfer to the held to maturity classification, net of amortization. Amortized cost is defined as the original purchase cost, adjusted for any accretion or amortization of a purchase discount or premium, less principal payments and any impairment previously recognized in earnings.
The Company's securities held to maturity with a continuous unrealized loss position at December 31, 2014 and 2013 are shown below, separately for periods less than 12 months and 12 months or more.
	31-Dec-14
	Less than 12 months						12 months or more						Total
			Unrealized Losses						Unrealized Losses						Unrealized Losses
(Dollars in millions)	Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized
	Value		in OCI		in OCI		Value		in OCI		in OCI		Value		in OCI		in OCI
U.S. government agency and government-sponsored agencies—residential mortgage backed securities	$	399	$	—	$	1	$	2,341	$	66	$	4	$	2,740	$	66	$	5
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	134		—		—		1,552		82		6		1,686		82		6
Total securities held to maturity	$	533	$	—	$	1	$	3,893	$	148	$	10	$	4,426	$	148	$	11
	31-Dec-13
	Less than 12 months						12 months or more						Total
			Unrealized Losses						Unrealized Losses						Unrealized Losses
(Dollars in millions)	Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized
	Value		in OCI		in OCI		Value		in OCI		in OCI		Value		in OCI		in OCI
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	$	3,873	$	76	$	68	$	54	$	1	$	1	$	3,927	$	77	$	69
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,016		46		10		489		46		2		$	1,505	$	92	$	12
Total securities held to maturity	$	4,889	$	122	$	78	$	543	$	47	$	3	$	5,432	$	169	$	81
The carrying amount and fair value of securities held to maturity by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.
	31-Dec-14
	Over One Year				Over Five Years				Over Ten Years				Total
	Through Five Years				Through Ten Years
(Dollars in millions)	Carrying		Fair		Carrying		Fair		Carrying		Fair		Carrying		Fair
	Amount		Value		Amount		Value		Amount		Value		Amount		Value
U.S. Treasury	$	486	$	489	$	—	$	—	$	—	$	—	$	486	$	489
U.S. government-sponsored agencies	25		25		100		100		—		—		125		125
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	1		1		—		—		5,941		6,012		5,942		6,013
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	49		50		793		836		896		899		1,738		1,785
Total securities held to maturity	$	561	$	565	$	893	$	936	$	6,837	$	6,911	$	8,291	$	8,412
Securities Pledged as Collateral
The Company separately identifies in the consolidated balance sheets, securities pledged as collateral in secured borrowings and other arrangements when the secured party can sell or repledge the securities. If the secured party cannot resell or repledge the securities that have been placed as collateral, those securities are not separately identified.
At December 31, 2014, the Company had $7.5 billion of securities available for sale pledged as collateral where the secured party cannot resell or repledge such securities. The following available for sale securities have been pledged: $0.6 billion to secure borrowings, $0.2 billion to support unrealized losses on derivative contracts and $6.7 billion to secure public and trust department deposits.
At December 31, 2014, the Company accepted securities as collateral for reverse repurchase agreements of $61 million, none of which has been repledged and $69 million in securities that it has given as collateral for repurchase agreements, none of which has been repledged. At December 31, 2013, the Company accepted securities as collateral for secured lending that it is permitted by contract to sell or repledge of $10 million (none of which have been repledged), respectively. These securities were received as collateral for secured lending activities and are not recognized on the Company's balance sheet.

Loans_and_Allowance_for_Loan_L

Loans and Allowance for Loan Losses	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Loans and Allowance for Loan Losses	Loans and Allowance for Loan Losses
	The following table provides the outstanding balances of loans at December 31, 2014 and 2013.
			December 31,
	(Dollars in millions)		2014			2013
	Loans held for investment:
	Commercial and industrial		$	27,623		$	23,528
	Commercial mortgage		14,016			13,092
	Construction		1,746			905
	Lease financing		800			854
	Total commercial portfolio		44,185			38,379
	Residential mortgage		28,977			25,547
	Home equity and other consumer loans		3,117			3,280
	Total consumer portfolio		32,094			28,827
	Total loans held for investment, before purchased credit-impaired loans		76,279			67,206
	Purchased credit-impaired loans(1)		525			1,106
	Total loans held for investment(2)		76,804			68,312
	Allowance for loan losses		(537		)	(568		)
	Loans held for investment, net		$	76,267		$	67,744
	-1	Includes $126 million and $251 million as of December 31, 2014 and December 31, 2013, respectively, of loans for which the Company will be reimbursed a portion of any future losses under the terms of the FDIC loss share agreements. Of these FDIC covered loans, $9 million and $15 million as of December 31, 2014 and December 31, 2013, respectively, were not accounted for under accounting guidance for loans acquired with deteriorated credit quality.
	-2	Includes $151 million and $88 million at December 31, 2014 and December 31, 2013, respectively, for net unamortized discounts and premiums and deferred fees and costs.
	Allowance for Loan Losses
	The following tables provide a reconciliation of changes in the allowance for loan losses by portfolio segment:
			For the Year Ended December 31, 2014
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	421		$	69		$	1		$	77		$	568
	(Reversal of) provision for loan losses		52			(13		)	—			(57		)	(18		)
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			2			—			2
	Other		(3		)	—			—			—			(3		)
	Loans charged-off		(38		)	(11		)	(1		)	—			(50		)
	Recoveries of loans previously charged-off		33			4			1			—			38
	Allowance for loan losses, end of period		$	465		$	49		$	3		$	20		$	537
			For the Year Ended December 31, 2013
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	418		$	124		$	1		$	110		$	653
	(Reversal of) provision for loan losses		18			(29		)	—			(33		)	(44		)
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			(1		)	—			(1		)
	Decrease in allowance covered by FDIC indemnification		—			—			(8		)	—			(8		)
	Loans charged-off		(44		)	(30		)	(3		)	—			(77		)
	Recoveries of loans previously charged-off		29			4			12			—			45
	Allowance for loan losses, end of period		$	421		$	69		$	1		$	77		$	568
			For the Year Ended December 31, 2012
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	474		$	138		$	17		$	135		$	764
	(Reversal of) provision for loan losses		(25		)	78			—			(25		)	28
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			(3		)	—			(3		)
	Decrease in allowance covered by FDIC indemnification		—			—			(5		)	—			(5		)
	Loans charged-off		(88		)	(95		)	(13		)	—			(196		)
	Recoveries of loans previously charged-off		57			3			5			—			65
	Allowance for loan losses, end of period		$	418		$	124		$	1		$	110		$	653
	The following tables show the allowance for loan losses and related loan balances by portfolio segment as of December 31, 2014 and 2013.
			31-Dec-14
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses:
	Individually evaluated for impairment		$	18		$	16		$	—		$	—		$	34
	Collectively evaluated for impairment		447			33			—			20			500
	Purchased credit-impaired loans		—			—			3			—			3
Total allowance for loan losses		$	465		$	49		$	3		$	20		$	537
Loans held for investment:
Individually evaluated for impairment		$	164		$	338		$	1		$	—		$	503
Collectively evaluated for impairment		44,021			31,756			—			—			75,777
Purchased credit-impaired loans		—			—			524			—			524
Total loans held for investment		$	44,185		$	32,094		$	525		$	—		$	76,804
		31-Dec-13
(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
								Credit-
								Impaired
Allowance for loan losses:
Individually evaluated for impairment		$	19		$	20		$	—		$	—		$	39
Collectively evaluated for impairment		402			49			—			77			528
Purchased credit-impaired loans		—			—			1			—			1
Total allowance for loan losses		$	421		$	69		$	1		$	77		$	568
Loans held for investment:
Collectively evaluated for impairment		$	266		$	339		$	3		$	—		$	608
Collectively evaluated for impairment		38,113			28,488			—			—			66,601
Purchased credit-impaired loans		—			—			1,103			—			1,103
Total loans held for investment		$	38,379		$	28,827		$	1,106		$	—		$	68,312
Nonaccrual and Past Due Loans
The following table presents nonaccrual loans as of December 31, 2014 and 2013.
		December 31,
(Dollars in millions)		2014			2013
Commercial and industrial		$	55		$	44
Commercial mortgage		40			51
Total commercial portfolio		95			95
Residential mortgage		231			286
Home equity and other consumer loans		40			46
Total consumer portfolio		271			332
Total nonaccrual loans, before purchased credit-impaired loans		366			427
Purchased credit-impaired loans		9			15
Total nonaccrual loans		$	375		$	442
Troubled debt restructured loans that continue to accrue interest		$	283		$	367
Troubled debt restructured nonaccrual loans (included in the total nonaccrual loans above)		$	184		$	225
The following tables show an aging of the balance of loans held for investment, excluding purchased credit-impaired loans, by class as of December 31, 2014 and 2013.
		31-Dec-14
		Aging Analysis of Loans
(Dollars in millions)		Current			30 to			90 Days or			Total Past Due			Total
					89 Days			More Past
					Past Due			Due
Commercial and industrial		$	28,392		$	19		$	12		$	31		$	28,423
Commercial mortgage		13,991			21			4			25			14,016
Construction		1,744			2			—			2			1,746
Total commercial portfolio		44,127			42			16			58			44,185
Residential mortgage		28,802			112			63			175			28,977
Home equity and other consumer loans		3,084			20			13			33			3,117
Total consumer portfolio		31,886			132			76			208			32,094
Total loans held for investment, excluding purchased credit-impaired loans		$	76,013		$	174		$	92		$	266		$	76,279
		31-Dec-13
		Aging Analysis of Loans
(Dollars in millions)		Current			30 to			90 Days or			Total Past Due			Total
					89 Days			More Past
					Past Due			Due
Commercial and industrial		$	24,310		$	66		$	6		$	72		$	24,382
Commercial mortgage		13,004			68			20			88			13,092
Construction		891			14			—			14			905
Total commercial portfolio		38,205			148			26			174			38,379
Residential mortgage		25,342			114			91			205			25,547
Home equity and other consumer loans		3,238			23			19			42			3,280
Total consumer portfolio		28,580			137			110			247			28,827
Total loans held for investment, excluding purchased credit-impaired loans		$	66,785		$	285		$	136		$	421		$	67,206
Loans 90 days or more past due and still accruing totaled $3 million and $5 million at December 31, 2014 and 2013, respectively. Purchased credit-impaired loans that were 90 days or more past due and still accruing totaled $47 million and $124 million at December 31, 2014 and 2013.
Credit Quality Indicators
Management analyzes the Company's loan portfolios by applying specific monitoring policies and procedures that vary according to the relative risk profile and other characteristics within the various loan portfolios. Loans within the commercial portfolio segment are classified as either pass or criticized. Criticized credits are those that are internally risk graded as special mention, substandard or doubtful. Special mention credits are potentially weak, as the borrower has begun to exhibit deteriorating trends, which, if not corrected, may jeopardize repayment of the loan and result in further downgrade. Adversely classified credits are those that are internally risk graded as substandard or doubtful. Substandard credits have well-defined weaknesses, which, if not corrected, could jeopardize the full satisfaction of the debt. A credit classified as doubtful has critical weaknesses that make full collection improbable on the basis of currently existing facts and conditions.
The following tables summarize the loans in the commercial portfolio segment and commercial loans within the purchased credit-impaired loans segment monitored for credit quality based on internal ratings, excluding $98 million and $213 million covered by FDIC loss share agreements, at December 31, 2014 and 2013, respectively. The amounts presented reflect unpaid principal balances less charge-offs.
		31-Dec-14
(Dollars in millions)		Pass			Special Mention			Classified			Total
Commercial and industrial		$	27,471		$	452		$	360		$	28,283
Construction		1,729			18			—			1,747
Commercial mortgage		13,522			128			183			13,833
Total commercial portfolio		42,722			598			543			43,863
Purchased credit-impaired loans		37			38			128			203
Total		$	42,759		$	636		$	671		$	44,066
		31-Dec-13
(Dollars in millions)		Pass			Special Mention			Classified			Total
Commercial and industrial		$	23,346		$	576		$	313		$	24,235
Construction		879			14			—			893
Commercial mortgage		12,562			142			228			12,932
Total commercial portfolio		36,787			732			541			38,060
Purchased credit-impaired loans		48			204			362			614
Total		$	36,835		$	936		$	903		$	38,674
The Company monitors the credit quality of its consumer portfolio segment and consumer loans within the purchased credit-impaired loans segment based primarily on payment status. The following tables summarize the loans in the consumer portfolio segment and purchased credit-impaired loans segment, which excludes $28 million and $38 million of loans covered by FDIC loss share agreements, at December 31, 2014 and 2013, respectively.
		31-Dec-14
(Dollars in millions)		Accrual			Nonaccrual			Total
Residential mortgage		$	28,746		$	231		$	28,977
Home equity and other consumer loans		3,077			40			3,117
Total consumer portfolio		31,823			271			32,094
Purchased credit-impaired loans		196			—			196
Total		$	32,019		$	271		$	32,290
		31-Dec-13
(Dollars in millions)		Accrual			Nonaccrual			Total
Residential mortgage		$	25,261		$	286		$	25,547
Home equity and other consumer loans		3,234			46			3,280
Total consumer portfolio		28,495			332			28,827
Purchased credit-impaired loans		242			—			242
Total		$	28,737		$	332		$	29,069
The Company also monitors the credit quality for substantially all of its consumer portfolio segment using credit scores provided by FICO and refreshed LTV ratios. FICO credit scores are refreshed at least quarterly to monitor the quality of the portfolio. Refreshed LTV measures the principal balance of the loan as a percentage of the estimated current value of the property securing the loan. Home equity loans are evaluated using combined LTV, which measures the principal balance of the combined loans that have liens against the property (including unused credit lines for home equity products) as a percentage of the estimated current value of the property securing the loans. The LTV ratios are refreshed on a quarterly basis, using the most recent home pricing index data available for the property location.
The following tables summarize the loans in the consumer portfolio segment and consumer loans within the purchased credit-impaired loans segment monitored for credit quality based on refreshed FICO scores and refreshed LTV ratios at December 31, 2014 and 2013. These tables exclude loans covered by FDIC loss share agreements, as discussed above. The amounts presented reflect unpaid principal balances less partial charge-offs. During the fourth quarter 2014, the Company changed the presentation of its LTV ratios to better align with management's methodology used to analyze credit quality. Prior period amounts have been adjusted to conform to the current year presentation.
		31-Dec-14
		FICO scores
(Dollars in millions)		720 and Above			Below 720			No FICO			Total
								Available(1)
Residential mortgage		$	22,505		$	5,717		$	493		$	28,715
Home equity and other consumer loans		2,209			754			83			3,046
Total consumer portfolio		24,714			6,471			576			31,761
Purchased credit-impaired loans		73			111			13			197
Total		$	24,787		$	6,582		$	589		$	31,958
Percentage of total		77		%	21		%	2		%	100		%
-1	Represents loans for which management was not able to obtain an updated FICO score (e.g., due to recent profile changes).
		31-Dec-13
		FICO scores
(Dollars in millions)		720 and Above			Below 720			No FICO			Total
								Available(1)
Residential mortgage		$	19,614		$	5,301		$	459		$	25,374
Home equity and other consumer loans		2,283			839			81			3,203
Total consumer portfolio		21,897			6,140			540			28,577
Purchased credit-impaired loans		94			135			15			244
Total		$	21,991		$	6,275		$	555		$	28,821
Percentage of total		76		%	22		%	2		%	100		%
-1	Represents loans for which management was not able to obtain an updated FICO score (e.g., due to recent profile changes).
		31-Dec-14
		LTV ratios
(Dollars in millions)		Less than or Equal to 80			Greater than 80 and Less than 100 Percent			Greater than or Equal to 100			No LTV			Total
		Percent						Percent			Available(1)
Residential mortgage		$	27,162		$	1,430		$	92		$	31		$	28,715
Home equity loans		2,364			270			118			50			2,802
Total consumer portfolio		29,526			1,700			210			81			31,517
Purchased credit-impaired loans		131			45			18			1			195
Total		$	29,657		$	1,745		$	228		$	82		$	31,712
Percentage of total		94		%	5		%	1		%	—		%	100		%
-1	Represents loans for which management was not able to obtain refreshed property values.
		31-Dec-13
		LTV ratios
(Dollars in millions)		Less than or Equal to 80			Greater than 80 and Less than 100 Percent			Greater than or Equal to 100			No LTV			Total
		Percent						Percent			Available(1)
Residential mortgage		$	23,613		$	1,477		$	231		$	53		$	25,374
Home equity loans		2,492			356			203			52			3,103
Total consumer portfolio		26,105			1,833			434			105			28,477
Purchased credit-impaired loans		152			57			31			—			240
Total		$	26,257		$	1,890		$	465		$	105		$	28,717
Percentage of total		91		%	7		%	2		%	—		%	100		%
-1	Represents loans for which management was not able to obtain refreshed property values.
Troubled Debt Restructurings
The following table provides a summary of the Company's recorded investment in TDRs as of December 31, 2014 and 2013. The summary includes those TDRs that are on nonaccrual status and those that continue to accrue interest. The Company had $33 million and $43 million in commitments to lend additional funds to borrowers with loan modifications classified as TDRs as of December 31, 2014 and 2013, respectively.
		December 31,
(Dollars in millions)		2014			2013
Commercial and industrial		$	100		$	212
Commercial mortgage		28			38
Total commercial portfolio		128			250
Residential mortgage		308			315
Home equity and other consumer loans		30			24
Total consumer portfolio		338			339
Total restructured loans, excluding purchased credit-impaired loans(1)		$	466		$	589
-1	Amounts exclude $1 million and $3 million of TDRs covered by FDIC loss share agreements at December 31, 2014 and 2013, respectively.
In 2014, TDR modifications in the commercial portfolio segment were primarily composed of interest rate changes, maturity extensions, covenant waivers, conversions from revolving lines of credit to term loans, or some combination thereof. In the consumer portfolio segment, primarily all of the modifications were composed of interest rate reductions and maturity extensions. There were charge-offs of $2 million related to TDR modifications in the year ended December 31, 2014 and none for the year ended December 31, 2013. For the commercial and consumer portfolio segments, the allowance for loan losses for TDRs is measured on an individual loan basis or in pools with similar risk characteristics.
The following table provides the pre- and post-modification outstanding recorded investment amounts of TDRs as of the date of the restructuring that occurred during the years ended December 31, 2014 and 2013.
		For the Year Ended						For the Year Ended
		December 31, 2014						December 31, 2013
(Dollars in millions)		Pre-Modification			Post-Modification			Pre-Modification			Post-Modification
		Outstanding			Outstanding			Outstanding			Outstanding
		Recorded			Recorded			Recorded			Recorded
		Investment(1)			Investment(2)			Investment(1)			Investment(2)
Commercial and industrial		$	111		$	111		$	161		$	158
Commercial mortgage		23			23			70			69
Total commercial portfolio		134			134			231			227
Residential mortgage		28			27			104			103
Home equity and other consumer loans		11			11			9			8
Total consumer portfolio		39			38			113			111
Total		$	173		$	172		$	344		$	338
-1	Represents the recorded investment in the loan immediately prior to the restructuring event.
-2	Represents the recorded investment in the loan immediately following the restructuring event. It includes the effect of paydowns that were required as part of the restructuring terms.
Amounts above exclude TDRs covered by FDIC loss share agreements with pre-modification and post-modification balances of $4 million and $4 million, respectively, for the year ended December 31, 2014. There were no restructurings related to loans covered by FDIC loss share agreements for the year ended December 31, 2013.
The following table provides the recorded investment amounts of TDRs at the date of default, for which there was a payment default during the years ended December 31, 2014 and 2013, and where the default occurred within the first twelve months after modification into a TDR. A payment default is defined as the loan being 60 days or more past due.
		December 31,
(Dollars in millions)		2014			2013
Commercial and industrial		$	10		$	10
Commercial mortgage		8			2
Total commercial portfolio		18			12
Residential mortgage		8			16
Home equity and other consumer loans		1			2
Total consumer portfolio		9			18
Total		$	27		$	30
For the consumer portfolio, historical payment defaults and the propensity to redefault are some of the factors considered when determining the allowance for loan losses for situations where impairment is measured using the present value of expected future cash flows discounted at the loan's effective interest rate.
Loan Impairment
Loans that are individually evaluated for impairment include larger nonaccruing loans within the commercial and industrial, construction, commercial mortgage loan portfolios and loans modified in a TDR. The Company records an impairment allowance when the value of an impaired loan is less than the recorded investment in the loan.
The following tables show information about impaired loans by class as of December 31, 2014 and 2013.
		31-Dec-14
		Recorded Investment												Unpaid Principal
														Balance
(Dollars in millions)		With an			Without an			Total			Allowance			With an			Without an
		Allowance			Allowance						for Impaired			Allowance			Allowance
											Loans
Commercial and industrial		$	89		$	35		$	124		$	14		$	120		$	39
Commercial mortgage		37			3			40			4			39			3
Total commercial portfolio		126			38			164			18			159			42
Residential mortgage		198			110			308			16			211			127
Home equity and other consumer loans		6			24			30			—			7			37
Total consumer portfolio		204			134			338			16			218			164
Total, excluding purchased credit-impaired loans		330			172			502			34			377			206
Purchased credit-impaired loans		—			1			1			—			—			2
Total		$	330		$	173		$	503		$	34		$	377		$	208
		31-Dec-13
		Recorded Investment												Unpaid Principal
														Balance
(Dollars in millions)		With an			Without an			Total			Allowance			With an			Without an
		Allowance			Allowance						for Impaired			Allowance			Allowance
											Loans
Commercial and industrial		$	117		$	104		$	221		$	16		$	121		$	114
Commercial mortgage		33			12			45			3			36			15
Total commercial portfolio		150			116			266			19			157			129
Residential mortgage		220			95			315			20			236			108
Home equity and other consumer loans		4			20			24			—			4			34
Total consumer portfolio		224			115			339			20			240			142
Total, excluding purchased credit-impaired loans		374			231			605			39			397			271
Purchased credit-impaired loans		2			1			3			—			2			6
Total		$	376		$	232		$	608		$	39		$	399		$	277
The following table presents the average recorded investment in impaired loans and the amount of interest income recognized for impaired loans during 2014, 2013 and 2012 for the commercial, consumer and purchased credit-impaired loans portfolio segments.
		Years Ended December 31,
		2014						2013						2012
(Dollars in millions)		Average			Recognized			Average			Recognized			Average			Recognized
		Recorded			Interest			Recorded			Interest			Recorded			Interest
		Investment			Income			Investment			Income			Investment			Income
Commercial and industrial		$	188		$	5		$	243		$	14		$	201		$	12
Commercial mortgage		36			2			53			9			107			1
Construction		—			—			8			3			44			2
Total commercial portfolio		224			7			304			26			352			15
Residential mortgage		310			10			293			10			221			8
Home equity and other consumer loans		27			2			22			1			7			1
Total consumer portfolio		337			12			315			11			228			9
Total, excluding purchased credit-impaired loans		561			19			619			37			580			24
Purchased credit-impaired loans		2			—			4			—			8			1
Total		$	563		$	19		$	623		$	37		$	588		$	25
During 2014, the Company transferred a net $203 million of commercial loans from held for investment to held for sale, and sold $196 million of commercial loans. No consumer loans were sold or transferred from held for investment to held for sale.
During 2013, the Company transferred a net $246 million of commercial loans from held for investment to held for sale, and sold $254 million of commercial loans. No consumer loans were sold or transferred from held for investment to held for sale.
Loans Acquired in Business Combinations
The Company accounts for certain loans acquired in business combinations in accordance with accounting guidance related to loans acquired with deteriorated credit quality (purchased credit-impaired loans). The following table presents the outstanding balances and carrying amounts of the Company's purchased credit-impaired loans at December 31, 2014 and 2013.
(Dollars in millions)		31-Dec-14			31-Dec-13
Total outstanding balance		$	889		$	1,733
Carrying amount		516			1,091
The accretable yield for purchased credit-impaired loans for the years ended December 31, 2014, 2013, and 2012 was as follows:
		For the Year Ended
		December 31,
(Dollars in millions)		2014			2013			2012
Accretable yield, beginning of period		$	378		$	590		$	424
Additions		—			31			171
Accretion		(268		)	(336		)	(297		)
Reclassifications from nonaccretable difference during the period		178			93			292
Accretable yield, end of period		$	288		$	378		$	590
Loan Concentrations
The Company's most significant concentration of credit risk within its loan portfolio includes residential mortgage loans, loans made to the real estate industry sector, financial and insurance industry, power and utilities industry, oil and gas industry, and manufacturing industry. At December 31, 2014, the Company had $29 billion in residential mortgage loans, primarily in California. The Company had $16 billion in loans made to the real estate industry and an additional $6 billion in unfunded commitments. At December 31, 2014, the Company had $5 billion in loans made to the financial and insurance industry and an additional $5 billion in unfunded commitments. At December 31, 2014, the Company had $5 billion in loans made to the power and utilities industry and an additional $9 billion in unfunded commitments. At December 31, 2014, the Company had $4 billion in loans made to the oil and gas industry and an additional $4 billion in unfunded commitments. At December 31, 2014, the Company had $4 billion in loans made to the manufacturing industry and an additional $3 billion in unfunded commitments.

Premises_and_Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2014
Premises and Equipment and Other Assets
Premises and Equipment	Premises and Equipment and Other Assets
	Premises and Equipment
	Premises and equipment are carried at cost, less accumulated depreciation and amortization. As of December 31, 2014 and 2013, the amounts were as follows:
		December 31,
		2014							2013
	(Dollars in millions)	Cost		Accumulated			Net Book		Cost		Accumulated			Net Book
				Depreciation and			Value				Depreciation and			Value
				Amortization							Amortization
	Land	$	148	$	—		$	148	$	154	$	—		$	154
	Premises	601		(334		)	267		621		(328		)	293
	Leasehold improvements	301		(230		)	71		298		(218		)	80
	Furniture, fixtures and equipment	682		(547		)	135		670		(509		)	161
	Total	$	1,732	$	(1,111	)	$	621	$	1,743	$	(1,055	)	$	688
	Rental, depreciation and amortization expenses were as follows:
		For the Years Ended December 31,
	(Dollars in millions)	2014		2013			2012
	Rental expense of premises	$	113	$	111		$	85
	Less: rental income	10		9			8
	Net rental expense	$	103	$	102		$	77
	Depreciation and amortization of premises and equipment	$	103	$	110		$	102
	Future minimum lease payments at December 31, 2014 were as follows:
	(Dollars in millions)	2014
	Years ending December 31,:
	2015	$	130
	2016	131
	2017	118
	2018	103
	2019	85
	Thereafter	501
	Total minimum lease payments	$	1,068
	Minimum rental income due in the future under subleases	$	105
	The Company's leases are for land, branch or office space. A majority of the leases provide for the payment of taxes, maintenance, insurance, and certain other expenses applicable to the leased premises. Many of the leases contain extension provisions and escalation clauses. These leases are generally renewable and may in certain cases contain provisions and options to expand or contract space, renew or terminate the lease or purchase the leased premises at predetermined contractual dates. In addition, escalation clauses may exist, which are tied to either a predetermined rate or may change based on a specified percentage increase or the Consumer Price Index.
	At December 31, 2014 and 2013, the Company had a liability of $6 million for asset retirement obligations. These obligations include environmental remediation on buildings and the removal of leasehold improvements from leased premises to be vacated in cases where management has sufficient information to estimate the obligation's fair value.
	Other Assets
	The following table shows the balances of other assets as of December 31, 2014 and 2013.
	(Dollars in millions)	31-Dec-14		31-Dec-13
	Other investments	$	2,711	$	2,211
	Prepaid expenses	145		509
	Intangible assets	240		290
	OREO	36		57
	Other	1,553		1,787
	Total other assets	$	4,685	$	4,854

Goodwill_and_Other_Intangible_

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets
	As a result of the acquisition of PB Capital Corporation, the Company recorded goodwill and intangibles assets totaling $238 million and less than $1 million, respectively. As a result of the acquisition of First Bank Association Bank Services, the Company recorded goodwill of $30 million. See Note 2 to these consolidated financial statements for information on the Company's business combinations.
	Goodwill
	The changes in the carrying amount of goodwill during 2014 and 2013 are shown in the table below.
	(Dollars in millions)	2014			2013
	Goodwill, beginning of year	$	3,228		$	2,942
	Net change from business combinations	(3		)	286
	Goodwill, end of year	$	3,225		$	3,228
	For impairment testing, goodwill was assigned to the following operating segments at December 31, 2014 and 2013:
	(Dollars in millions)	2014			2013
	Retail Banking & Wealth Markets	$	1,524		$	1,527
	Commercial Banking	1,034			1,034
	U.S. Corporate Banking	149			149
	Transaction Banking	251			251
	Investment Banking & Markets	253			253
	Asian Corporate Banking	14			14
	Goodwill, end of year	$	3,225		$	3,228
	The Company reviews its goodwill for impairment on an annual basis and whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The annual goodwill impairment test was performed as of October 1, 2014, and no impairment was recognized.
	Intangible Assets
	The table below reflects the Company's identifiable intangible assets and accumulated amortization at December 31, 2014 and 2013.
		31-Dec-14								31-Dec-13
	(Dollars in millions)	Gross			Accumulated			Net		Gross		Accumulated			Net
		Carrying			Amortization			Carrying		Carrying		Amortization			Carrying
		Amount						Amount		Amount					Amount
	Core deposit intangibles	$	565		$	(468	)	$	97	$	667	$	(530	)	$	137
	Trade names	114			(21		)	93		114		(16		)	98
	Customer relationships	60			(25		)	35		63		(22		)	41
	Other	29			(14		)	15		25		(11		)	14
	Total intangible assets with a definite useful life	$	768		$	(528	)	$	240	$	869	$	(579	)	$	290
	Total amortization expense for 2014, 2013 and 2012 was $53 million, $65 million and $81 million, respectively.
	Estimated future amortization expense at December 31, 2014 is as follows:
	(Dollars in millions)	Core Deposit			Trade Name			Customer		Other		Total Identifiable
		Intangibles (CDI)						Relationships				Intangible Assets
	Years ending December 31, :
	2015	$	30		$	3		$	5	$	4	$	42
	2016	18			3			5		3		29
	2017	14			3			4		2		23
	2018	7			3			4		1		15
	2019	6			3			3		1		13
	Thereafter	22			78			14		4		118
	Total estimated amortization expense	$	97		$	93		$	35	$	15	$	240

Variable_Interest_Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2014
Variable Interest Entities
Variable Interest Entities	Variable Interest Entities
	In the normal course of business, the Company has certain financial interests in entities which have been determined to be VIEs. Generally, a VIE is a corporation, partnership, trust or other legal structure where the equity investors do not have substantive voting rights, an obligation to absorb the entity’s losses or the right to receive the entity’s returns, or the ability to direct the significant activities of the entity. The following discusses the Company’s consolidated and unconsolidated VIEs.
	Consolidated VIEs
	The following tables present the assets and liabilities of consolidated VIEs recorded on the Company’s consolidated balance sheets at December 31, 2014 and 2013.
		December 31, 2014
		Consolidated Assets								Consolidated Liabilities
	(Dollars in millions)	Interest Bearing		Loans Held for		Other Assets		Total Assets		Other Liabilities		Total
		Deposits in		Investment, net								Liabilities
		Banks
	LIHC investments	$	9	$	—	$	230	$	239	$	—	$	—
	Leasing investments	10		653		147		810		80		80
	Total consolidated VIEs	$	19	$	653	$	377	$	1,049	$	80	$	80
		December 31, 2013
		Consolidated Assets								Consolidated Liabilities
	(Dollars in millions)	Interest Bearing		Loans Held for		Other Assets		Total Assets		Long-Term Debt		Total
		Deposits in		Investment, net								Liabilities
		Banks
	LIHC investments	$	9	$	—	$	262	$	271	$	4	$	4
	Leasing investments	1		750		8		759		—		—
	Total consolidated VIEs	$	10	$	750	$	270	$	1,030	$	4	$	4
	LIHC Investments
	The Company sponsors, manages and syndicates two LIHC investment fund structures. These investments are designed to generate a return primarily through the realization of U.S. federal tax credits and deductions. The Company is considered a primary beneficiary and has consolidated these investments because the Company has the power to direct activities that most significantly impact the funds’ economic performances and also has the obligation to absorb losses of the funds that could potentially be significant to the funds. Neither creditors nor equity investors in the LIHC investments have any recourse to the general credit of the Company, and the Company’s creditors do not have any recourse to the assets of the consolidated LIHC investments.
	Leasing Investments
	The Company has leasing investments primarily in the wind, rail and coal industries. The Company is considered the primary beneficiary and has consolidated these investments because the Company has the power to direct the activities of these entities that significantly impact the entities’ economic performances. The Company also has the right to receive potentially significant benefits or the obligation to absorb potentially significant losses of these investments.
	Unconsolidated VIEs
	The following tables present the Company’s carrying amounts related to the unconsolidated VIEs and location on the consolidated balance sheets at December 31, 2014 and 2013. The tables also present the Company’s maximum exposure to loss resulting from its involvement with these VIEs. The maximum exposure to loss represents the carrying amount of the Company’s involvement plus any legally binding unfunded commitments in the unlikely event that all of the assets in the VIEs become worthless.
		December 31, 2014
		Unconsolidated Assets								Unconsolidated Liabilities
	(Dollars in millions)	Securities		Loans Held for		Other Assets		Total Assets		Other		Total		Maximum
		Available for		Investment						Liabilities		Liabilities		Exposure to
		Sale												Loss
	LIHC investments	$	25	$	163	$	1,117	$	1,305	$	433	$	433	$	1,305
	Leasing investments	—		21		886		907		55		55		923
	Other investments	—		29		20		49		—		—		51
	Total unconsolidated VIEs	$	25	$	213	$	2,023	$	2,261	$	488	$	488	$	2,279
		December 31, 2013
		Unconsolidated Assets								Unconsolidated Liabilities
	(Dollars in millions)	Securities		Loans Held for		Other Assets		Total Assets		Other		Total		Maximum
		Available for		Investment						Liabilities		Liabilities		Exposure to
		Sale												Loss
	LIHC investments	$	122	$	158	$	1,000	$	1,280	$	445	$	445	$	1,280
	Leasing investments	—		—		700		700		—		—		700
	Other investments	—		15		12		27		—		—		27
	Total unconsolidated VIEs	$	122	$	173	$	1,712	$	2,007	$	445	$	445	$	2,007
	LIHC Investments
	The Company makes investments in partnerships and funds formed by third parties. The primary purpose of the partnerships and funds is to invest in low-income housing units and distribute tax credits and tax benefits associated with the underlying properties to investors. The Company is a limited partner investor and is allocated tax credits and deductions, but has no voting or other rights to direct the activities of the funds, and therefore is not considered the primary beneficiary and does not consolidate these investments.
	Leasing Investments
	The unconsolidated VIEs related to leasing investments are primarily renewable energy investments. Through its subsidiaries, the Company makes equity investments in LLCs established by a third party sponsor. The LLCs are created to operate and manage wind, solar, hydroelectric and cogeneration power plant projects. Power generated by the projects is sold to third parties through long-term purchase power agreements. As a limited investor member, the Company is allocated production tax credits and taxable income or losses associated with the projects. The Company has no voting or other rights to direct the activities of the LLCs, and therefore is not considered the primary beneficiary and does not consolidate these investments.
	Other Investments
	The Company has direct equity investments in structures formed by third parties. The Company has no voting or other rights to direct the activities of the investments that would most significantly impact the entities’ performance, and therefore is not considered the primary beneficiary and does not consolidate these investments.

Deposits

Deposits	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Deposits	Deposits
	At December 31, 2014, the Company had $3.7 billion in interest bearing time deposits with a remaining term of greater than one year, of which $1.0 billion related to deposits of $100,000 and over. Maturity information for all interest bearing time deposits with a remaining term of greater than one year is summarized below.
	(Dollars in millions)	December 31,
		2014
	Due after one year through two years	$	1,570
	Due after two years through three years	1,134
	Due after three years through four years	812
	Due after four years through five years	167
	Due after five years	20
	Total	$	3,703

Commercial_Paper_and_Other_Sho

Commercial Paper and Other Short-Term Borrowings	12 Months Ended
	Dec. 31, 2014
Short-term Debt [Abstract]
Commercial Paper and Other Short-Term Borrowings	Commercial Paper and Other Short-Term Borrowings
	The following is a summary of the Company's commercial paper and other short-term borrowings:
	(Dollars in millions)	31-Dec-14			31-Dec-13
	Federal funds purchased and securities sold under repurchase agreements, with weighted average interest rates of 0.12% and 0.07% at December 31, 2014 and December 31, 2013	$	111		$	39
	Commercial paper, with weighted average interest rates of 0.16% and 0.19% at December 31, 2014 and December 31, 2013, respectively	2,593			2,524
	Total commercial paper and other short-term borrowings	$	2,704		$	2,563
	Federal funds purchased and securities sold under repurchase agreements:
	Maximum outstanding at any month end	$	329		$	359
	Average balance during the year	170			263
	Weighted average interest rate during the year	0.14		%	0.12		%
	Commercial paper:
	Maximum outstanding at any month end	$	3,322		$	3,655
	Average balance during the year	2,542			2,393
	Weighted average interest rate during the year	0.16		%	0.18		%
	Other borrowed funds:
	Term federal funds purchased:
	Maximum outstanding at any month end	$	252		$	269
	Average balance during the year	43			50
	Weighted average interest rate during the year	0.14		%	0.15		%
	All other borrowed funds:
	Maximum outstanding at any month end	$	—		$	—
	Average balance during the year	54			45
	Weighted average interest rate during the year	2.06		%	1.71		%
	In September 2008, the Company established a $500 million, three-year unsecured revolving credit facility with BTMU. This credit facility was renewed and expires in July 2017. For additional information regarding the Company's revolving credit facility with BTMU, see Note 21 to our Consolidated Financial Statements included in this Form 10-K.
	At December 31, 2014, federal funds purchased and securities sold under repurchase agreements had a weighted average remaining maturity of two days. The commercial paper outstanding had a weighted average remaining maturity of 47 days.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt
	Long-term debt consists of borrowings having an original maturity of one year or more. The following is a summary of the Company's long-term debt:
	(Dollars in millions)		31-Dec-14		31-Dec-13
	Debt issued by MUAH
	Senior debt:
	Fixed rate 3.50% notes due June 2022		$	398	$	397
	Subordinated debt to BTMU:
	Floating rate subordinated debt due December 2023. This note, which bears interest at 1.38% above 3-month LIBOR, had a rate of 1.63% at December 31, 2014 and 1.63% at December 31, 2013		300		300
	Junior subordinated debt payable to trusts(1):
	Floating rate notes with maturities ranging from March 2033 to September 2036. These notes bear a combined weighted-average rate of 2.35% at December 31, 2014 and 2.60% at December 31, 2013		52		66
	Total debt issued by MUAH		750		763
	Debt issued by MUB and other subsidiaries
	Senior debt:
	Fixed FHLB advances with maturities ranging from February 2015 to February 2016. These notes bear a combined weighted-average rate of 2.56% at December 31, 2014 and 2.55% at December 31, 2013		800		800
	Floating rate notes due June 2014. These notes, which bear interest at 0.95% above 3-month LIBOR, had a rate of 1.19% at December 31, 2013		—		300
	Fixed rate 3.00% notes due June 2016		700		699
	Fixed rate 1.50% notes due September 2016		499		499
	Floating rate notes due September 2016. These notes, which bear interest at 0.75% above 3-month LIBOR, had a rate of 1.00% at December 31, 2014 and 1.00% at December 31, 2013		500		500
	Fixed rate 2.125% notes due June 2017		499		499
	Fixed rate 2.625% notes due September 2018		1,000		1,000
	Fixed rate 2.250% notes due May 2019		499		—
	Floating rate notes due May 2017. These notes, which bear interest at 0.40% above 3-month LIBOR, had a rate of 0.63% at December 31, 2014		250		—
	Note payable:
	Fixed rate 6.03% notes due July 2014 (related to consolidated VIE)		—		4
	Subordinated debt:
	Fixed rate 5.95% notes due May 2016		711		718
	Subordinated debt due to BTMU:
	Floating rate subordinated debt due June 2023. This note, which bears interest at 1.2% above 3-month LIBOR, had a rate of 1.45% at December 31, 2014 and 1.45% at December 31, 2013		750		750
	Capital lease obligations with a combined weighted-average interest rate of 4.92% at December 31, 2014 and 4.88% at December 31, 2013 (1)		14		15
	Total debt issued by MUB and other subsidiaries		6,222		5,784
	Total long-term debt		$	6,972	$	6,547
	-1	Long-term debt assumed through acquisitions
	Senior Debt
	The Floating Rate Notes due May 2017 (May 2017 Notes) and the Fixed Rate 2.250% Notes due May 2019 (May 2019 Notes) were issued to purchasers at a price of 100% and 99.774% of their principal amount, respectively.  The Bank may redeem any of the May 2017 Notes, in whole or in part, on May 5, 2016 at a redemption price equal to 100% of the principal amount being redeemed plus accrued interest. The Bank may redeem any of the May 2019 Notes, in whole or in part, on or after April 6, 2019 at a redemption price equal to 100% of the principal amount being redeemed plus accrued interest. None of the Senior Notes are subject to repayment at the option of the holders prior to maturity. Interest payments are due quarterly for the May 2017 Notes and semi-annually for May 2019 Notes.
	The Floating Rate Notes (Floating Rate Notes) due September 2016, the Fixed Rate 1.50% Notes due September 2016 and the Fixed Rate 2.625% Notes (Fixed Rate Notes) due September 2018 were issued to purchasers at a price of 100%, 99.746% and 99.977% of their principal amount, respectively. The Floating Rate Notes are not redeemable at the option of the Bank prior to maturity. The Bank may redeem either of the Fixed Rate Notes, in whole or in part, on and after August 26, 2016 at a redemption price equal to 100% of the principal amount being redeemed plus interest accrued to, but excluding, the date of redemption upon not less than 30 nor more than 60 days' notice provided by the Bank to holders. None of the Senior Notes are subject to repayment at the option of the holders prior to maturity. Interest payments are due on March 26, June 26, September 26 and December 26 of each year for the Floating Rate Notes and on March 26 and September 26 of each year for the Fixed Rate Notes.
	The net proceeds from the sale of the Senior Notes were used by the Bank for general corporate purposes in the ordinary course of its banking business and were issued as part of the Bank’s $8 billion bank note program under which the Bank may issue, from time to time, senior unsecured debt obligations with maturities of more than one year from their respective dates of issue and subordinated debt obligations with maturities of five years or more from their respective dates of issue. After issuing the Senior Notes, there is $1.9 billion available for issuance under the program.
	FHLB Senior Debt
	The Bank borrows periodically from the FHLB on a medium-term basis. The advances are secured by certain of the Bank's assets and bear either a fixed or a floating interest rate. The floating rates are tied to the three-month LIBOR plus a spread, reset every 90 days. At December 31, 2014, the $800 million in FHLB advances had a weighted average remaining maturity of approximately 22 months. As of December 31, 2014 and 2013, the Bank had pledged loans and securities of $54.7 billion and$50.8 billion, respectively, as collateral for short- and medium-term advances from the Federal Reserve Bank and FHLB.
	Junior Subordinated Debt payable to Trusts
	The junior subordinated debt payable to trusts was assumed from our PCBC acquisition. These trusts were formed for the sole purpose of issuing preferred securities to third party investors. The proceeds from issuing the preferred securities were used by the trusts to purchase junior subordinated debt issued by PCBC prior to the acquisition. The junior subordinated debt qualifies as Tier 1 risk-based capital under Federal Reserve guidelines.
	Subordinated Debt due to BTMU
	On June 28, 2013, the Bank borrowed $750 million from BTMU under a subordinated debt agreement. The subordinated debt bears interest at a rate of three-month LIBOR plus 1.2%, payable quarterly, and will mature on June 28, 2023. The terms and conditions of the agreement are equivalent to those which would apply in a similar transaction with a non-related party. The Bank may prepay the subordinated debt prior to the stated maturity in whole or in part on or after June 28, 2018, but only if the Bank obtains prior written approval of the OCC. The subordinated debt due to BTMU is a junior obligation to the Bank's existing and future outstanding senior indebtedness, and qualifies as Tier 2 capital under the federal banking agency risk-based capital guidelines.
	On December 27, 2013, the Company borrowed $300 million from BTMU under a subordinated debt agreement. The subordinated debt bears interest equal to a per annum rate of three-month LIBOR plus 1.38%, payable quarterly, and matures on December 27, 2023. The terms and conditions of the agreement are equivalent to those which would apply in a similar transaction with a non-related party. The Company may prepay the subordinated debt prior to the stated maturity date in whole or in part on or after December 27, 2018 but only if the Company obtains the prior written approval of the Federal Reserve. The subordinated debt due to BTMU is a junior obligation to the Company's existing and future outstanding senior indebtedness, and qualifies as Tier 2 capital under the federal banking agency risk-based capital guidelines.
	Senior Debt Issued Subsequent to December 31, 2014
	On February 10, 2015, MUAH issued $250 million in aggregate principal amount of Floating Rate Senior Notes due 2018, $450 million in aggregate principal amount of 1.625% Fixed Rate Senior Notes due 2018, $1 billion in aggregate principal amount of 2.25% Fixed Rate Senior Notes due 2020, and $500 million in aggregate principal amount of 3.00% Fixed Rate Senior Notes due 2025. The net proceeds will be used by the Company for general corporate purposes, including working capital, acquisitions and other business opportunities.

Fair_Value_Measurement_and_Fai

Fair Value Measurement and Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurement and Fair Value of Financial Instruments	—Fair Value Measurement and Fair Value of Financial Instruments
	Valuation Methodologies
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., an exit price) in an orderly transaction between willing market participants at the measurement date. The Company has an established and documented process for determining fair value for financial assets and liabilities that are measured at fair value on either a recurring or nonrecurring basis. When available, quoted market prices are used to determine fair value. If quoted market prices are not available, fair value is based upon valuation techniques that use, where possible, current market-based or independently sourced parameters, such as yield curves, foreign exchange rates, credit spreads, commodity prices, and implied volatilities. Valuation adjustments may be made to ensure the financial instruments are recorded at fair value. These adjustments include amounts that reflect counterparty credit quality and that consider the Company's own creditworthiness in determining the fair value of its trading assets and liabilities.
	Fair Value Hierarchy
	In determining fair value, the Company maximizes the use of observable market inputs and minimizes the use of unobservable inputs. Observable inputs reflect market-derived or market-based information obtained from independent sources, while unobservable inputs reflect the Company's estimate about market data. Based on the observability of the significant inputs used, the Company classifies its fair value measurements in accordance with the three-level hierarchy as defined by GAAP. This hierarchy is based on the quality, observability, and reliability of the information used to determine fair value.
	Level 1:    Valuations are based on quoted prices in active markets for identical assets or liabilities. Since the valuations are based on quoted prices that are readily available in an active market, they do not entail a significant degree of judgment.
	Level 2:    Valuations are based on quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuations for which all significant assumptions are observable or can be corroborated by observable market data.
	Level 3:    Valuations are based on at least one significant unobservable input that is supported by little or no market activity and is significant to the fair value measurement. Values are determined using pricing models and discounted cash flow models that include management judgment and estimation, which may be significant.
	In assigning the appropriate levels, the Company performs a detailed analysis of the assets and liabilities that are measured at fair value. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. The level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement in its entirety. Therefore, an item may be classified in Level 3 even though there may be many significant inputs that are readily observable.
	Valuation Processes. The Company has established a valuation committee to oversee its valuation framework for measuring fair value and to establish valuation policies and procedures. The valuation committee's responsibilities include reviewing fair value measurements and categorizations within the fair value hierarchy and monitoring the use of pricing sources, mark-to-model valuations, dealer quotes, and other valuation processes. The valuation committee reports to the Company's Risk & Capital Committee and meets at least quarterly.
	Independent Price Verification is performed periodically by the Company to test the market data and valuations of substantially all instruments measured at fair value on a recurring basis. As part of its independent price verification procedures, the Company compares pricing sources, tests data variance within certain thresholds and performs variance analysis, utilizing third party valuations and both internal and external models. Results are formally reported on a quarterly basis to the valuation committee.
	A description of the valuation methodologies used for certain financial assets and liabilities measured at fair value is as follows:
	Recurring Fair Value Measurements:
	Trading Account Assets:    Trading account assets are recorded at fair value and primarily consist of securities and derivatives held for trading purposes. See discussion below on securities available for sale, which utilize the same valuation methodology as trading account securities. See also discussion below on derivatives valuation.
	Securities Available for Sale:    Securities available for sale are recorded at fair value based on readily available quoted market prices, if available. These highly liquid securities are classified as Level 1 and include exchange traded equities. If such quoted market prices are not available, management utilizes third-party pricing services and broker quotations from dealers in the specific instruments. These securities are classified as Level 2 and include U.S treasuries, U.S. government-sponsored agencies, RMBS and CMBS, CLOs, and certain other debt securities. If no market prices or broker quotes are available, internal pricing models are used. To the extent possible, these pricing model valuations utilize observable market inputs obtained for similar securities. Typical inputs include LIBOR and U.S. Treasury yield curves, benchmark yields, consensus prepayment estimates and credit spreads. When pricing model valuations use significant unobservable inputs, the securities are classified as Level 3. These other debt securities primarily include direct bank purchase bonds. The valuation of these securities is based upon a return on equity method, which incorporates a market-required return on capital, probability of default and loss severity.
	Other Assets:    Other assets include interest rate hedging contracts and other risk management derivatives; see discussion below on derivatives.
	Derivatives:    The Company's derivatives are primarily traded in over-the-counter markets where quoted market prices are not readily available. The Company values its derivatives using pricing models that are widely accepted in the financial services industry with inputs that are observable in the market or can be derived from or corroborated by observable market data. These models reflect the contractual terms of the derivatives including the period to maturity and market observable inputs such as yield curves and option volatility. Valuation adjustments are made to reflect counterparty credit quality and to consider the creditworthiness of the Company. These derivatives, which are included in trading account assets, trading account liabilities, other assets and other liabilities are generally classified as Level 2. Trading account assets and trading account liabilities include Level 3 derivatives comprised of embedded derivatives contained in market-linked CDs and perfectly matched over-the-counter options, whose fair value is obtained through unadjusted third party broker quotes, which incorporate significant unobservable inputs.
	Trading Account Liabilities:    Trading account liabilities are recorded at fair value and primarily consist of securities sold, not yet purchased and derivatives. See discussion above on derivatives valuation. Securities sold, not yet purchased consist of U.S. Government securities and are classified as Level 2, which utilize the same valuation methodology as trading account securities.
	Other Liabilities:    The fair value of the Company's FDIC clawback liability is determined using a discounted cash flow model with significant unobservable inputs, which include probability of default and loss severity. The FDIC clawback liability is classified as Level 3. Other liabilities also includes interest rate hedging contracts and other risk management derivatives; see discussion above on derivatives.
	Nonrecurring Fair Value Measurements:
	Individually Impaired Loans:    Individually impaired loans are valued at the time the loan is identified as impaired based on the present value of the remaining expected cash flows. Because the discount factor applied is based on the loan's original effective yield rather than a current market rate, that present value does not represent fair value. However, as a practical expedient, an impaired loan may be measured based on a loan's observable market price or the underlying collateral securing the loan (provided the loan is collateral dependent), which does approximate fair value. Collateral may be real estate or business assets, including equipment. The value of collateral is determined based on independent appraisals. Appraised values may be adjusted based on management's historical knowledge, changes in market conditions from the time of valuation, and management's knowledge of the client and the client's business. The loan's market price is determined using market pricing for similar assets, adjusted for management judgment. Impaired loans are reviewed and evaluated at least quarterly for additional impairment and adjusted accordingly. Impaired loans that are adjusted to fair value based on underlying collateral or the loan's market price are classified as Level 3.
	Loans Held for Sale:    Residential mortgage and commercial loans held for sale are recorded at the lower of cost or fair value. The fair value of fixed-rate residential loans is based on whole loan forward prices obtained from GSEs. These loans are classified as Level 2. The fair value of commercial loans held for sale may be based on secondary market offerings for loans with similar characteristics or a valuation methodology utilizing the appraised value to outstanding loan balance ratio. These loan values are classified as Level 3.
	Private Equity Investments:    Private equity investments are recorded either at cost or using the equity method and are evaluated for impairment. The valuation of these investments requires significant management judgment due to the absence of quoted market prices, lack of liquidity and the long-term nature of these assets. When required, the fair value of the investments was estimated using the net asset value or based on the investee's business model, current and projected financial performance, capital needs and our exit strategy. Private equity investments are generally classified as Level 3.
	Other Real Estate Owned:    OREO represents collateral acquired through foreclosure and is initially recorded at fair value as established by a current appraisal, adjusted for disposition costs. Subsequently, OREO is measured at lower of cost or fair value. OREO values are reviewed on an ongoing basis and any subsequent decline in fair value is recorded as a foreclosed asset expense in the current period. The value of OREO is determined based on independent appraisals and is generally classified as Level 3.
	Fair Value Measurements on a Recurring Basis
	The following tables present financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2013, by major category and by valuation hierarchy level.
			31-Dec-14
	(Dollars in millions)		Level 1			Level 2			Level 3				Netting			Fair Value
													Adjustment (1)
	Assets
	Trading account assets:
	U.S. Treasury securities		$	—		$	69		$	—			$	—		$	69
	U.S. government-sponsored agencies		—			125			—				—			125
	State and municipal securities		—			10			—				—			10
	Interest rate derivative contracts		—			928			5				(172		)	761
	Commodity derivative contracts		—			417			5				(392		)	30
	Foreign exchange derivative contracts		1			104			1				(63		)	43
	Equity derivative contracts		—			—			300				(224		)	76
	Total trading account assets		1			1,653			311				(851		)	1,114
	Securities available for sale:
	Residential mortgage-backed securities:
	U.S. government and government-sponsored agencies		—			7,560			—				—			7,560
	Privately issued		—			168			—				—			168
	Privately issued - commercial mortgage-backed securities		—			1,691			—				—			1,691
	Collateralized loan obligations		—			2,494			—				—			2,494
	Other		—			9			—				—			9
	Other debt securities:
	Direct bank purchase bonds		—			—			1,741				—			1,741
	Other		—			3			49				—			52
	Equity securities		9			—			—				—			9
	Total securities available for sale		9			11,925			1,790				—			13,724
	Other assets:
	Interest rate hedging contracts		—			36			—				(36		)	—
	Other derivative contracts		—			—			2				—			2
	Total other assets		—			36			2				(36		)	2
	Total assets		$	10		$	13,614		$	2,103			$	(887	)	$	14,840
	Percentage of Total		—		%	92		%	14		%		(6		)%	100		%
	Percentage of Total Company Assets		—		%	12		%	2		%		(1		)%	13		%
	Liabilities
	Trading account liabilities:
	Interest rate derivative contracts		$	1		$	829		$	—			$	(667	)	$	163
	Commodity derivative contracts		—			403			5				(93		)	315
	Foreign exchange derivative contracts		1			78			1				(24		)	56
	Equity derivative contracts		—			—			299				—			299
Securities sold, not yet purchased		—			61			—				—			61
Total trading account liabilities		2			1,371			305				(784		)	894
Other liabilities:
FDIC clawback liability		—			—			105				—			105
Interest rate hedging contracts		—			4			—				(3		)	1
Other derivative contracts		—			1			2				—			3
Total other liabilities		—			5			107				(3		)	109
Total liabilities		$	2		$	1,376		$	412			$	(787	)	$	1,003
Percentage of Total		—		%	137		%	41		%		(78		)%	100		%
Percentage of Total Company Liabilities		—		%	1		%	—		%		(1		)%	—		%
-1	Amounts represent the impact of legally enforceable master netting agreements between the same counterparties that allow the Company to net settle all contracts.
		31-Dec-13
(Dollars in millions)		Level 1			Level 2			Level 3				Netting			Fair Value
												Adjustment (1)
Assets
Trading account assets:
U.S. Treasury securities		$	—		$	8		$	—			$	—		$	8
U.S. government-sponsored agencies		—			116			—				—			116
State and municipal securities		—			5			—				—			5
Other loans		—			140			—				—			140
Interest rate derivative contracts		1			705			7				(212		)	501
Commodity derivative contracts		—			67			9				(66		)	10
Foreign exchange derivative contracts		1			30			2				(18		)	15
Equity derivative contracts		—			—			253				(197		)	56
Total trading account assets		2			1,071			271				(493		)	851
Securities available for sale:
U.S. government-sponsored agencies		—			73			—				—			73
Residential mortgage-backed securities:
U.S government and government-sponsored agencies		—			8,900			—				—			8,900
Privately issued		—			222			—				—			222
Privately issued - commercial mortgage-backed securities		—			1,870			—				—			1,870
Collateralized loan obligations		—			2,673			—				—			2,673
Other		—			35			—				—			35
Other debt securities:
Direct bank purchase bonds		—			—			1,960				—			1,960
Other		—			18			58				—			76
Equity securities		8			—			—				—			8
Total securities available for sale		8			13,791			2,018				—			15,817
Other assets:
Interest rate hedging contracts		—			8			—				—			8
Other derivative contracts		—			1			1				—			2
Total other assets		—			9			1				—			10
Total assets		$	10		$	14,871		$	2,290			$	(493	)	$	16,678
Percentage of Total		—		%	89		%	14		%		(3		)%	100		%
Percentage of Total Company Assets		—		%	14		%	2		%		—		%	16		%
Liabilities
Trading account liabilities:
Interest rate derivative contracts		$	3		$	606		$	—			$	(379	)	$	230
Commodity derivative contracts		—			53			8				(33		)	28
Foreign exchange derivative contracts		1			26			2				(11		)	18
Equity derivative contracts		—			—			254				—			254
Securities sold, not yet purchased		—			10			—				—			10
Total trading account liabilities		4			695			264				(423		)	540
Other liabilities:
FDIC clawback liability		—			—			96				—			96
Interest rate hedging contracts		—			13			—				—			13
Other derivative contracts		—			1			3				—			4
Total other liabilities		—			14			99				—			113
Total liabilities		$	4		$	709		$	363			$	(423	)	$	653
Percentage of Total		1		%	109		%	55		%		(65		)%	100		%
Percentage of Total Company Liabilities		—		%	1		%	—		%		—		%	1		%
-1	Amounts represent the impact of legally enforceable master netting agreements between the same counterparties that allow the Company to net settle all contracts.
The following tables present a reconciliation of the assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2014 and 2013. Level 3 available for sale securities at December 31, 2014 primarily consist of direct bank purchase bonds. The Company's policy is to recognize transfers in and out of Level 1, 2 and 3 as of the end of a reporting period.
		For the Year Ended
		31-Dec-14
(Dollars in millions)		Trading			Securities			Other				Trading			Other
		Assets			Available for			Assets				Liabilities			Liabilities
					Sale
Asset (liability) balance, beginning of period		$	271		$	2,018		$	1			$	(264	)	$	(99	)
Total gains (losses) (realized/unrealized):
Included in income before taxes		61			—			1				(61		)	(8		)
Included in other comprehensive income		—			29			—				—			—
Purchases/additions		4			197			—				—			—
Sales		—			—			—				(5		)	—
Settlements		(25		)	(454		)	—				25			—
Asset (liability) balance, end of period		$	311		$	1,790		$	2			$	(305	)	$	(107	)
Changes in unrealized gains (losses) included in income before taxes for assets and liabilities still held at end of period		$	61		$	—		$	1			$	(61	)	$	(8	)
		For the Year Ended
		31-Dec-13
(Dollars in millions)		Trading			Securities			Other				Trading			Other
		Assets			Available for			Assets				Liabilities			Liabilities
					Sale
Asset (liability) balance, beginning of period		$	136		$	1,499		$	—			$	(136	)	$	(95	)
Total gains (losses) (realized/unrealized):
Included in income before taxes		119			—			—				(120		)	(4		)
Included in other comprehensive income		—			28			—				—			—
Purchases/additions		24			700			1				—			—
Sales		—			(14		)	—				(16		)	—
Settlements		(8		)	(195		)	—				8			—
Asset (liability) balance, end of period		$	271		$	2,018		$	1			$	(264	)	$	(99	)
Changes in unrealized gains (losses) included in income before taxes for assets and liabilities still held at end of period		$	119		$	—		$	—			$	(120	)	$	(4	)
The following table presents information about significant unobservable inputs related to the Company's significant Level 3 assets and liabilities at December 31, 2014.
		31-Dec-14
(Dollars in millions)		Level 3			Valuation Technique(s)		Significant Unobservable	Range of Inputs		Weighted
		Fair Value					Input(s)			Average
Securities available for sale:
Direct bank purchase bonds		$	1,741		Return on equity		Market-required return on capital	8.0 - 10.0	%	9.9	%
							Probability of default	0.0 - 25.0	%	0.5	%
							Loss severity	10.0 - 60.0	%	31.1	%
Other liabilities:
FDIC clawback liability		$	105		Discounted cash flow		Probability of default	0.1 - 100.0	%	58.4	%
							Loss severity	0.0 - 100.0	%	39.1	%
The direct bank purchase bonds use a return on equity valuation technique. This technique uses significant unobservable inputs such as market-required return on capital, probability of default, and loss severity. Increases (decreases) in any of these inputs in isolation would result in a lower (higher) fair value measurement.
The FDIC clawback liability uses a discounted cash flow valuation technique. This technique uses significant unobservable inputs such as probability of default and loss severity. Increases (decreases) in probability of default and loss severity would result in a lower (higher) liability.
Fair Value Measurement on a Nonrecurring Basis
Certain assets may be measured at fair value on a nonrecurring basis. These assets are subject to fair value adjustments that result from the application of the lower of cost or fair value accounting or write-downs of individual assets. For assets measured at fair value on a nonrecurring basis during the years ended December 31, 2014 and 2013 that were still held on the consolidated balance sheet as of the respective periods ended, the following tables present the fair value of such assets by the level of valuation assumptions used to determine each fair value adjustment.
		31-Dec-14													Loss for the Year Ended December 31, 2014
(Dollars in millions)		Fair			Level 1			Level 2				Level 3
		Value
Loans:
Impaired loans		$	109		$	—		$	—			$	109		$	(37	)
Other assets:
OREO		15			—			—				15			(6		)
Total		$	124		$	—		$	—			$	124		$	(43	)
		31-Dec-13													Loss for the Year Ended December 31, 2013
(Dollars in millions)		Fair			Level 1			Level 2				Level 3
		Value
Loans:
Impaired loans		$	59		$	—		$	—			$	59		$	(47	)
Other assets:
OREO		21			—			—				21			(11		)
Private equity investments		—			—			—				—			(5		)
Total		$	80		$	—		$	—			$	80		$	(63	)
Loans include individually impaired loans that are measured based on the fair value of the underlying collateral or the fair value of the loan. The fair value of impaired loans was determined based on appraised values of the underlying collateral or market pricing for the loan, adjusted for management judgment, as of the measurement date. The fair value of OREO was primarily based on independent appraisals.
Fair Value of Financial Instruments Disclosures
In addition to financial instruments recorded at fair value in the Company's financial statements, the disclosure of the estimated fair value of financial instruments that are not carried at fair value is also required. Excluded from this disclosure requirement are lease financing arrangements, investments accounted for under the equity method, employee pension and other postretirement obligations and all nonfinancial assets and liabilities, including goodwill and other intangible assets such as long-term customer relationships. The fair values presented are estimates for certain individual financial instruments and do not represent an estimate of the fair value of the Company as a whole.
Certain financial instruments that are not recognized at fair value on the consolidated balance sheet are carried at amounts that approximate fair value due to their short-term nature. These financial instruments include cash and due from banks, interest bearing deposits in banks, federal funds sold and purchased, securities purchased under resale agreements, securities sold under repurchase agreements and commercial paper. In addition, the fair value of deposits with no stated maturity, such as noninterest bearing demand deposits, interest bearing checking, and market rate and other savings are deemed to equal their carrying amounts.
Financial instruments for which their carrying amounts do not approximate fair value include securities held to maturity, loans, FDIC indemnification asset, interest bearing deposits with stated maturities, certain other short-term borrowings, long-term debt and off-balance sheet instruments.
Securities Held to Maturity:    The fair value of U.S. government agency and government-sponsored agencies RMBS, CMBS and CLOs classified as held to maturity are based on unadjusted third party pricing service prices.
Loans:    The fair value of purchased credit-impaired loans was estimated using a discounted cash flow methodology that considered factors including the type of loan and related collateral, risk classification, term of loan, performance status and current discount rates. The fair values of mortgage loans were estimated based on quoted market prices for loans with similar credit and interest rate risk characteristics. The fair values of other loans were estimated based upon the type of loan and maturity and were determined by discounting the future expected cash flows using the current origination rates for similar loans made to borrowers with similar credit ratings and include adjustments for liquidity premiums.
FDIC Indemnification Asset:    The fair value of the FDIC indemnification asset was estimated using the present value of the cash flows that the Company expects to collect from the FDIC under the loss share agreements.
Interest Bearing Deposits:    The fair values of savings accounts and certain money market accounts were based on the amounts payable on demand at the reporting date. The fair value of fixed maturity CDs was estimated using a discounted cash flow calculation that applies current interest rates being offered on certificates with similar maturities.
Commercial Paper and Other Short-Term Borrowings:    The fair values of Federal Reserve Bank term borrowings, FHLB borrowings and term federal funds purchased were estimated using a discounted cash flow calculation that applies current market rates for applicable maturities. The carrying amounts of other short-term borrowed funds were assumed to approximate their fair value due to their limited duration.
Long-Term Debt:    The fair value of senior and subordinated debt was estimated using either a discounted cash flow analysis based on current market interest rates for debt with similar maturities and credit quality or estimated using market quotes. The fair value of junior subordinated debt payable to trusts was estimated using market quotes of similar securities.
Off-Balance Sheet Instruments:    Commitments to extend credit and issued standby and commercial letters of credit are instruments that generate ongoing fees, which are recognized over the term of the commitment period. In situations where the credit quality of the counterparty to a commitment has declined, the Company records a reserve. A reasonable estimate of the fair value of these instruments is the carrying amount of deferred fees plus the related reserve.
The tables below present the carrying amount and estimated fair value of certain financial instruments by the level of valuation assumptions held by the Company as of December 31, 2014 and 2013.
		31-Dec-14
(Dollars in millions)		Carrying			Fair			Level 1				Level 2			Level 3
		Amount			Value
Assets
Cash and cash equivalents		$	5,751		$	5,751		$	5,751			$	—		$	—
Securities held to maturity		8,291			8,412			—				8,412			—
Loans held for investment (1)		75,475			77,324			—				—			77,324
FDIC indemnification asset		52			5			—				—			5
Other assets		7			6			—				—			6
Liabilities
Deposits		$	86,004		$	86,076		$	—			$	86,076		$	—
Commercial paper and other short-term borrowings		2,704			2,704			—				2,704			—
Long-term debt		6,972			7,073			—				7,073			—
Off-Balance Sheet Instruments
Commitments to extend credit and standby and commercial letters of credit		$	269		$	269		$	—			$	—		$	269
-1	Excludes lease financing. The carrying amount is net of the allowance for loan and lease losses.
		31-Dec-13
(Dollars in millions)		Carrying			Fair			Level 1				Level 2			Level 3
		Amount			Value
Assets
Cash and cash equivalents		$	6,203		$	6,203		$	6,203			$	—		$	—
Securities held to maturity		6,509			6,439			—				6,439			—
Loans held for investment, net of allowance for loan losses(1)		66,898			68,132			—				—			68,132
FDIC indemnification asset		141			95			—				—			95
Other assets		3			3			—				—			3
Liabilities
Deposits		$	80,101		$	80,228		$	—			$	80,228		$	—
Commercial paper and other short-term borrowings		2,563			2,563			—				2,563			—
Long-term debt		6,547			6,709			—				6,709			—
Off-Balance Sheet Instruments
Commitments to extend credit and standby and commercial letters of credit		$	273		$	273		$	—			$	—		$	273
-1	Excludes lease financing, net of related allowance.

Derivative_Instruments_and_Oth

Derivative Instruments and Other Financial Instruments Used For Hedging	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Other Financial Instruments Used For Hedging	Derivative Instruments and Other Financial Instruments Used For Hedging
	The Company enters into certain derivative and other financial instruments primarily to assist customers with their risk management objectives and to manage the Company’s exposure to interest rate risk. When entering into derivatives on behalf of customers the Company generally acts as a financial intermediary by offsetting a significant portion of the market risk for these derivatives with third parties. The Company may also enter into derivatives for other risk management purposes and, subject to certain limits, may take market risk when buying and selling derivatives for its own account. All derivative instruments are recognized as assets or liabilities on the consolidated balance sheets at fair value.
	Counterparty credit risk is inherent in derivative instruments. In order to reduce its exposure to counterparty credit risk, the Company utilizes credit approvals, limits, monitoring procedures and master netting and credit support annex agreements. Additionally, the Company considers counterparty credit quality and the creditworthiness of the Company in estimating the fair value of derivative instruments.
	The table below presents the notional amounts and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheets, segregated between derivative instruments designated and qualifying as hedging instruments and derivative instruments not designated and qualifying as hedging instruments as of December 31, 2014 and December 31, 2013, respectively. Asset and liability values are presented gross, excluding the impact of legally enforceable master netting and credit support annex agreements. The fair value of asset and liability derivatives designated and qualifying as hedging instruments and derivatives designated as other risk management are included in other assets and other liabilities, respectively. The fair value of asset and liability trading derivatives are included in trading account assets and trading account liabilities, respectively.
			31-Dec-14												31-Dec-13
							Fair Value												Fair Value
	(Dollars in millions)		Notional				Asset				Liability				Notional				Asset			Liability
			Amount				Derivatives				Derivatives				Amount				Derivatives			Derivatives
	Cash flow hedges
	Interest rate contracts		$	9,750			$	34			$	4			$	4,300			$	8		$	13
	Fair value hedges
	Interest rate contracts		500				2				—				—				—			—
	Not designated and qualifying as hedging instruments:
	Trading
	Interest rate contracts		46,944				933				830				44,427				713			609
	Commodity contracts		4,741				422				408				5,714				76			61
	Foreign exchange contracts		5,661				106				80				5,645				33			29
	Equity contracts		3,797				300				299				4,027				253			254
	Other contracts		—				—				—				140				—			—
	Total Trading		61,143				1,761				1,617				59,953				1,075			953
	Other risk management		286				2				3				185				2			4
	Total derivative instruments		$	71,679			$	1,799			$	1,624			$	64,438			$	1,085		$	970
	We recognized net losses of $1 million and net losses of $6 million on other risk management derivatives for the years ended December 31, 2014 and 2013, respectively, which are included in other noninterest income.
	Derivatives Designated and Qualifying as Hedging Instruments
	The Company uses interest rate derivatives to manage the financial impact on the Company from changes in market interest rates. These instruments are used to manage interest rate risk relating to specified groups of assets and liabilities, primarily LIBOR-based commercial loans, CDs, borrowings, and debt issuances. Derivatives that qualify for hedge accounting are designated as either fair value or cash flow hedges.
	Cash Flow Hedges
	The Company used interest rate swaps with a notional amount of $9.75 billion at December 31, 2014 to hedge the risk of changes in cash flows attributable to changes in the designated benchmark interest rate on LIBOR indexed loans. To the extent effective, payments received (or paid) under the swap contract offset fluctuations in interest income on loans caused by changes in the relevant LIBOR index. At December 31, 2014, the weighted average remaining life of the current cash flow hedges was approximately 3.37 years.
	For cash flow hedges, the effective portion of the gain or loss on the hedging instruments is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during which the hedged cash flows are recognized in net interest income. Gains and losses representing hedge ineffectiveness are recognized in earnings in the period in which they arise. At December 31, 2014, the Company expects to reclassify approximately $103 million of income from AOCI to net interest income during the year ending December 31, 2015. This amount could differ from amounts actually realized due to changes in interest rates, hedge terminations or the addition of other hedges subsequent to December 31, 2014.
	The following tables present the amount and location of the net gains and losses recorded in the Company's consolidated statements of income and changes in stockholder's equity for derivatives designated as cash flow hedges for the years ended December 31, 2014 and 2013:
			Amount of Gain (Loss)								Gain (Loss) Reclassified from										Gain (Loss) Recognized in Income
			Recognized in OCI on								Accumulated OCI										on Derivative Instruments (Ineffective Portion)
			Derivative Instruments								into Income (Effective Portion)
			(Effective Portion)
			For the Years Ended										For the Years Ended									For the Years Ended
			December 31,										December 31,									December 31,
	(Dollars in millions)		2014				2013				Location		2014				2013				Location	2014		2013
	Derivatives in cash flow hedging relationships
											Interest income		$	115			$	44
	Interest rate contracts		$	126			$	29			Interest expense		2				(1		)		Noninterest expense (1)	$	2	$	—
	Total		$	126			$	29					$	117			$	43				$	2	$	—
	-1	Amount recognized was less than $1 million in 2013.
	Fair Value Hedges
	The Company engages in an interest rate hedging strategy in which one or more interest rate swaps are associated with a specified interest bearing liability, in order to convert the liability from a fixed rate to a floating rate instrument. This strategy mitigates the changes in fair value of the hedged liability caused by changes in the designated benchmark interest rate, U.S. dollar LIBOR.
	For fair value hedges, any ineffectiveness is recognized in noninterest expense in the period in which it arises. The change in the fair value of the hedged item and the hedging instrument, to the extent completely effective, offsets with no impact on earnings.
	The following table presents the gains (losses) on the Company's fair value hedges and hedged item for the year ended December 31, 2014:
					For the Year Ended December 31, 2014
		(Dollars in millions)			Derivative				Hedged Item				Hedge Ineffectiveness
		Interest rate risk on long-term debt			$	2			$	(1	)		$	1
			Total		$	2			$	(1	)		$	1
	There were no fair value hedges during 2013.
	Derivatives Not Designated and Qualifying as Hedging Instruments
	Trading Derivatives
	Derivative instruments classified as trading include both derivatives entered into as an accommodation for customers and, subject to certain limits, for the Company's own account. Trading derivatives are included in trading assets or trading liabilities with changes in fair value reflected in income from trading account activities. The majority of the Company's derivative transactions for customers were essentially offset by contracts with third parties that reduce or eliminate market risk exposures.
	The Company offers market-linked CDs, which allow the client to earn the higher of either a minimum fixed rate of interest or a return tied to either equity, commodity or currency indices. The Company offsets its exposure to the embedded derivative contained in market-linked CDs with a matched over-the-counter option. Both the embedded derivative (when bifurcated) and hedge options are recorded at fair value with the realized and unrealized changes in fair value recorded in noninterest income within trading account activities.
	The following table presents the amount of the net gains and losses for derivative instruments classified as trading reported in the consolidated statements of income under the heading trading account activities for the twelve months ended December 31, 2014 and 2013:
			Gain (Loss) Recognized in Income on
			Derivative Instruments
			For the Years Ended
	(Dollars in millions)		31-Dec-14				31-Dec-13
	Trading derivatives:
	Interest rate contracts		$	36			$	30
	Equity contracts		3				—
	Foreign exchange contracts		19				18
	Commodity contracts		8				2
Other contracts		1				—
Total		$	67			$	50
Offsetting Assets and Liabilities
The Company primarily enters into derivative contracts and repurchase agreements with counterparties utilizing a standard International Swaps and Derivatives Association master netting agreement or master repurchase agreements, which generally establish the terms and conditions of the transactions, including a legal right to set-off amounts payable and receivable between the Company and a counterparty, regardless of whether or not such amounts have matured or have contingency features.
The following tables present the offsetting of financial assets and liabilities as of December 31, 2014 and 2013:
		31-Dec-14
														Gross Amounts Not Offset in
														Balance Sheet
(Dollars in millions)		Gross Amounts				Gross Amounts				Net Amounts				Financial				Cash Collateral			Net Amount
		of Recognized				Offset in				Presented in				Instruments				Received/Pledged
		Assets/Liabilities				Balance Sheet				Balance Sheet
Financial Assets:
Derivative assets		$	1,799			$	887			$	912			$	113			$	—		$	799
Securities purchased under resale agreements		62				—				62				61				—			1
Total		$	1,861			$	887			$	974			$	174			$	—		$	800
Financial Liabilities:
Derivative liabilities		$	1,624			$	787			$	837			$	162			$	—		$	675
Securities sold under repurchase agreements		68				—				68				68				—			—
Total		$	1,692			$	787			$	905			$	230			$	—		$	675
		31-Dec-13
														Gross Amounts Not Offset in Balance Sheet
(Dollars in millions)		Gross Amounts				Gross Amounts				Net Amounts				Financial				Cash Collateral			Net Amount
		of Recognized				Offset in				Presented in				Instruments				Received/Pledged
		Assets/Liabilities				Balance Sheet				Balance Sheet
Financial Assets:
Derivative assets		$	1,085			$	493			$	592			$	79			$	—		$	513
Securities purchased under resale agreements		10				—				10				10				—			—
Total		$	1,095			$	493			$	602			$	89			$	—		$	513
Financial Liabilities:
Derivative liabilities		$	970			$	423			$	547			$	144			$	—		$	403
Securities sold under repurchase agreements		8				—				8				8				—			—
Total		$	978			$	423			$	555			$	152			$	—		$	403

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income
	The following table presents the change in each of the components of accumulated other comprehensive loss and the related tax effect of the change allocated to each component.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2012
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	82		$	(32	)	$	50
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(15		)	6			(9		)
	Net change		67			(26		)	41
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		187			(74		)	113
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(107		)	42			(65		)
	Reclassification of unrealized (gains) losses on held to maturity securities transferred to securities available for sale		301			(118		)	183
	Less: accretion of fair value adjustment on securities available for sale		(9		)	4			(5		)
	Less: accretion of fair value adjustment on held to maturity securities		(24		)	9			(15		)
	Less: amortization of net unrealized (gains) losses on held to maturity securities		90			(35		)	55
	Net change		438			(172		)	266
	Foreign currency translation adjustment		2			(1		)	1
	Pension and other benefits:
	Amortization of transition amount		1			(1		)	—
	Recognized net actuarial gain (loss)(1)		99			(39		)	60
	Pension and other benefits arising during the year		(121		)	48			(73		)
	Net change(1)		(21		)	8			(13		)
	Net change in AOCI		$	486		$	(191	)	$	295
	-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2013
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	29		$	(11	)	$	18
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(43		)	17			(26		)
	Net change		(14		)	6			(8		)
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		(401		)	157			(244		)
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(178		)	70			(108		)
	Less: accretion of fair value adjustment on securities available for sale		(75		)	30			(45		)
	Less: accretion of fair value adjustment on held to maturity securities		(12		)	5			(7		)
	Less: amortization of net unrealized (gains) losses on held to maturity securities		(137		)	54			(83		)
	Net change		(803		)	316			(487		)
	Foreign currency translation adjustment		(7		)	3			(4		)
	Pension and other benefits:
	Recognized net actuarial gain (loss)(1)		116			(46		)	70
	Pension and other benefits arising during the year		526			(207		)	319
	Net change(1)		642			(253		)	389
	Net change in AOCI		$	(182	)	$	72		$	(110	)
	-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2014
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	126		$	(50	)	$	76
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(117		)	46			(71		)
	Net change		9			(4		)	5
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		348			(136		)	212
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(18		)	7			(11		)
	Less: accretion of fair value adjustment on securities available for sale		(48		)	19			(29		)
	Less: accretion of fair value adjustment on held to maturity securities		—			—			—
	Less: amortization of net unrealized (gains) losses on held to maturity securities		19			(8		)	11
	Net change		301			(118		)	183
	Foreign currency translation adjustment		(11		)	4			(7		)
Pension and other benefits:
Amortization of prior service costs		(17		)	7			(10		)
Recognized net actuarial gain (loss)(1)		62			(24		)	38
Pension and other benefits arising during the year		(517		)	203			(314		)
Net change(1)		(472		)	186			(286		)
Net change in AOCI		$	(173	)	$	68		$	(105	)
-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
The following table presents the change in accumulated other comprehensive loss balances.
(Dollars in millions)		Net			Net			Foreign			Pension and			Accumulated
		Unrealized			Unrealized			Currency			Other			Other
		Gains (Losses)			Gains (Losses)			Translation			Benefits			Comprehensive
		on Cash			on Securities			Adjustment			Adjustment			Loss
		Flow
		Hedges
Balance, December 31, 2011		$	(17	)	$	(107	)	$	—		$	(685	)	$	(809	)
Other comprehensive income before reclassifications		50			148			1			—			199
Amounts reclassified from accumulated other comprehensive loss		(9		)	118			—			(13		)	96
Balance, December 31, 2012		$	24		$	159		$	1		$	(698	)	$	(514	)
Balance, December 31, 2012		$	24		$	159		$	1		$	(698	)	$	(514	)
Other comprehensive income before reclassifications		18			(379		)	(4		)	—			(365		)
Amounts reclassified from accumulated other comprehensive loss		(26		)	(108		)	—			389			255
Balance, December 31, 2013		$	16		$	(328	)	$	(3	)	$	(309	)	$	(624	)
Balance, December 31, 2013		$	16		$	(328	)	$	(3	)	$	(309	)	$	(624	)
Other comprehensive income before reclassifications		76			194			(7		)	—			263
Amounts reclassified from accumulated other comprehensive loss		(71		)	(11		)	—			(286		)	(368		)
Balance, December 31, 2014		$	21		$	(145	)	$	(10	)	$	(595	)	$	(729	)

Management_Stock_Plans

Management Stock Plans	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Management Stock Plans	Management Stock Plans
	In April 2010, the Company adopted the UnionBanCal Plan (UNBC Plan). Under the UNBC Plan, the Company grants restricted stock units settled in ADRs representing shares of common stock of the Company's indirect parent company, MUFG, to key employees at the discretion of the Executive Compensation and Benefits Committee of the Board of Directors (the Committee). The Committee determines the number of shares, vesting requirements and other features and conditions of the restricted stock units. Under the UNBC Plan, MUFG ADRs are purchased in the open market upon the vesting of the restricted stock units, through a revocable trust. There is no amount authorized to be issued under the UNBC Plan since all shares are purchased in the open market. These awards generally vest pro-rata on each anniversary of the grant date and become fully vested three years from the grant date, provided that the employee has completed the specified continuous service requirement. Generally, the grants vest earlier if the employee dies, is permanently and totally disabled, retires under certain grant, age and service conditions, or terminates employment under certain conditions.
	Under the UNBC Plan, the restricted stock unit participants do not have dividend rights, voting rights or other stockholder rights. The grant date fair value of these awards is equal to the closing price of the MUFG ADRs on date of grant.
	Effective July 1, 2014, the U.S. branch banking operations of BTMU were integrated under the Bank's operations and the Company assumed the obligations of the stock bonus plan established by BTMU Headquarters for the Americas (HQA Plan). The HQA Plan is substantially similar to the UNBC Plan however, participants in the HQA Plan are entitled to “dividend equivalent credits” on their unvested restricted stock units when MUFG pays dividends to its shareholders. The credit is equal to the dividends that the participants would have received on the shares had the shares been issued to the participants when the restricted stock units were granted. Accumulated dividend equivalents are paid to participants in cash on an annual basis.
	The following table is a summary of the UNBC Plan and the HQA Plan, which together are presented as the "Stock Bonus Plans":
	Grant Date	Units		Fair Value			Vesting	Pro-rata
		Granted		of Stock			Duration	Vesting Date
	April 15, 2012	4,816,795		4.78			3 years	April 15
	July 15, 2012	74,175		4.72			3 years	July 15
	April 15, 2013	3,656,340		6.66			3 years	April 15
	July 15, 2013	78,725		6.67			3 years	July 15
	April 15, 2014	9,135,710		5.4			3 years	April 15
	July 10, 2014	56,056		5.91			3 years	July 10
	15-Sep-14	46,552		5.8			3 years	15-Sep
	The following table is a rollforward of the restricted stock units under the Stock Bonus Plans for the years ended December 31, 2014 and 2013.
		Restricted Stock Units
		2014		2013
	Units outstanding, beginning of year	7,851,017		8,857,884
	Activity during the year:
	HQA Plan units outstanding as of July 1, 2014	3,315,313		—
	Granted	9,238,318		3,735,065
	Vested	(4,351,084	)	(4,325,661	)
	Forfeited	(952,075	)	(416,271	)
	Units outstanding, end of year	15,101,489		7,851,017
	The following table is a summary of the Company's compensation costs, the corresponding tax benefit, and unrecognized compensation costs:
		Years Ended
		December 31,
	(Dollars in millions)	2014			2013			2012
	Compensation costs	$	34		$	21		$	18
	Tax benefit	13			8			7
	Unrecognized compensation costs	42			27			26

Employee_Pension_and_Other_Pos

Employee Pension and Other Postretirement Benefits	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Employee Pension and Other Postretirement Benefits	Employee Pension and Other Postretirement Benefits
	Retirement Plan
	The Company maintains the Union Bank Retirement Plan (the Pension Plan), which is a noncontributory qualified defined benefit pension plan covering substantially all of the domestic employees of the Company. The Pension Plan provides retirement benefits based on years of credited service and the final average compensation amount, as defined in the Pension Plan. Employees become eligible for the Pension Plan after 1 year of service. Effective October 1, 2012, the Company established a new cash balance formula for all future eligible employees; such participants receive annual pay credits based on eligible pay multiplied by a percentage determined by their age and years of service, and also receive an annual interest credit based on 30-year Treasury bond yields. All participants become vested upon completing 3 years of vesting service.
	In April 2014, the Company amended the Pension Plan to transition the majority of participants to the cash balance formula for benefits earned after December 31, 2014. Benefits earned under a final average pay formula became fixed as of that date for such participants. The cash balance formula provides the same benefits that apply to all eligible employees hired after October 1, 2012.
	Effective July 1, 2014, the U.S. branch banking operations of BTMU were integrated under the Bank's operations. The Company assumed the service cost associated with employees of BTMU’s banking operations in the Americas who became employees of the Bank. These employees became eligible to participate in the Pension Plan on January 1, 2015.
	The Company's funding policy is to make contributions between the minimum required and the maximum deductible amount as allowed by the Internal Revenue Code. Contributions are intended to provide not only for benefits attributed to services to date, but also for those expected to be earned in the future.
	In December 2014, the Company's Pension Plan was amended and restated as the MUFG Union Bank, N.A. Retirement Plan. This change became effective January 1, 2015.
	Other Postretirement Benefits
	The Company maintains the Union Bank Health Benefit Plan and the Union Bank Employee Insurance Plan, which are qualified plans providing certain healthcare benefits for its retired employees and life insurance benefits for those employees who retired prior to January 1, 2001, which together are presented as "Other Benefits Plan." The healthcare cost is shared between the Company and the retiree. The life insurance plan is noncontributory. The accounting for the Other Benefits Plan anticipates future cost-sharing changes that are consistent with the Company's intent to maintain a level of cost-sharing at approximately 25% to 50%, depending on the retiree's age and length of service with the Company. Assets set aside to cover such obligations are primarily invested in mutual funds and insurance contracts. The Union Bank Health Benefit Plan was also amended in April 2014 to discontinue the availability of retiree health benefits for the majority of employees.
	In December 2014, the Union Bank Health Benefit Plan and the Union Bank Employee Insurance Plan were amended and restated as the MUFG Union Bank, N.A. Health Benefit Plan and MUFG Union Bank, N.A. Employee Insurance Plan, respectively. This change became effective January 1, 2015.
	The following table sets forth the fair value of the assets in the Company's Pension Plan and Other Benefits Plan as of December 31, 2014 and 2013.
			Pension Plan								Other Benefits
											Plan
			Years Ended								Years Ended
			December 31,								December 31,
	(Dollars in millions)		2014				2013				2014			2013
	Change in plan assets:
	Fair value of plan assets, beginning of year		$	2,716			$	2,019			$	245		$	210
	Actual return on plan assets		164				391				14			37
	Employer contributions		100				380				13			12
	Plan participants' contributions		—				—				7			7
	Benefits paid		(83		)		(74		)		(22		)	(21		)
	Fair value of plan assets, end of year		$	2,897			$	2,716			$	257		$	245
	The investment objective for the Company's Pension Plan and Other Benefits Plan, collectively the Plans, is to maximize total return within reasonable and prudent levels of risk. The Plans' asset allocation strategy is the principal determinant in achieving expected investment returns on the Plans' assets. The Pension Plan asset allocation strategy favors equities, with a target allocation of 63% in equity securities, 25% in debt securities, and 12% in real estate investments. Similarly, the Other Benefits Plan asset allocation strategy favors equities with a target allocation of 70% in equity securities and 30% in debt securities. Additionally, the Other Benefits Plan holds an investment in an insurance contract with Hartford Life that is separate from the target allocation. Actual asset allocations may fluctuate within acceptable ranges due to market value variability. If market fluctuations cause an asset class to fall outside of its strategic asset allocation range, the portfolio will be re-balanced as appropriate. A core equity position of domestic large cap and small cap stocks will be maintained, in conjunction with a diversified portfolio of international equities and fixed income securities. Plan asset performance is compared against established indices and peer groups to evaluate whether the risk associated with the portfolio is appropriate for the level of return.
	The Company periodically reviews the Plans' strategic asset allocation policy and the expected long-term rate of return for plan assets. The investment return volatility of different asset classes and the liability structure of the plans are evaluated to determine whether adjustments are required to the Plans' strategic asset allocation policy, taking into account the principles established in the Company's funding policy. Management periodically reviews and adjusts the long-term rate of return on assets assumption for the Plans based on the expected long-term rate of return for the asset classes and their weightings in the Plans' strategic asset allocation policy and taking into account the prevailing economic and regulatory climate and practices of other companies both within and outside our industry.
	The following table provides the fair value by level within the fair value hierarchy of the Company's period-end assets by major asset category for the Pension Plan and Other Benefits Plan. For information about the fair value hierarchy levels, refer to Note 11 to these consolidated financial statements. The Plans do not hold any equity or debt securities issued by the Company or any related parties.
			31-Dec-14
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Pension Plan Investments:
	Cash and cash equivalents		$	1			$	52			$	—		$	53
	U.S. Government securities		—				251				—			251
	Corporate bonds		—				442				—			442
	Equity securities		295				6				—			301
	Real estate funds		—				—				270			270
	Limited partnerships		—				138				28			166
	Mutual funds		1,422				—				—			1,422
	Other		6				23				—			29
	Total Plan Investments		$	1,724			$	912			$	298		$	2,934
	Accrued dividends and interest receivable													7
	Net pending trades													(44		)
	Total Plan Assets													$	2,897
			31-Dec-13
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Pension Plan Investments:
	Cash and cash equivalents		$	—			$	28			$	—		$	28
	U.S. Government securities		—				230				—			230
	Corporate bonds		—				364				—			364
	Equity securities		233				—				—			233
	Real estate funds		—				—				242			242
	Limited partnerships		—				134				22			156
	Common collective funds		—				60				—			60
	Mutual funds		1,407				—				—			1,407
	Other		(1		)		28				—			27
	Total Plan Investments		$	1,639			$	844			$	264		$	2,747
	Accrued dividends and interest receivable													4
	Net pending trades													(35		)
	Total Plan Assets													$	2,716
			Level 3 Assets for Year Ended December 31, 2014
	(Dollars in millions)		Real Estate Funds				Limited Partnership				Total
	Beginning balance—January 1, 2014		$	242			$	22			$	264
	Unrealized gains (losses)		21				5				26
	Purchases, issuances, sales, and settlements, net		7				1				8
	Ending balance—December 31, 2014		$	270			$	28			$	298
			Level 3 Assets for Year Ended December 31, 2013
(Dollars in millions)		Real Estate Funds				Limited Partnership				Total
Beginning balance—January 1, 2013		$	156			$	18			$	174
Unrealized gains (losses)		18				—				18
Purchases, issuances, sales, and settlements, net		68				4				72
Ending balance—December 31, 2013		$	242			$	22			$	264
		31-Dec-14
(Dollars in millions)		Level 1				Level 2				Level 3			Total
Other Postretirement Benefits Plan Investments:
Cash and cash equivalents		$	—			$	3			—			$	3
U.S. Government securities		—				36				—			36
Corporate bonds		—				23				—			23
Municipal bonds		—				1				—			1
Mutual funds		136				—				—			136
Pooled separate account		—				65				—			65
Total Plan Investments		$	136			$	128			$	—		$	264
Net pending trades													(7		)
Total Plan Assets													$	257
		31-Dec-13
(Dollars in millions)		Level 1				Level 2				Level 3			Total
Other Postretirement Benefits Plan Investments:
Cash and cash equivalents		$	—			$	2			$	—		$	2
U.S. Government securities		—				33				—			33
Corporate bonds		—				19				—			19
Municipal bonds		—				1				—			1
Mutual funds		133				—				—			133
Pooled separate account		—				63				—			63
Total Plan Investments		$	133			$	118			$	—		$	251
Net pending trades													(6		)
Total Plan Assets													$	245
A description of the valuation methodologies used to determine the fair value of the Plans' assets included within the tables above is as follows:
Cash and Cash Equivalents
Cash and cash equivalents include short-term investments of government securities and other debt securities with remaining maturities of less than three months. These short-term investments are classified as Level 2 measurements based on unadjusted prices for similar securities in an active market.
U.S. Government Securities
U.S. Treasury securities are fixed income securities that are debt instruments issued by the United States Department of the Treasury. These securities are classified as Level 2 measurements based on valuations provided by a third-party pricing provider using quoted market prices in an active market for similar securities.
U.S. agency mortgage-backed securities are collateralized by residential mortgage loans and may be prepaid at par prior to maturity. These securities are classified as Level 2 measurements based on valuations provided by a third-party pricing provider using quoted market prices in an active market for similar securities.
Corporate Bonds
Corporate bonds are fixed income securities in investment-grade bonds of U.S. issuers from diverse industries. These securities are classified as Level 2 based on valuations provided by a third-party pricing provider using quoted market prices in an active market for similar securities.
Equity Securities
Equity securities are common stock and the fair value is recorded based on quoted market prices obtained from an exchange. These securities are classified as Level 1 measurements based on unadjusted prices for identical instruments in active markets.
Real Estate Funds
Real estate funds invest in real estate property with a focus on apartment complexes and retail shopping centers. The valuations of these investments require significant judgment due to the absence of quoted market prices, lack of liquidity and the scarcity of observable sales of similar assets. The values are estimated by adjusting the previous quarter's net asset value for the current quarter's income and depreciation. These funds are classified as Level 3 measurements due to the use of significant unobservable inputs and judgment to estimate fair value.
Limited Partnerships
Limited partnerships invest in equity securities of diverse foreign companies in developed markets across diverse industries. Limited partnerships are valued using the net asset value of the partnership at the end of the period. These partnerships are classified as Level 2 measurements due to the use of quoted market prices of the underlying securities in actively traded markets as the primary input to derive the net asset value.
Limited partnerships also invest in real estate properties. These partnerships' value is estimated by adjusting the previous quarter's net asset value for the current quarter's income and depreciation. These partnerships are classified as Level 3 measurements due to the use of significant unobservable inputs and judgment to estimate fair value.
Common Collective Funds
Common collective funds invest in bonds of U.S. and foreign issuers and in equity securities of U.S. and foreign real estate companies. These funds are valued using the net asset value of the fund at the end of the period. These funds are classified as Level 2 measurements due to the use of quoted market prices of the underlying securities in actively traded markets as the primary input to derive the net asset value.
Mutual Funds
Mutual funds invest in equity securities that seek to track the performance of the Standard & Poor's 500, S&P Completion and the EAFE® indexes. These funds are valued using an exchange traded net asset value at the end of the period. These mutual funds are classified as Level 1 measurements based on unadjusted quoted prices for identical instruments in active markets.
Pooled Separate Account
The pooled separate account is an investment with Hartford Life Company. The investment consists of four funds that mainly invest in U.S. agency guaranteed mortgage-backed securities, investment-grade bonds of U.S. issuers from diverse industries, and exchange traded equity securities of U.S. and foreign companies. These funds are valued using quoted market prices of the funds' underlying investments to derive the funds' net asset value at the end of the period. This investment is classified as a Level 2 measurement due to the use of quoted market prices of similar securities in actively traded markets as the primary input to derive the net asset value.
The following table sets forth the benefit obligation activity and the funded status for each of the Company's plans at December 31, 2014 and 2013. In addition, the table sets forth the over (under) funded status at December 31, 2014 and 2013. This pension benefits table does not include the obligations for the ESBPs.
		Pension Benefits								Other Benefits
		Years Ended								Years Ended
		December 31,								December 31,
(Dollars in millions)		2014				2013				2014			2013
Accumulated benefit obligation		$	2,717			$	2,046
Change in benefit obligation
Benefit obligation, beginning of year		$	2,263			$	2,394			$	270		$	293
Service cost		75				87				10			14
Interest cost		105				99				11			11
Plan participants' contributions		—				—				7			7
Actuarial loss/(gain)		607				(243		)		42			(34		)
Effect of plan amendments		(150		)						(29		)
Medicare Part D subsidy		—				—				1			—
Benefits paid		(83		)		(74		)		(22		)	(21		)
Benefit obligation, end of year		2,817				2,263				290			270
Fair value of plan assets, end of year		2,897				2,716				257			245
Over (Under) funded status		$	80			$	453			$	(33	)	$	(25	)
During October 2014 the Society of Actuaries published a series of updated mortality tables and projection scales for use in measuring pension liabilities.  The Company has adopted the new mortality tables and a modified projection scale for use in the actuarial calculations for the December 31, 2014 pension and other postretirement obligations and the 2015 net periodic pension cost.  The new tables resulted in an increase of $232 million and $35 million to the projected benefit obligations of the Pension plan and Other Benefits plan, respectively, at December 31, 2014.
The following table illustrates the changes that were reflected in AOCI during 2014, 2013 and 2012. Pension benefits do not include the ESBPs.
		Pension								Other Benefits
		Benefits
(Dollars in millions)		Net Actuarial				Prior Service Credit				Transition Assets			Net Actuarial			Prior Service Credit
		(Gain) Loss											(Gain) Loss
Amounts Recognized in Other Comprehensive Loss:
Balance, December 31, 2011		$	1,016			$	—			$	1		$	90		$	—
Arising during the year		115				—				—			(2		)	—
Recognized in net income during the year		(89		)		—				(1		)	(8		)	—
Balance, December 31, 2012		$	1,042			$	—			$	—		$	80		$	—
Arising during the year		(468		)		—				—			(56		)	—
Recognized in net income during the year		(107		)		—				—			(7		)	—
Balance, December 31, 2013		$	467			$	—			$	—		$	17		$	—
Arising during the year		636				(150		)		—			46			(28		)
Recognized in net income during the year		(59		)		12				—			(1		)	5
Balance, December 31, 2014		$	1,044			$	(138	)		$	—		$	62		$	(23	)
At December 31, 2014 and 2013, the following amounts were recognized in accumulated other comprehensive loss for pension, including ESBPs, and other benefits.
		31-Dec-14
		Pension Benefits											Other Benefits
(Dollars in millions)		Gross				Tax				Net of Tax			Gross			Tax			Net of Tax
Net actuarial loss		$	1,044			$	411			$	633		$	62		$	25		$	37
Prior service credit		(138		)		(54		)		(84		)	(23		)	(9		)	(14		)
Pension and other benefits adjustment		906				357				549			39			16			23
Executive Supplemental Benefits Plans
Net actuarial loss		39				15				24			—			—			—
Prior service credit		(2		)		(1		)		(1		)	—			—			—
Executive supplemental benefits plans adjustment		37				14				23			—			—			—
Pension and other benefits adjustment		$	943			$	371			$	572		$	39		$	16		$	23
		31-Dec-13
		Pension Benefits											Other Benefits
(Dollars in millions)		Gross				Tax				Net of Tax			Gross			Tax			Net of Tax
Net actuarial loss		$	467			$	184			$	283		$	17		$	7		$	10
Pension and other benefits adjustment		467				184				283			17			7			10
Executive Supplemental Benefits Plans
Net actuarial loss		26				10				16			—			—			—
Executive supplemental benefits plans adjustment		26				10				16			—			—			—
Pension and other benefits adjustment		$	493			$	194			$	299		$	17		$	7		$	10
The Company expects to make a $175 million cash contribution to the Pension Plan in 2015.
Estimated Future Benefit Payments and Subsidies
The following pension and postretirement benefit payments, which reflect expected future service, as appropriate, are expected to be paid over the next 10 years and Medicare Part D Subsidies are expected to be received over the next 10 years. This table does not include the ESBPs.
(Dollars in millions)		Pension				Postretirement				Medicare Part D
		Benefits				Benefits				Subsidies
Years ending December 31,
2015		$	92			$	15			$	1
2016		104				16				1
2017		114				17				1
2018		123				18				1
2019		132				19				1
Years 2020 - 2024		795				101				6
The following tables summarize the weighted average assumptions used in computing the present value of the benefit obligations and the net periodic benefit cost.
		Pension						Other Benefits
		Benefits
		Years Ended						Years Ended
		December 31,						December 31,
		2014			2013			2014			2013
Discount rate in determining net periodic benefit cost prior to Plan amendments		4.9	%		4.2	%		4.6	%		3.9	%
Discount rate in determining net periodic benefit cost after Plan amendments		4.5			n/a			4.2			n/a
Discount rate in determining benefit obligations at year end		3.9			4.9			3.8			4.6
Rate of increase in future compensation levels for determining net periodic benefit cost		4.7			4.7			—			—
Rate of increase in future compensation levels for determining benefit obligations at year end		4.7			4.7			—			—
Expected return on plan assets		7.5			7.5			7.5			7.5
		Pension Benefits											Other Benefits									Superannuation,
																						SERP (1) and ESBP
		Years Ended											Years Ended									Years Ended
		December 31,											December 31,									December 31,
(Dollars in millions)		2014				2013				2012			2014			2013			2012			2014		2013		2012
Components of net periodic benefit cost:
Service cost (2)		$	81			$	87			$	77		$	10		$	14		$	14		$	1	$	1	$	2
Interest cost		105				99				101			11			11			12			4		3		2
Expected return on plan assets		(193		)		(166		)		(147		)	(18		)	(15		)	(13		)	—		—		—
Amortization of prior service credit		(12		)		—				—			(5		)	—			1			—		—		—
Recognized net actuarial loss		59				107				89			1			7			8			2		2		2
Total net periodic benefit cost		$	40			$	127			$	120		$	(1	)	$	17		$	22		$	7	$	6	$	6
-1	Supplemental Executive Retirement Plan
-2	Pension Benefits for 2014 includes $6 million of service cost associated with transferred employees as a result of the business integration initiative.
At December 31, 2014 and 2013, the following amounts were forecasted to be recognized in 2015 and 2014 net periodic benefit costs, respectively.
		Years Ended December 31,
		2015								2014
(Dollars in millions)		Pension				Other				Pension			Other
		Benefits				Benefits				Benefits			Benefits
Net actuarial loss		$	109			$	5			$	55		$	—
Prior service credit		(18		)		(8		)		—			—
Amounts to be reclassified from accumulated other comprehensive loss		$	91			$	(3	)		$	55		$	—
The Company's assumed weighted-average healthcare cost trend rates are as follows.
		Years Ended December 31,
		2014			2013			2012
Healthcare cost trend rate assumed for next year		7.53	%		7.71	%		8.31	%
Rate to which cost trend rate is assumed to decline (the ultimate trend rate)		4.5	%		4.5	%		4.5	%
Year the rate reaches the ultimate trend rate		2021			2021			2021
The healthcare cost trend rate assumptions have a significant effect on the amounts reported for the Health Plan. A one-percentage-point change in assumed healthcare cost trend rates would have the following effects:
(Dollars in millions)		One-Percentage-				One-Percentage-
		Point Increase				Point Decrease
Effect on total of service and interest cost components		$	2			$	(2	)
Effect on postretirement benefit obligation		19				(22		)
Executive Supplemental Benefit Plans
The Company has several ESBPs, which provide eligible employees with supplemental retirement benefits. The plans are nonqualified defined benefit plans and unfunded. The accrued liability for ESBPs included in other liabilities on the Company's consolidated balance sheets was $98 million and $85 million at December 31, 2014 and 2013, respectively.
Section 401(k) Savings Plans
The Company has a defined contribution plan authorized under Section 401(k) of the Internal Revenue Code. All benefits-eligible employees are eligible to participate in the plan. Employees may contribute up to 75% of their pre-tax covered compensation or up to 10% of their after-tax covered compensation through salary deductions to a combined maximum of 75% of total covered compensation, subject to statutory limits. Effective January 1, 2014, the Company contributes 100% of every pre-tax dollar an employee contributes up to the first 3% of the employee's pre-tax covered compensation and 50% of every pre-tax dollar an employee contributes on the next 2% of the employee's pre-tax covered compensation, for a maximum matching opportunity of 4%. Employees are fully vested in the Company's matching contributions immediately. All employer contributions are tax deductible by the Company. The Company's combined matching contribution expense was $37 million, $32 million and $29 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Other_Noninterest_Expense

Other Noninterest Expense	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Other Noninterest Expense	Other Noninterest Expense
	The detail of other noninterest expense is as follows.
		Years Ended December 31,
	(Dollars in millions)	2014		2013		2012
	Software	$	94	$	83	$	70
	LIHC investment amortization	89		76		63
	Advertising and public relations	39		61		57
	Communications	40		45		39
	Data processing	32		36		36
	Other	159		150		198
	Total other noninterest expense	$	453	$	451	$	463

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The following table is an analysis of the effective tax rate.
		Years Ended December 31,
		2014			2013			2012
	Federal income tax rate	35	%		35	%		35	%
	Net tax effects of:
	State income taxes, net of federal income tax benefit	7			5			6
	Tax-exempt interest income	(2	)		(1	)		(1	)
	Tax credits	(13	)		(13	)		(10	)
	Other	(2	)		(3	)		(3	)
	Effective tax rate	25	%		23	%		27	%
	The components of income tax expense were as follows.
		Years Ended December 31,
	(Dollars in millions)	2014				2013				2012
	Taxes currently payable:
	Federal	$	82			$	79			$	93
	State	76				43				32
	Foreign	13				12				14
	Total currently payable	171				134				139
	Taxes deferred:
	Federal	72				71				62
	State	28				(8		)		20
	Foreign	3				(2		)		(1		)
	Total deferred	103				61				81
	Total income tax expense	$	274			$	195			$	220
	The components of the Company's net deferred tax balances as of December 31, 2014 and 2013 were as follows.
		December 31,
	(Dollars in millions)	2014				2013
	Deferred tax assets:
	Allowance for credit losses	$	283			$	287
	Accrued expense, net	272				216
	Unrealized losses on pension and postretirement benefits	389				204
	Unrealized net losses on securities available for sale	97				262
	Fair value adjustments for valuation of FDIC covered assets	159				183
	Other	110				97
	Total deferred tax assets	1,310				1,249
	Deferred tax liabilities:
	Leasing	759				698
	Intangible assets	99				105
	Pension liabilities	389				363
	Other	5				17
	Total deferred tax liabilities	1,252				1,183
	Net deferred tax asset	$	58			$	66
	At December 31, 2014, we had net operating loss and tax credit carry forwards for which related deferred tax assets of $38 million and $43 million, respectively, were recorded. The net operating loss and tax credit carry forwards expire in varying amounts through 2033.
	Deferred tax assets are evaluated for realization based on the existence of sufficient taxable income of the appropriate character. Management has determined that no valuation allowance is required.
	The changes in unrecognized tax positions were as follows.
		Years Ended December 31,
	(Dollars in millions)	2014				2013				2012
	Balance, beginning of year	$	16			$	269			$	274
	Gross increases as a result of tax positions taken during prior periods	—				1				7
	Gross decreases as a result of tax positions taken during prior periods	(10		)		(256		)		(13		)
	Gross increases as a result of tax positions taken during current period	2				2				1
	Balance, end of year	$	8			$	16			$	269
	The amount of unrecognized tax positions that would affect the effective tax rate, if recognized, was $7 million, $12 million and $113 million at December 31, 2014, 2013 and 2012, respectively.
	The Company recognizes interest and penalties as a component of income tax expense. For 2014, 2013 and 2012, the Company reversed $3 million and $12 million and $14 million of gross interest and penalties as a benefit to income tax expense, respectively. As of December 31, 2014, there was no accrual recorded for gross interest and penalties. As of December 31, 2013 and 2012, we accrued $3 million, and $15 million of gross interest and penalties, respectively.
	The Company is subject to U.S. federal income tax as well as various state and foreign income taxes. With limited exception, the Company is not open to examination for periods before 2010 by U.S. federal and state taxing authorities.

Regulatory_Capital_Requirement

Regulatory Capital Requirements	12 Months Ended
	Dec. 31, 2014
Regulatory Capital Requirements [Abstract]
Regulatory Capital Requirements	Regulatory Capital Requirements
	The Company and the Bank are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory, and possibly additional discretionary, actions by regulators that, if undertaken, could have a material effect on the Company's consolidated financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, the Company and the Bank must meet specific capital guidelines that involve quantitative measures of the Company's and Bank's assets, liabilities, and certain off-balance sheet items as calculated under regulatory accounting practices. The capital amounts and the Bank's prompt corrective action classification are also subject to qualitative judgments by the regulators about components, risk-weightings and other factors. Prompt corrective action provisions are not applicable to BHCs such as the Company. The Bank is subject to laws and regulations that limit the amount of dividends it can pay to the Company.
	Quantitative measures established by regulation to help ensure capital adequacy require the Company and the Bank to maintain minimum amounts and ratios (set forth in the tables below) of Total and Tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined) and of Tier 1 capital (as defined) to quarterly average assets (as defined). As of December 31, 2014, management believes the capital ratios of the Bank met all regulatory requirements of "well-capitalized" institutions, which are 10% for the Total risk-based capital ratio and 6% for the Tier 1 risk-based capital ratio. Furthermore, management believes, as of December 31, 2014 and 2013, that the Company and the Bank met all capital adequacy requirements to which they are subject.
	The Company's and the Bank's capital amounts and ratios are presented in the following tables.
			Actual					Minimum
								Regulatory
								Requirement
	(Dollars in millions)		Amount		Ratio			Amount		Ratio
	Capital Ratios for the Company (U.S. Basel I):
	As of December 31, 2014:
	Tier 1 capital (to risk-weighted assets)		$	12,367	12.79	%	≥	$	3,867	4	%
	Total capital (to risk-weighted assets)		14,246		14.74		≥	7,733		8
	Tier 1 leverage(1)		12,367		11.25		≥	4,396		4
	As of December 31, 2013:
	Tier 1 capital (to risk-weighted assets)		11,471		12.41		≥	3,696		4
	Total capital (to risk-weighted assets)		13,499		14.61		≥	7,393		8
	Tier 1 leverage(1)		11,471		11.27		≥	4,073		4
	-1	Tier 1 capital divided by quarterly average assets (excluding certain intangible assets).
			Actual					Minimum					To Be Well-Capitalized Under Prompt Corrective Action Provisions
								Regulatory
								Requirement
	(Dollars in millions)		Amount		Ratio			Amount		Ratio			Amount		Ratio
	Capital Ratios for the Bank:
	As of December 31, 2014 (U.S. Basel III):
	Common equity tier 1 capital (to risk-weighted assets)		$	12,087	13.09	%	≥	n/a		n/a		≥	n/a		n/a
	Tier 1 capital (to risk-weighted assets)		12,088		13.09		≥	$	5,080	5.5	%	≥	$	5,542	6	%
	Total capital (to risk-weighted assets)		13,656		14.78		≥	7,389		8		≥	9,237		10
	Tier 1 leverage(1)		12,088		11.09		≥	4,361		4		≥	5,452		5
	As of December 31, 2013 (U.S. Basel I):
	Tier 1 capital (to risk-weighted assets)		11,274		12.94		≥	3,485		4		≥	5,228		6
	Total capital (to risk-weighted assets)		12,990		14.91		≥	6,970		8		≥	8,713		10
	Tier 1 leverage(1)		11,274		11.13		≥	4,051		4		≥	5,063		5
	-1	Tier 1 capital divided by quarterly average assets (excluding certain intangible assets).

Restrictions_on_Cash_and_Due_f

Restrictions on Cash and Due from Banks, Securities, Loans and Dividends	12 Months Ended
	Dec. 31, 2014
Restricted Cash and Investments [Abstract]
Restrictions on Cash and Due from Banks, Securities, Loans and Dividends	Restrictions on Cash and Due from Banks, Securities, Loans and Dividends
	Federal Reserve regulations require the Bank to maintain reserve balances based on the types and amounts of deposits received. The required reserve balances were $549 million and $398 million at December 31, 2014 and 2013, respectively.
	As of December 31, 2014 and 2013, loans of $54.2 billion and $50.2 billion, respectively, were pledged as collateral for borrowings, including those to the Federal Reserve Bank and FHLB, to secure public and trust department deposits, and for repurchase agreements as required by contract or law. See Note 3 to these consolidated financial statements for the carrying amounts of securities that were pledged as collateral.
	The Federal Reserve Act restricts the amount and the terms of both credit and non-credit transactions between a bank and its non-bank affiliates. Such transactions may not exceed 10% of the bank's capital and surplus (which for this purpose represents Tier 1 and Tier 2 capital, as calculated under the risk-based capital guidelines, plus the balance of the allowance for loan losses excluded from Tier 2 capital) with any single non-bank affiliate and 20% of the bank's capital and surplus with all its non-bank affiliates. Transactions that are extensions of credit may require collateral to be held to provide added security to the bank. See Note 18 to these consolidated financial statements for further discussion of risk-based capital. At December 31, 2014, $366 million remained outstanding from Bankers Commercial Corporation on notes payable to the Bank and $121 million remained outstanding from all other non-bank affiliates. The Bankers Commercial Corporation notes were fully collateralized with equipment lease assets.
	The declaration of a dividend by the Bank to the Company is subject to the approval of the OCC if the total of all dividends declared in the current calendar year plus the preceding two years exceeds the Bank's total net income in the current calendar year plus the preceding two years. The payment of dividends is also limited by minimum capital requirements imposed on national banks by the OCC.

Commitments_Contingencies_and_

Commitments, Contingencies and Guarantees	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Guarantees	Commitments, Contingencies and Guarantees
	The following table summarizes the Company's commitments.
	(Dollars in millions)	31-Dec-14
	Commitments to extend credit	$	34,991
	Issued standby and commercial letters of credit	$	5,836
	Other commitments	$	175
	Commitments to extend credit are legally binding agreements to lend to a customer provided there are no violations of any condition established in the contract. Commitments have fixed expiration dates or other termination clauses and may require maintenance of compensatory balances. Since many of the commitments to extend credit may expire without being drawn upon, the total commitment amounts do not necessarily represent future cash flow requirements.
	Standby and commercial letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. Standby letters of credit generally are contingent upon the failure of the customer to perform according to the terms of the underlying contract with the third party, while commercial letters of credit are issued specifically to facilitate foreign or domestic trade transactions. Additionally, the Company enters into risk participations in bankers' acceptances wherein a fee is received to guarantee a portion of the credit risk on an acceptance of another bank. The majority of these types of commitments have terms of 1 year or less. At December 31, 2014, the carrying amount of the Company's risk participations in bankers' acceptances and standby and commercial letters of credit totaled $4 million. Estimated exposure to loss related to these commitments is covered by the allowance for losses on unfunded credit commitments. The carrying amounts of the standby and commercial letters of credit and the allowance for losses on unfunded credit commitments are included in other liabilities on the consolidated balance sheet.
	The credit risk involved in issuing loan commitments and standby and commercial letters of credit is essentially the same as that involved in extending loans to customers and is represented by the contractual amount of these instruments. Collateral may be obtained based on management's credit assessment of the customer.
	Other commitments include commitments to fund principal investments and other securities.
	Principal investments include direct investments in private and public companies. The Company issues commitments to provide equity and mezzanine capital financing to private and public companies through direct investments. The timing of future cash requirements to fund such commitments is generally dependent on the investment cycle. This cycle, the period over which privately-held companies are funded by private equity investors and ultimately sold, merged, or taken public through an initial offering, can vary based on overall market conditions as well as the nature and type of industry in which the companies operate.
	The Company has rental commitments under long-term operating lease agreements. For detail of these commitments, see Note 5 to these consolidated financial statements.
	The Company occasionally enters into financial guarantee contracts where a premium is received from another financial institution counterparty to guarantee a portion of the credit risk on interest rate swap contracts entered into between the financial institution and its customer. The Company becomes liable to pay the financial institution only if the financial institution is unable to collect amounts owed to them by their customer. As of December 31, 2014, the current exposure to loss under these contracts totaled $20 million, and the maximum potential exposure to loss in the future was estimated at $39 million.
	The Company is subject to various pending and threatened legal actions that arise in the normal course of business. The Company maintains liabilities for losses from legal actions that are recorded when they are determined to be both probable in their occurrence and can be reasonably estimated. Management believes the disposition of all claims currently pending, including potential losses from claims that may exceed the liabilities recorded, and claims for loss contingencies that are considered reasonably possible to occur, will not have a material effect, either individually or in the aggregate, on the Company's consolidated financial condition, results of operations or liquidity.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions
	Effective July 1, 2014, the U.S. branch banking operations of BTMU were integrated under the Bank's operations. The integration did not involve a legal entity combination, but rather an integration of personnel and certain business and support activities. As a result of this initiative, all of BTMU's banking activities in the Americas are managed by employees of the Bank, which includes the addition of approximately 2,300 U.S. employees formerly employed by BTMU. This initiative also included the transfer of ownership of BTMU’s U.S. corporate customer list, available-for-sale securities of $70 million and employee-related liabilities to the Bank. Immediately after the transfer, the transferred liabilities were adjusted to conform to the Company's GAAP accounting policies resulting in a $9 million increase in retained earnings and a $9 million decrease in liabilities, resulting in total liabilities transferred of $30 million. The Company's additional paid-in capital increased by $31 million.
	As a result of this initiative, the Bank and BTMU entered into a master services agreement, which provides for employees of the Bank to perform and make available various business, banking, financial, and administrative and support services (the Services) and facilities for BTMU in connection with the operation and administration of BTMU's businesses in the U.S. (including BTMU's U.S. branches). In consideration for the Services, BTMU pays to the Bank fee income, which reflects market-based pricing. Costs related to the Services performed by the transferred employees are primarily reflected in salaries and employee benefits expense. For the year ended December 31, 2014, the Company recorded $319 million in fee income from this initiative, including $206 million related to support services provided by the Company to BTMU. Substantially offsetting the fee income was $193 million, primarily in salaries and benefits expense, related to these support services. The remaining fee income was recognized through revenue sharing agreements with BTMU, with associated costs included within the Company’s 2014 results. The Company also recorded $14 million of expenses due to BTMU, which are included within noninterest expense. Amounts due from and to BTMU, which are included in other assets and other liabilities, respectively, are generally settled monthly and were $61 million and $16 million, respectively, at December 31, 2014.
	Prior to July 1, 2014, independent of the business integration initiative, the Company had, and expects to have in the future, banking transactions and other transactions in the ordinary course of business with BTMU and with its affiliates. During 2014, 2013 and 2012, such transactions included, but were not limited to, purchases and sales of loans, purchases and sales of interest rate derivatives and foreign exchange transactions, funds transfers, custodianships, investment advice and management, customer referrals, facility leases, and administrative and trust services. In September 2008, the Company established a $500 million, three-year unsecured revolving credit facility with BTMU. This credit facility was renewed and expires in July 2017. As of December 31, 2014, the Company had no outstanding balance under this facility. In the opinion of management, these transactions were made at rates, terms and conditions prevailing in the market and do not involve more than the normal risk of collectability or present other unfavorable features. In addition, some compensation for services rendered to the Company is paid to the expatriate officers from BTMU, and reimbursed by the Company to BTMU under a service agreement. The Company incurred expenditures related to the implementation of Basel III, which were reimbursed by BTMU, of $15 million in 2014, and expenditures related to the implementation of Basel II, which were reimbursed by BTMU, of $19 million and $39 million in 2013 and 2012, respectively.
	The Company received a $1.2 billion common equity contribution from BTMU and also issued $300 million of subordinated debt to BTMU during the fourth quarter of 2013. During the second quarter of 2013, the Bank issued $750 million of subordinated debt to BTMU. See Note 10 to these consolidated financial statements for more information on subordinated debt due to BTMU.
	At December 31, 2014 and 2013, the Company had derivative contracts totaling $634 million and $735 million, respectively, in notional balances, with $1 million in net unrealized gains and $7 million in net unrealized losses with BTMU and its affiliates in 2014 and 2013, respectively. In 2014, 2013 and 2012, the Company recorded noninterest income of $38 million, $33 million and $21 million, respectively, and noninterest expenses of $9 million, $13 million and $18 million, respectively, for fees paid, revenue sharing and facility and staff arrangements.
	The Company may extend credit to BTMU, in the form of daylight overdrafts in BTMU's accounts with the Company in the ordinary course of business. There were no overdraft balances outstanding as of December 31, 2014 and 2013.

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Business Segments	Business Segments
	The Company has five reportable segments: Retail Banking & Wealth Markets, Commercial Banking, U.S. Corporate Banking, Transaction Banking, and Investment Banking & Markets. Below is a detailed description of these reportable segments.
	Retail Banking & Wealth Markets
	Retail Banking & Wealth Markets offers a range of banking products and services to individuals and small businesses, including high net worth individuals and institutional clients, delivered generally through a network of branches, private banking offices, ATMs, broker mortgage referrals, telephone services, and web-based and mobile banking applications. These products and services include mortgages, home equity lines of credit, consumer and commercial loans, deposit accounts, financial planning and investments.
	The Consumer Lending Division provides the centralized origination, underwriting, processing, servicing, collection and administration for consumer assets including residential mortgages.
	The Consumer and Business Banking Division serves its customers through 353 full-service branches in California and 46 full-service branches in Washington and Oregon, as well as through ATMs, call centers, web-based and mobile internet banking applications and through alliances with other financial institutions. Consumer and Business Banking provides checking and deposit products and services; bill and loan payment, merchant, and various types of financing and investment services; and products including credit cards.
	The Wealth Markets Division serves its customers through the Private Bank; UnionBanc Investment Services, LLC, a subsidiary of MUB and a registered broker-dealer and investment advisor; and Asset Management which includes Highmark, a subsidiary of MUB and a registered investment advisor. Wealth Markets provides investment management and advisory services to institutional clients, wealth planning, deposits and risk management strategies, trust and estate administration, as well as investment sub-advisory services to the unaffiliated Highmark Funds. Products provided to its customers include traditional brokerage, managed accounts, annuities, mutual funds, fixed income products and insurance and customized lending.
	Commercial Banking
	Commercial Banking provides a broad spectrum of commercial credit products including commercial loans, accounts receivable, inventory, trade and real estate financing to primarily U.S.-based corporate customers with annual sales generally ranging from $15 million to $2 billion. Commercial Banking offers its customers a range of noncredit services and products, which include global treasury management and capital markets solutions, foreign exchange and various interest rate risk and commodity risk management products through cooperation with other segments.
	Commercial Banking is comprised of five main divisions: Western Markets, which serves companies primarily in California, Oregon and Washington; Petroleum, which serves oil and gas companies; Expansion Markets, which serves clients nationally, outside of the western states, and also targets certain defined industries such as entertainment and technology; Specialized Products, which focuses on specific industries on a national basis including commercial finance, funds finance, environmental services, non-profits, healthcare, and transportation, aerospace and defense; and Real Estate Industries, which serves professional real estate investors and developers. Additionally, through its Community Development Finance unit, tax credit investments are made in affordable housing projects, as well as construction and permanent financing.
	U.S. Corporate Banking
	U.S. Corporate Banking provides commercial lending products, including commercial loans, lines of credit and project financing, to corporate customers with revenues generally greater than $2 billion. The segment employs an industry-focused strategy including dedicated coverage teams in General Industries, Power and Utilities, Oil and Gas, Telecom and Media, Technology, Healthcare, Public Finance, and Financial Institutions (predominantly Insurance and Asset Managers). By working with the Company's other segments, U.S. Corporate Banking offers its customers a range of noncredit services, which include global treasury management and capital market solutions, and foreign exchange and various interest rate risk and commodity risk management products.
	Transaction Banking
	Transaction Banking works alongside the Company's other segments to provide working capital management and asset servicing solutions, including deposits and treasury management, trade finance, and institutional trust and custody, to the Company's customers. This segment also manages the digital banking channels for retail, small business, wealth management and commercial clients, as well as commercial product development. The client base consists of financial institutions, corporations, government agencies, insurance companies, mutual funds, investment managers and non-profit organizations.
	Investment Banking & Markets
	Investment Banking & Markets, which includes Global Capital Markets of the Americas, works with the Company's other segments to provide customers structured credit services, including project finance, leasing and equipment finance, and securitizations. Investment Banking & Markets also provides capital markets solutions, including syndicated loans, equity and debt underwriting, tax equity and merchant banking investments; risk management solutions, including foreign exchange, interest rate and energy risk management solutions; and facilitates merchant and investment banking-related transactions.
	Other
	"Other" includes the Asian Corporate Banking segment, Corporate Treasury and the impact of certain corporate activities. The Asian Corporate Banking segment offers a range of credit, deposit, and investment management products and services to companies located primarily in the U.S. that are affiliated with companies headquartered in Japan and other Asian countries. Corporate Treasury is responsible for ALM, wholesale funding and the ALM investment and derivatives hedging portfolios. These Treasury management activities are carried out to manage the net interest rate and liquidity risks of the Company's balance sheet and to manage those risks within the guidelines established by ALCO. For additional discussion regarding these risk management activities, see "Quantitative and Qualitative Disclosures About Market Risk" in Part II, Item 7A. of this Form 10-K.
	Additionally, "Other" is comprised of certain corporate activities of the Company; the net impact of funds transfer pricing charges and credits allocated to the reportable segments; the residual costs of support groups; the unallocated allowance; goodwill, intangible assets, and the related amortization/accretion associated with the Company's privatization transaction; the elimination of the fully taxable-equivalent basis amount; the difference between the marginal tax rate and the consolidated effective tax rate; and the FDIC covered assets.
	The information, set forth in the tables that follow, is prepared using various management accounting methodologies to measure the performance of the individual segments. Unlike GAAP there is no standardized or authoritative guidance for management accounting. Consequently, reported results are not necessarily comparable with those presented by other companies and they are not necessarily indicative of the results that would be reported by the business units if they were unique economic entities. The management reporting accounting methodologies, which are enhanced from time to time, measure segment profitability by assigning balance sheet and income statement items to each operating segment. Methodologies that are applied to the measurement of segment profitability include a funds transfer pricing system, an activity-based costing methodology, other indirect costs and a methodology to allocate the provision for credit losses. The fund transfer pricing system assigns a cost of funds or a credit for funds to assets or liabilities based on their type, maturity or repricing characteristics. The activity-based costing methodology allocates certain indirect costs, such as operations and technology expense, to the segments based on studies of billable unit costs for product or data processing. Other indirect costs, such as corporate overhead, are allocated to the segments based on internal surveys and metrics that serve as proxies for estimated usage. During the normal course of business, the Company occasionally changes or updates its management accounting methodologies or organizational structure.  During 2014, the Company revised the funds transfer pricing methodology with respect to reference rates for certain commercial deposits. The Company also continued to refine its organizational structure resulting from the internal management structure implemented as part of the BTMU Americas Holdings business integration initiative established in 2013. Prior period results have been adjusted to reflect these changes.
	The Company generally applies a "market view" perspective in measuring the business segments. The market view is a measurement of customer markets aggregated to show all revenues generated and expenses incurred from all products and services sold to those customers regardless of where product areas organizationally report. Therefore, revenues and expenses are included in both the business segment that provides the service and the business segment that manages the customer relationship. The duplicative results from this internal management accounting view are eliminated in "Reconciling Items." During 2014, the Company updated its market view methodology for the Project Finance division within the Investment Banking & Markets segment to also include these revenues and expenses in the U.S. Corporate segment. The Company also updated its market view methodology to better align certain acquired assets with other similar assets. Prior period results have been adjusted to reflect these changes.
	As of and for the Twelve Months Ended December 31, 2014:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,385		$	1,016		$	173		$	442		$	175	$	65		$	(394	)	$	2,862
	Noninterest income (expense)	330			221			119			165			357		157			(226		)	1,123
	Total revenue	1,715			1,237			292			607			532		222			(620		)	3,985
	Noninterest expense	1,347			440			112			363			166		630			(159		)	2,899
	(Reversal of) provision for credit losses	(7		)	21			(24		)	(3		)	35		(5		)	(11		)	6
	Income (loss) before income taxes and including noncontrolling interests	375			776			204			247			331		(403		)	(450		)	1,080
	Income tax expense (benefit)	148			188			80			97			84		(146		)	(177		)	274
	Net income (loss) including noncontrolling interest	227			588			124			150			247		(257		)	(273		)	806
	Deduct: net loss from noncontrolling interests	—			—			—			—			—		19			—			19
	Net income (loss) attributable to MUAH	$	227		$	588		$	124		$	150		$	247	$	(238	)	$	(273	)	$	825
	Total assets, end of period	$	37,722		$	38,727		$	5,130		$	1,779		$	6,195	$	27,707		$	(3,582	)	$	113,678
	As of and for the Twelve Months Ended December 31, 2013:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,348		$	913		$	137		$	446		$	184	$	38		$	(350	)	$	2,716
	Noninterest income (expense)	371			193			81			160			210		66			(205		)	876
	Total revenue	1,719			1,106			218			606			394		104			(555		)	3,592
	Noninterest expense	1,423			406			54			356			100		567			(129		)	2,777
	(Reversal of) provision for credit losses	(35		)	17			2			(3		)	6		(13		)	(3		)	(29		)
	Income (loss) before income taxes and including noncontrolling interests	331			683			162			253			288		(450		)	(423		)	844
	Income tax expense (benefit)	130			174			64			99			78		(184		)	(166		)	195
	Net income (loss) including noncontrolling interest	201			509			98			154			210		(266		)	(257		)	649
	Deduct: net loss from noncontrolling interests	—			—			—			—			—		18			—			18
	Net income (loss) attributable to MUAH	$	201		$	509		$	98		$	154		$	210	$	(248	)	$	(257	)	$	667
	Total assets, end of period	$	34,421		$	32,661		$	4,755		$	1,574		$	5,937	$	29,225		$	(2,679	)	$	105,894
	As of and for the Twelve Months Ended December 31, 2012:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,201		$	778		$	113		$	496		$	174	$	190		$	(350	)	$	2,602
	Noninterest income (expense)	336			208			72			167			207		32			(204		)	818
	Total revenue	1,537			986			185			663			381		222			(554		)	3,420
Noninterest expense	1,294			389			54			351			77		550			(132		)	2,583
(Reversal of) provision for credit losses	55			(52		)	21			(1		)	6		(25		)	4			8
Income (loss) before income taxes and including noncontrolling interests	188			649			110			313			298		(303		)	(426		)	829
Income tax expense (benefit)	74			179			43			123			86		(118		)	(167		)	220
Net income (loss) including noncontrolling interest	114			470			67			190			212		(185		)	(259		)	609
Deduct: net loss from noncontrolling interests	—			—			—			—			—		19			—			19
Net income (loss) attributable to MUAH	$	114		$	470		$	67		$	190		$	212	$	(166	)	$	(259	)	$	628
Total assets, end of period	$	31,809		$	25,318		$	3,822		$	1,564		$	7,137	$	29,133		$	(1,775	)	$	97,008

Condensed_MUFG_Americas_Holdin

Condensed MUFG Americas Holdings Corporation Unconsolidated Financial Statements (Parent Company)	12 Months Ended
	Dec. 31, 2014
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed UnionBanCal Corporation Unconsolidated Financial Statements (Parent Company)	Condensed MUFG Americas Holding Corporation Unconsolidated Financial Statements (Parent Company)
	Condensed Balance Sheets
		December 31,
	(Dollars in millions)	2014			2013
	Assets
	Cash and cash equivalents	$	328		$	191
	Investment in subsidiaries	15,404			14,784
	Other assets	4			5
	Total assets	$	15,736		$	14,980
	Liabilities and Stockholder's Equity
	Long-term debt	$	750		$	763
	Other liabilities	1			2
	Total liabilities	751			765
	Stockholder's equity	14,985			14,215
	Total liabilities and stockholder's equity	$	15,736		$	14,980
	Condensed Statements of Income
		Years Ended December 31,
	(Dollars in millions)	2014			2013			2012
	Income:
	Dividends from bank subsidiary	$	—		$	—		$	950
	Interest income on advances to subsidiaries and deposits in bank	—			—			1
	Total income	—			—			951
	Expense:
	Interest expense	21			31			23
	Other expense	4			4			—
	Total expense	25			35			23
	Income (loss) before income taxes and equity in undistributed net income of subsidiaries	(25		)	(35		)	928
	Income tax benefit	(10		)	(14		)	(9		)
	Income (loss) before equity in undistributed net income of subsidiaries	(15		)	(21		)	937
	Equity in undistributed net income (loss) of subsidiaries:
	Bank subsidiary	761			625			(403		)
	Nonbank subsidiaries	79			63			94
	Net Income	$	825		$	667		$	628
	Condensed Statements of Cash Flows
		Years Ended December 31,
	(Dollars in millions)	2014			2013			2012
	Cash Flows from Operating Activities:
	Net income	$	825		$	667		$	628
	Adjustments to reconcile net income (loss) to net cash provided by operating activities:
	Equity in undistributed net (income) loss of subsidiaries	(840		)	(688		)	309
	Other, net	1			14			(14		)
	Net cash provided by (used in) operating activities	(14		)	(7		)	923
	Cash Flows from Investing Activities:
	Investments in and advances to subsidiaries	—			(1,700		)	—
	Repayment of investments in and advances to subsidiaries	165			35			650
	Net cash acquired from (paid for) acquisitions	—			—			(1,457		)
	Net cash used in investing activities	165			(1,665		)	(807		)
	Cash Flows from Financing Activities:
	Capital contribution from BTMU	—			1,200			—
	Proceeds from issuance of subordinated loan due to BTMU	—			300			—
	Proceeds from issuance of senior debt	—			—			397
	Repayment of subordinated debt	—			(400		)	—
	Repayment of junior subordinated debt	(14		)	—			—
	Other, net	—			—			(2		)
	Net cash provided by (used in) financing activities	(14		)	1,100			395
	Net increase (decrease) in cash and cash equivalents	137			(572		)	511
	Cash and cash equivalents at beginning of year	191			763			252
	Cash and cash equivalents at end of year	$	328		$	191		$	763

Summary_of_Significant_Account1

Summary of Significant Accounting Policies and Nature of Operations (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Financial Statement Presentation	Principles of Consolidation and Basis of Financial Statement Presentation
	The consolidated financial statements include the accounts of the Company and other entities in which the Company has a controlling financial interest. The Company determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a VIE. The primary beneficiary of a VIE is the entity that has the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and has the obligation to absorb losses or receive benefits from the VIE that could potentially be significant to the VIE. Results of operations from VIEs are included from the dates that the Company became the primary beneficiary. All intercompany transactions and balances with consolidated entities are eliminated in consolidation.
	The Company accounts for equity investments over which it exerts significant influence using the equity method of accounting. Non-marketable equity investments where the Company does not exert significant influence are accounted for at cost. Investments accounted for under both the equity method and cost method are included in other assets.
	The accounting and reporting policies of the Company conform to accounting principles generally accepted in the United States of America (GAAP) The policies that materially affect the determination of financial position, results of operations and cash flows are summarized below.
	The preparation of financial statements in conformity with GAAP also requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Although such estimates contemplate current conditions and management's expectations of how they may change in the future, it is reasonably possible that actual results could differ significantly from those estimates. This could materially affect the Company's results of operations and financial condition in the near term. Significant estimates made by management in the preparation of the Company's financial statements include, but are not limited to, the fair value of assets acquired and liabilities assumed (Note 2), the evaluation of other-than-temporary impairment on investment securities (Note 3), the allowance for credit losses (Note 4), purchased credit-impaired loans (Note 4), goodwill impairment (Note 6), fair value of financial instruments (Note 11), hedge accounting (Note 12), pension accounting (Note 15), and income taxes (Note 17).
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash and cash equivalents include cash and due from banks, interest bearing deposits in banks, and federal funds sold and securities purchased under resale agreements, which have original maturities less than 90 days.
Resale and Repurchase Agreements	Resale and Repurchase Agreements
	Transactions involving purchases of securities under agreements to resell (reverse repurchase agreements or reverse repos) or sales of securities under agreements to repurchase (repurchase agreements or repos) are accounted for as collateralized financings except where the Company does not have an agreement to sell (or purchase) the same or substantially the same securities before maturity at a fixed or determinable price. These agreements accounted for as collateralized financings are recorded at the amounts at which the securities were acquired or sold, plus accrued interest, and are carried at amortized cost. The Company's policy is to obtain possession of collateral with a market value equal to or in excess of the principal amount financed under resale agreements. Collateral is valued daily, and the Company may require counterparties to deposit additional collateral or return collateral pledged, when appropriate.
Trading Account Assets and Liabilities	Trading Account Assets and Liabilities
	Trading account assets and liabilities are recorded at fair value and include certain securities and derivatives. Securities are classified as trading when management acquires them with the intent to hold for short periods of time in order to take advantage of anticipated changes in fair values or as an accommodation to customers. Substantially all of the securities have a high degree of liquidity and a readily determinable fair value. Interest on securities classified as trading is included in interest income, and realized gains and losses from sale and unrealized fair value adjustments are recognized in noninterest income.
	Derivatives included in trading account assets and liabilities are entered into for trading purposes or as an accommodation to customers. Contracts primarily include interest rate swaps and options, commodity swaps and options, foreign exchange contracts and equity options relating to our market-linked CD product. The Company nets derivative assets and liabilities, and the related cash collateral receivables and payables, when a legally enforceable master netting arrangement exists between the Company and the derivative counterparty. Changes in fair values and realized income or expense for trading asset and liability derivatives are included in noninterest income.
Securities	Securities
	Securities are classified based on management's intent and are recorded on the consolidated balance sheet as of the trade date, when acquired in a regular-way trade. Debt securities for which management has both the positive intent and ability to hold to maturity are classified as held to maturity and are carried at amortized cost. Debt securities and equity securities with readily determinable fair values that are not classified as trading assets or held to maturity are classified as available for sale and are carried at fair value, with the unrealized gains or losses reported net of taxes as a component of AOCI in stockholder's equity until realized.
	Interest income on debt securities classified as either available for sale or held to maturity includes the amortization of premiums and the accretion of discounts using a method that produces a level yield and is included in interest income on securities.
	Debt securities in the available for sale and held to maturity portfolios are subject to impairment testing when their fair value is lower than amortized cost at the end of a reporting period.
	Realized gains and losses on the sale of available for sale securities are included in net interest income. The specific identification method is used to calculate realized gains and losses on sales.
	Securities available for sale that are pledged under an agreement to repurchase and which may be sold or repledged under that agreement are separately identified as pledged as collateral.
Other-than-Temporary Impairment	Other-than-Temporary Impairment
	Debt securities available for sale and debt securities held to maturity are subject to impairment testing when a security's fair value is lower than its amortized cost. Debt securities with unrealized losses are considered other-than-temporarily impaired if we intend to sell the debt security, if it is more likely than not that we will be required to sell the security before recovery of its amortized cost basis, or if we do not expect to recover the entire amortized cost basis of the security. If we intend to sell the security, or if it is more likely than not that we will be required to sell the security before recovery, an other-than-temporary impairment write-down is recognized in earnings equal to the entire difference between the amortized cost basis and fair value of the debt security. However, even if we do not expect to sell a debt security we must evaluate the expected cash flows to be received and determine if a credit loss exists. In the event of a credit loss, only the amount of impairment associated with the credit loss is recognized in income. Amounts related to factors other than credit losses are recorded in other comprehensive income. For further information on our other-than-temporary impairment analysis, see Note 3 to our Consolidated Financial Statements in this Form  10-K.
	Marketable equity securities are subject to testing for other-than-temporary impairment when there is a severe or sustained decline in market price below the amount recorded for that investment. The Company considers the issuer's financial condition, capital strength, and near-term prospects in assessing whether other-than-temporary impairment exists. An other-than-temporary impairment results in a write-down recognized in earnings equal to the entire difference between the carrying amount and fair value of the equity security.
Loans Held for Investment, Purchased Credit-Impaired Loans, Other Acquired Loans and Loans Held for Sale	Loans Held for Investment, Purchased Credit-Impaired Loans, Other Acquired Loans and Loans Held for Sale
	Loans held for investment are reported at the principal amounts outstanding, net of charge-offs, unamortized nonrefundable loan fees, direct loan origination costs, purchase premiums and discounts, and a historical fair value adjustment related to the Company's privatization transaction. Where loans are held for investment, the net basis adjustment excluding charge-offs on the loan is generally recognized in interest income on an effective yield basis over the contractual loan term.
	Nonaccrual loans are those for which management has discontinued accrual of interest because there exists significant uncertainty as to the full and timely collection of either principal or interest. Loans are generally placed on nonaccrual when such loans have become contractually past due 90 days with respect to principal or interest. Past due status is determined based on the contractual terms of the loan and the number of payment cycles since the last payment date. Interest accruals are continued past 90 days for certain small business loans and consumer installment loans, which are charged off at 120 days. For the commercial loan portfolio segment, interest accruals are also continued for loans that are both well-secured and in the process of collection.
	When a loan is placed on nonaccrual status, all previously accrued but uncollected interest is reversed against current period interest income. When full collection of the outstanding principal balance is in doubt, subsequent payments received are first applied to unpaid principal and then to uncollected interest. A loan may be returned to accrual status at such time as the loan is brought fully current as to both principal and interest, and such loan is considered to be fully collectible on a timely basis. The Company's policy also allows management to continue the recognition of interest income on certain loans placed on nonaccrual status. This portion of the nonaccrual portfolio is referred to as "Cash Basis Nonaccrual" under which the accrual of interest is suspended and interest income is recognized only when collected. This policy applies to consumer portfolio segment loans and commercial portfolio segment loans that are well-secured and in management's judgment are considered to be fully collectible but the timely collection of payments is in doubt.
	A TDR is a restructuring of a loan in which the creditor, for economic or legal reasons related to the borrower's financial difficulties, grants a concession to the borrower that it would not otherwise consider. A loan subject to such a restructuring is accounted for as a TDR. A TDR typically involves a modification of terms such as a reduction of the interest rate below the current market rate for a loan with similar risk characteristics or extending the maturity date of the loan without corresponding compensation or additional support. The Company measures impairment of a TDR using the methodology described for individually impaired loans (see "Allowance for Loan Losses" below). For the consumer portfolio segment, TDRs are initially placed on nonaccrual and typically, a minimum of six consecutive months of sustained performance is required before returning to accrual status. For the commercial portfolio segment, the Company generally determines accrual status for TDRs by performing an individual assessment of each loan, which may include, among other factors, the consideration of demonstrated performance by the borrower under the previous terms.
	Except for certain transactions between entities under common control, loans acquired in a transfer, including business combinations, are recorded at fair value at the acquisition date, factoring in credit losses expected to be incurred over the life of the loan.
	For acquired loans where there is evidence of credit deterioration since origination and it is probable at the date of acquisition that the Company will not collect all contractually required principal and interest payments, the loans are accounted for as purchased credit-impaired loans. This guidance requires that the excess of the cash flows initially expected to be collected over the loan's fair value at the acquisition date (i.e., the accretable yield) be accreted into interest income over the loan's estimated remaining life using the effective yield method, provided that the timing and amount of future cash flows is reasonably estimable. Accordingly, such loans are not classified as nonaccrual and are considered to be accruing. The difference between the contractually required payments and the cash flows expected to be collected at acquisition, considering the impact of prepayments, is referred to as the nonaccretable difference. Accordingly, an allowance for loan losses is not carried over or recorded for purchased credit-impaired loans as of the acquisition date. Substantially all of the remaining purchased credit-impaired loans are aggregated within pools based on common risk characteristics, which results in the pool becoming the unit of account.
	Subsequent to acquisition of purchased credit-impaired loans, estimates of cash flows expected to be collected are updated each reporting period based on updated assumptions that are reflective of current market conditions. If there is a probable decrease in cash flows expected to be collected (other than due to decreases in interest rate indices or changes in prepayments), the Company charges the provision for credit losses, resulting in an increase to the allowance for loan losses. If there is a probable and significant increase in cash flows expected to be collected, the Company will first reverse any previously established allowance for loan losses and then increase interest income as a prospective yield adjustment over the remaining life of the pool of loans, which also has the effect of reclassifying a portion of the nonaccretable difference to accretable yield. The impact of changes in variable interest rates is recognized prospectively as adjustments to interest income.
	Modifications of purchased credit-impaired loans that are accounted for within loan pools do not result in the removal of these loans from the pool even if the modification would otherwise be considered a TDR. Each pool is accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. Accordingly, modifications of loans within such pools are not considered TDRs.
	For other acquired loans, the purchase premium or discount is accreted to interest income over the remaining contractual life of the loans when the loans are performing, or immediately upon sale or prepayment.
	Loans held for sale, which are recorded in other assets, are carried at the lower of cost or fair value and measured on an individual basis for commercial loans and on an aggregate basis for residential mortgage loans. Changes in fair value are recognized in other noninterest income. Nonrefundable fees, direct loan origination costs, and purchase premiums and discounts related to loans held for sale are deferred and recognized as a component of the gain or loss on sale. Contractual interest earned on loans held for sale is recognized in interest income.
	The Company primarily offers two types of leases to customers: 1) direct financing leases where the assets leased are acquired without additional financing from other sources, and 2) leveraged leases where a substantial portion of the financing is provided by debt with no recourse to the Company. Direct financing leases and leverage leases are recorded based on the amount of minimum lease payments receivable, unguaranteed residual value accruing to the benefit of the lessor, unamortized initial direct costs, and are reduced for any unearned income. Leveraged leases are also recorded net of any nonrecourse debt.
Allowance for Loan Losses	Allowance for Loan Losses
	The Company maintains an allowance for loan losses to absorb losses inherent in the loan portfolio. The allowance is based on ongoing, quarterly assessments of the probable estimated losses inherent in the loan portfolio. The allowance is increased by the provision for loan losses, which is charged against current period operating results and decreased by the amount of charge-offs, net of recoveries. The Company's methodology for assessing the appropriateness of the allowance consists of several key elements, which include the allowance for loans collectively evaluated for impairment, the allowance for loans individually evaluated for impairment, and the unallocated allowance. Management estimates probable losses inherent in the portfolio based on a loss emergence period. The loss emergence period is the estimated average period of time between a material adverse event that affects the creditworthiness of a borrower and the subsequent recognition of a loss. Updates of the loss emergence period are performed when significant events cause management to reexamine data. Management develops and documents its systematic methodology for determining the allowance for loan losses by first dividing its portfolio into segments—the commercial segment, consumer segment and purchased credit-impaired loans. The Company further divides the portfolio segments into classes based on initial measurement attributes, risk characteristics or its method of monitoring and assessing credit risk. The classes for the Company include commercial and industrial, commercial mortgage, construction, residential mortgage, home equity and other consumer loans, and purchased credit-impaired loans. While the Company's methodology attributes portions of the allowance to specific portfolio segments, the entire allowance is available to absorb credit losses inherent in the total loan portfolio.
	For the commercial portfolio segment, the allowance for loans collectively evaluated for impairment is calculated by applying loss factors to outstanding loans and most unused commitments, based on the internal risk rating of such loans. Loss factors are based on historical loss experience and may be adjusted for significant qualitative considerations that, in management's judgment, affect the collectability of the portfolio as of the evaluation date. Those qualitative considerations are based upon management's evaluation of certain risks that may be identified from current conditions and developments within the portfolio that are not directly measured in the computation of the loss factors. Loss factors for individually graded credits are derived from a loan migration application that tracks historical losses over an economic cycle, which management believes captures the inherent losses in our loan portfolio.
	For the consumer portfolio segment, loans are generally pooled by product type with similar risk characteristics. The Company estimates the allowance for loans collectively evaluated for impairment based on forecasted losses. For the purchased credit-impaired segment, we charge the provision for loan losses, resulting in an increase to the allowance for loan losses when there is a probable decrease in cash flows expected to be collected.
	The allowance for loans collectively evaluated for impairment also includes attributions for certain sectors within the commercial and consumer portfolio segments to account for probable losses based on incurred loss events that are currently not reflected in the derived loss factors. Segment attributions are calculated based on migration scenarios for the commercial portfolio and specific attributes applicable to the consumer portfolio. Segment considerations are revised periodically as portfolio and environmental conditions change.
	Estimates of cash flows expected to be collected for purchased credit-impaired loans are updated each reporting period. If there is a probable decrease in expected cash flows to be collected after acquisition (other than due to decreases in interest rate indices or changes in voluntary prepayments), the Company charges the provision for loan losses and establishes an allowance for loan losses.
	The Company individually evaluates for impairment larger nonaccruing loans within the commercial portfolio. Residential mortgage and consumer loans are not individually evaluated for impairment unless they represent TDRs. Loans are considered impaired when the evaluation of current information regarding the borrower's financial condition, loan collateral, and cash flows indicates that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement, including interest payments. The amount of impairment is measured using the present value of expected future cash flows discounted at the loan's effective rate, the loan's observable market price, or the fair value of the collateral, if the loan is collateral dependent.
	The unallocated allowance is composed of attributions that are intended to capture probable losses from adverse changes in credit migration and other inherent losses that are not currently reflected in the allowance for loan losses that are ascribed to our portfolio segments.
	Significant risk characteristics considered in estimating the allowance for credit losses include the following:
	•	Commercial and industrial—industry specific economic trends and individual borrower financial condition
	•	Construction and commercial mortgage loans—type of property (i.e., residential, commercial, industrial), geographic concentrations, and risks and individual borrower financial condition
	•	Residential mortgage and consumer—historical and expected future charge-offs, borrower's credit, property collateral, and loan characteristics
	Loans are charged-off in whole or in part when they are considered to be uncollectible. Loans in the commercial loan portfolio segment are generally considered uncollectible based on an evaluation of borrower financial condition as well as the value of any collateral. Loans in the consumer portfolio segment are generally considered uncollectible based on past due status or the execution of certain TDR modifications such as discharge through Chapter 7 bankruptcy and the value of any collateral. Recoveries of amounts previously charged off are recorded as a recovery to the allowance for loan losses.
Allowance for Losses on Unfunded Credit Commitments	Allowance for Losses on Unfunded Credit Commitments
	The Company maintains an allowance for losses on unfunded credit commitments to absorb losses inherent in those commitments upon funding. The Company's methodology for assessing the appropriateness of this allowance is the same as that used for the allowance for loan losses (see "Allowance for Loan Losses" above) and incorporates an assumption based upon historical experience of likely utilization of the commitment. The allowance for losses on unfunded credit commitments is classified as other liabilities and the change in this allowance is recognized in the provision for credit losses. Losses on unfunded credit commitments are identified when exposures committed to customers facing difficulty are drawn upon, and subsequently result in charge-offs.
Premises and Equipment	Premises and Equipment
	Premises and equipment are carried at cost, less accumulated depreciation and amortization, impairment, and fair value adjustments related to the Company's privatization transaction. Depreciation and amortization are calculated using the straight-line method over the estimated useful life of each asset. Lives of premises range from ten to fifty years; lives of furniture, fixtures and equipment range from three to eight years. Leasehold improvements are amortized over the term of the respective lease or the estimated useful life of the improvement, whichever is shorter.
	Long-lived assets that are held for use are evaluated periodically for impairment when events or changes in circumstances indicate that the carrying amount may not be recoverable. Impairment is determined if the expected undiscounted future cash flows of a long-lived asset or group of assets is lower than its carrying amount. In the event of impairment, the Company recognizes a loss for the difference between the carrying amount and the fair value of the asset. The impairment loss is recognized in noninterest expense. Restoration of a previously recognized impairment loss is prohibited.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets
	Intangible assets represent purchased assets that lack physical substance and can be separately distinguished from goodwill because of contractual or other legal rights or because the asset is capable of being sold, exchanged, or licensed. Intangible assets are recorded at fair value at the date of acquisition.
	Intangible assets that have indefinite lives are tested for impairment at least annually, and more frequently in certain circumstances. Intangible assets that have finite lives, which include core deposit intangibles, customer relationships, non-compete agreements and trade names, are amortized either using the straight-line method or a method that patterns the manner in which the economic benefit is consumed. Intangible assets are amortized over their estimated periods of benefit, which range from three to forty years. The Company periodically evaluates the recoverability of intangible assets and takes into account events or circumstances that warrant revised estimates of useful lives or that indicate that impairment exists.
	Goodwill is assessed for impairment at least annually at the reporting unit level either qualitatively or quantitatively. If the elected qualitative assessment results indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then the quantitative impairment test is required. Various valuation methodologies are applied to carry out the first step of the quantitative impairment test by comparing the fair value of the reporting unit to its carrying amount, including goodwill. If the fair value of the reporting unit is less than its carrying amount, a second step is required to measure the amount of impairment by comparing the implied fair value of the goodwill assigned to the reporting unit with the carrying amount of that goodwill. Goodwill impairment is recognized through a direct write down to its carrying amount and subsequent reversals of goodwill impairment are prohibited.
Federal Deposit Insurance Corporation (FDIC) Indemnification Asset	FDIC Indemnification Asset
	In conjunction with the FDIC-assisted acquisitions of Frontier and Tamalpais in 2010, the Company entered into loss share agreements with the FDIC. Under the terms of the purchase and assumption and loss share agreements, the FDIC will reimburse the Company for certain losses on the covered assets, subject to specific compliance, servicing, notification and reporting requirements.
	At the date of the acquisitions, the Company recorded an indemnification asset at fair value based on the present value of cash flows expected to be collected from the FDIC under the loss share agreements. Subsequent to acquisition, the indemnification asset is accounted for on the same basis as the related FDIC covered assets and is linked to the losses on those assets. The difference between the carrying amount and the undiscounted cash flows that the Company expects to collect from the FDIC is amortized into noninterest income over the life of the FDIC indemnification asset. Any increases in expected cash flows of covered loans due to decreases in expected credit losses are amortized over the lesser of the contractual term of the FDIC loss share agreement and the remaining life of the indemnified assets. Any decreases in cash flows of the covered loans due to increases in expected credit losses will increase the FDIC indemnification asset and adjust the provision for credit losses. At the date of the acquisitions, the Company also recorded a standalone liability for the FDIC's ability to clawback a portion of the loss share reimbursements paid to the Company. Because such consideration is contingently payable to the FDIC, the Company accounts for this liability as a form of contingent consideration that is recorded at fair value through noninterest expense.
Other Real Estate Owned	Other Real Estate Owned
	OREO represents the collateral acquired through foreclosure in full or partial satisfaction of the related loan. OREO is initially recorded in other assets at the date physical possession is received at the fair value as established by a current appraisal, adjusted for estimated costs to sell the asset. Any write-down on the date of transfer from loan classification is charged to the allowance for loan losses. Subsequently, OREO is measured at the lower of the acquisition date fair value or fair value less estimated costs to sell the asset. OREO values are reviewed on an ongoing basis and subsequent declines in an individual property's fair value are recognized in earnings in the current period or in certain instances as a charge to the allowance for loan losses. The net operating results from these assets are included in the current period in noninterest expense as foreclosed asset expense.
Other Investments	Other Investments
	The Company invests in private equity investments, which include direct investments in private companies. These nonmarketable equity investments are initially recorded at cost and are accounted for using the cost or equity method of accounting depending on whether the Company has significant influence over the investee. Under the equity method, the investment is adjusted for the Company's share of the investee's net income or loss for the period. Under the cost method, dividends received are recognized in other noninterest income, and dividends received in excess of the investee's earnings are considered a return of investment and are recorded as a reduction of investment cost. These investments are evaluated for other-than-temporary impairment if events or conditions indicate that it is probable that the carrying amount of the investment will not be fully recovered in the foreseeable future. If an investment is determined to be other-than-temporarily impaired, it is written down to its fair value through earnings. Fair value is estimated based on a company's business model, current and projected financial performance, capital needs and our exit strategy. As a practical expedient, fair value can also be estimated using the net asset value of the fund. All of these investments are included within other assets and any other-than-temporary impairment is recognized in other noninterest income.
	The Company invests in limited liability partnerships and other entities operating qualified affordable housing projects. These LIHC investments provide tax benefits to investors in the form of tax deductions from operating losses and tax credits. The unguaranteed LIHC investments are initially recorded at cost, and subsequently accounted for under the equity method of accounting with equity method losses recognized through noninterest expense. These investments are reviewed periodically for impairment.
	The Company invests in guaranteed LIHC investments where the availability of tax credits are guaranteed by a creditworthy entity. The investments are initially recorded at cost. When certain criteria are met, the investment is amortized over the period the tax credits are allocated to provide a constant effective yield, as a component of income tax expense. In other instances, the investment is accounted for under the equity method of accounting with equity method losses recorded in noninterest expense. These investments are reviewed periodically for impairment.
	The Company also invests in limited liability entities and trusts that operate renewable energy projects, either directly or indirectly. Tax credits, taxable income and distributions associated with these renewable energy projects may be allocated to investors according to the terms of the partnership agreements. These investments are accounted for under the equity method and are reviewed periodically for impairment, considering projected operating results and realizability of tax credits.
Derivative Instruments Used in Hedging Relationships	Derivative Instruments Used in Hedging Relationships
	The Company enters into a variety of derivative contracts as a means of managing the Company's interest rate exposure and designates such derivatives under qualifying hedge relationships. All such derivative instruments are recorded at fair value and are included in other assets or other liabilities. The Company offsets derivative assets and liabilities, and the related cash collateral receivables and payables, when a legally enforceable master netting arrangement exists between the company and the derivative counterparty.
	At hedge inception, the Company designates a derivative instrument as a hedge of the fair value of a recognized asset or liability (i.e., fair value hedge), or a hedge of the variability in the expected future cash flows associated with either an existing recognized asset or liability or a probable forecasted transaction (i.e., cash flow hedge).
	Where hedge accounting is applied at hedge inception, the Company formally documents its risk management objective and strategy for undertaking the hedge, which includes identification of the hedging instrument, the hedged item or transaction, the nature of the risk being hedged, and how the hedge's effectiveness will be assessed prospectively and retrospectively. Both at the inception of the hedge and on an ongoing basis, the hedging instrument must be highly effective in offsetting changes in fair values or cash flows of the hedged item in order to qualify for hedge accounting.
	For fair value hedges, any ineffectiveness is recognized in noninterest expense in the period in which it arises. For cash flow hedges, only ineffectiveness resulting from over-hedging is recorded in earnings as an adjustment to noninterest expense, with other changes in the fair value of the derivative instrument recognized in other comprehensive income. The amount in other comprehensive income is subsequently reclassified to net interest income in the period in which the cash flow from the hedged item is recognized in earnings. If a derivative instrument is no longer determined to be highly effective as a designated hedge, hedge accounting is discontinued and subsequent fair value adjustments of the derivative instrument are recorded in earnings.
Transfers of Financial Assets	Transfers of Financial Assets
	Transfers of financial assets in which the Company has surrendered control over the transferred assets are accounted for as sales. Control is generally considered to have been surrendered when the transferred assets have been legally isolated from the Company, the transferee has the right to pledge or exchange the assets without any significant constraints, and the Company has not entered into a repurchase agreement, does not hold significant call options and has not written significant put options on the transferred assets. In assessing whether control has been surrendered, the Company considers whether the transferee would be a consolidated affiliate and the impact of all arrangements or agreements made contemporaneously with, or in contemplation of, the transfer, even if they were not entered into at the time of transfer.
Transfer Pricing	Transfer Pricing
	As a result of the business integration initiative, employees of the Company perform management and support services to BTMU in connection with the operation and administration of BTMU’s businesses in the Americas. In consideration for the services provided, BTMU pays the Company fees under a master services agreement, which reflects market-based pricing for those services. The Company recognizes transfer pricing revenue when delivery (performance) has occurred or services have been rendered. Revenue is recognized based on the gross amount billed to BTMU without netting the associated costs to perform those services. Gross presentation is deemed appropriate in these instances as the Company acts as a principal when providing these services directly to BTMU.
Operating Leases	Operating Leases
	The Company enters into a variety of lease contracts generally for premises and equipment as a lessee. Lease contracts that do not transfer substantially all of the benefits and risks of ownership and do not meet the accounting requirements for capital lease classification are treated as operating leases. The Company accounts for the payments of rent on these contracts on a straight-line basis over the lease term. At inception of the lease term, any periods for which no rents are paid or escalation clauses are stipulated in the lease contract are included in the determination of the rent expense and recognized ratably over the lease term.
	The Company records liabilities for legal obligations associated with the future retirement of buildings and leasehold improvements at fair value when incurred. The assets are increased by the related liability and depreciated over the shorter of the estimated useful life of that asset or the lease term.
Income Taxes	Income Taxes
	The Company files consolidated U.S. federal income tax returns, foreign tax returns and various combined and separate company state income tax returns.
	Management evaluates two components of income tax expense: current and deferred. Current income tax expense approximates taxes to be paid or refunded for the current period and includes income tax expense related to the Company's uncertain tax positions. Management determines deferred income taxes using the balance sheet method. Under this method, the net deferred tax asset or liability is based on the tax effects of the differences between the book and tax bases of assets and liabilities, and recognizes enacted changes in tax rates and laws in the period in which they occur. Deferred income tax expense results from changes in deferred tax assets and liabilities between periods. Deferred tax assets are recognized subject to management's judgment that realization is more likely than not. A tax position that meets the "more likely than not" recognition threshold is measured to determine the amount of benefit to recognize. The tax position is measured at the largest amount of benefit that is greater than 50% likely of being realized upon settlement. Foreign taxes paid are generally applied as credits to reduce U.S. federal income taxes payable. Interest and penalties are recognized as a component of income tax expense.
Employee Pension and Other Postretirement Benefits	Employee Pension and Other Postretirement Benefits
	The Company provides a variety of pension and other postretirement benefit plans for eligible employees and retirees. Provisions for the costs of these employee pension and other postretirement benefit plans are accrued and charged to expense when the benefit is earned.
Stock-Based Compensation	Stock-Based Compensation
	The Company grants restricted stock units settled in ADRs representing shares of common stock of the Company's ultimate parent company, MUFG, to employees. Stock-based compensation is measured at fair value on the grant date and is recognized in the Company's results of operations on a straight-line basis over the vesting period. The amortization of stock-based compensation reflects estimated forfeitures adjusted for actual forfeitures experience.
Business Combinations	Business Combinations
	The Company accounts for all business combinations using the acquisition method of accounting. Except for certain transactions between entities under common control, assets and liabilities acquired are recorded at fair value at the acquisition date, with the excess of purchase price over the fair value of the net assets acquired (including identifiable intangibles) recorded as goodwill. Management may further adjust the acquisition date fair values for a period of up to one year from the date of acquisition. The recognition at the acquisition date of an allowance for loan losses is not carried over or recorded as of acquisition date, as credit-related factors are incorporated directly into the fair value measurement of the loans.
Recently Issued Accounting Pronouncements That Are Not Yet Effective	Recently Issued Accounting Pronouncements
	Accounting for Investments in Qualified Affordable Housing Projects
	In January 2014, the FASB issued ASU 2014-1, Accounting for Investments in Qualified Affordable Housing Projects, which amends guidance on the accounting for investments in qualified affordable housing projects and permits reporting entities to make an accounting policy election to account for investments in qualified affordable housing projects using the proportional amortization method, if certain conditions are met.  Under the proportional amortization method, reporting entities amortize the initial cost of the investment in proportion to tax credits and tax benefits received and recognize the amortization as a component of income tax expense. This guidance is effective for interim and annual periods beginning on January 1, 2015 with early adoption permitted. The guidance is required to be applied retrospectively to all periods presented upon adoption. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
	Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure
	In January 2014, the FASB issued ASU 2014-4, Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure, which provides guidance on when an in-substance repossession or foreclosure of residential real estate has occurred and when a creditor should derecognize the consumer mortgage loan and recognize the residential real estate. The guidance clarifies that an in-substance repossession or foreclosure occurs upon either (1) the creditor obtaining legal title to the residential real estate property upon completion of a foreclosure, or (2) the borrower conveying all interest in the residential real estate property to the creditor to satisfy the loan through completion of a deed in lieu of foreclosure or through a similar legal agreement. In addition, the standard requires additional interim and annual disclosures. The guidance is effective for interim and annual periods beginning on January 1, 2015, with early adoption permitted. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
	Presentation of Financial Statements and Property, Plant and Equipment and Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity
	In April 2014, the FASB issued ASU 2014-8, Presentation of Financial Statements and Property, Plant and Equipment and Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity, which amends the criteria for reporting discontinued operations and requires additional disclosures for discontinued operations which meet the new criteria. The amendments in ASU 2014-8 limit discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have or will have a major effect on an entity’s operations and financial results. The guidance is effective for interim and annual periods beginning on January 1, 2015 with early adoption permitted. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
	Revenue from Contracts with Customers
	In May 2014, the FASB issued ASU 2014-9, Revenue from Contracts with Customers, which provides guidance on the core principle 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. This standard applies to all contracts with customers, except financial instruments, guarantees, lease contracts, insurance contracts, and certain non-monetary exchanges. It provides the following five-step revenue recognition model: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the entity satisfies a performance obligation. In addition, the standard requires additional disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. The standard is effective for interim and annual periods beginning on January 1, 2017. Management is currently assessing the impact of this guidance on the Company’s financial position and results of operations.
	Transfers and Servicing - Amendments to Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosure
	In June 2014, the FASB issued ASU 2014-11, Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, which changes the accounting for repurchase-to-maturity transactions and repurchase financing arrangements. The guidance requires that repurchase-to-maturity transactions be accounted for as secured borrowings consistent with the accounting for other repurchase agreements. Additionally, the guidance requires separate accounting for a transfer of a financial asset executed contemporaneously with a repurchase agreement with the same counterparty, which will result in secured borrowing accounting for the repurchase agreement. It also requires enhanced disclosures about repurchase agreements and other similar transactions. The guidance is effective on January 1, 2015. Earlier application is prohibited. The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
	Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period
	In June 2014, the FASB issued ASU 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period, which provides guidance that a performance target that affects vesting of a share-based payment and that could be achieved after the completion of the employee’s requisite service period is a performance condition under the accounting guidance for share-based awards. The standard clarifies that the performance target would not be reflected in estimating the fair value of the award at the grant date. Instead, compensation cost for the award would be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. If the performance target becomes probable of being achieved before the end of the requisite service period, the remaining unrecognized compensation cost should be recognized prospectively over the remaining requisite service period. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or results of operations.
	Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure
	In August 2014, the FASB issued ASU 2014-14, Classification of Certain Government-Guaranteed Residential Mortgage Loans upon Foreclosure, which provides guidance on the accounting for the classification of foreclosed loans that are fully-government-guaranteed.  The guidance clarifies that a residential mortgage loan be derecognized and that a separate other receivable be recognized upon foreclosure if the loan has both of the following characteristics: (1) The loan has a government guarantee that is not separable from the loan before foreclosure entitling the creditor to the full unpaid principal balance of the loan, and (2) At the time of foreclosure, the creditor has the intent to make a claim on the guarantee and the ability to recover the full unpaid principal balance of the loan through the guarantee.  The guidance is effective for interim and annual periods beginning on January 1, 2015, with early adoption permitted.  The adoption of this guidance did not significantly impact the Company’s financial position or results of operations.
	Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity
	In November 2014, the FASB issued ASU 2014-16, Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity, which provides guidance on identifying whether the host contract in certain hybrid instruments is in the form of debt or equity. Such identification impacts the analysis of whether an embedded derivative exists in the instrument. The standard requires an entity to determine the nature of the host contract by considering all stated and implied substantive terms and features of the hybrid financial instrument, weighing each term and feature on the basis of the relevant facts and circumstances (commonly referred to as the whole-instrument approach). Under this approach, an entity would determine the nature of the host contract by considering the economic characteristics and risks of the entire hybrid financial instrument, including the embedded derivative feature that is being evaluated for separate accounting from the host contract. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or result of operations.
	Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items
	In January 2015, the FASB issued ASU 2015-01, Simplifying Income Statement Presentation by Eliminating the Concept of Extraordinary Items, which eliminates the need to determine whether to classify an item as an extraordinary item in the income statement. Under current guidance, a reporting entity is required to separately classify, present and disclose extraordinary events apart from events that are unusual in nature or occur infrequently (but not both). The existing presentation and disclosure guidance for items that are unusual in nature or occur infrequently will be expanded to include items that are both unusual in nature and occur infrequently. The guidance is effective for interim and annual periods beginning on January 1, 2016, with early adoption permitted. The guidance may be applied either prospectively or retrospectively. Management does not expect the adoption of this guidance to significantly impact the Company’s financial position or results of operations.
	Amendments to the Consolidation Analysis
	In February 2015, the FASB issued ASU 2015-02, which is intended to improve current GAAP by making changes to targeted areas of the consolidation guidance.  This standard simplifies current GAAP as it reduces the number of consolidation models by eliminating specialized consolidation guidance for certain investment funds that are exempt from applying the VIE model.  The standard also changes the determination of whether limited partnerships and similar entities are VIEs or voting interest entities, the evaluation of the fees paid to decision makers and the application of the related-party guidance in determining whether a controlling financial interest exists.  The guidance is effective for periods beginning on January 1, 2016, with early adoption permitted. The standard may be applied using a modified or full retrospective approach.  Management is currently evaluating the impact to the Company’s financial position and results of operations.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies and Nature of Operations Summary of Significant Accounting Policies and Nature of Operations (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Reclassification Adjustments	The following tables display the affected line items for 2013 and 2012:
		For the Year Ended December 31, 2013
	(Dollars in millions)	As Previously Reported			Reclassification Amounts			As Revised
	Cash Flows from Operating Activities:
	Depreciation, amortization and accretion, net	$	509		$	(75	)	$	434
	Loans originated for sale	(276		)	(346		)	(622		)
	Net proceeds from sale of loans originated for sale	226			373			599
	Net cash provided by (used in) operating activities	737			(48		)	689
	Cash Flows from Investing Activities:
	Proceeds from sales of loans	627			(373		)	254
	Net decrease (increase) in loans	(5,333		)	421			(4,912		)
	Net cash provided by (used in) investing activities	(8,579		)	48			(8,531		)
	Cash Flows from Financing Activities:
	Net cash provided by (used in) financing activities	8,554			—			8,554
	Net change in cash and cash equivalents	$	712		$	—		$	712
	Supplemental Schedule of Noncash Investing and Financing Activities:
	Net transfer of loans held for investment to loans held for sale	$	592		$	(346	)	$	246
		For the Year Ended December 31, 2012
	(Dollars in millions)	As Previously Reported			Reclassification Amounts			As Revised
	Cash Flows from Operating Activities:
	Depreciation, amortization and accretion, net	$	518		$	(102	)	$	416
	Loans originated for sale	(58		)	(153		)	(211		)
	Net proceeds from sale of loans originated for sale	34			114			148
	Net cash provided by (used in) operating activities	601			(141		)	460
	Cash Flows from Investing Activities:
	Proceeds from sales of loans	316			(114		)	202
	Net decrease (increase) in loans	(4,355		)	255			(4,100		)
	Net cash provided by (used in) investing activities	249			141			390
	Cash Flows from Financing Activities:
	Net cash provided by (used in) financing activities	446			—			446
	Net change in cash and cash equivalents	$	1,296		$	—		$	1,296
	Supplemental Schedule of Noncash Investing and Financing Activities:
	Net transfer of loans held for investment to loans held for sale	$	308		$	(153	)	$	155

Securities_Tables

Securities (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Amortized Cost, Gross Unrealized Gains, Gross Unrealized Losses, and Fair Values of Securities	At December 31, 2014 and 2013, the amortized cost, gross unrealized gains, gross unrealized losses, and fair values of securities are presented below.
		31-Dec-14
	(Dollars in millions)	Amortized		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Value
				Gains		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	7,649	$	2	$	91	$	7,560
	Privately issued	166		3		1		168
	Commercial mortgage-backed securities	1,689		15		13		1,691
	Collateralized loan obligations	2,527		4		37		2,494
	Other	8		1		—		9
	Asset Liability Management securities	12,039		25		142		11,922
	Other debt securities:
	Direct bank purchase bonds	1,719		49		27		1,741
	Other	53		—		1		52
	Equity securities	8		2		1		9
	Total securities available for sale	$	13,819	$	76	$	171	$	13,724
		31-Dec-13
	(Dollars in millions)	Amortized		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Value
				Gains		Losses
	Asset Liability Management securities:
	U.S. government-sponsored agencies	$	73	$	—	$	—	$	73
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	9,194		2		296		8,900
	Privately issued	220		4		2		222
	Commercial mortgage-backed securities	1,947		8		85		1,870
	Collateralized loan obligations	2,670		25		22		2,673
	Other	34		1		—		35
	Asset Liability Management securities	14,138		40		405		13,773
	Other debt securities:
	Direct bank purchase bonds	1,968		35		43		1,960
	Other	81		—		5		76
	Equity securities	7		1		—		8
	Total securities available for sale	$	16,194	$	76	$	453	$	15,817
Securities in Unrealized Loss Position	The Company's securities held to maturity with a continuous unrealized loss position at December 31, 2014 and 2013 are shown below, separately for periods less than 12 months and 12 months or more.
		31-Dec-14
		Less than 12 months						12 months or more						Total
				Unrealized Losses						Unrealized Losses						Unrealized Losses
	(Dollars in millions)	Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized
		Value		in OCI		in OCI		Value		in OCI		in OCI		Value		in OCI		in OCI
	U.S. government agency and government-sponsored agencies—residential mortgage backed securities	$	399	$	—	$	1	$	2,341	$	66	$	4	$	2,740	$	66	$	5
	U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	134		—		—		1,552		82		6		1,686		82		6
	Total securities held to maturity	$	533	$	—	$	1	$	3,893	$	148	$	10	$	4,426	$	148	$	11
		31-Dec-13
		Less than 12 months						12 months or more						Total
				Unrealized Losses						Unrealized Losses						Unrealized Losses
	(Dollars in millions)	Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized		Fair		Recognized		Not Recognized
		Value		in OCI		in OCI		Value		in OCI		in OCI		Value		in OCI		in OCI
	U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	$	3,873	$	76	$	68	$	54	$	1	$	1	$	3,927	$	77	$	69
	U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,016		46		10		489		46		2		$	1,505	$	92	$	12
	Total securities held to maturity	$	4,889	$	122	$	78	$	543	$	47	$	3	$	5,432	$	169	$	81
	The Company's securities available for sale with a continuous unrealized loss position at December 31, 2014 and 2013 are shown below, identified for periods less than 12 months and 12 months or more.
		31-Dec-14
		Less than 12 months				12 months or more				Total
	(Dollars in millions)	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
		Value		Losses		Value		Losses		Value		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	611	$	1	$	6,258	$	90	$	6,869	$	91
	Privately issued	9		—		49		1		58		1
	Commercial mortgage-backed securities	143		—		842		13		985		13
	Collateralized loan obligations	657		6		1,481		31		2,138		37
	Other	—		—		1		—		1		—
	Asset Liability Management securities	1,420		7		8,631		135		10,051		142
	Other debt securities:
	Direct bank purchase bonds	75		3		937		24		1,012		27
	Other	—		—		22		1		22		1
	Equity securities	1		1		5		—		6		1
	Total securities available for sale	$	1,496	$	11	$	9,595	$	160	$	11,091	$	171
		31-Dec-13
		Less than 12 months				12 months or more				Total
	(Dollars in millions)	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
		Value		Losses		Value		Losses		Value		Losses
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	8,508	$	293	$	147	$	3	$	8,655	$	296
	Privately issued	72		2		18		—		90		2
	Commercial mortgage-backed securities	1,274		80		58		5		1,332		85
	Collateralized loan obligations	1,879		21		10		1		1,889		22
	Other	—		—		1		—		1		—
	Asset Liability Management securities	11,733		396		234		9		11,967		405
	Other debt securities:
	Direct bank purchase bonds	537		18		778		25		1,315		43
	Other	15		1		34		4		49		5
	Equity Securities	5		—		—		—		5		—
	Total securities available for sale	$	12,290	$	415	$	1,046	$	38	$	13,336	$	453
Debt Securities by Contractual Maturity	The carrying amount and fair value of securities held to maturity by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.
		31-Dec-14
		Over One Year				Over Five Years				Over Ten Years				Total
		Through Five Years				Through Ten Years
	(Dollars in millions)	Carrying		Fair		Carrying		Fair		Carrying		Fair		Carrying		Fair
		Amount		Value		Amount		Value		Amount		Value		Amount		Value
	U.S. Treasury	$	486	$	489	$	—	$	—	$	—	$	—	$	486	$	489
	U.S. government-sponsored agencies	25		25		100		100		—		—		125		125
	U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	1		1		—		—		5,941		6,012		5,942		6,013
	U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	49		50		793		836		896		899		1,738		1,785
	Total securities held to maturity	$	561	$	565	$	893	$	936	$	6,837	$	6,911	$	8,291	$	8,412
	The fair value of debt securities available for sale by contractual maturity are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.
		31-Dec-14
	(Dollars in millions)	One Year or		Over One Year		Over Five Years		Over Ten Years		Total Fair
		Less		Through		Through				Value
				Five Years		Ten Years
	Asset Liability Management securities:
	Residential mortgage-backed securities:
	U.S. government agency and government-sponsored agencies	$	—	$	13	$	458	$	7,089	$	7,560
	Privately issued	—		4		—		164		168
	Commercial mortgage-backed securities	—		—		36		1,655		1,691
	Collateralized loan obligations	30		80		572		1,812		2,494
	Other	—		2		7		—		9
	Asset Liability Management securities	30		99		1,073		10,720		11,922
	Other debt securities:
	Direct bank purchase bonds	72		547		663		459		1,741
	Other	5		12		4		31		52
	Total debt securities available for sale	$	107	$	658	$	1,740	$	11,210	$	13,715
Proceeds from Sales of Securities Available for Sale and Gross Realized Gains and Losses	The proceeds from sales of securities available for sale and gross realized gains and losses for the years ended December 31, 2014, 2013 and 2012 are shown below. The specific identification method is used to calculate realized gains and losses on sales.
		For the Year Ended December 31,
	(Dollars in millions)	2014		2013		2012
	Proceeds from sales	$	1,376	$	8,340	$	6,845
	Gross realized gains	23		190		113
	Gross realized losses	—		3		2
Schedule of Held to Maturity Securities Recognized and Not Recognized in Other Comprehensive Income (OCI) and Fair Values	t December 31, 2014 and 2013, the amortized cost, gross unrealized gains and losses recognized in Other Comprehensive Income (OCI), carrying amount, gross unrealized gains and losses not recognized in OCI, and fair values of securities held to maturity are presented below.
		31-Dec-14
				Recognized in						Not Recognized in
				OCI						OCI
	(Dollars in millions)	Amortized		Gross		Gross		Carrying		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Amount		Unrealized		Unrealized		Value
				Gains		Losses				Gains		Losses
	U.S. Treasury	$	486	$	—	$	—	$	486	$	3	$	—	$	489
	U.S. government-sponsored agencies	125		—		—		125		—		—		125
	U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	6,002		6		66		5,942		76		5		6,013
	U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,820		—		82		1,738		53		6		1,785
	Total securities held to maturity	$	8,433	$	6	$	148	$	8,291	$	132	$	11	$	8,412
		31-Dec-13
				Recognized in						Not Recognized in
				OCI						OCI
	(Dollars in millions)	Amortized		Gross		Gross		Carrying		Gross		Gross		Fair
		Cost		Unrealized		Unrealized		Amount		Unrealized		Unrealized		Value
				Gains		Losses				Gains		Losses
	U.S. government agency and government-sponsored agencies - residential mortgage-backed securities	$	5,065	$	7	$	77	$	4,995	$	8	$	69	$	4,934
	U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities	1,606		—		92		1,514		3		12		1,505
	Total securities held to maturity	$	6,671	$	7	$	169	$	6,509	$	11	$	81	$	6,439

Loans_and_Allowance_for_Loan_L1

Loans and Allowance for Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Summary of Loans	The following table provides the outstanding balances of loans at December 31, 2014 and 2013.
			December 31,
	(Dollars in millions)		2014			2013
	Loans held for investment:
	Commercial and industrial		$	27,623		$	23,528
	Commercial mortgage		14,016			13,092
	Construction		1,746			905
	Lease financing		800			854
	Total commercial portfolio		44,185			38,379
	Residential mortgage		28,977			25,547
	Home equity and other consumer loans		3,117			3,280
	Total consumer portfolio		32,094			28,827
	Total loans held for investment, before purchased credit-impaired loans		76,279			67,206
	Purchased credit-impaired loans(1)		525			1,106
	Total loans held for investment(2)		76,804			68,312
	Allowance for loan losses		(537		)	(568		)
	Loans held for investment, net		$	76,267		$	67,744
	-1	Includes $126 million and $251 million as of December 31, 2014 and December 31, 2013, respectively, of loans for which the Company will be reimbursed a portion of any future losses under the terms of the FDIC loss share agreements. Of these FDIC covered loans, $9 million and $15 million as of December 31, 2014 and December 31, 2013, respectively, were not accounted for under accounting guidance for loans acquired with deteriorated credit quality.
	-2	Includes $151 million and $88 million at December 31, 2014 and December 31, 2013, respectively, for net unamortized discounts and premiums and deferred fees and costs.
Reconciliation of Changes in Allowance for Loan Losses by Portfolio Segment	The following tables provide a reconciliation of changes in the allowance for loan losses by portfolio segment:
			For the Year Ended December 31, 2014
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	421		$	69		$	1		$	77		$	568
	(Reversal of) provision for loan losses		52			(13		)	—			(57		)	(18		)
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			2			—			2
	Other		(3		)	—			—			—			(3		)
	Loans charged-off		(38		)	(11		)	(1		)	—			(50		)
	Recoveries of loans previously charged-off		33			4			1			—			38
	Allowance for loan losses, end of period		$	465		$	49		$	3		$	20		$	537
			For the Year Ended December 31, 2013
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	418		$	124		$	1		$	110		$	653
	(Reversal of) provision for loan losses		18			(29		)	—			(33		)	(44		)
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			(1		)	—			(1		)
	Decrease in allowance covered by FDIC indemnification		—			—			(8		)	—			(8		)
	Loans charged-off		(44		)	(30		)	(3		)	—			(77		)
	Recoveries of loans previously charged-off		29			4			12			—			45
	Allowance for loan losses, end of period		$	421		$	69		$	1		$	77		$	568
			For the Year Ended December 31, 2012
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses, beginning of period		$	474		$	138		$	17		$	135		$	764
	(Reversal of) provision for loan losses		(25		)	78			—			(25		)	28
	(Reversal of) provision for purchased credit-impaired loan losses not subject to FDIC indemnification		—			—			(3		)	—			(3		)
	Decrease in allowance covered by FDIC indemnification		—			—			(5		)	—			(5		)
	Loans charged-off		(88		)	(95		)	(13		)	—			(196		)
	Recoveries of loans previously charged-off		57			3			5			—			65
	Allowance for loan losses, end of period		$	418		$	124		$	1		$	110		$	653
Allowance for Loan Losses and Related Loan Balances by Portfolio Segment	The following tables show the allowance for loan losses and related loan balances by portfolio segment as of December 31, 2014 and 2013.
			31-Dec-14
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses:
	Individually evaluated for impairment		$	18		$	16		$	—		$	—		$	34
	Collectively evaluated for impairment		447			33			—			20			500
	Purchased credit-impaired loans		—			—			3			—			3
	Total allowance for loan losses		$	465		$	49		$	3		$	20		$	537
	Loans held for investment:
	Individually evaluated for impairment		$	164		$	338		$	1		$	—		$	503
	Collectively evaluated for impairment		44,021			31,756			—			—			75,777
	Purchased credit-impaired loans		—			—			524			—			524
	Total loans held for investment		$	44,185		$	32,094		$	525		$	—		$	76,804
			31-Dec-13
	(Dollars in millions)		Commercial			Consumer			Purchased			Unallocated			Total
									Credit-
									Impaired
	Allowance for loan losses:
	Individually evaluated for impairment		$	19		$	20		$	—		$	—		$	39
	Collectively evaluated for impairment		402			49			—			77			528
	Purchased credit-impaired loans		—			—			1			—			1
	Total allowance for loan losses		$	421		$	69		$	1		$	77		$	568
	Loans held for investment:
	Collectively evaluated for impairment		$	266		$	339		$	3		$	—		$	608
	Collectively evaluated for impairment		38,113			28,488			—			—			66,601
	Purchased credit-impaired loans		—			—			1,103			—			1,103
	Total loans held for investment		$	38,379		$	28,827		$	1,106		$	—		$	68,312
Summary of Nonaccrual Loans	The following table presents nonaccrual loans as of December 31, 2014 and 2013.
			December 31,
	(Dollars in millions)		2014			2013
	Commercial and industrial		$	55		$	44
	Commercial mortgage		40			51
	Total commercial portfolio		95			95
	Residential mortgage		231			286
	Home equity and other consumer loans		40			46
	Total consumer portfolio		271			332
	Total nonaccrual loans, before purchased credit-impaired loans		366			427
	Purchased credit-impaired loans		9			15
	Total nonaccrual loans		$	375		$	442
	Troubled debt restructured loans that continue to accrue interest		$	283		$	367
	Troubled debt restructured nonaccrual loans (included in the total nonaccrual loans above)		$	184		$	225
Aging of Balance of Loans Held for Investment, Excluding Purchased Credit-Impaired Loans	The following tables show an aging of the balance of loans held for investment, excluding purchased credit-impaired loans, by class as of December 31, 2014 and 2013.
			31-Dec-14
			Aging Analysis of Loans
	(Dollars in millions)		Current			30 to			90 Days or			Total Past Due			Total
						89 Days			More Past
						Past Due			Due
	Commercial and industrial		$	28,392		$	19		$	12		$	31		$	28,423
	Commercial mortgage		13,991			21			4			25			14,016
	Construction		1,744			2			—			2			1,746
	Total commercial portfolio		44,127			42			16			58			44,185
	Residential mortgage		28,802			112			63			175			28,977
	Home equity and other consumer loans		3,084			20			13			33			3,117
	Total consumer portfolio		31,886			132			76			208			32,094
	Total loans held for investment, excluding purchased credit-impaired loans		$	76,013		$	174		$	92		$	266		$	76,279
			31-Dec-13
			Aging Analysis of Loans
	(Dollars in millions)		Current			30 to			90 Days or			Total Past Due			Total
						89 Days			More Past
						Past Due			Due
	Commercial and industrial		$	24,310		$	66		$	6		$	72		$	24,382
	Commercial mortgage		13,004			68			20			88			13,092
	Construction		891			14			—			14			905
	Total commercial portfolio		38,205			148			26			174			38,379
	Residential mortgage		25,342			114			91			205			25,547
	Home equity and other consumer loans		3,238			23			19			42			3,280
	Total consumer portfolio		28,580			137			110			247			28,827
	Total loans held for investment, excluding purchased credit-impaired loans		$	66,785		$	285		$	136		$	421		$	67,206
Loans in Commercial Portfolio Segment and Commercial Loans within Purchased Credit-Impaired Loans Segment Monitored for Credit Quality Based on Internal Ratings	The following tables summarize the loans in the commercial portfolio segment and commercial loans within the purchased credit-impaired loans segment monitored for credit quality based on internal ratings, excluding $98 million and $213 million covered by FDIC loss share agreements, at December 31, 2014 and 2013, respectively. The amounts presented reflect unpaid principal balances less charge-offs.
			31-Dec-14
	(Dollars in millions)		Pass			Special Mention			Classified			Total
	Commercial and industrial		$	27,471		$	452		$	360		$	28,283
	Construction		1,729			18			—			1,747
	Commercial mortgage		13,522			128			183			13,833
	Total commercial portfolio		42,722			598			543			43,863
	Purchased credit-impaired loans		37			38			128			203
	Total		$	42,759		$	636		$	671		$	44,066
			31-Dec-13
	(Dollars in millions)		Pass			Special Mention			Classified			Total
	Commercial and industrial		$	23,346		$	576		$	313		$	24,235
	Construction		879			14			—			893
	Commercial mortgage		12,562			142			228			12,932
	Total commercial portfolio		36,787			732			541			38,060
	Purchased credit-impaired loans		48			204			362			614
	Total		$	36,835		$	936		$	903		$	38,674
Loans in Consumer Portfolio an Purchased credit-impaired loans	The Company monitors the credit quality of its consumer portfolio segment and consumer loans within the purchased credit-impaired loans segment based primarily on payment status. The following tables summarize the loans in the consumer portfolio segment and purchased credit-impaired loans segment, which excludes $28 million and $38 million of loans covered by FDIC loss share agreements, at December 31, 2014 and 2013, respectively.
			31-Dec-14
	(Dollars in millions)		Accrual			Nonaccrual			Total
	Residential mortgage		$	28,746		$	231		$	28,977
	Home equity and other consumer loans		3,077			40			3,117
	Total consumer portfolio		31,823			271			32,094
	Purchased credit-impaired loans		196			—			196
	Total		$	32,019		$	271		$	32,290
			31-Dec-13
	(Dollars in millions)		Accrual			Nonaccrual			Total
	Residential mortgage		$	25,261		$	286		$	25,547
	Home equity and other consumer loans		3,234			46			3,280
	Total consumer portfolio		28,495			332			28,827
	Purchased credit-impaired loans		242			—			242
	Total		$	28,737		$	332		$	29,069
Loans in Consumer Portfolio Segment and Consumer Loans within Purchased Credit-Impaired Loans Segment Monitored for Credit Quality Based on Refreshed FICO Scores and Refreshed LTV ratios	The following tables summarize the loans in the consumer portfolio segment and consumer loans within the purchased credit-impaired loans segment monitored for credit quality based on refreshed FICO scores and refreshed LTV ratios at December 31, 2014 and 2013. These tables exclude loans covered by FDIC loss share agreements, as discussed above. The amounts presented reflect unpaid principal balances less partial charge-offs. During the fourth quarter 2014, the Company changed the presentation of its LTV ratios to better align with management's methodology used to analyze credit quality. Prior period amounts have been adjusted to conform to the current year presentation.
			31-Dec-14
			FICO scores
	(Dollars in millions)		720 and Above			Below 720			No FICO			Total
									Available(1)
	Residential mortgage		$	22,505		$	5,717		$	493		$	28,715
	Home equity and other consumer loans		2,209			754			83			3,046
	Total consumer portfolio		24,714			6,471			576			31,761
	Purchased credit-impaired loans		73			111			13			197
	Total		$	24,787		$	6,582		$	589		$	31,958
	Percentage of total		77		%	21		%	2		%	100		%
	-1	Represents loans for which management was not able to obtain an updated FICO score (e.g., due to recent profile changes).
			31-Dec-13
			FICO scores
	(Dollars in millions)		720 and Above			Below 720			No FICO			Total
									Available(1)
	Residential mortgage		$	19,614		$	5,301		$	459		$	25,374
	Home equity and other consumer loans		2,283			839			81			3,203
	Total consumer portfolio		21,897			6,140			540			28,577
	Purchased credit-impaired loans		94			135			15			244
	Total		$	21,991		$	6,275		$	555		$	28,821
	Percentage of total		76		%	22		%	2		%	100		%
	-1	Represents loans for which management was not able to obtain an updated FICO score (e.g., due to recent profile changes).
			31-Dec-14
			LTV ratios
	(Dollars in millions)		Less than or Equal to 80			Greater than 80 and Less than 100 Percent			Greater than or Equal to 100			No LTV			Total
			Percent						Percent			Available(1)
	Residential mortgage		$	27,162		$	1,430		$	92		$	31		$	28,715
	Home equity loans		2,364			270			118			50			2,802
	Total consumer portfolio		29,526			1,700			210			81			31,517
	Purchased credit-impaired loans		131			45			18			1			195
	Total		$	29,657		$	1,745		$	228		$	82		$	31,712
	Percentage of total		94		%	5		%	1		%	—		%	100		%
	-1	Represents loans for which management was not able to obtain refreshed property values.
			31-Dec-13
			LTV ratios
	(Dollars in millions)		Less than or Equal to 80			Greater than 80 and Less than 100 Percent			Greater than or Equal to 100			No LTV			Total
			Percent						Percent			Available(1)
	Residential mortgage		$	23,613		$	1,477		$	231		$	53		$	25,374
	Home equity loans		2,492			356			203			52			3,103
	Total consumer portfolio		26,105			1,833			434			105			28,477
	Purchased credit-impaired loans		152			57			31			—			240
	Total		$	26,257		$	1,890		$	465		$	105		$	28,717
	Percentage of total		91		%	7		%	2		%	—		%	100		%
	-1	Represents loans for which management was not able to obtain refreshed property values.
Summary of Troubled Debt Restructurings	The following table provides a summary of the Company's recorded investment in TDRs as of December 31, 2014 and 2013. The summary includes those TDRs that are on nonaccrual status and those that continue to accrue interest. The Company had $33 million and $43 million in commitments to lend additional funds to borrowers with loan modifications classified as TDRs as of December 31, 2014 and 2013, respectively.
			December 31,
	(Dollars in millions)		2014			2013
	Commercial and industrial		$	100		$	212
	Commercial mortgage		28			38
	Total commercial portfolio		128			250
	Residential mortgage		308			315
	Home equity and other consumer loans		30			24
	Total consumer portfolio		338			339
	Total restructured loans, excluding purchased credit-impaired loans(1)		$	466		$	589
	-1	Amounts exclude $1 million and $3 million of TDRs covered by FDIC loss share agreements at December 31, 2014 and 2013, respectively.
Pre- and Post-Modification Outstanding Recorded Investment Amounts of Troubled Debt Restructurings	The following table provides the pre- and post-modification outstanding recorded investment amounts of TDRs as of the date of the restructuring that occurred during the years ended December 31, 2014 and 2013.
			For the Year Ended						For the Year Ended
			December 31, 2014						December 31, 2013
	(Dollars in millions)		Pre-Modification			Post-Modification			Pre-Modification			Post-Modification
			Outstanding			Outstanding			Outstanding			Outstanding
			Recorded			Recorded			Recorded			Recorded
			Investment(1)			Investment(2)			Investment(1)			Investment(2)
	Commercial and industrial		$	111		$	111		$	161		$	158
	Commercial mortgage		23			23			70			69
	Total commercial portfolio		134			134			231			227
	Residential mortgage		28			27			104			103
	Home equity and other consumer loans		11			11			9			8
	Total consumer portfolio		39			38			113			111
	Total		$	173		$	172		$	344		$	338
	-1	Represents the recorded investment in the loan immediately prior to the restructuring event.
	-2	Represents the recorded investment in the loan immediately following the restructuring event. It includes the effect of paydowns that were required as part of the restructuring terms.
Recorded Investment Amounts of Troubled Debt Restructurings	The following table provides the recorded investment amounts of TDRs at the date of default, for which there was a payment default during the years ended December 31, 2014 and 2013, and where the default occurred within the first twelve months after modification into a TDR. A payment default is defined as the loan being 60 days or more past due.
			December 31,
	(Dollars in millions)		2014			2013
	Commercial and industrial		$	10		$	10
	Commercial mortgage		8			2
	Total commercial portfolio		18			12
	Residential mortgage		8			16
	Home equity and other consumer loans		1			2
	Total consumer portfolio		9			18
	Total		$	27		$	30
Information about Impaired Loans by Class	The following tables show information about impaired loans by class as of December 31, 2014 and 2013.
			31-Dec-14
			Recorded Investment												Unpaid Principal
															Balance
	(Dollars in millions)		With an			Without an			Total			Allowance			With an			Without an
			Allowance			Allowance						for Impaired			Allowance			Allowance
												Loans
	Commercial and industrial		$	89		$	35		$	124		$	14		$	120		$	39
	Commercial mortgage		37			3			40			4			39			3
	Total commercial portfolio		126			38			164			18			159			42
	Residential mortgage		198			110			308			16			211			127
	Home equity and other consumer loans		6			24			30			—			7			37
	Total consumer portfolio		204			134			338			16			218			164
	Total, excluding purchased credit-impaired loans		330			172			502			34			377			206
	Purchased credit-impaired loans		—			1			1			—			—			2
	Total		$	330		$	173		$	503		$	34		$	377		$	208
			31-Dec-13
			Recorded Investment												Unpaid Principal
															Balance
	(Dollars in millions)		With an			Without an			Total			Allowance			With an			Without an
			Allowance			Allowance						for Impaired			Allowance			Allowance
												Loans
	Commercial and industrial		$	117		$	104		$	221		$	16		$	121		$	114
	Commercial mortgage		33			12			45			3			36			15
	Total commercial portfolio		150			116			266			19			157			129
	Residential mortgage		220			95			315			20			236			108
	Home equity and other consumer loans		4			20			24			—			4			34
	Total consumer portfolio		224			115			339			20			240			142
	Total, excluding purchased credit-impaired loans		374			231			605			39			397			271
	Purchased credit-impaired loans		2			1			3			—			2			6
	Total		$	376		$	232		$	608		$	39		$	399		$	277
Average Investment in Impaired Loans and Interest Income Recognized for Impaired Loans	The following table presents the average recorded investment in impaired loans and the amount of interest income recognized for impaired loans during 2014, 2013 and 2012 for the commercial, consumer and purchased credit-impaired loans portfolio segments.
			Years Ended December 31,
			2014						2013						2012
	(Dollars in millions)		Average			Recognized			Average			Recognized			Average			Recognized
			Recorded			Interest			Recorded			Interest			Recorded			Interest
			Investment			Income			Investment			Income			Investment			Income
	Commercial and industrial		$	188		$	5		$	243		$	14		$	201		$	12
	Commercial mortgage		36			2			53			9			107			1
	Construction		—			—			8			3			44			2
	Total commercial portfolio		224			7			304			26			352			15
	Residential mortgage		310			10			293			10			221			8
	Home equity and other consumer loans		27			2			22			1			7			1
	Total consumer portfolio		337			12			315			11			228			9
	Total, excluding purchased credit-impaired loans		561			19			619			37			580			24
	Purchased credit-impaired loans		2			—			4			—			8			1
	Total		$	563		$	19		$	623		$	37		$	588		$	25
Outstanding Balances and Carrying Amounts of Purchased Credit-Impaired Loans	The following table presents the outstanding balances and carrying amounts of the Company's purchased credit-impaired loans at December 31, 2014 and 2013.
	(Dollars in millions)		31-Dec-14			31-Dec-13
	Total outstanding balance		$	889		$	1,733
	Carrying amount		516			1,091
Changes in Accretable Balance for Purchased Credit-Impaired Loans	The accretable yield for purchased credit-impaired loans for the years ended December 31, 2014, 2013, and 2012 was as follows:
			For the Year Ended
			December 31,
	(Dollars in millions)		2014			2013			2012
	Accretable yield, beginning of period		$	378		$	590		$	424
	Additions		—			31			171
	Accretion		(268		)	(336		)	(297		)
	Reclassifications from nonaccretable difference during the period		178			93			292
	Accretable yield, end of period		$	288		$	378		$	590

Premises_and_Equipment_Tables

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Premises and Equipment and Other Assets
Premises and Equipment at Carried Cost, Less Accumulated Depreciation and Amortization	Premises and equipment are carried at cost, less accumulated depreciation and amortization. As of December 31, 2014 and 2013, the amounts were as follows:
		December 31,
		2014							2013
	(Dollars in millions)	Cost		Accumulated			Net Book		Cost		Accumulated			Net Book
				Depreciation and			Value				Depreciation and			Value
				Amortization							Amortization
	Land	$	148	$	—		$	148	$	154	$	—		$	154
	Premises	601		(334		)	267		621		(328		)	293
	Leasehold improvements	301		(230		)	71		298		(218		)	80
	Furniture, fixtures and equipment	682		(547		)	135		670		(509		)	161
	Total	$	1,732	$	(1,111	)	$	621	$	1,743	$	(1,055	)	$	688
Rental, Depreciation and Amortization Expenses	Rental, depreciation and amortization expenses were as follows:
		For the Years Ended December 31,
	(Dollars in millions)	2014		2013			2012
	Rental expense of premises	$	113	$	111		$	85
	Less: rental income	10		9			8
	Net rental expense	$	103	$	102		$	77
	Depreciation and amortization of premises and equipment	$	103	$	110		$	102
Future Minimum Lease Payments	Future minimum lease payments at December 31, 2014 were as follows:
	(Dollars in millions)	2014
	Years ending December 31,:
	2015	$	130
	2016	131
	2017	118
	2018	103
	2019	85
	Thereafter	501
	Total minimum lease payments	$	1,068
	Minimum rental income due in the future under subleases	$	105
Schedule of other assets	The following table shows the balances of other assets as of December 31, 2014 and 2013.
	(Dollars in millions)	31-Dec-14		31-Dec-13
	Other investments	$	2,711	$	2,211
	Prepaid expenses	145		509
	Intangible assets	240		290
	OREO	36		57
	Other	1,553		1,787
	Total other assets	$	4,685	$	4,854

Goodwill_and_Other_Intangible_1

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	For impairment testing, goodwill was assigned to the following operating segments at December 31, 2014 and 2013:
	(Dollars in millions)	2014			2013
	Retail Banking & Wealth Markets	$	1,524		$	1,527
	Commercial Banking	1,034			1,034
	U.S. Corporate Banking	149			149
	Transaction Banking	251			251
	Investment Banking & Markets	253			253
	Asian Corporate Banking	14			14
	Goodwill, end of year	$	3,225		$	3,228
	The changes in the carrying amount of goodwill during 2014 and 2013 are shown in the table below.
	(Dollars in millions)	2014			2013
	Goodwill, beginning of year	$	3,228		$	2,942
	Net change from business combinations	(3		)	286
	Goodwill, end of year	$	3,225		$	3,228
Identifiable Intangible Assets and Accumulated Amortization	The table below reflects the Company's identifiable intangible assets and accumulated amortization at December 31, 2014 and 2013.
		31-Dec-14								31-Dec-13
	(Dollars in millions)	Gross			Accumulated			Net		Gross		Accumulated			Net
		Carrying			Amortization			Carrying		Carrying		Amortization			Carrying
		Amount						Amount		Amount					Amount
	Core deposit intangibles	$	565		$	(468	)	$	97	$	667	$	(530	)	$	137
	Trade names	114			(21		)	93		114		(16		)	98
	Customer relationships	60			(25		)	35		63		(22		)	41
	Other	29			(14		)	15		25		(11		)	14
	Total intangible assets with a definite useful life	$	768		$	(528	)	$	240	$	869	$	(579	)	$	290
Estimated Future Amortization Expense	Estimated future amortization expense at December 31, 2014 is as follows:
	(Dollars in millions)	Core Deposit			Trade Name			Customer		Other		Total Identifiable
		Intangibles (CDI)						Relationships				Intangible Assets
	Years ending December 31, :
	2015	$	30		$	3		$	5	$	4	$	42
	2016	18			3			5		3		29
	2017	14			3			4		2		23
	2018	7			3			4		1		15
	2019	6			3			3		1		13
	Thereafter	22			78			14		4		118
	Total estimated amortization expense	$	97		$	93		$	35	$	15	$	240

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2014
Consolidated VIEs
Variable Interest Entities
Schedule of assets and liabilities of VIEs	The following tables present the assets and liabilities of consolidated VIEs recorded on the Company’s consolidated balance sheets at December 31, 2014 and 2013.
		December 31, 2014
		Consolidated Assets								Consolidated Liabilities
	(Dollars in millions)	Interest Bearing		Loans Held for		Other Assets		Total Assets		Other Liabilities		Total
		Deposits in		Investment, net								Liabilities
		Banks
	LIHC investments	$	9	$	—	$	230	$	239	$	—	$	—
	Leasing investments	10		653		147		810		80		80
	Total consolidated VIEs	$	19	$	653	$	377	$	1,049	$	80	$	80
		December 31, 2013
		Consolidated Assets								Consolidated Liabilities
	(Dollars in millions)	Interest Bearing		Loans Held for		Other Assets		Total Assets		Long-Term Debt		Total
		Deposits in		Investment, net								Liabilities
		Banks
	LIHC investments	$	9	$	—	$	262	$	271	$	4	$	4
	Leasing investments	1		750		8		759		—		—
	Total consolidated VIEs	$	10	$	750	$	270	$	1,030	$	4	$	4
Unconsolidated VIEs
Variable Interest Entities
Schedule of assets and liabilities of VIEs	The following tables present the Company’s carrying amounts related to the unconsolidated VIEs and location on the consolidated balance sheets at December 31, 2014 and 2013. The tables also present the Company’s maximum exposure to loss resulting from its involvement with these VIEs. The maximum exposure to loss represents the carrying amount of the Company’s involvement plus any legally binding unfunded commitments in the unlikely event that all of the assets in the VIEs become worthless.
		December 31, 2014
		Unconsolidated Assets								Unconsolidated Liabilities
	(Dollars in millions)	Securities		Loans Held for		Other Assets		Total Assets		Other		Total		Maximum
		Available for		Investment						Liabilities		Liabilities		Exposure to
		Sale												Loss
	LIHC investments	$	25	$	163	$	1,117	$	1,305	$	433	$	433	$	1,305
	Leasing investments	—		21		886		907		55		55		923
	Other investments	—		29		20		49		—		—		51
	Total unconsolidated VIEs	$	25	$	213	$	2,023	$	2,261	$	488	$	488	$	2,279
		December 31, 2013
		Unconsolidated Assets								Unconsolidated Liabilities
	(Dollars in millions)	Securities		Loans Held for		Other Assets		Total Assets		Other		Total		Maximum
		Available for		Investment						Liabilities		Liabilities		Exposure to
		Sale												Loss
	LIHC investments	$	122	$	158	$	1,000	$	1,280	$	445	$	445	$	1,280
	Leasing investments	—		—		700		700		—		—		700
	Other investments	—		15		12		27		—		—		27
	Total unconsolidated VIEs	$	122	$	173	$	1,712	$	2,007	$	445	$	445	$	2,007

Deposits_Tables

Deposits (Tables)	12 Months Ended
	Dec. 31, 2014
Deposits [Abstract]
Maturity Information of Time Deposits with Remaining Term of Greater Than One Year	Maturity information for all interest bearing time deposits with a remaining term of greater than one year is summarized below.
	(Dollars in millions)	December 31,
		2014
	Due after one year through two years	$	1,570
	Due after two years through three years	1,134
	Due after three years through four years	812
	Due after four years through five years	167
	Due after five years	20
	Total	$	3,703

Commercial_Paper_and_Other_Sho1

Commercial Paper and Other Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2014
Short-term Debt [Abstract]
Summary of Commercial Paper and Other Short-Term Borrowings	The following is a summary of the Company's commercial paper and other short-term borrowings:
	(Dollars in millions)	31-Dec-14			31-Dec-13
	Federal funds purchased and securities sold under repurchase agreements, with weighted average interest rates of 0.12% and 0.07% at December 31, 2014 and December 31, 2013	$	111		$	39
	Commercial paper, with weighted average interest rates of 0.16% and 0.19% at December 31, 2014 and December 31, 2013, respectively	2,593			2,524
	Total commercial paper and other short-term borrowings	$	2,704		$	2,563
	Federal funds purchased and securities sold under repurchase agreements:
	Maximum outstanding at any month end	$	329		$	359
	Average balance during the year	170			263
	Weighted average interest rate during the year	0.14		%	0.12		%
	Commercial paper:
	Maximum outstanding at any month end	$	3,322		$	3,655
	Average balance during the year	2,542			2,393
	Weighted average interest rate during the year	0.16		%	0.18		%
	Other borrowed funds:
	Term federal funds purchased:
	Maximum outstanding at any month end	$	252		$	269
	Average balance during the year	43			50
	Weighted average interest rate during the year	0.14		%	0.15		%
	All other borrowed funds:
	Maximum outstanding at any month end	$	—		$	—
	Average balance during the year	54			45
	Weighted average interest rate during the year	2.06		%	1.71		%

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of Long-Term Debt	Long-Term Debt
	Long-term debt consists of borrowings having an original maturity of one year or more. The following is a summary of the Company's long-term debt:
	(Dollars in millions)		31-Dec-14		31-Dec-13
	Debt issued by MUAH
	Senior debt:
	Fixed rate 3.50% notes due June 2022		$	398	$	397
	Subordinated debt to BTMU:
	Floating rate subordinated debt due December 2023. This note, which bears interest at 1.38% above 3-month LIBOR, had a rate of 1.63% at December 31, 2014 and 1.63% at December 31, 2013		300		300
	Junior subordinated debt payable to trusts(1):
	Floating rate notes with maturities ranging from March 2033 to September 2036. These notes bear a combined weighted-average rate of 2.35% at December 31, 2014 and 2.60% at December 31, 2013		52		66
	Total debt issued by MUAH		750		763
	Debt issued by MUB and other subsidiaries
	Senior debt:
	Fixed FHLB advances with maturities ranging from February 2015 to February 2016. These notes bear a combined weighted-average rate of 2.56% at December 31, 2014 and 2.55% at December 31, 2013		800		800
	Floating rate notes due June 2014. These notes, which bear interest at 0.95% above 3-month LIBOR, had a rate of 1.19% at December 31, 2013		—		300
	Fixed rate 3.00% notes due June 2016		700		699
	Fixed rate 1.50% notes due September 2016		499		499
	Floating rate notes due September 2016. These notes, which bear interest at 0.75% above 3-month LIBOR, had a rate of 1.00% at December 31, 2014 and 1.00% at December 31, 2013		500		500
	Fixed rate 2.125% notes due June 2017		499		499
	Fixed rate 2.625% notes due September 2018		1,000		1,000
	Fixed rate 2.250% notes due May 2019		499		—
	Floating rate notes due May 2017. These notes, which bear interest at 0.40% above 3-month LIBOR, had a rate of 0.63% at December 31, 2014		250		—
	Note payable:
	Fixed rate 6.03% notes due July 2014 (related to consolidated VIE)		—		4
	Subordinated debt:
	Fixed rate 5.95% notes due May 2016		711		718
	Subordinated debt due to BTMU:
	Floating rate subordinated debt due June 2023. This note, which bears interest at 1.2% above 3-month LIBOR, had a rate of 1.45% at December 31, 2014 and 1.45% at December 31, 2013		750		750
	Capital lease obligations with a combined weighted-average interest rate of 4.92% at December 31, 2014 and 4.88% at December 31, 2013 (1)		14		15
	Total debt issued by MUB and other subsidiaries		6,222		5,784
	Total long-term debt		$	6,972	$	6,547
	-1	Long-term debt assumed through acquisitions

Fair_Value_Measurement_and_Fai1

Fair Value Measurement and Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis	The following tables present financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2014 and 2013, by major category and by valuation hierarchy level.
			31-Dec-14
	(Dollars in millions)		Level 1			Level 2			Level 3				Netting			Fair Value
													Adjustment (1)
	Assets
	Trading account assets:
	U.S. Treasury securities		$	—		$	69		$	—			$	—		$	69
	U.S. government-sponsored agencies		—			125			—				—			125
	State and municipal securities		—			10			—				—			10
	Interest rate derivative contracts		—			928			5				(172		)	761
	Commodity derivative contracts		—			417			5				(392		)	30
	Foreign exchange derivative contracts		1			104			1				(63		)	43
	Equity derivative contracts		—			—			300				(224		)	76
	Total trading account assets		1			1,653			311				(851		)	1,114
	Securities available for sale:
	Residential mortgage-backed securities:
	U.S. government and government-sponsored agencies		—			7,560			—				—			7,560
	Privately issued		—			168			—				—			168
	Privately issued - commercial mortgage-backed securities		—			1,691			—				—			1,691
	Collateralized loan obligations		—			2,494			—				—			2,494
	Other		—			9			—				—			9
	Other debt securities:
	Direct bank purchase bonds		—			—			1,741				—			1,741
	Other		—			3			49				—			52
	Equity securities		9			—			—				—			9
	Total securities available for sale		9			11,925			1,790				—			13,724
	Other assets:
	Interest rate hedging contracts		—			36			—				(36		)	—
	Other derivative contracts		—			—			2				—			2
	Total other assets		—			36			2				(36		)	2
	Total assets		$	10		$	13,614		$	2,103			$	(887	)	$	14,840
	Percentage of Total		—		%	92		%	14		%		(6		)%	100		%
	Percentage of Total Company Assets		—		%	12		%	2		%		(1		)%	13		%
	Liabilities
	Trading account liabilities:
	Interest rate derivative contracts		$	1		$	829		$	—			$	(667	)	$	163
	Commodity derivative contracts		—			403			5				(93		)	315
	Foreign exchange derivative contracts		1			78			1				(24		)	56
	Equity derivative contracts		—			—			299				—			299
	Securities sold, not yet purchased		—			61			—				—			61
	Total trading account liabilities		2			1,371			305				(784		)	894
	Other liabilities:
	FDIC clawback liability		—			—			105				—			105
	Interest rate hedging contracts		—			4			—				(3		)	1
	Other derivative contracts		—			1			2				—			3
	Total other liabilities		—			5			107				(3		)	109
	Total liabilities		$	2		$	1,376		$	412			$	(787	)	$	1,003
	Percentage of Total		—		%	137		%	41		%		(78		)%	100		%
	Percentage of Total Company Liabilities		—		%	1		%	—		%		(1		)%	—		%
	-1	Amounts represent the impact of legally enforceable master netting agreements between the same counterparties that allow the Company to net settle all contracts.
			31-Dec-13
	(Dollars in millions)		Level 1			Level 2			Level 3				Netting			Fair Value
													Adjustment (1)
	Assets
	Trading account assets:
	U.S. Treasury securities		$	—		$	8		$	—			$	—		$	8
	U.S. government-sponsored agencies		—			116			—				—			116
	State and municipal securities		—			5			—				—			5
	Other loans		—			140			—				—			140
	Interest rate derivative contracts		1			705			7				(212		)	501
	Commodity derivative contracts		—			67			9				(66		)	10
	Foreign exchange derivative contracts		1			30			2				(18		)	15
	Equity derivative contracts		—			—			253				(197		)	56
	Total trading account assets		2			1,071			271				(493		)	851
Securities available for sale:
U.S. government-sponsored agencies		—			73			—				—			73
Residential mortgage-backed securities:
U.S government and government-sponsored agencies		—			8,900			—				—			8,900
Privately issued		—			222			—				—			222
Privately issued - commercial mortgage-backed securities		—			1,870			—				—			1,870
Collateralized loan obligations		—			2,673			—				—			2,673
Other		—			35			—				—			35
Other debt securities:
Direct bank purchase bonds		—			—			1,960				—			1,960
Other		—			18			58				—			76
Equity securities		8			—			—				—			8
Total securities available for sale		8			13,791			2,018				—			15,817
Other assets:
Interest rate hedging contracts		—			8			—				—			8
Other derivative contracts		—			1			1				—			2
Total other assets		—			9			1				—			10
Total assets		$	10		$	14,871		$	2,290			$	(493	)	$	16,678
Percentage of Total		—		%	89		%	14		%		(3		)%	100		%
Percentage of Total Company Assets		—		%	14		%	2		%		—		%	16		%
Liabilities
Trading account liabilities:
Interest rate derivative contracts		$	3		$	606		$	—			$	(379	)	$	230
Commodity derivative contracts		—			53			8				(33		)	28
Foreign exchange derivative contracts		1			26			2				(11		)	18
Equity derivative contracts		—			—			254				—			254
Securities sold, not yet purchased		—			10			—				—			10
Total trading account liabilities		4			695			264				(423		)	540
Other liabilities:
FDIC clawback liability		—			—			96				—			96
Interest rate hedging contracts		—			13			—				—			13
Other derivative contracts		—			1			3				—			4
Total other liabilities		—			14			99				—			113
Total liabilities		$	4		$	709		$	363			$	(423	)	$	653
Percentage of Total		1		%	109		%	55		%		(65		)%	100		%
Percentage of Total Company Liabilities		—		%	1		%	—		%		—		%	1		%
-1	Amounts represent the impact of legally enforceable master netting agreements between the same counterparties that allow the Company to net settle all contracts.
Fair Value Assets and Liabilities Measured on Recurring Basis Unobservable Input Reconciliation	The following tables present a reconciliation of the assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the years ended December 31, 2014 and 2013. Level 3 available for sale securities at December 31, 2014 primarily consist of direct bank purchase bonds. The Company's policy is to recognize transfers in and out of Level 1, 2 and 3 as of the end of a reporting period.
			For the Year Ended
			31-Dec-14
	(Dollars in millions)		Trading			Securities			Other				Trading			Other
			Assets			Available for			Assets				Liabilities			Liabilities
						Sale
	Asset (liability) balance, beginning of period		$	271		$	2,018		$	1			$	(264	)	$	(99	)
	Total gains (losses) (realized/unrealized):
	Included in income before taxes		61			—			1				(61		)	(8		)
	Included in other comprehensive income		—			29			—				—			—
	Purchases/additions		4			197			—				—			—
	Sales		—			—			—				(5		)	—
	Settlements		(25		)	(454		)	—				25			—
	Asset (liability) balance, end of period		$	311		$	1,790		$	2			$	(305	)	$	(107	)
	Changes in unrealized gains (losses) included in income before taxes for assets and liabilities still held at end of period		$	61		$	—		$	1			$	(61	)	$	(8	)
			For the Year Ended
			31-Dec-13
	(Dollars in millions)		Trading			Securities			Other				Trading			Other
			Assets			Available for			Assets				Liabilities			Liabilities
						Sale
	Asset (liability) balance, beginning of period		$	136		$	1,499		$	—			$	(136	)	$	(95	)
	Total gains (losses) (realized/unrealized):
	Included in income before taxes		119			—			—				(120		)	(4		)
	Included in other comprehensive income		—			28			—				—			—
	Purchases/additions		24			700			1				—			—
	Sales		—			(14		)	—				(16		)	—
	Settlements		(8		)	(195		)	—				8			—
	Asset (liability) balance, end of period		$	271		$	2,018		$	1			$	(264	)	$	(99	)
	Changes in unrealized gains (losses) included in income before taxes for assets and liabilities still held at end of period		$	119		$	—		$	—			$	(120	)	$	(4	)
Significant Unobservable Inputs Level 3 Assets and Liabilities	The following table presents information about significant unobservable inputs related to the Company's significant Level 3 assets and liabilities at December 31, 2014.
			31-Dec-14
	(Dollars in millions)		Level 3			Valuation Technique(s)		Significant Unobservable	Range of Inputs		Weighted
			Fair Value					Input(s)			Average
	Securities available for sale:
	Direct bank purchase bonds		$	1,741		Return on equity		Market-required return on capital	8.0 - 10.0	%	9.9	%
								Probability of default	0.0 - 25.0	%	0.5	%
								Loss severity	10.0 - 60.0	%	31.1	%
	Other liabilities:
	FDIC clawback liability		$	105		Discounted cash flow		Probability of default	0.1 - 100.0	%	58.4	%
								Loss severity	0.0 - 100.0	%	39.1	%
Financial Assets Measured at Fair Value on Nonrecurring Basis	Certain assets may be measured at fair value on a nonrecurring basis. These assets are subject to fair value adjustments that result from the application of the lower of cost or fair value accounting or write-downs of individual assets. For assets measured at fair value on a nonrecurring basis during the years ended December 31, 2014 and 2013 that were still held on the consolidated balance sheet as of the respective periods ended, the following tables present the fair value of such assets by the level of valuation assumptions used to determine each fair value adjustment.
			31-Dec-14													Loss for the Year Ended December 31, 2014
	(Dollars in millions)		Fair			Level 1			Level 2				Level 3
			Value
	Loans:
	Impaired loans		$	109		$	—		$	—			$	109		$	(37	)
	Other assets:
	OREO		15			—			—				15			(6		)
	Total		$	124		$	—		$	—			$	124		$	(43	)
			31-Dec-13													Loss for the Year Ended December 31, 2013
	(Dollars in millions)		Fair			Level 1			Level 2				Level 3
			Value
	Loans:
	Impaired loans		$	59		$	—		$	—			$	59		$	(47	)
	Other assets:
	OREO		21			—			—				21			(11		)
	Private equity investments		—			—			—				—			(5		)
	Total		$	80		$	—		$	—			$	80		$	(63	)
Carrying Amount and Estimated Fair Value of Financial Instruments	The tables below present the carrying amount and estimated fair value of certain financial instruments by the level of valuation assumptions held by the Company as of December 31, 2014 and 2013.
			31-Dec-14
	(Dollars in millions)		Carrying			Fair			Level 1				Level 2			Level 3
			Amount			Value
	Assets
	Cash and cash equivalents		$	5,751		$	5,751		$	5,751			$	—		$	—
	Securities held to maturity		8,291			8,412			—				8,412			—
	Loans held for investment (1)		75,475			77,324			—				—			77,324
	FDIC indemnification asset		52			5			—				—			5
	Other assets		7			6			—				—			6
	Liabilities
	Deposits		$	86,004		$	86,076		$	—			$	86,076		$	—
	Commercial paper and other short-term borrowings		2,704			2,704			—				2,704			—
	Long-term debt		6,972			7,073			—				7,073			—
	Off-Balance Sheet Instruments
	Commitments to extend credit and standby and commercial letters of credit		$	269		$	269		$	—			$	—		$	269
	-1	Excludes lease financing. The carrying amount is net of the allowance for loan and lease losses.
			31-Dec-13
	(Dollars in millions)		Carrying			Fair			Level 1				Level 2			Level 3
			Amount			Value
	Assets
	Cash and cash equivalents		$	6,203		$	6,203		$	6,203			$	—		$	—
	Securities held to maturity		6,509			6,439			—				6,439			—
	Loans held for investment, net of allowance for loan losses(1)		66,898			68,132			—				—			68,132
	FDIC indemnification asset		141			95			—				—			95
	Other assets		3			3			—				—			3
	Liabilities
	Deposits		$	80,101		$	80,228		$	—			$	80,228		$	—
	Commercial paper and other short-term borrowings		2,563			2,563			—				2,563			—
	Long-term debt		6,547			6,709			—				6,709			—
	Off-Balance Sheet Instruments
	Commitments to extend credit and standby and commercial letters of credit		$	273		$	273		$	—			$	—		$	273
	-1	Excludes lease financing, net of related allowance.

Derivative_Instruments_and_Oth1

Derivative Instruments and Other Financial Instruments Used For Hedging (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts, Balance Sheet Location and Fair Value Amounts of Derivative Instruments	The table below presents the notional amounts and fair value amounts of the Company's derivative instruments reported on the consolidated balance sheets, segregated between derivative instruments designated and qualifying as hedging instruments and derivative instruments not designated and qualifying as hedging instruments as of December 31, 2014 and December 31, 2013, respectively. Asset and liability values are presented gross, excluding the impact of legally enforceable master netting and credit support annex agreements. The fair value of asset and liability derivatives designated and qualifying as hedging instruments and derivatives designated as other risk management are included in other assets and other liabilities, respectively. The fair value of asset and liability trading derivatives are included in trading account assets and trading account liabilities, respectively.
			31-Dec-14												31-Dec-13
							Fair Value												Fair Value
	(Dollars in millions)		Notional				Asset				Liability				Notional				Asset			Liability
			Amount				Derivatives				Derivatives				Amount				Derivatives			Derivatives
	Cash flow hedges
	Interest rate contracts		$	9,750			$	34			$	4			$	4,300			$	8		$	13
	Fair value hedges
	Interest rate contracts		500				2				—				—				—			—
	Not designated and qualifying as hedging instruments:
	Trading
	Interest rate contracts		46,944				933				830				44,427				713			609
	Commodity contracts		4,741				422				408				5,714				76			61
	Foreign exchange contracts		5,661				106				80				5,645				33			29
	Equity contracts		3,797				300				299				4,027				253			254
	Other contracts		—				—				—				140				—			—
	Total Trading		61,143				1,761				1,617				59,953				1,075			953
	Other risk management		286				2				3				185				2			4
	Total derivative instruments		$	71,679			$	1,799			$	1,624			$	64,438			$	1,085		$	970
Amount and Location of Gains and Losses for Derivatives Designated as Cash Flow Hedges	The following tables present the amount and location of the net gains and losses recorded in the Company's consolidated statements of income and changes in stockholder's equity for derivatives designated as cash flow hedges for the years ended December 31, 2014 and 2013:
			Amount of Gain (Loss)								Gain (Loss) Reclassified from										Gain (Loss) Recognized in Income
			Recognized in OCI on								Accumulated OCI										on Derivative Instruments (Ineffective Portion)
			Derivative Instruments								into Income (Effective Portion)
			(Effective Portion)
			For the Years Ended										For the Years Ended									For the Years Ended
			December 31,										December 31,									December 31,
	(Dollars in millions)		2014				2013				Location		2014				2013				Location	2014		2013
	Derivatives in cash flow hedging relationships
											Interest income		$	115			$	44
	Interest rate contracts		$	126			$	29			Interest expense		2				(1		)		Noninterest expense (1)	$	2	$	—
	Total		$	126			$	29					$	117			$	43				$	2	$	—
	-1	Amount recognized was less than $1 million in 2013.
Schedule of Derivative Instruments Gain (Loss) on Fair Value Hedges	The following table presents the gains (losses) on the Company's fair value hedges and hedged item for the year ended December 31, 2014:
					For the Year Ended December 31, 2014
		(Dollars in millions)			Derivative				Hedged Item				Hedge Ineffectiveness
		Interest rate risk on long-term debt			$	2			$	(1	)		$	1
			Total		$	2			$	(1	)		$	1
Gain or (Loss) Recognized in Income on Derivative Instruments	The following table presents the amount of the net gains and losses for derivative instruments classified as trading reported in the consolidated statements of income under the heading trading account activities for the twelve months ended December 31, 2014 and 2013:
			Gain (Loss) Recognized in Income on
			Derivative Instruments
			For the Years Ended
	(Dollars in millions)		31-Dec-14				31-Dec-13
	Trading derivatives:
	Interest rate contracts		$	36			$	30
	Equity contracts		3				—
	Foreign exchange contracts		19				18
	Commodity contracts		8				2
	Other contracts		1				—
	Total		$	67			$	50
Summary of Offsetting Assets and Liabilities	The following tables present the offsetting of financial assets and liabilities as of December 31, 2014 and 2013:
			31-Dec-14
															Gross Amounts Not Offset in
															Balance Sheet
	(Dollars in millions)		Gross Amounts				Gross Amounts				Net Amounts				Financial				Cash Collateral			Net Amount
			of Recognized				Offset in				Presented in				Instruments				Received/Pledged
			Assets/Liabilities				Balance Sheet				Balance Sheet
	Financial Assets:
	Derivative assets		$	1,799			$	887			$	912			$	113			$	—		$	799
	Securities purchased under resale agreements		62				—				62				61				—			1
	Total		$	1,861			$	887			$	974			$	174			$	—		$	800
	Financial Liabilities:
	Derivative liabilities		$	1,624			$	787			$	837			$	162			$	—		$	675
	Securities sold under repurchase agreements		68				—				68				68				—			—
	Total		$	1,692			$	787			$	905			$	230			$	—		$	675
			31-Dec-13
															Gross Amounts Not Offset in Balance Sheet
	(Dollars in millions)		Gross Amounts				Gross Amounts				Net Amounts				Financial				Cash Collateral			Net Amount
			of Recognized				Offset in				Presented in				Instruments				Received/Pledged
			Assets/Liabilities				Balance Sheet				Balance Sheet
	Financial Assets:
	Derivative assets		$	1,085			$	493			$	592			$	79			$	—		$	513
	Securities purchased under resale agreements		10				—				10				10				—			—
	Total		$	1,095			$	493			$	602			$	89			$	—		$	513
	Financial Liabilities:
	Derivative liabilities		$	970			$	423			$	547			$	144			$	—		$	403
	Securities sold under repurchase agreements		8				—				8				8				—			—
	Total		$	978			$	423			$	555			$	152			$	—		$	403

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss	The following table presents the change in each of the components of accumulated other comprehensive loss and the related tax effect of the change allocated to each component.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2012
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	82		$	(32	)	$	50
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(15		)	6			(9		)
	Net change		67			(26		)	41
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		187			(74		)	113
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(107		)	42			(65		)
	Reclassification of unrealized (gains) losses on held to maturity securities transferred to securities available for sale		301			(118		)	183
	Less: accretion of fair value adjustment on securities available for sale		(9		)	4			(5		)
	Less: accretion of fair value adjustment on held to maturity securities		(24		)	9			(15		)
	Less: amortization of net unrealized (gains) losses on held to maturity securities		90			(35		)	55
	Net change		438			(172		)	266
	Foreign currency translation adjustment		2			(1		)	1
	Pension and other benefits:
	Amortization of transition amount		1			(1		)	—
	Recognized net actuarial gain (loss)(1)		99			(39		)	60
	Pension and other benefits arising during the year		(121		)	48			(73		)
	Net change(1)		(21		)	8			(13		)
	Net change in AOCI		$	486		$	(191	)	$	295
	-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2013
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	29		$	(11	)	$	18
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(43		)	17			(26		)
	Net change		(14		)	6			(8		)
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		(401		)	157			(244		)
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(178		)	70			(108		)
	Less: accretion of fair value adjustment on securities available for sale		(75		)	30			(45		)
	Less: accretion of fair value adjustment on held to maturity securities		(12		)	5			(7		)
	Less: amortization of net unrealized (gains) losses on held to maturity securities		(137		)	54			(83		)
	Net change		(803		)	316			(487		)
	Foreign currency translation adjustment		(7		)	3			(4		)
	Pension and other benefits:
	Recognized net actuarial gain (loss)(1)		116			(46		)	70
	Pension and other benefits arising during the year		526			(207		)	319
	Net change(1)		642			(253		)	389
	Net change in AOCI		$	(182	)	$	72		$	(110	)
	-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
	(Dollars in millions)		Before			Tax			Net of
			Tax			Effect			Tax
			Amount
	For the Year Ended December 31, 2014
	Cash flow hedge activities:
	Unrealized net gains (losses) on hedges arising during the period		$	126		$	(50	)	$	76
	Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt		(117		)	46			(71		)
	Net change		9			(4		)	5
	Securities:
	Unrealized holding gains (losses) arising during the period on securities available for sale		348			(136		)	212
	Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net		(18		)	7			(11		)
	Less: accretion of fair value adjustment on securities available for sale		(48		)	19			(29		)
	Less: accretion of fair value adjustment on held to maturity securities		—			—			—
	Less: amortization of net unrealized (gains) losses on held to maturity securities		19			(8		)	11
	Net change		301			(118		)	183
	Foreign currency translation adjustment		(11		)	4			(7		)
	Pension and other benefits:
Amortization of prior service costs		(17		)	7			(10		)
Recognized net actuarial gain (loss)(1)		62			(24		)	38
Pension and other benefits arising during the year		(517		)	203			(314		)
Net change(1)		(472		)	186			(286		)
Net change in AOCI		$	(173	)	$	68		$	(105	)
-1	These amounts are included in the computation of net periodic pension cost. For further information, see Note 15 to these consolidated financial statements.
Change in Accumulated Other Comprehensive Loss Balances	The following table presents the change in accumulated other comprehensive loss balances.
	(Dollars in millions)		Net			Net			Foreign			Pension and			Accumulated
			Unrealized			Unrealized			Currency			Other			Other
			Gains (Losses)			Gains (Losses)			Translation			Benefits			Comprehensive
			on Cash			on Securities			Adjustment			Adjustment			Loss
			Flow
			Hedges
	Balance, December 31, 2011		$	(17	)	$	(107	)	$	—		$	(685	)	$	(809	)
	Other comprehensive income before reclassifications		50			148			1			—			199
	Amounts reclassified from accumulated other comprehensive loss		(9		)	118			—			(13		)	96
	Balance, December 31, 2012		$	24		$	159		$	1		$	(698	)	$	(514	)
	Balance, December 31, 2012		$	24		$	159		$	1		$	(698	)	$	(514	)
	Other comprehensive income before reclassifications		18			(379		)	(4		)	—			(365		)
	Amounts reclassified from accumulated other comprehensive loss		(26		)	(108		)	—			389			255
	Balance, December 31, 2013		$	16		$	(328	)	$	(3	)	$	(309	)	$	(624	)
	Balance, December 31, 2013		$	16		$	(328	)	$	(3	)	$	(309	)	$	(624	)
	Other comprehensive income before reclassifications		76			194			(7		)	—			263
	Amounts reclassified from accumulated other comprehensive loss		(71		)	(11		)	—			(286		)	(368		)
	Balance, December 31, 2014		$	21		$	(145	)	$	(10	)	$	(595	)	$	(729	)

Management_Stock_Plans_Tables

Management Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Bonus Plan	The following table is a summary of the UNBC Plan and the HQA Plan, which together are presented as the "Stock Bonus Plans":
	Grant Date	Units		Fair Value			Vesting	Pro-rata
		Granted		of Stock			Duration	Vesting Date
	April 15, 2012	4,816,795		4.78			3 years	April 15
	July 15, 2012	74,175		4.72			3 years	July 15
	April 15, 2013	3,656,340		6.66			3 years	April 15
	July 15, 2013	78,725		6.67			3 years	July 15
	April 15, 2014	9,135,710		5.4			3 years	April 15
	July 10, 2014	56,056		5.91			3 years	July 10
	15-Sep-14	46,552		5.8			3 years	15-Sep
Rollforward of Restricted Stock Units Under Stock Bonus Plan	The following table is a rollforward of the restricted stock units under the Stock Bonus Plans for the years ended December 31, 2014 and 2013.
		Restricted Stock Units
		2014		2013
	Units outstanding, beginning of year	7,851,017		8,857,884
	Activity during the year:
	HQA Plan units outstanding as of July 1, 2014	3,315,313		—
	Granted	9,238,318		3,735,065
	Vested	(4,351,084	)	(4,325,661	)
	Forfeited	(952,075	)	(416,271	)
	Units outstanding, end of year	15,101,489		7,851,017
Summary of Compensation Costs, Corresponding Tax Benefit, and Unrecognized Compensation Costs	The following table is a summary of the Company's compensation costs, the corresponding tax benefit, and unrecognized compensation costs:
		Years Ended
		December 31,
	(Dollars in millions)	2014			2013			2012
	Compensation costs	$	34		$	21		$	18
	Tax benefit	13			8			7
	Unrecognized compensation costs	42			27			26

Employee_Pension_and_Other_Pos1

Employee Pension and Other Postretirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2014
Employee Pension and Other Postretirement Benefits tables
Fair Value of Assets in Pension Plan and Other Benefits Plan	The following table sets forth the fair value of the assets in the Company's Pension Plan and Other Benefits Plan as of December 31, 2014 and 2013.
			Pension Plan								Other Benefits
											Plan
			Years Ended								Years Ended
			December 31,								December 31,
	(Dollars in millions)		2014				2013				2014			2013
	Change in plan assets:
	Fair value of plan assets, beginning of year		$	2,716			$	2,019			$	245		$	210
	Actual return on plan assets		164				391				14			37
	Employer contributions		100				380				13			12
	Plan participants' contributions		—				—				7			7
	Benefits paid		(83		)		(74		)		(22		)	(21		)
	Fair value of plan assets, end of year		$	2,897			$	2,716			$	257		$	245
Table of Benefit Obligation Activity and Funded Status for Each of Plans	The following table sets forth the benefit obligation activity and the funded status for each of the Company's plans at December 31, 2014 and 2013. In addition, the table sets forth the over (under) funded status at December 31, 2014 and 2013. This pension benefits table does not include the obligations for the ESBPs.
			Pension Benefits								Other Benefits
			Years Ended								Years Ended
			December 31,								December 31,
	(Dollars in millions)		2014				2013				2014			2013
	Accumulated benefit obligation		$	2,717			$	2,046
	Change in benefit obligation
	Benefit obligation, beginning of year		$	2,263			$	2,394			$	270		$	293
	Service cost		75				87				10			14
	Interest cost		105				99				11			11
	Plan participants' contributions		—				—				7			7
	Actuarial loss/(gain)		607				(243		)		42			(34		)
	Effect of plan amendments		(150		)						(29		)
	Medicare Part D subsidy		—				—				1			—
	Benefits paid		(83		)		(74		)		(22		)	(21		)
	Benefit obligation, end of year		2,817				2,263				290			270
	Fair value of plan assets, end of year		2,897				2,716				257			245
	Over (Under) funded status		$	80			$	453			$	(33	)	$	(25	)
Table of Amounts Recognized in Accumulated Other Comprehensive Loss for Pension, Including ESBPs, and Other Benefits	The following table illustrates the changes that were reflected in AOCI during 2014, 2013 and 2012. Pension benefits do not include the ESBPs.
			Pension								Other Benefits
			Benefits
	(Dollars in millions)		Net Actuarial				Prior Service Credit				Transition Assets			Net Actuarial			Prior Service Credit
			(Gain) Loss											(Gain) Loss
	Amounts Recognized in Other Comprehensive Loss:
	Balance, December 31, 2011		$	1,016			$	—			$	1		$	90		$	—
	Arising during the year		115				—				—			(2		)	—
	Recognized in net income during the year		(89		)		—				(1		)	(8		)	—
	Balance, December 31, 2012		$	1,042			$	—			$	—		$	80		$	—
	Arising during the year		(468		)		—				—			(56		)	—
	Recognized in net income during the year		(107		)		—				—			(7		)	—
	Balance, December 31, 2013		$	467			$	—			$	—		$	17		$	—
	Arising during the year		636				(150		)		—			46			(28		)
	Recognized in net income during the year		(59		)		12				—			(1		)	5
	Balance, December 31, 2014		$	1,044			$	(138	)		$	—		$	62		$	(23	)
	At December 31, 2014 and 2013, the following amounts were recognized in accumulated other comprehensive loss for pension, including ESBPs, and other benefits.
			31-Dec-14
			Pension Benefits											Other Benefits
	(Dollars in millions)		Gross				Tax				Net of Tax			Gross			Tax			Net of Tax
	Net actuarial loss		$	1,044			$	411			$	633		$	62		$	25		$	37
	Prior service credit		(138		)		(54		)		(84		)	(23		)	(9		)	(14		)
	Pension and other benefits adjustment		906				357				549			39			16			23
	Executive Supplemental Benefits Plans
	Net actuarial loss		39				15				24			—			—			—
	Prior service credit		(2		)		(1		)		(1		)	—			—			—
	Executive supplemental benefits plans adjustment		37				14				23			—			—			—
	Pension and other benefits adjustment		$	943			$	371			$	572		$	39		$	16		$	23
			31-Dec-13
			Pension Benefits											Other Benefits
	(Dollars in millions)		Gross				Tax				Net of Tax			Gross			Tax			Net of Tax
	Net actuarial loss		$	467			$	184			$	283		$	17		$	7		$	10
	Pension and other benefits adjustment		467				184				283			17			7			10
	Executive Supplemental Benefits Plans
	Net actuarial loss		26				10				16			—			—			—
	Executive supplemental benefits plans adjustment		26				10				16			—			—			—
	Pension and other benefits adjustment		$	493			$	194			$	299		$	17		$	7		$	10
Estimated Future Benefit Payments and Subsidies	The following pension and postretirement benefit payments, which reflect expected future service, as appropriate, are expected to be paid over the next 10 years and Medicare Part D Subsidies are expected to be received over the next 10 years. This table does not include the ESBPs.
	(Dollars in millions)		Pension				Postretirement				Medicare Part D
			Benefits				Benefits				Subsidies
	Years ending December 31,
	2015		$	92			$	15			$	1
	2016		104				16				1
	2017		114				17				1
	2018		123				18				1
	2019		132				19				1
	Years 2020 - 2024		795				101				6
Summary of Weighted Average Assumptions Used in Computing Present Value of Benefit Obligations and Net Periodic Benefit Cost	The following tables summarize the weighted average assumptions used in computing the present value of the benefit obligations and the net periodic benefit cost.
			Pension						Other Benefits
			Benefits
			Years Ended						Years Ended
			December 31,						December 31,
			2014			2013			2014			2013
	Discount rate in determining net periodic benefit cost prior to Plan amendments		4.9	%		4.2	%		4.6	%		3.9	%
	Discount rate in determining net periodic benefit cost after Plan amendments		4.5			n/a			4.2			n/a
	Discount rate in determining benefit obligations at year end		3.9			4.9			3.8			4.6
	Rate of increase in future compensation levels for determining net periodic benefit cost		4.7			4.7			—			—
	Rate of increase in future compensation levels for determining benefit obligations at year end		4.7			4.7			—			—
	Expected return on plan assets		7.5			7.5			7.5			7.5
Components of Net Periodic Benefit Cost
			Pension Benefits											Other Benefits									Superannuation,
																							SERP (1) and ESBP
			Years Ended											Years Ended									Years Ended
			December 31,											December 31,									December 31,
	(Dollars in millions)		2014				2013				2012			2014			2013			2012			2014		2013		2012
	Components of net periodic benefit cost:
	Service cost (2)		$	81			$	87			$	77		$	10		$	14		$	14		$	1	$	1	$	2
	Interest cost		105				99				101			11			11			12			4		3		2
	Expected return on plan assets		(193		)		(166		)		(147		)	(18		)	(15		)	(13		)	—		—		—
	Amortization of prior service credit		(12		)		—				—			(5		)	—			1			—		—		—
	Recognized net actuarial loss		59				107				89			1			7			8			2		2		2
	Total net periodic benefit cost		$	40			$	127			$	120		$	(1	)	$	17		$	22		$	7	$	6	$	6
	-1	Supplemental Executive Retirement Plan
	-2	Pension Benefits for 2014 includes $6 million of service cost associated with transferred employees as a result of the business integration initiative.
Summary of Amounts Forecasted to be Recognized, Net Periodic Benefit Costs	At December 31, 2014 and 2013, the following amounts were forecasted to be recognized in 2015 and 2014 net periodic benefit costs, respectively.
			Years Ended December 31,
			2015								2014
	(Dollars in millions)		Pension				Other				Pension			Other
			Benefits				Benefits				Benefits			Benefits
	Net actuarial loss		$	109			$	5			$	55		$	—
	Prior service credit		(18		)		(8		)		—			—
	Amounts to be reclassified from accumulated other comprehensive loss		$	91			$	(3	)		$	55		$	—
Schedule of Assumed Weighted-Average Healthcare Cost Trend Rates	The Company's assumed weighted-average healthcare cost trend rates are as follows.
			Years Ended December 31,
			2014			2013			2012
	Healthcare cost trend rate assumed for next year		7.53	%		7.71	%		8.31	%
	Rate to which cost trend rate is assumed to decline (the ultimate trend rate)		4.5	%		4.5	%		4.5	%
	Year the rate reaches the ultimate trend rate		2021			2021			2021
Schedule of Effect of One-Percentage-Point Change in Assumed Healthcare Cost Trend Rates	The healthcare cost trend rate assumptions have a significant effect on the amounts reported for the Health Plan. A one-percentage-point change in assumed healthcare cost trend rates would have the following effects:
	(Dollars in millions)		One-Percentage-				One-Percentage-
			Point Increase				Point Decrease
	Effect on total of service and interest cost components		$	2			$	(2	)
	Effect on postretirement benefit obligation		19				(22		)
Retirement Plan
Employee Pension and Other Postretirement Benefits tables
Fair Value by Level Within Fair Value Hierarchy Assets by Major Asset Category for Pension Plan and Other Benefits Plan	The following table provides the fair value by level within the fair value hierarchy of the Company's period-end assets by major asset category for the Pension Plan and Other Benefits Plan. For information about the fair value hierarchy levels, refer to Note 11 to these consolidated financial statements. The Plans do not hold any equity or debt securities issued by the Company or any related parties.
			31-Dec-14
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Pension Plan Investments:
	Cash and cash equivalents		$	1			$	52			$	—		$	53
	U.S. Government securities		—				251				—			251
	Corporate bonds		—				442				—			442
	Equity securities		295				6				—			301
	Real estate funds		—				—				270			270
	Limited partnerships		—				138				28			166
	Mutual funds		1,422				—				—			1,422
	Other		6				23				—			29
	Total Plan Investments		$	1,724			$	912			$	298		$	2,934
	Accrued dividends and interest receivable													7
	Net pending trades													(44		)
	Total Plan Assets													$	2,897
			31-Dec-13
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Pension Plan Investments:
	Cash and cash equivalents		$	—			$	28			$	—		$	28
	U.S. Government securities		—				230				—			230
	Corporate bonds		—				364				—			364
	Equity securities		233				—				—			233
	Real estate funds		—				—				242			242
	Limited partnerships		—				134				22			156
	Common collective funds		—				60				—			60
	Mutual funds		1,407				—				—			1,407
	Other		(1		)		28				—			27
	Total Plan Investments		$	1,639			$	844			$	264		$	2,747
	Accrued dividends and interest receivable													4
	Net pending trades													(35		)
	Total Plan Assets													$	2,716
Changes in Fair Value of Assets Measured at Level 3
			Level 3 Assets for Year Ended December 31, 2014
	(Dollars in millions)		Real Estate Funds				Limited Partnership				Total
	Beginning balance—January 1, 2014		$	242			$	22			$	264
	Unrealized gains (losses)		21				5				26
	Purchases, issuances, sales, and settlements, net		7				1				8
	Ending balance—December 31, 2014		$	270			$	28			$	298
			Level 3 Assets for Year Ended December 31, 2013
	(Dollars in millions)		Real Estate Funds				Limited Partnership				Total
	Beginning balance—January 1, 2013		$	156			$	18			$	174
	Unrealized gains (losses)		18				—				18
	Purchases, issuances, sales, and settlements, net		68				4				72
	Ending balance—December 31, 2013		$	242			$	22			$	264
Other postretirement benefits
Employee Pension and Other Postretirement Benefits tables
Fair Value by Level Within Fair Value Hierarchy Assets by Major Asset Category for Pension Plan and Other Benefits Plan
			31-Dec-14
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Other Postretirement Benefits Plan Investments:
	Cash and cash equivalents		$	—			$	3			—			$	3
	U.S. Government securities		—				36				—			36
	Corporate bonds		—				23				—			23
	Municipal bonds		—				1				—			1
	Mutual funds		136				—				—			136
	Pooled separate account		—				65				—			65
	Total Plan Investments		$	136			$	128			$	—		$	264
	Net pending trades													(7		)
	Total Plan Assets													$	257
			31-Dec-13
	(Dollars in millions)		Level 1				Level 2				Level 3			Total
	Other Postretirement Benefits Plan Investments:
	Cash and cash equivalents		$	—			$	2			$	—		$	2
	U.S. Government securities		—				33				—			33
	Corporate bonds		—				19				—			19
	Municipal bonds		—				1				—			1
	Mutual funds		133				—				—			133
	Pooled separate account		—				63				—			63
	Total Plan Investments		$	133			$	118			$	—		$	251
	Net pending trades													(6		)
	Total Plan Assets													$	245

Other_Noninterest_Expense_Tabl

Other Noninterest Expense (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Summary of Other Noninterest Expense	The detail of other noninterest expense is as follows.
		Years Ended December 31,
	(Dollars in millions)	2014		2013		2012
	Software	$	94	$	83	$	70
	LIHC investment amortization	89		76		63
	Advertising and public relations	39		61		57
	Communications	40		45		39
	Data processing	32		36		36
	Other	159		150		198
	Total other noninterest expense	$	453	$	451	$	463

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of effective tax rate	The following table is an analysis of the effective tax rate.
		Years Ended December 31,
		2014			2013			2012
	Federal income tax rate	35	%		35	%		35	%
	Net tax effects of:
	State income taxes, net of federal income tax benefit	7			5			6
	Tax-exempt interest income	(2	)		(1	)		(1	)
	Tax credits	(13	)		(13	)		(10	)
	Other	(2	)		(3	)		(3	)
	Effective tax rate	25	%		23	%		27	%
Components of Income Tax Expense	The components of income tax expense were as follows.
		Years Ended December 31,
	(Dollars in millions)	2014				2013				2012
	Taxes currently payable:
	Federal	$	82			$	79			$	93
	State	76				43				32
	Foreign	13				12				14
	Total currently payable	171				134				139
	Taxes deferred:
	Federal	72				71				62
	State	28				(8		)		20
	Foreign	3				(2		)		(1		)
	Total deferred	103				61				81
	Total income tax expense	$	274			$	195			$	220
Schedule of components of the Company's net deferred tax balances	The components of the Company's net deferred tax balances as of December 31, 2014 and 2013 were as follows.
		December 31,
	(Dollars in millions)	2014				2013
	Deferred tax assets:
	Allowance for credit losses	$	283			$	287
	Accrued expense, net	272				216
	Unrealized losses on pension and postretirement benefits	389				204
	Unrealized net losses on securities available for sale	97				262
	Fair value adjustments for valuation of FDIC covered assets	159				183
	Other	110				97
	Total deferred tax assets	1,310				1,249
	Deferred tax liabilities:
	Leasing	759				698
	Intangible assets	99				105
	Pension liabilities	389				363
	Other	5				17
	Total deferred tax liabilities	1,252				1,183
	Net deferred tax asset	$	58			$	66
Schedule of changes in unrecognized tax positions	The changes in unrecognized tax positions were as follows.
		Years Ended December 31,
	(Dollars in millions)	2014				2013				2012
	Balance, beginning of year	$	16			$	269			$	274
	Gross increases as a result of tax positions taken during prior periods	—				1				7
	Gross decreases as a result of tax positions taken during prior periods	(10		)		(256		)		(13		)
	Gross increases as a result of tax positions taken during current period	2				2				1
	Balance, end of year	$	8			$	16			$	269

Regulatory_Capital_Requirement1

Regulatory Capital Requirements (Tables)	12 Months Ended
	Dec. 31, 2014
Regulatory Capital Requirements [Abstract]
Summary of Capital Amounts and Ratios	The Company's and the Bank's capital amounts and ratios are presented in the following tables.
			Actual					Minimum
								Regulatory
								Requirement
	(Dollars in millions)		Amount		Ratio			Amount		Ratio
	Capital Ratios for the Company (U.S. Basel I):
	As of December 31, 2014:
	Tier 1 capital (to risk-weighted assets)		$	12,367	12.79	%	≥	$	3,867	4	%
	Total capital (to risk-weighted assets)		14,246		14.74		≥	7,733		8
	Tier 1 leverage(1)		12,367		11.25		≥	4,396		4
	As of December 31, 2013:
	Tier 1 capital (to risk-weighted assets)		11,471		12.41		≥	3,696		4
	Total capital (to risk-weighted assets)		13,499		14.61		≥	7,393		8
	Tier 1 leverage(1)		11,471		11.27		≥	4,073		4
	-1	Tier 1 capital divided by quarterly average assets (excluding certain intangible assets).
			Actual					Minimum					To Be Well-Capitalized Under Prompt Corrective Action Provisions
								Regulatory
								Requirement
	(Dollars in millions)		Amount		Ratio			Amount		Ratio			Amount		Ratio
	Capital Ratios for the Bank:
	As of December 31, 2014 (U.S. Basel III):
	Common equity tier 1 capital (to risk-weighted assets)		$	12,087	13.09	%	≥	n/a		n/a		≥	n/a		n/a
	Tier 1 capital (to risk-weighted assets)		12,088		13.09		≥	$	5,080	5.5	%	≥	$	5,542	6	%
	Total capital (to risk-weighted assets)		13,656		14.78		≥	7,389		8		≥	9,237		10
	Tier 1 leverage(1)		12,088		11.09		≥	4,361		4		≥	5,452		5
	As of December 31, 2013 (U.S. Basel I):
	Tier 1 capital (to risk-weighted assets)		11,274		12.94		≥	3,485		4		≥	5,228		6
	Total capital (to risk-weighted assets)		12,990		14.91		≥	6,970		8		≥	8,713		10
	Tier 1 leverage(1)		11,274		11.13		≥	4,051		4		≥	5,063		5
	-1	Tier 1 capital divided by quarterly average assets (excluding certain intangible assets).

Commitments_Contingencies_and_1

Commitments, Contingencies and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Summary of Commitments	The following table summarizes the Company's commitments.
	(Dollars in millions)	31-Dec-14
	Commitments to extend credit	$	34,991
	Issued standby and commercial letters of credit	$	5,836
	Other commitments	$	175

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Schedule of reportable business segments	As of and for the Twelve Months Ended December 31, 2014:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,385		$	1,016		$	173		$	442		$	175	$	65		$	(394	)	$	2,862
	Noninterest income (expense)	330			221			119			165			357		157			(226		)	1,123
	Total revenue	1,715			1,237			292			607			532		222			(620		)	3,985
	Noninterest expense	1,347			440			112			363			166		630			(159		)	2,899
	(Reversal of) provision for credit losses	(7		)	21			(24		)	(3		)	35		(5		)	(11		)	6
	Income (loss) before income taxes and including noncontrolling interests	375			776			204			247			331		(403		)	(450		)	1,080
	Income tax expense (benefit)	148			188			80			97			84		(146		)	(177		)	274
	Net income (loss) including noncontrolling interest	227			588			124			150			247		(257		)	(273		)	806
	Deduct: net loss from noncontrolling interests	—			—			—			—			—		19			—			19
	Net income (loss) attributable to MUAH	$	227		$	588		$	124		$	150		$	247	$	(238	)	$	(273	)	$	825
	Total assets, end of period	$	37,722		$	38,727		$	5,130		$	1,779		$	6,195	$	27,707		$	(3,582	)	$	113,678
	As of and for the Twelve Months Ended December 31, 2013:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,348		$	913		$	137		$	446		$	184	$	38		$	(350	)	$	2,716
	Noninterest income (expense)	371			193			81			160			210		66			(205		)	876
	Total revenue	1,719			1,106			218			606			394		104			(555		)	3,592
	Noninterest expense	1,423			406			54			356			100		567			(129		)	2,777
	(Reversal of) provision for credit losses	(35		)	17			2			(3		)	6		(13		)	(3		)	(29		)
	Income (loss) before income taxes and including noncontrolling interests	331			683			162			253			288		(450		)	(423		)	844
	Income tax expense (benefit)	130			174			64			99			78		(184		)	(166		)	195
	Net income (loss) including noncontrolling interest	201			509			98			154			210		(266		)	(257		)	649
	Deduct: net loss from noncontrolling interests	—			—			—			—			—		18			—			18
	Net income (loss) attributable to MUAH	$	201		$	509		$	98		$	154		$	210	$	(248	)	$	(257	)	$	667
	Total assets, end of period	$	34,421		$	32,661		$	4,755		$	1,574		$	5,937	$	29,225		$	(2,679	)	$	105,894
	As of and for the Twelve Months Ended December 31, 2012:
	(Dollars in millions)	Retail			Commercial			U.S. Corporate			Transaction			Investment		Other			Reconciling			MUFG Americas Holdings
		Banking &			Banking			Banking			Banking			Banking &					Items			Corporation
		Wealth												Markets
		Markets
	Results of operations—Market View
	Net interest income (expense)	$	1,201		$	778		$	113		$	496		$	174	$	190		$	(350	)	$	2,602
	Noninterest income (expense)	336			208			72			167			207		32			(204		)	818
	Total revenue	1,537			986			185			663			381		222			(554		)	3,420
	Noninterest expense	1,294			389			54			351			77		550			(132		)	2,583
	(Reversal of) provision for credit losses	55			(52		)	21			(1		)	6		(25		)	4			8
	Income (loss) before income taxes and including noncontrolling interests	188			649			110			313			298		(303		)	(426		)	829
	Income tax expense (benefit)	74			179			43			123			86		(118		)	(167		)	220
	Net income (loss) including noncontrolling interest	114			470			67			190			212		(185		)	(259		)	609
	Deduct: net loss from noncontrolling interests	—			—			—			—			—		19			—			19
	Net income (loss) attributable to MUAH	$	114		$	470		$	67		$	190		$	212	$	(166	)	$	(259	)	$	628
	Total assets, end of period	$	31,809		$	25,318		$	3,822		$	1,564		$	7,137	$	29,133		$	(1,775	)	$	97,008

Condensed_MUFG_Americas_Holdin1

Condensed MUFG Americas Holdings Corporation Unconsolidated Financial Statements (Parent Company) (Tables) (MUFG Americas Holdings Corporation)	12 Months Ended
	Dec. 31, 2014
MUFG Americas Holdings Corporation
Condensed Balance Sheets	Condensed Balance Sheets
		December 31,
	(Dollars in millions)	2014			2013
	Assets
	Cash and cash equivalents	$	328		$	191
	Investment in subsidiaries	15,404			14,784
	Other assets	4			5
	Total assets	$	15,736		$	14,980
	Liabilities and Stockholder's Equity
	Long-term debt	$	750		$	763
	Other liabilities	1			2
	Total liabilities	751			765
	Stockholder's equity	14,985			14,215
	Total liabilities and stockholder's equity	$	15,736		$	14,980
Condensed Statements of Income	Condensed Statements of Income
		Years Ended December 31,
	(Dollars in millions)	2014			2013			2012
	Income:
	Dividends from bank subsidiary	$	—		$	—		$	950
	Interest income on advances to subsidiaries and deposits in bank	—			—			1
	Total income	—			—			951
	Expense:
	Interest expense	21			31			23
	Other expense	4			4			—
	Total expense	25			35			23
	Income (loss) before income taxes and equity in undistributed net income of subsidiaries	(25		)	(35		)	928
	Income tax benefit	(10		)	(14		)	(9		)
	Income (loss) before equity in undistributed net income of subsidiaries	(15		)	(21		)	937
	Equity in undistributed net income (loss) of subsidiaries:
	Bank subsidiary	761			625			(403		)
	Nonbank subsidiaries	79			63			94
	Net Income	$	825		$	667		$	628
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows
		Years Ended December 31,
	(Dollars in millions)	2014			2013			2012
	Cash Flows from Operating Activities:
	Net income	$	825		$	667		$	628
	Adjustments to reconcile net income (loss) to net cash provided by operating activities:
	Equity in undistributed net (income) loss of subsidiaries	(840		)	(688		)	309
	Other, net	1			14			(14		)
	Net cash provided by (used in) operating activities	(14		)	(7		)	923
	Cash Flows from Investing Activities:
	Investments in and advances to subsidiaries	—			(1,700		)	—
	Repayment of investments in and advances to subsidiaries	165			35			650
	Net cash acquired from (paid for) acquisitions	—			—			(1,457		)
	Net cash used in investing activities	165			(1,665		)	(807		)
	Cash Flows from Financing Activities:
	Capital contribution from BTMU	—			1,200			—
	Proceeds from issuance of subordinated loan due to BTMU	—			300			—
	Proceeds from issuance of senior debt	—			—			397
	Repayment of subordinated debt	—			(400		)	—
	Repayment of junior subordinated debt	(14		)	—			—
	Other, net	—			—			(2		)
	Net cash provided by (used in) financing activities	(14		)	1,100			395
	Net increase (decrease) in cash and cash equivalents	137			(572		)	511
	Cash and cash equivalents at beginning of year	191			763			252
	Cash and cash equivalents at end of year	$	328		$	191		$	763

Summary_of_Significant_Account3

Summary of Significant Accounting Policies and Nature of Operations (Details)	12 Months Ended
	Dec. 31, 2014
	type_of_lease
Significant Accounting Policies
Loans placed on nonaccrual status when past due term (days)	90 days
Interest accrual period (days)	120 days
Consecutive payment period for accrual status	6 months
Number of types of leases offered to customers	2
Minimum
Significant Accounting Policies
Intangible assets amortized period	3 years
Maximum
Significant Accounting Policies
Intangible assets amortized period	40 years
Premises | Minimum
Significant Accounting Policies
Estimated useful life	10 years
Premises | Maximum
Significant Accounting Policies
Estimated useful life	50 years
Furniture, fixtures and equipment | Minimum
Significant Accounting Policies
Estimated useful life	3 years
Furniture, fixtures and equipment | Maximum
Significant Accounting Policies
Estimated useful life	8 years

Summary_of_Significant_Account4

Summary of Significant Accounting Policies and Nature of Operations - Reclassification Adjustments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities:
Depreciation, amortization and accretion, net	$324	$434	$416
Loans originated for sale	-841	-622	-211
Net proceeds from sale of loans originated for sale	839	599	148
Net cash provided by (used in) operating activities	1,622	689	460
Cash Flows from Investing Activities:
Proceeds from sales of loans	196	254	202
Net decrease (increase) in loans	-8,664	-4,912	-4,100
Net cash provided by (used in) investing activities	-8,520	-8,531	390
Cash Flows from Financing Activities:
Net cash provided by (used in) financing activities	6,446	8,554	446
Net change in cash and cash equivalents	-452	712	1,296
Supplemental Schedule of Noncash Investing and Financing Activities:
Net transfer of loans held for investment to loans held for sale	196	246	155
As Previously Reported
Cash Flows from Operating Activities:
Depreciation, amortization and accretion, net		509	518
Loans originated for sale		-276	-58
Net proceeds from sale of loans originated for sale		226	34
Net cash provided by (used in) operating activities		737	601
Cash Flows from Investing Activities:
Proceeds from sales of loans		627	316
Net decrease (increase) in loans		-5,333	-4,355
Net cash provided by (used in) investing activities		-8,579	249
Cash Flows from Financing Activities:
Net cash provided by (used in) financing activities		8,554	446
Net change in cash and cash equivalents		712	1,296
Supplemental Schedule of Noncash Investing and Financing Activities:
Net transfer of loans held for investment to loans held for sale		592	308
Reclassification Amounts
Cash Flows from Operating Activities:
Depreciation, amortization and accretion, net		-75	-102
Loans originated for sale		-346	-153
Net proceeds from sale of loans originated for sale		373	114
Net cash provided by (used in) operating activities		-48	-141
Cash Flows from Investing Activities:
Proceeds from sales of loans		-373	-114
Net decrease (increase) in loans		421	255
Net cash provided by (used in) investing activities		48	141
Cash Flows from Financing Activities:
Net cash provided by (used in) financing activities		0	0
Net change in cash and cash equivalents		0	0
Supplemental Schedule of Noncash Investing and Financing Activities:
Net transfer of loans held for investment to loans held for sale		($346)	($153)

Business_Combinations_Details

Business Combinations (Details) (USD $)	3 Months Ended
	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Nov. 30, 2013
Business Acquisitions
Goodwill		$3,225,000,000	$3,228,000,000	$2,942,000,000
PB Capital
Business Acquisitions
Purchase price, paid in cash	3,700,000,000
Loans acquired excluding the effects of purchase accounting adjustments	3,500,000,000
Fair value of net assets acquired	3,400,000,000
Goodwill	238,000,000	238,000,000
First Bank Association Bank Services
Business Acquisitions
Goodwill		30,000,000
Deposits					$570,000,000

Securities_Schedule_of_Availab

Securities - Schedule of Available For Sale Securities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Securities available for sale
Amortized Cost	$13,819	$16,194
Gross Unrealized Gains	76	76
Gross Unrealized Losses	171	453
Fair Value	13,724	15,817
U.S. government sponsored agencies
Securities available for sale
Amortized Cost		73
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value		73
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Securities available for sale
Amortized Cost	7,649	9,194
Gross Unrealized Gains	2	2
Gross Unrealized Losses	91	296
Fair Value	7,560	8,900
Residential mortgage-backed securities, Privately issued
Securities available for sale
Amortized Cost	166	220
Gross Unrealized Gains	3	4
Gross Unrealized Losses	1	2
Fair Value	168	222
Commercial mortgage-backed securities
Securities available for sale
Amortized Cost	1,689	1,947
Gross Unrealized Gains	15	8
Gross Unrealized Losses	13	85
Fair Value	1,691	1,870
Collateralized loan obligations
Securities available for sale
Amortized Cost	2,527	2,670
Gross Unrealized Gains	4	25
Gross Unrealized Losses	37	22
Fair Value	2,494	2,673
Other Asset Liability Management Securities, Other
Securities available for sale
Amortized Cost	8	34
Gross Unrealized Gains	1	1
Gross Unrealized Losses	0	0
Fair Value	9	35
Asset Liability Management securities
Securities available for sale
Amortized Cost	12,039	14,138
Gross Unrealized Gains	25	40
Gross Unrealized Losses	142	405
Fair Value	11,922	13,773
Other debt securities, Direct bank purchase bonds
Securities available for sale
Amortized Cost	1,719	1,968
Gross Unrealized Gains	49	35
Gross Unrealized Losses	27	43
Fair Value	1,741	1,960
Other debt securities, Other
Securities available for sale
Amortized Cost	53	81
Gross Unrealized Gains	0	0
Gross Unrealized Losses	1	5
Fair Value	52	76
Equity securities
Securities available for sale
Amortized Cost	8	7
Gross Unrealized Gains	2	1
Gross Unrealized Losses	1	0
Fair Value	$9	$8

Securities_Schedule_of_Continu

Securities - Schedule of Continuous Unrealized Loss Position (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	$1,496	$12,290
Securities available for sale, 12 months or more, Fair Value	9,595	1,046
Securities available for sale, Fair Value, Total	11,091	13,336
Securities available for sale, Less than 12 months, Unrealized Losses	11	415
Securities available for sale, 12 months or more, Unrealized Losses	160	38
Securities available for sale, Unrealized Losses, Total	171	453
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	611	8,508
Securities available for sale, 12 months or more, Fair Value	6,258	147
Securities available for sale, Fair Value, Total	6,869	8,655
Securities available for sale, Less than 12 months, Unrealized Losses	1	293
Securities available for sale, 12 months or more, Unrealized Losses	90	3
Securities available for sale, Unrealized Losses, Total	91	296
Residential mortgage-backed securities, Privately issued
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	9	72
Securities available for sale, 12 months or more, Fair Value	49	18
Securities available for sale, Fair Value, Total	58	90
Securities available for sale, Less than 12 months, Unrealized Losses	0	2
Securities available for sale, 12 months or more, Unrealized Losses	1	0
Securities available for sale, Unrealized Losses, Total	1	2
Commercial mortgage-backed securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	143	1,274
Securities available for sale, 12 months or more, Fair Value	842	58
Securities available for sale, Fair Value, Total	985	1,332
Securities available for sale, Less than 12 months, Unrealized Losses	0	80
Securities available for sale, 12 months or more, Unrealized Losses	13	5
Securities available for sale, Unrealized Losses, Total	13	85
Collateralized loan obligations
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	657	1,879
Securities available for sale, 12 months or more, Fair Value	1,481	10
Securities available for sale, Fair Value, Total	2,138	1,889
Securities available for sale, Less than 12 months, Unrealized Losses	6	21
Securities available for sale, 12 months or more, Unrealized Losses	31	1
Securities available for sale, Unrealized Losses, Total	37	22
Other Asset Liability Management Securities, Other
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	0	0
Securities available for sale, 12 months or more, Fair Value	1	1
Securities available for sale, Fair Value, Total	1	1
Securities available for sale, Less than 12 months, Unrealized Losses	0	0
Securities available for sale, 12 months or more, Unrealized Losses	0	0
Securities available for sale, Unrealized Losses, Total	0	0
Asset Liability Management securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	1,420	11,733
Securities available for sale, 12 months or more, Fair Value	8,631	234
Securities available for sale, Fair Value, Total	10,051	11,967
Securities available for sale, Less than 12 months, Unrealized Losses	7	396
Securities available for sale, 12 months or more, Unrealized Losses	135	9
Securities available for sale, Unrealized Losses, Total	142	405
Other debt securities, Direct bank purchase bonds
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	75	537
Securities available for sale, 12 months or more, Fair Value	937	778
Securities available for sale, Fair Value, Total	1,012	1,315
Securities available for sale, Less than 12 months, Unrealized Losses	3	18
Securities available for sale, 12 months or more, Unrealized Losses	24	25
Securities available for sale, Unrealized Losses, Total	27	43
Other debt securities, Other
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	0	15
Securities available for sale, 12 months or more, Fair Value	22	34
Securities available for sale, Fair Value, Total	22	49
Securities available for sale, Less than 12 months, Unrealized Losses	0	1
Securities available for sale, 12 months or more, Unrealized Losses	1	4
Securities available for sale, Unrealized Losses, Total	1	5
Equity securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	1	5
Securities available for sale, 12 months or more, Fair Value	5	0
Securities available for sale, Fair Value, Total	6	5
Securities available for sale, Less than 12 months, Unrealized Losses	1	0
Securities available for sale, 12 months or more, Unrealized Losses	0	0
Securities available for sale, Unrealized Losses, Total	$1	$0

Securities_Fair_Value_of_Debt_

Securities - Fair Value of Debt Securities AFS Contractual Maturity (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Securities available for sale
One Year or Less	$107
Over One Year Through Five Years	658
Over Five Years Through Ten Years	1,740
Over Ten Years	11,210
Total Fair Value	13,715
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Securities available for sale
One Year or Less	0
Over One Year Through Five Years	13
Over Five Years Through Ten Years	458
Over Ten Years	7,089
Total Fair Value	7,560
Residential mortgage-backed securities, Privately issued
Securities available for sale
One Year or Less	0
Over One Year Through Five Years	4
Over Five Years Through Ten Years	0
Over Ten Years	164
Total Fair Value	168
Commercial mortgage-backed securities
Securities available for sale
One Year or Less	0
Over One Year Through Five Years	0
Over Five Years Through Ten Years	36
Over Ten Years	1,655
Total Fair Value	1,691
Collateralized loan obligations
Securities available for sale
One Year or Less	30
Over One Year Through Five Years	80
Over Five Years Through Ten Years	572
Over Ten Years	1,812
Total Fair Value	2,494
Other Asset Liability Management Securities, Other
Securities available for sale
One Year or Less	0
Over One Year Through Five Years	2
Over Five Years Through Ten Years	7
Over Ten Years	0
Total Fair Value	9
Asset Liability Management securities
Securities available for sale
One Year or Less	30
Over One Year Through Five Years	99
Over Five Years Through Ten Years	1,073
Over Ten Years	10,720
Total Fair Value	11,922
Other debt securities, Direct bank purchase bonds
Securities available for sale
One Year or Less	72
Over One Year Through Five Years	547
Over Five Years Through Ten Years	663
Over Ten Years	459
Total Fair Value	1,741
Other debt securities, Other
Securities available for sale
One Year or Less	5
Over One Year Through Five Years	12
Over Five Years Through Ten Years	4
Over Ten Years	31
Total Fair Value	$52

Securities_Proceeds_from_Sales

Securities - Proceeds from Sales of Securities AFS (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales	$1,376	$8,340	$6,845
Gross realized gains	23	190	113
Gross realized losses	$0	$3	$2

Securities_Unrealized_GainsLos

Securities - Unrealized Gains/Loss in OCI (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Securities held to maturity
Securities held to maturity, Amortized Cost	$8,433	$6,671
Securities held to maturity, Gross Unrealized Gains, Recognized in Other Comprehensive Income (OCI)	6	7
Securities held to maturity, gross unrealized losses, recognized in other comprehensive income (OCI)	148	169
Total securities held to maturity, carrying amount	8,291	6,509
Securities held to maturity, Gross Unrealized Gains, Not Recognized in OCI	132	11
Securities held to maturity, Gross Unrealized Losses, Not Recognized in OCI	11	81
Total securities held to maturity, Fair Value	8,412	6,439
U.S. Treasury
Securities held to maturity
Securities held to maturity, Amortized Cost	486
Securities held to maturity, Gross Unrealized Gains, Recognized in Other Comprehensive Income (OCI)	0
Securities held to maturity, gross unrealized losses, recognized in other comprehensive income (OCI)	0
Total securities held to maturity, carrying amount	486
Securities held to maturity, Gross Unrealized Gains, Not Recognized in OCI	3
Securities held to maturity, Gross Unrealized Losses, Not Recognized in OCI	0
Total securities held to maturity, Fair Value	489
U.S. government-sponsored agencies
Securities held to maturity
Securities held to maturity, Amortized Cost	125
Securities held to maturity, Gross Unrealized Gains, Recognized in Other Comprehensive Income (OCI)	0
Securities held to maturity, gross unrealized losses, recognized in other comprehensive income (OCI)	0
Total securities held to maturity, carrying amount	125
Securities held to maturity, Gross Unrealized Gains, Not Recognized in OCI	0
Securities held to maturity, Gross Unrealized Losses, Not Recognized in OCI	0
Total securities held to maturity, Fair Value	125
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities
Securities held to maturity
Securities held to maturity, Amortized Cost	6,002	5,065
Securities held to maturity, Gross Unrealized Gains, Recognized in Other Comprehensive Income (OCI)	6	7
Securities held to maturity, gross unrealized losses, recognized in other comprehensive income (OCI)	66	77
Total securities held to maturity, carrying amount	5,942	4,995
Securities held to maturity, Gross Unrealized Gains, Not Recognized in OCI	76	8
Securities held to maturity, Gross Unrealized Losses, Not Recognized in OCI	5	69
Total securities held to maturity, Fair Value	6,013	4,934
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities
Securities held to maturity
Securities held to maturity, Amortized Cost	1,820	1,606
Securities held to maturity, Gross Unrealized Gains, Recognized in Other Comprehensive Income (OCI)	0	0
Securities held to maturity, gross unrealized losses, recognized in other comprehensive income (OCI)	82	92
Total securities held to maturity, carrying amount	1,738	1,514
Securities held to maturity, Gross Unrealized Gains, Not Recognized in OCI	53	3
Securities held to maturity, Gross Unrealized Losses, Not Recognized in OCI	6	12
Total securities held to maturity, Fair Value	$1,785	$1,505

Securities_Held_to_Maturity_Co

Securities - Held to Maturity Continuous Unrealized Loss Position (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Securities held to maturity
Less than 12 months, Fair Value	$533	$4,889
Less than 12 months, Unrealized Losses, Recognized in OCI	0	122
Less than 12 months, Unrealized Losses, Not Recognized in OCI	1	78
12 months or more, Fair Value	3,893	543
12 months or more, Unrealized Losses, Recognized in OCI	148	47
12 months or more, Unrealized Losses, Not Recognized in OCI	10	3
Total, Fair Value	4,426	5,432
Total, Unrealized Losses, Recognized in OCI	148	169
Total, Unrealized Losses, Not Recognized in OCI	11	81
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities
Securities held to maturity
Less than 12 months, Fair Value	399	3,873
Less than 12 months, Unrealized Losses, Recognized in OCI	0	76
Less than 12 months, Unrealized Losses, Not Recognized in OCI	1	68
12 months or more, Fair Value	2,341	54
12 months or more, Unrealized Losses, Recognized in OCI	66	1
12 months or more, Unrealized Losses, Not Recognized in OCI	4	1
Total, Fair Value	2,740	3,927
Total, Unrealized Losses, Recognized in OCI	66	77
Total, Unrealized Losses, Not Recognized in OCI	5	69
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities
Securities held to maturity
Less than 12 months, Fair Value	134	1,016
Less than 12 months, Unrealized Losses, Recognized in OCI	0	46
Less than 12 months, Unrealized Losses, Not Recognized in OCI	0	10
12 months or more, Fair Value	1,552	489
12 months or more, Unrealized Losses, Recognized in OCI	82	46
12 months or more, Unrealized Losses, Not Recognized in OCI	6	2
Total, Fair Value	1,686	1,505
Total, Unrealized Losses, Recognized in OCI	82	92
Total, Unrealized Losses, Not Recognized in OCI	$6	$12

Securities_Carrying_Amount_and

Securities - Carrying Amount and Fair Value Securities Held to Maturity (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Securities held to maturity
Over One Year Through Five Years, Carrying Amount	$561
Over Five Years Through Ten Years, Carrying Amount	893
Over Ten Years, Carrying Amount	6,837
Total securities held to maturity, carrying amount	8,291	6,509
Over One Year Through Five Years, Fair Value	565
Over Five Years Through Ten Years, Fair Value	936
Over Ten Years, Fair Value	6,911
Total securities held to maturity, Fair Value	8,412	6,439
U.S. Treasury
Securities held to maturity
Over One Year Through Five Years, Carrying Amount	486
Over Five Years Through Ten Years, Carrying Amount	0
Over Ten Years, Carrying Amount	0
Total securities held to maturity, carrying amount	486
Over One Year Through Five Years, Fair Value	489
Over Five Years Through Ten Years, Fair Value	0
Over Ten Years, Fair Value	0
Total securities held to maturity, Fair Value	489
U.S. government-sponsored agencies
Securities held to maturity
Over One Year Through Five Years, Carrying Amount	25
Over Five Years Through Ten Years, Carrying Amount	100
Over Ten Years, Carrying Amount	0
Total securities held to maturity, carrying amount	125
Over One Year Through Five Years, Fair Value	25
Over Five Years Through Ten Years, Fair Value	100
Over Ten Years, Fair Value	0
Total securities held to maturity, Fair Value	125
U.S. government agency and government-sponsored agencies - residential mortgage-backed securities
Securities held to maturity
Over One Year Through Five Years, Carrying Amount	1
Over Five Years Through Ten Years, Carrying Amount	0
Over Ten Years, Carrying Amount	5,941
Total securities held to maturity, carrying amount	5,942	4,995
Over One Year Through Five Years, Fair Value	1
Over Five Years Through Ten Years, Fair Value	0
Over Ten Years, Fair Value	6,012
Total securities held to maturity, Fair Value	6,013	4,934
U.S. government agency and government-sponsored agencies - commercial mortgage-backed securities
Securities held to maturity
Over One Year Through Five Years, Carrying Amount	49
Over Five Years Through Ten Years, Carrying Amount	793
Over Ten Years, Carrying Amount	896
Total securities held to maturity, carrying amount	1,738	1,514
Over One Year Through Five Years, Fair Value	50
Over Five Years Through Ten Years, Fair Value	836
Over Ten Years, Fair Value	899
Total securities held to maturity, Fair Value	$1,785	$1,505

Securities_Securities_Pledged_

Securities - Securities Pledged as Collateral (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Securities Pledged as Collateral
Securities available for sale pledged as collateral	$7,500,000,000
Borrowings
Securities Pledged as Collateral
Securities available for sale pledged as collateral	600,000,000
Derivative
Securities Pledged as Collateral
Securities available for sale pledged as collateral	200,000,000
Public and trust deposits
Securities Pledged as Collateral
Securities available for sale pledged as collateral	6,700,000,000
Permitted by contract to sell or repledge	61,000,000	10,000,000
Repledged to secure public agency or bankruptcy deposits and to cover short sales	0	0
Securities given as collateral for repurchase agreements	$69,000,000

Loans_and_Allowance_for_Loan_L2

Loans and Allowance for Loan Losses - Outstanding Balance of Loans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Loans disclosures
Loans excluding purchased credit-impaired loans	$76,279	$67,206
Purchased credit-impaired loans	525	1,106
Total loans held for investment	76,804	68,312
Allowance for loan losses	-537	-568	-653	-764
Loans held for investment, net	76,267	67,744
Loans covered under a loss share agreement with FDIC	126	251
Covered loans not accounted for under accounting guidance for loans acquired with deteriorated credit quality	9	15
Unamortized discounts and premiums and deferred fees and costs	151	88
Commercial portfolio
Loans disclosures
Loans excluding purchased credit-impaired loans	44,185	38,379
Total loans held for investment	44,185	38,379
Allowance for loan losses	-465	-421	-418	-474
Commercial portfolio | Commercial and industrial
Loans disclosures
Loans excluding purchased credit-impaired loans	27,623	23,528
Commercial portfolio | Commercial mortgage
Loans disclosures
Loans excluding purchased credit-impaired loans	14,016	13,092
Commercial portfolio | Construction
Loans disclosures
Loans excluding purchased credit-impaired loans	1,746	905
Commercial portfolio | Lease financing
Loans disclosures
Loans excluding purchased credit-impaired loans	800	854
Consumer portfolio
Loans disclosures
Loans excluding purchased credit-impaired loans	32,094	28,827
Total loans held for investment	32,094	28,827
Allowance for loan losses	-49	-69	-124	-138
Consumer portfolio | Residential mortgage
Loans disclosures
Loans excluding purchased credit-impaired loans	28,977	25,547
Consumer portfolio | Home equity and other consumer loans
Loans disclosures
Loans excluding purchased credit-impaired loans	$3,117	$3,280

Loans_and_Allowance_for_Loan_L3

Loans and Allowance for Loan Losses - Reconciliation of Changes in Allowance for Loan Losses by Portfolio Segment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period	$568	$653	$764
(Reversal of) provision for loan losses	-18	-44	28
(Reversal of) provision for FDIC covered loan losses not subject to FDIC indemnification	2	-1	-3
Decrease in allowance covered by FDIC indemnification		-8	-5
Other	-3
Loans charged off	-50	-77	-196
Recoveries of loans previously charged off	38	45	65
Allowance for loan losses, end of period	537	568	653
Commercial portfolio
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period	421	418	474
(Reversal of) provision for loan losses	52	18	-25
Other	-3
Loans charged off	-38	-44	-88
Recoveries of loans previously charged off	33	29	57
Allowance for loan losses, end of period	465	421	418
Consumer portfolio
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period	69	124	138
(Reversal of) provision for loan losses	-13	-29	78
Loans charged off	-11	-30	-95
Recoveries of loans previously charged off	4	4	3
Allowance for loan losses, end of period	49	69	124
Purchased credit-impaired loans
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period	1	1	17
(Reversal of) provision for FDIC covered loan losses not subject to FDIC indemnification	2	-1	-3
Decrease in allowance covered by FDIC indemnification		-8	-5
Loans charged off	-1	-3	-13
Recoveries of loans previously charged off	1	12	5
Allowance for loan losses, end of period	3	1	1
Unallocated portfolio
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for loan losses, beginning of period	77	110	135
(Reversal of) provision for loan losses	-57	-33	-25
Allowance for loan losses, end of period	$20	$77	$110

Loans_and_Allowance_for_Loan_L4

Loans and Allowance for Loan Losses - Loan Losses and Related Loan Balances by Portfolio Segment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Allowance for loan losses:
Individually evaluated for impairment	$34	$39
Collectively evaluated for impairment	500	528
Purchased credit-impaired loans	3	1
Total allowance for loan losses	537	568	653	764
Loans held for investment:
Individually evaluated for impairment	503	608
Collectively evaluated for impairment	75,777	66,601
Purchased credit-impaired loans	524	1,103
Total loans held for investment	76,804	68,312
Commercial portfolio
Allowance for loan losses:
Individually evaluated for impairment	18	19
Collectively evaluated for impairment	447	402
Purchased credit-impaired loans	0	0
Total allowance for loan losses	465	421	418	474
Loans held for investment:
Individually evaluated for impairment	164	266
Collectively evaluated for impairment	44,021	38,113
Purchased credit-impaired loans	0	0
Total loans held for investment	44,185	38,379
Consumer portfolio
Allowance for loan losses:
Individually evaluated for impairment	16	20
Collectively evaluated for impairment	33	49
Purchased credit-impaired loans	0	0
Total allowance for loan losses	49	69	124	138
Loans held for investment:
Individually evaluated for impairment	338	339
Collectively evaluated for impairment	31,756	28,488
Purchased credit-impaired loans	0	0
Total loans held for investment	32,094	28,827
Purchased credit-impaired loans
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	0	0
Purchased credit-impaired loans	3	1
Total allowance for loan losses	3	1	1	17
Loans held for investment:
Individually evaluated for impairment	1	3
Collectively evaluated for impairment	0	0
Purchased credit-impaired loans	524	1,103
Total loans held for investment	525	1,106
Unallocated portfolio
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	20	77
Purchased credit-impaired loans	0	0
Total allowance for loan losses	20	77	110	135
Loans held for investment:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	0	0
Purchased credit-impaired loans	0	0
Total loans held for investment	$0	$0

Loans_and_Allowance_for_Loan_L5

Loans and Allowance for Loan Losses - Nonaccural Loans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Nonaccrual loans
Nonaccrual loans	$375	$442
Nonaccrual loans, before purchased credit-impaired loans	366	427
Troubled debt restructured loans that continue to accrue interest	283	367
Troubled debt restructured nonaccrual loans (included in the total nonaccrual loans above)	184	225
Commercial portfolio
Nonaccrual loans
Nonaccrual loans	95	95
Commercial portfolio | Commercial and industrial
Nonaccrual loans
Nonaccrual loans	55	44
Commercial portfolio | Commercial mortgage
Nonaccrual loans
Nonaccrual loans	40	51
Consumer portfolio
Nonaccrual loans
Nonaccrual loans	271	332
Consumer portfolio | Residential mortgage
Nonaccrual loans
Nonaccrual loans	231	286
Consumer portfolio | Home equity and other consumer loans
Nonaccrual loans
Nonaccrual loans	40	46
Purchased credit-impaired loans
Nonaccrual loans
Nonaccrual loans	$9	$15

Loans_and_Allowance_for_Loan_L6

Loans and Allowance for Loan Losses - Balance of Loans Held for Investment, by Class (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Aging of loans
Current	$76,013	$66,785
30 to 89 Days Past Due	174	285
90 Days or More Past Due	92	136
Total Past Due	266	421
Total loans held for investment, before purchased credit-impaired loans	76,279	67,206
Total loans 90 days or more past due and still accruing	3	5
Commercial portfolio
Aging of loans
Current	44,127	38,205
30 to 89 Days Past Due	42	148
90 Days or More Past Due	16	26
Total Past Due	58	174
Total loans held for investment, before purchased credit-impaired loans	44,185	38,379
Commercial portfolio | Commercial and industrial
Aging of loans
Current	28,392	24,310
30 to 89 Days Past Due	19	66
90 Days or More Past Due	12	6
Total Past Due	31	72
Total loans held for investment, before purchased credit-impaired loans	28,423	24,382
Commercial portfolio | Commercial mortgage
Aging of loans
Current	13,991	13,004
30 to 89 Days Past Due	21	68
90 Days or More Past Due	4	20
Total Past Due	25	88
Total loans held for investment, before purchased credit-impaired loans	14,016	13,092
Commercial portfolio | Construction
Aging of loans
Current	1,744	891
30 to 89 Days Past Due	2	14
90 Days or More Past Due	0	0
Total Past Due	2	14
Total loans held for investment, before purchased credit-impaired loans	1,746	905
Consumer portfolio
Aging of loans
Current	31,886	28,580
30 to 89 Days Past Due	132	137
90 Days or More Past Due	76	110
Total Past Due	208	247
Total loans held for investment, before purchased credit-impaired loans	32,094	28,827
Consumer portfolio | Residential mortgage
Aging of loans
Current	28,802	25,342
30 to 89 Days Past Due	112	114
90 Days or More Past Due	63	91
Total Past Due	175	205
Total loans held for investment, before purchased credit-impaired loans	28,977	25,547
Consumer portfolio | Home equity and other consumer loans
Aging of loans
Current	3,084	3,238
30 to 89 Days Past Due	20	23
90 Days or More Past Due	13	19
Total Past Due	33	42
Total loans held for investment, before purchased credit-impaired loans	3,117	3,280
Purchased credit-impaired loans
Aging of loans
Total loans 90 days or more past due and still accruing	$47	$124

Loans_and_Allowance_for_Loan_L7

Loans and Allowance for Loan Losses - Purchased Credit-Impaired Loans Segment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Aging of loans
Loans covered under a loss share agreement with FDIC	$126	$251
Commercial Loan
Aging of loans
Loans covered under a loss share agreement with FDIC	98	213
Total loans	44,066	38,674
Commercial portfolio
Aging of loans
Total loans	43,863	38,060
Commercial portfolio | Commercial and industrial
Aging of loans
Total loans	28,283	24,235
Commercial portfolio | Construction
Aging of loans
Total loans	1,747	893
Commercial portfolio | Commercial mortgage
Aging of loans
Total loans	13,833	12,932
Purchased credit-impaired loans | Commercial Loan
Aging of loans
Total loans	203	614
Pass | Commercial Loan
Aging of loans
Total loans	42,759	36,835
Pass | Commercial portfolio
Aging of loans
Total loans	42,722	36,787
Pass | Commercial portfolio | Commercial and industrial
Aging of loans
Total loans	27,471	23,346
Pass | Commercial portfolio | Construction
Aging of loans
Total loans	1,729	879
Pass | Commercial portfolio | Commercial mortgage
Aging of loans
Total loans	13,522	12,562
Pass | Purchased credit-impaired loans | Commercial Loan
Aging of loans
Total loans	37	48
Special Mention | Commercial Loan
Aging of loans
Total loans	636	936
Special Mention | Commercial portfolio
Aging of loans
Total loans	598	732
Special Mention | Commercial portfolio | Commercial and industrial
Aging of loans
Total loans	452	576
Special Mention | Commercial portfolio | Construction
Aging of loans
Total loans	18	14
Special Mention | Commercial portfolio | Commercial mortgage
Aging of loans
Total loans	128	142
Special Mention | Purchased credit-impaired loans | Commercial Loan
Aging of loans
Total loans	38	204
Classified | Commercial Loan
Aging of loans
Total loans	671	903
Classified | Commercial portfolio
Aging of loans
Total loans	543	541
Classified | Commercial portfolio | Commercial and industrial
Aging of loans
Total loans	360	313
Classified | Commercial portfolio | Construction
Aging of loans
Total loans	0	0
Classified | Commercial portfolio | Commercial mortgage
Aging of loans
Total loans	183	228
Classified | Purchased credit-impaired loans | Commercial Loan
Aging of loans
Total loans	$128	$362

Loans_and_Allowance_for_Loan_L8

Loans and Allowance for Loan Losses - Loans in Consumer Portfolio Segment and Purchased Credit Impaired Loans Segment (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Consumer portfolio loans
Nonaccrual	$375	$442
Total loans held for investment, before purchased credit-impaired loans	76,279	67,206
Consumer
Consumer portfolio loans
Accrual	32,019	28,737
Nonaccrual	271	332
Total loans held for investment, before purchased credit-impaired loans	32,290	29,069
Loans not covered	28	38
Consumer portfolio
Consumer portfolio loans
Accrual	31,823	28,495
Nonaccrual	271	332
Total loans held for investment, before purchased credit-impaired loans	32,094	28,827
Consumer portfolio | Residential mortgage
Consumer portfolio loans
Accrual	28,746	25,261
Nonaccrual	231	286
Total loans held for investment, before purchased credit-impaired loans	28,977	25,547
Consumer portfolio | Home equity and other consumer loans
Consumer portfolio loans
Accrual	3,077	3,234
Nonaccrual	40	46
Total loans held for investment, before purchased credit-impaired loans	3,117	3,280
Purchased credit-impaired loans
Consumer portfolio loans
Nonaccrual	9	15
Purchased credit-impaired loans | Consumer
Consumer portfolio loans
Accrual	196	242
Nonaccrual	0	0
Total loans held for investment, before purchased credit-impaired loans	$196	$242

Loans_and_Allowance_for_Loan_L9

Loans and Allowance for Loan Losses - FICO Scores (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consumer
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	$31,958	$28,821
Percentage of total	100.00%	100.00%
Consumer | FICO Score 720 and Above
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	24,787	21,991
Percentage of total	77.00%	76.00%
Consumer | FICO Score Below 720
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	6,582	6,275
Percentage of total	21.00%	22.00%
Consumer | No FICO Available
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	589	555
Percentage of total	2.00%	2.00%
Consumer portfolio
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	31,761	28,577
Consumer portfolio | FICO Score 720 and Above
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	24,714	21,897
Consumer portfolio | FICO Score Below 720
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	6,471	6,140
Consumer portfolio | No FICO Available
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	576	540
Consumer portfolio | Residential mortgage
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	28,715	25,374
Consumer portfolio | Residential mortgage | FICO Score 720 and Above
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	22,505	19,614
Consumer portfolio | Residential mortgage | FICO Score Below 720
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	5,717	5,301
Consumer portfolio | Residential mortgage | No FICO Available
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	493	459
Consumer portfolio | Home equity and other consumer loans
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	3,046	3,203
Consumer portfolio | Home equity and other consumer loans | FICO Score 720 and Above
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	2,209	2,283
Consumer portfolio | Home equity and other consumer loans | FICO Score Below 720
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	754	839
Consumer portfolio | Home equity and other consumer loans | No FICO Available
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	83	81
Purchased credit-impaired loans | Consumer
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	197	244
Purchased credit-impaired loans | Consumer | FICO Score 720 and Above
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	73	94
Purchased credit-impaired loans | Consumer | FICO Score Below 720
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	111	135
Purchased credit-impaired loans | Consumer | No FICO Available
Credit quality of consumer loans
Loan balances, excluding loans serviced by third parties and loans covered by FDIC loss share agreements	$13	$15

Recovered_Sheet1

Loans and Allowance for Loan Losses - LTV Ratios (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consumer
Credit quality of consumer loans
Loans categorized by LTV ratio	$31,712	$28,717
Percentage of total loans categorized by LTV ratio	100.00%	100.00%
Consumer | Less than or Equal to 80 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	29,657	26,257
Percentage of total loans categorized by LTV ratio	94.00%	91.00%
Consumer | Greater than 80 and Less than 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	1,745	1,890
Percentage of total loans categorized by LTV ratio	5.00%	7.00%
Consumer | Greater than or Equal to 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	228	465
Percentage of total loans categorized by LTV ratio	1.00%	2.00%
Consumer | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	82	105
Percentage of total loans categorized by LTV ratio	0.00%	0.00%
Consumer portfolio
Credit quality of consumer loans
Loans categorized by LTV ratio	31,517	28,477
Consumer portfolio | Less than or Equal to 80 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	29,526	26,105
Consumer portfolio | Greater than 80 and Less than 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	1,700	1,833
Consumer portfolio | Greater than or Equal to 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	210	434
Consumer portfolio | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	81	105
Consumer portfolio | Residential mortgage
Credit quality of consumer loans
Loans categorized by LTV ratio	28,715	25,374
Consumer portfolio | Residential mortgage | Less than or Equal to 80 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	27,162	23,613
Consumer portfolio | Residential mortgage | Greater than 80 and Less than 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	1,430	1,477
Consumer portfolio | Residential mortgage | Greater than or Equal to 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	92	231
Consumer portfolio | Residential mortgage | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	31	53
Consumer portfolio | Home Equity loans
Credit quality of consumer loans
Loans categorized by LTV ratio	2,802	3,103
Consumer portfolio | Home Equity loans | Less than or Equal to 80 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	2,364	2,492
Consumer portfolio | Home Equity loans | Greater than 80 and Less than 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	270	356
Consumer portfolio | Home Equity loans | Greater than or Equal to 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	118	203
Consumer portfolio | Home Equity loans | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	50	52
Purchased credit-impaired loans | Consumer
Credit quality of consumer loans
Loans categorized by LTV ratio	195	240
Purchased credit-impaired loans | Consumer | Less than or Equal to 80 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	131	152
Purchased credit-impaired loans | Consumer | Greater than 80 and Less than 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	45	57
Purchased credit-impaired loans | Consumer | Greater than or Equal to 100 Percent
Credit quality of consumer loans
Loans categorized by LTV ratio	18	31
Purchased credit-impaired loans | Consumer | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	$1	$0

Recovered_Sheet2

Loans and Allowance for Loan Losses - Summary of Recorded Investment in TDR's (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pre- and Post - modification recorded investments
Commitment to lend additional funds to borrowers with loan modifications classified as TDRs	$33	$43
Total excluding purchased credit-impaired loans	466	589
TDRs covered by FDIC loss share agreements	1	3
TDR modifications charge-offs	2
Commercial portfolio
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	128	250
Commercial portfolio | Commercial and industrial
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	100	212
Commercial portfolio | Commercial mortgage
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	28	38
Consumer portfolio
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	338	339
Consumer portfolio | Residential mortgage
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	308	315
Consumer portfolio | Home equity and other consumer loans
Pre- and Post - modification recorded investments
Total excluding purchased credit-impaired loans	$30	$24

Recovered_Sheet3

Loans and Allowance for Loan Losses - Pre and Post Modification Outstanding Recorded Investment Amounts of TDRs (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	$173,000,000	$344,000,000
Post-Modification Outstanding Recorded Investment	172,000,000	338,000,000
TDRS covered by FDIC loss share agreements with pre-modification balance	4,000,000	0
TDRS covered by FDIC loss share agreements with post-modification balance	4,000,000
Commercial portfolio
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	134,000,000	231,000,000
Post-Modification Outstanding Recorded Investment	134,000,000	227,000,000
Commercial portfolio | Commercial and industrial
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	111,000,000	161,000,000
Post-Modification Outstanding Recorded Investment	111,000,000	158,000,000
Commercial portfolio | Commercial mortgage
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	23,000,000	70,000,000
Post-Modification Outstanding Recorded Investment	23,000,000	69,000,000
Consumer portfolio
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	39,000,000	113,000,000
Post-Modification Outstanding Recorded Investment	38,000,000	111,000,000
Consumer portfolio | Residential mortgage
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	28,000,000	104,000,000
Post-Modification Outstanding Recorded Investment	27,000,000	103,000,000
Consumer portfolio | Home equity and other consumer loans
Pre- and Post - modification recorded investments
Pre-Modification Outstanding Recorded Investment	11,000,000	9,000,000
Post-Modification Outstanding Recorded Investment	$11,000,000	$8,000,000

Recovered_Sheet4

Loans and Allowance for Loan Losses - Recorded Investment Amounts of TDRs at Date of Default (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	$27	$30
Minimum defaulting period	60 days
Commercial portfolio
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	18	12
Commercial portfolio | Commercial and industrial
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	10	10
Commercial portfolio | Commercial mortgage
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	8	2
Consumer portfolio
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	9	18
Consumer portfolio | Residential mortgage
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	8	16
Consumer portfolio | Home equity and other consumer loans
Pre- and Post - modification recorded investments
Total troubled debt restructured loans at date of default	$1	$2

Recovered_Sheet5

Loans and Allowance for Loan Losses - Impaired Loans by Class (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Loan impairment
Recorded investment with an allowance	$330	$376
Recorded investment without an allowance	173	232
Impaired loans	503	608
Allowance for impaired loans	34	39
Unpaid principal balance with an allowance	377	399
Unpaid principal balance without an allowance	208	277
Commercial portfolio
Loan impairment
Recorded investment with an allowance	126	150
Recorded investment without an allowance	38	116
Impaired loans	164	266
Allowance for impaired loans	18	19
Unpaid principal balance with an allowance	159	157
Unpaid principal balance without an allowance	42	129
Commercial portfolio | Commercial and industrial
Loan impairment
Recorded investment with an allowance	89	117
Recorded investment without an allowance	35	104
Impaired loans	124	221
Allowance for impaired loans	14	16
Unpaid principal balance with an allowance	120	121
Unpaid principal balance without an allowance	39	114
Commercial portfolio | Commercial mortgage
Loan impairment
Recorded investment with an allowance	37	33
Recorded investment without an allowance	3	12
Impaired loans	40	45
Allowance for impaired loans	4	3
Unpaid principal balance with an allowance	39	36
Unpaid principal balance without an allowance	3	15
Consumer portfolio
Loan impairment
Recorded investment with an allowance	204	224
Recorded investment without an allowance	134	115
Impaired loans	338	339
Allowance for impaired loans	16	20
Unpaid principal balance with an allowance	218	240
Unpaid principal balance without an allowance	164	142
Consumer portfolio | Residential mortgage
Loan impairment
Recorded investment with an allowance	198	220
Recorded investment without an allowance	110	95
Impaired loans	308	315
Allowance for impaired loans	16	20
Unpaid principal balance with an allowance	211	236
Unpaid principal balance without an allowance	127	108
Consumer portfolio | Home equity and other consumer loans
Loan impairment
Recorded investment with an allowance	6	4
Recorded investment without an allowance	24	20
Impaired loans	30	24
Allowance for impaired loans	0	0
Unpaid principal balance with an allowance	7	4
Unpaid principal balance without an allowance	37	34
Total, excluding purchased credit impaired loans
Loan impairment
Recorded investment with an allowance	330	374
Recorded investment without an allowance	172	231
Impaired loans	502	605
Allowance for impaired loans	34	39
Unpaid principal balance with an allowance	377	397
Unpaid principal balance without an allowance	206	271
Purchased credit-impaired loans
Loan impairment
Recorded investment with an allowance	0	2
Recorded investment without an allowance	1	1
Impaired loans	1	3
Allowance for impaired loans	0	0
Unpaid principal balance with an allowance	0	2
Unpaid principal balance without an allowance	$2	$6

Recovered_Sheet6

Loans and Allowance for Loan Losses - Average Recorded Investment in Impaired Loans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loan impairment
Average Recorded Investment	$563	$623	$588
Recognized Interest Income	19	37	25
Commercial portfolio
Loan impairment
Average Recorded Investment	224	304	352
Recognized Interest Income	7	26	15
Allowance for loan losses:
Transfer of loans from held for investment to held for sale	203	246
Loans receivable sold during the period	196	254
Commercial portfolio | Commercial and industrial
Loan impairment
Average Recorded Investment	188	243	201
Recognized Interest Income	5	14	12
Commercial portfolio | Commercial mortgage
Loan impairment
Average Recorded Investment	36	53	107
Recognized Interest Income	2	9	1
Commercial portfolio | Construction
Loan impairment
Average Recorded Investment	0	8	44
Recognized Interest Income	0	3	2
Consumer portfolio
Loan impairment
Average Recorded Investment	337	315	228
Recognized Interest Income	12	11	9
Consumer portfolio | Residential mortgage
Loan impairment
Average Recorded Investment	310	293	221
Recognized Interest Income	10	10	8
Consumer portfolio | Home equity and other consumer loans
Loan impairment
Average Recorded Investment	27	22	7
Recognized Interest Income	2	1	1
Total, excluding purchased credit impaired loans
Loan impairment
Average Recorded Investment	561	619	580
Recognized Interest Income	19	37	24
Purchased credit-impaired loans
Loan impairment
Average Recorded Investment	2	4	8
Recognized Interest Income	$0	$0	$1

Recovered_Sheet7

Loans and Allowance for Loan Losses - Outstanding Balance and Carrying Amounts of Purchased Credit Impaired Loans (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Receivables [Abstract]
Total outstanding balance	$889	$1,733
Carrying amount	$516	$1,091

Recovered_Sheet8

Loans and Allowance for Loan Losses - Accretable Yield for Purchased Credit-Impaired Loans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield, beginning of period	$378	$590	$424
Additions	0	31	171
Accretion	-268	-336	-297
Reclassifications from nonaccretable difference during the period	178	93	292
Accretable yield, end of period	288	378	590
Concentrations of Credit Risk
Loans	76,804	68,312
Loans Receivable | Credit Risk | Real estate | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	16,000
Additional unfunded commitments to extend credit	6,000
Loans Receivable | Credit Risk | Financial and insurance | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	5,000
Additional unfunded commitments to extend credit	5,000
Loans Receivable | Credit Risk | Power and utilities | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	5,000
Additional unfunded commitments to extend credit	9,000
Loans Receivable | Credit Risk | Oil and gas | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	4,000
Additional unfunded commitments to extend credit	4,000
Loans Receivable | Credit Risk | Manufacturing | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	4,000
Additional unfunded commitments to extend credit	3,000
Loans Receivable | Credit Risk | Residential mortgage loans | Unfunded Loan Commitment
Concentrations of Credit Risk
Loans	$29,000

Premises_and_Equipment_Premise

Premises and Equipment - Premises and Equipment Carried at Cost (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Premises and Equipment
Cost	$1,732	$1,743
Accumulated Depreciation and Amortization	-1,111	-1,055
Net Book Value	621	688
Land
Premises and Equipment
Cost	148	154
Accumulated Depreciation and Amortization	0	0
Net Book Value	148	154
Premises
Premises and Equipment
Cost	601	621
Accumulated Depreciation and Amortization	-334	-328
Net Book Value	267	293
Leasehold improvements
Premises and Equipment
Cost	301	298
Accumulated Depreciation and Amortization	-230	-218
Net Book Value	71	80
Furniture, fixtures and equipment
Premises and Equipment
Cost	682	670
Accumulated Depreciation and Amortization	-547	-509
Net Book Value	$135	$161

Premises_and_Equipment_Rental_

Premises and Equipment - Rental, Depreciation, and Amortization Expenses (Details) (Premises and equipment, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Premises and equipment
Rental, depreciation and amortization expenses
Rental expense of premises	$113	$111	$85
Less: rental income	10	9	8
Net rental expense	103	102	77
Depreciation and amortization of premises and equipment	$103	$110	$102

Premises_and_Equipment_Future_

Premises and Equipment - Future minimum lease payments (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Premises and Equipment and Other Assets
2015	$130
2016	131
2017	118
2018	103
2019	85
Thereafter	501
Total minimum lease payments	1,068
Minimum rental income due in the future under subleases	$105

Premises_and_Equipment_Additio

Premises and Equipment - Additional Information (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Premises and Equipment and Other Assets
Liability for asset retirement obligations	$6	$6

Premises_and_Equipment_Other_A

Premises and Equipment - Other Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Assets
Other investments	$2,711	$2,211
Prepaid expenses	145	509
Intangible assets	240	290
OREO	36	57
Other	1,553	1,787
Total other assets	$4,685	$4,854

Goodwill_and_Other_Intangible_2

Goodwill and Other Intangible Assets - Additional Information (Details) (USD $)	0 Months Ended
	Oct. 01, 2014	Apr. 01, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013
Goodwill and Other Intangible Assets
Goodwill			$3,225,000,000	$3,228,000,000	$2,942,000,000
Goodwill impairment recognized	0	0
PB Capital Commercial Real Estate Division
Goodwill and Other Intangible Assets
Goodwill			238,000,000			238,000,000
PB Capital Commercial Real Estate Division | Maximum
Goodwill and Other Intangible Assets
Intangible assets			1,000,000
First Bank Association Bank Services
Goodwill and Other Intangible Assets
Goodwill			$30,000,000

Goodwill_and_Other_Intangible_3

Goodwill and Other Intangible Assets - Schedule of Goodwill (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill rollforward
Goodwill, beginning of year	$3,228	$2,942
Net change from business combinations	-3	286
Goodwill, end of year	3,225	3,228
Retail Banking and Wealth Markets
Goodwill rollforward
Goodwill, end of year	1,524	1,527
Commercial Banking
Goodwill rollforward
Goodwill, end of year	1,034	1,034
US Corporate Banking
Goodwill rollforward
Goodwill, end of year	149	149
Transaction Banking
Goodwill rollforward
Goodwill, end of year	251	251
Investment Banking and Markets
Goodwill rollforward
Goodwill, end of year	253	253
Asian Corporate Banking
Goodwill rollforward
Goodwill, end of year	$14	$14

Goodwill_and_Other_Intangible_4

Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intangible Assets
Amortization Expense	$53	$65	$81
Gross Carrying Amount	768	869
Accumulated Amortization	-528	-579
Net Carrying Amount	240	290
Core deposit intangibles
Intangible Assets
Gross Carrying Amount	565	667
Accumulated Amortization	-468	-530
Net Carrying Amount	97	137
Trade names
Intangible Assets
Gross Carrying Amount	114	114
Accumulated Amortization	-21	-16
Net Carrying Amount	93	98
Customer Relationships
Intangible Assets
Gross Carrying Amount	60	63
Accumulated Amortization	-25	-22
Net Carrying Amount	35	41
Other intangibles assets
Intangible Assets
Gross Carrying Amount	29	25
Accumulated Amortization	-14	-11
Net Carrying Amount	$15	$14

Goodwill_and_Other_Intangible_5

Goodwill and Other Intangible Assets - Estimated Future Amortization Expense (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule Of Estimated Future Amortization Expense
2015	$42
2016	29
2017	23
2018	15
2019	13
Thereafter	118
Total estimated amortization expense	240	290
Core deposit intangibles
Schedule Of Estimated Future Amortization Expense
2015	30
2016	18
2017	14
2018	7
2019	6
Thereafter	22
Total estimated amortization expense	97	137
Trade names
Schedule Of Estimated Future Amortization Expense
2015	3
2016	3
2017	3
2018	3
2019	3
Thereafter	78
Total estimated amortization expense	93	98
Customer Relationships
Schedule Of Estimated Future Amortization Expense
2015	5
2016	5
2017	4
2018	4
2019	3
Thereafter	14
Total estimated amortization expense	35	41
Other
Schedule Of Estimated Future Amortization Expense
2015	4
2016	3
2017	2
2018	1
2019	1
Thereafter	4
Total estimated amortization expense	$15	$14

Variable_Interest_Entities_Ass

Variable Interest Entities - Assets and Liabilities of Consolidated VIEs (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Consolidated Assets
Interest Bearing Deposits in Banks	$3,930,000,000	$4,329,000,000
Loans Held for Investment, net	76,267,000,000	67,744,000,000
Other assets	4,685,000,000	4,854,000,000
Consolidated Liabilities
Other liabilities	1,889,000,000	1,675,000,000
Long-term debt	6,972,000,000	6,547,000,000
Consolidated VIEs
Consolidated Assets
Interest Bearing Deposits in Banks	19,000,000	10,000,000
Loans Held for Investment, net	653,000,000	750,000,000
Other assets	377,000,000	270,000,000
Total assets	1,049,000,000	1,030,000,000
Consolidated Liabilities
Other liabilities	80,000,000
Long-term debt		4,000,000
Total Liabilities	80,000,000	4,000,000
Consolidated VIEs | LIHC investments
Consolidated Assets
Interest Bearing Deposits in Banks	9,000,000	9,000,000
Loans Held for Investment, net	0	0
Other assets	230,000,000	262,000,000
Total assets	239,000,000	271,000,000
Consolidated Liabilities
Other liabilities	0
Long-term debt		4,000,000
Total Liabilities	0	4,000,000
Number of LIHC investment fund	2
Consolidated VIEs | Leasing investments
Consolidated Assets
Interest Bearing Deposits in Banks	10,000,000	1,000,000
Loans Held for Investment, net	653,000,000	750,000,000
Other assets	147,000,000	8,000,000
Total assets	810,000,000	759,000,000
Consolidated Liabilities
Other liabilities	80,000,000
Long-term debt		0
Total Liabilities	$80,000,000	$0

Variable_Interest_Entities_Car

Variable Interest Entities - Carrying Amounts related to Unconsolidated VIEs (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Unconsolidated Assets
Securities available for sale	$13,724	$15,817
Loans Held for Investment	76,804	68,312
Other Assets	4,685	4,854
Unconsolidated Liabilities
Other Liabilities	1,889	1,675
Unconsolidated VIEs
Unconsolidated Assets
Securities available for sale	25	122
Loans Held for Investment	213	173
Other Assets	2,023	1,712
Total Assets	2,261	2,007
Unconsolidated Liabilities
Other Liabilities	488	445
Total Liabilities	488	445
Maximum Exposure to Loss	2,279	2,007
Unconsolidated VIEs | LIHC investments
Unconsolidated Assets
Securities available for sale	25	122
Loans Held for Investment	163	158
Other Assets	1,117	1,000
Total Assets	1,305	1,280
Unconsolidated Liabilities
Other Liabilities	433	445
Total Liabilities	433	445
Maximum Exposure to Loss	1,305	1,280
Unconsolidated VIEs | Leasing investments
Unconsolidated Assets
Securities available for sale	0	0
Loans Held for Investment	21	0
Other Assets	886	700
Total Assets	907	700
Unconsolidated Liabilities
Other Liabilities	55	0
Total Liabilities	55	0
Maximum Exposure to Loss	923	700
Unconsolidated VIEs | Other investments
Unconsolidated Assets
Securities available for sale	0	0
Loans Held for Investment	29	15
Other Assets	20	12
Total Assets	49	27
Unconsolidated Liabilities
Other Liabilities	0	0
Total Liabilities	0	0
Maximum Exposure to Loss	$51	$27

Deposits_Details

Deposits (Details) (USD $)	Dec. 31, 2014
Deposits [Abstract]
Interest bearing time deposits with remaining term of greater than one year	$3,703,000,000
Deposits of $100,000 and over	$1,000,000,000

Deposits_Schedule_of_Maturitie

Deposits - Schedule of Maturities of Time Deposits (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Deposits [Abstract]
Due after one year through two years	$1,570
Due after two years through three years	1,134
Due after three years through four years	812
Due after four years through five years	167
Due after five years	20
Total	$3,703

Commercial_Paper_and_Other_Sho2

Commercial Paper and Other Short-Term Borrowings - Summary of Commercial Paper and Other Short-Term Borrowings (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Commercial Paper and Short-Term Borrowings
Federal funds purchased and securities sold under repurchase agreements, with weighted average interest rates of 0.12% and 0.07% at December 31, 2014 and December 31, 2013	$111	$39
Commercial paper, with weighted average interest rates of 0.16% and 0.19% at December 31, 2014 and December 31, 2013, respectively	2,593	2,524
Total commercial paper and other short-term borrowings	2,704	2,563
Federal funds purchased and securities sold under repurchase agreements
Commercial Paper and Short-Term Borrowings
Maximum outstanding at any month end	329	359
Average balance during the year	170	263
Weighted average interest rate during the year	0.14%	0.12%
Commercial paper
Commercial Paper and Short-Term Borrowings
Maximum outstanding at any month end	3,322	3,655
Average balance during the year	2,542	2,393
Weighted average interest rate during the year	0.16%	0.18%
Term federal funds purchased
Commercial Paper and Short-Term Borrowings
Maximum outstanding at any month end	252	269
Average balance during the year	43	50
Weighted average interest rate during the year	0.14%	0.15%
Other borrowed funds
Commercial Paper and Short-Term Borrowings
Maximum outstanding at any month end	0	0
Average balance during the year	$54	$45
Weighted average interest rate during the year	2.06%	1.71%

Commercial_Paper_and_Other_Sho3

Commercial Paper and Other Short-Term Borrowings - Additional Information (Details)	Dec. 31, 2014	Dec. 31, 2013
Federal funds purchased and securities sold under repurchase agreements
Commercial Paper and Short-Term Borrowings
Weighted average interest rate (as a percent)	0.12%	0.07%
Commercial paper
Commercial Paper and Short-Term Borrowings
Weighted average interest rate (as a percent)	0.16%	0.19%

Commercial_Paper_and_Other_Sho4

Commercial Paper and Other Short-Term Borrowings - Narrative (Details) (USD $)	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Sep. 30, 2008
Federal funds purchased and securities sold under repurchase agreements
Standby Letters of Credit
Weighted average remaining maturity days	2 days
Commercial paper
Standby Letters of Credit
Weighted average remaining maturity days	47 days
BTMU
Standby Letters of Credit
Revolving credit facility borrowing capacity		$500,000,000
Unsecured revolving credit facility years		3 years

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	0 Months Ended	12 Months Ended		0 Months Ended	9 Months Ended	0 Months Ended
	Dec. 27, 2013	Dec. 31, 2014	Dec. 31, 2013	Jun. 28, 2013	Sep. 30, 2014	Sep. 26, 2013	6-May-14	Feb. 10, 2015
Debt Instrument
Long-term debt		6,972,000,000	6,547,000,000
MUFG Americas Holdings Corporation
Debt Instrument
Long-term debt		750,000,000	763,000,000
MUFG Americas Holdings Corporation | Senior debt | Fixed rate 3.50% notes due June 2022
Debt Instrument
Long-term debt		398,000,000	397,000,000
Debt instrument, Fixed interest rate (as a percent)		3.50%	3.50%
MUFG Americas Holdings Corporation | Subordinated Debt | Floating rate subordinated debt due December 2023
Debt Instrument
Long-term debt		300,000,000	300,000,000
Debt instrument, face amount	300,000,000
Debt instrument, weighted-average interest rate (as a percent)		1.63%	1.63%
MUFG Americas Holdings Corporation | Subordinated Debt | Floating rate subordinated debt due December 2023 | LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)	1.38%	1.38%
MUFG Americas Holdings Corporation | Junior subordinated debt payable to trusts | Floating rate notes ranging March 2033 to September 2036
Debt Instrument
Long-term debt		52,000,000	66,000,000
Debt instrument, weighted-average interest rate (as a percent)		2.35%	2.60%
MUFG Union Bank, N.A. and other subsidiaries
Debt Instrument
Long-term debt		6,222,000,000	5,784,000,000
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Federal Home Loan Bank advances
Debt Instrument
Long-term debt		800,000,000	800,000,000
Debt instrument, weighted-average interest rate (as a percent)		2.56%	2.55%
Reset period		90 days
Federal Home Loan Bank advances		800,000,000
Federal Home Loan Bank advances, weighted average remaining maturity period		22 months
Federal Home Loan advances, collateral pledged		54,700,000,000	50,800,000,000
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due June 2014
Debt Instrument
Long-term debt		0	300,000,000
Debt instrument, weighted-average interest rate (as a percent)			1.19%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due June 2014 | LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)			0.95%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Fixed rate 3.00% notes due June 2016
Debt Instrument
Long-term debt		700,000,000	699,000,000
Debt instrument, Fixed interest rate (as a percent)		3.00%	3.00%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Fixed rate 1.50% notes due September 2016
Debt Instrument
Long-term debt			499,000,000
Debt instrument, Fixed interest rate (as a percent)		1.50%	1.50%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due September 2016
Debt Instrument
Long-term debt		500,000,000	500,000,000
Debt instrument, weighted-average interest rate (as a percent)		0.75%	0.75%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due September 2016 | LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)		1.00%	1.00%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Fixed rate 2.125% notes due June 2017
Debt Instrument
Long-term debt		499,000,000	499,000,000
Debt instrument, Fixed interest rate (as a percent)		2.13%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Fixed rate 2.625% notes due September 2018
Debt Instrument
Long-term debt		1,000,000,000	1,000,000,000
Debt instrument, Fixed interest rate (as a percent)		2.63%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Fixed Rate 2.25% notes due May 2019
Debt Instrument
Long-term debt		499,000,000	0
Debt instrument, Fixed interest rate (as a percent)		2.25%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due May 2017
Debt Instrument
Long-term debt		250,000,000	0
Debt instrument, weighted-average interest rate (as a percent)		0.63%
MUFG Union Bank, N.A. and other subsidiaries | Senior debt | Floating rate notes due May 2017 | LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)		0.40%
MUFG Union Bank, N.A. and other subsidiaries | Subordinated Debt | Fixed rate 5.95% notes due May 2016
Debt Instrument
Long-term debt		711,000,000	718,000,000
Debt instrument, Fixed interest rate (as a percent)		5.95%	5.95%
MUFG Union Bank, N.A. and other subsidiaries | Subordinated Debt | Floating rate notes due to BTMU June 2023
Debt Instrument
Long-term debt		750,000,000	750,000,000
Debt instrument, face amount				750,000,000
Debt instrument, weighted-average interest rate (as a percent)		1.45%	1.45%
MUFG Union Bank, N.A. and other subsidiaries | Subordinated Debt | Floating rate notes due to BTMU June 2023 | LIBOR
Debt Instrument
Interest rate above variable interest rate (as a percent)		1.20%		1.20%
MUFG Union Bank, N.A. and other subsidiaries | Subordinated Debt | Capital Lease Obligations
Debt Instrument
Debt instrument, weighted-average interest rate (as a percent)		4.92%	4.88%
MUFG Union Bank, N.A. and other subsidiaries | Note payable | Fixed rate 6.03% notes due July 2014 (related to consolidated VIE)
Debt Instrument
Long-term debt		0	4,000,000
Debt instrument, Fixed interest rate (as a percent)		6.03%	6.03%
MUFG Union Bank, N.A. and other subsidiaries | Junior subordinated debt payable to trusts | Capital Lease Obligations
Debt Instrument
Long-term debt		14,000,000	15,000,000
Bank
Debt Instrument
Authorized amount under the bank note program		8,000,000,000
Amount available for issuance under the bank note program		1,900,000,000
Bank | Senior debt | Minimum
Debt Instrument
Maturity term					1 year
Bank | Senior debt | Fixed rate 1.50% notes due September 2016
Debt Instrument
Long-term debt		499,000,000
Debt instrument, Fixed interest rate (as a percent)						1.50%
Issuance price to purchasers as a percentage of principal amount (as a percent)						99.75%
Bank | Senior debt | Floating rate notes due September 2016
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)						2.63%
Issuance price to purchasers as a percentage of principal amount (as a percent)						100.00%
Bank | Senior debt | Fixed rate 2.625% notes due September 2018
Debt Instrument
Issuance price to purchasers as a percentage of principal amount (as a percent)						99.98%
Redemption price as a percentage of principal amount (as a percent)						100.00%
Bank | Senior debt | Fixed Rate 2.25% notes due May 2019
Debt Instrument
Issuance price to purchasers as a percentage of principal amount (as a percent)							99.77%
Redemption price as a percentage of principal amount (as a percent)							100.00%
Bank | Senior debt | Floating rate notes due May 2017
Debt Instrument
Debt instrument, Fixed interest rate (as a percent)							2.25%
Issuance price to purchasers as a percentage of principal amount (as a percent)							100.00%
Redemption price as a percentage of principal amount (as a percent)							100.00%
Bank | Subordinated Debt | Maximum
Debt Instrument
Maturity term		5 years
Subsequent Event | Bank | Senior debt | Floating rate notes due 2018
Debt Instrument
Debt instrument, face amount								250,000,000
Subsequent Event | Bank | Senior debt | Fixed Rate 1.625% Notes Due 2018
Debt Instrument
Debt instrument, face amount								450,000,000
Debt instrument, Fixed interest rate (as a percent)								1.63%
Subsequent Event | Bank | Senior debt | Fixed Rate 2.25% Notes Due 2020
Debt Instrument
Debt instrument, face amount								1,000,000,000
Debt instrument, Fixed interest rate (as a percent)								2.25%
Subsequent Event | Bank | Senior debt | Fixed Rate 3.00% Notes Due 2025
Debt Instrument
Debt instrument, face amount								$500,000,000
Debt instrument, Fixed interest rate (as a percent)								3.00%

Fair_Value_Measurement_and_Fai2

Fair Value Measurement and Fair Value of Financial Instruments - Fair Value Measurements on a Recurring Basis (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair value measurements
Trading account assets	$1,114	$851
Securities available for sale	13,715
Other liabilities	1,889	1,675
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Fair value measurements
Securities available for sale	7,560
Residential mortgage-backed securities, Privately issued
Fair value measurements
Securities available for sale	168
Privately issued - commercial mortgage-backed securities
Fair value measurements
Securities available for sale	1,691
Collateralized loan obligations
Fair value measurements
Securities available for sale	2,494
Other
Fair value measurements
Securities available for sale	9
Other debt securities, Direct bank purchase bonds
Fair value measurements
Securities available for sale	1,741
Other debt securities, Other
Fair value measurements
Securities available for sale	52
Level 3
Fair value measurements
Other assets	6	3
Fair Value Measurements Recurring
Fair value measurements
Trading account assets	1,114	851
Securities available for sale	13,724	15,817
Other assets	2	10
Total assets	14,840	16,678
Percentage of Total	100.00%	100.00%
Percentage of Total Company Assets	13.00%	16.00%
Trading account liabilities	894	540
FDIC clawback liability		96
Other liabilities	109	113
Total liabilities	1,003	653
Percentage of Total	100.00%	100.00%
Percentage of Total Company Liabilities	0.00%	1.00%
Fair Value Measurements Recurring | U.S. Treasury
Fair value measurements
Trading account assets	69	8
Fair Value Measurements Recurring | U.S. government-sponsored agencies
Fair value measurements
Trading account assets	125	116
Securities available for sale		73
Fair Value Measurements Recurring | State and municipal securities
Fair value measurements
Trading account assets	10	5
Fair Value Measurements Recurring | Other loans
Fair value measurements
Trading account assets		140
Fair Value Measurements Recurring | Interest rate derivative contracts
Fair value measurements
Trading account assets	761	501
Trading account liabilities	163	230
Fair Value Measurements Recurring | Commodity derivative contracts
Fair value measurements
Trading account assets	30	10
Trading account liabilities	315	28
Fair Value Measurements Recurring | Foreign exchange derivative contracts
Fair value measurements
Trading account assets	43	15
Trading account liabilities	56	18
Fair Value Measurements Recurring | Equity Derivative contracts
Fair value measurements
Trading account assets	76	56
Trading account liabilities	299	254
Fair Value Measurements Recurring | Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Fair value measurements
Securities available for sale	7,560	8,900
Fair Value Measurements Recurring | Residential mortgage-backed securities, Privately issued
Fair value measurements
Securities available for sale	168	222
Fair Value Measurements Recurring | Privately issued - commercial mortgage-backed securities
Fair value measurements
Securities available for sale	1,691	1,870
Fair Value Measurements Recurring | Collateralized loan obligations
Fair value measurements
Securities available for sale	2,494	2,673
Fair Value Measurements Recurring | Other
Fair value measurements
Securities available for sale	9	35
Fair Value Measurements Recurring | Other debt securities, Direct bank purchase bonds
Fair value measurements
Securities available for sale	1,741	1,960
Fair Value Measurements Recurring | Other debt securities, Other
Fair value measurements
Securities available for sale	52	76
Fair Value Measurements Recurring | Equity securities
Fair value measurements
Securities available for sale	9	8
Fair Value Measurements Recurring | Interest rate hedging contracts
Fair value measurements
Other assets	0	8
Other liabilities	1	13
Fair Value Measurements Recurring | Other derivative contracts
Fair value measurements
Other assets	2	2
Other liabilities	3	4
Fair Value Measurements Recurring | Securities sold, not yet purchased
Fair value measurements
Trading account liabilities	61	10
Fair Value Measurements Recurring | Level 1
Fair value measurements
Trading account assets	1	2
Securities available for sale	9	8
Total assets	10	10
Trading account liabilities	2	4
Total liabilities	2	4
Percentage of Total		1.00%
Fair Value Measurements Recurring | Level 1 | Interest rate derivative contracts
Fair value measurements
Trading account assets		1
Trading account liabilities	1	3
Fair Value Measurements Recurring | Level 1 | Foreign exchange derivative contracts
Fair value measurements
Trading account assets	1	1
Trading account liabilities	1	1
Fair Value Measurements Recurring | Level 1 | Equity securities
Fair value measurements
Securities available for sale	9	8
Fair Value Measurements Recurring | Level 2
Fair value measurements
Trading account assets	1,653	1,071
Securities available for sale	11,925	13,791
Other assets	36	9
Total assets	13,614	14,871
Percentage of Total	92.00%	89.00%
Percentage of Total Company Assets	12.00%	14.00%
Trading account liabilities	1,371	695
Other liabilities	5	14
Total liabilities	1,376	709
Percentage of Total	137.00%	109.00%
Percentage of Total Company Liabilities	1.00%	1.00%
Fair Value Measurements Recurring | Level 2 | U.S. Treasury
Fair value measurements
Trading account assets	69	8
Fair Value Measurements Recurring | Level 2 | U.S. government-sponsored agencies
Fair value measurements
Trading account assets	125	116
Securities available for sale		73
Fair Value Measurements Recurring | Level 2 | State and municipal securities
Fair value measurements
Trading account assets	10	5
Fair Value Measurements Recurring | Level 2 | Other loans
Fair value measurements
Trading account assets		140
Fair Value Measurements Recurring | Level 2 | Interest rate derivative contracts
Fair value measurements
Trading account assets	928	705
Trading account liabilities	829	606
Fair Value Measurements Recurring | Level 2 | Commodity derivative contracts
Fair value measurements
Trading account assets	417	67
Trading account liabilities	403	53
Fair Value Measurements Recurring | Level 2 | Foreign exchange derivative contracts
Fair value measurements
Trading account assets	104	30
Trading account liabilities	78	26
Fair Value Measurements Recurring | Level 2 | Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Fair value measurements
Securities available for sale	7,560	8,900
Fair Value Measurements Recurring | Level 2 | Residential mortgage-backed securities, Privately issued
Fair value measurements
Securities available for sale	168	222
Fair Value Measurements Recurring | Level 2 | Privately issued - commercial mortgage-backed securities
Fair value measurements
Securities available for sale	1,691	1,870
Fair Value Measurements Recurring | Level 2 | Collateralized loan obligations
Fair value measurements
Securities available for sale	2,494	2,673
Fair Value Measurements Recurring | Level 2 | Other
Fair value measurements
Securities available for sale	9	35
Fair Value Measurements Recurring | Level 2 | Other debt securities, Other
Fair value measurements
Securities available for sale	3	18
Fair Value Measurements Recurring | Level 2 | Interest rate hedging contracts
Fair value measurements
Other assets	36	8
Other liabilities	4	13
Fair Value Measurements Recurring | Level 2 | Other derivative contracts
Fair value measurements
Other assets		1
Other liabilities	1	1
Fair Value Measurements Recurring | Level 2 | Securities sold, not yet purchased
Fair value measurements
Trading account liabilities	61	10
Fair Value Measurements Recurring | Level 3
Fair value measurements
Trading account assets	311	271
Securities available for sale	1,790	2,018
Other assets	2	1
Total assets	2,103	2,290
Percentage of Total	14.00%	14.00%
Percentage of Total Company Assets	2.00%	2.00%
Trading account liabilities	305	264
FDIC clawback liability		96
Other liabilities	107	99
Total liabilities	412	363
Percentage of Total	41.00%	55.00%
Fair Value Measurements Recurring | Level 3 | Interest rate derivative contracts
Fair value measurements
Trading account assets	5	7
Fair Value Measurements Recurring | Level 3 | Commodity derivative contracts
Fair value measurements
Trading account assets	5	9
Trading account liabilities	5	8
Fair Value Measurements Recurring | Level 3 | Foreign exchange derivative contracts
Fair value measurements
Trading account assets	1	2
Trading account liabilities	1	2
Fair Value Measurements Recurring | Level 3 | Equity Derivative contracts
Fair value measurements
Trading account assets	300	253
Trading account liabilities	299	254
Fair Value Measurements Recurring | Level 3 | Other debt securities, Direct bank purchase bonds
Fair value measurements
Securities available for sale		1,960
Fair Value Measurements Recurring | Level 3 | Other debt securities, Other
Fair value measurements
Securities available for sale	49	58
Fair Value Measurements Recurring | Level 3 | Other derivative contracts
Fair value measurements
Other assets	2	1
Other liabilities	2	3
Fair Value Measurements Recurring | Netting Adjustment
Fair value measurements
Trading account assets	-851	-493
Other assets	-36
Total assets	-887	-493
Percentage of Total	-6.00%	-3.00%
Percentage of Total Company Assets	-1.00%
Trading account liabilities	-784	-423
Other liabilities	-3
Total liabilities	-787	-423
Percentage of Total	-78.00%	-65.00%
Percentage of Total Company Liabilities	-1.00%
Fair Value Measurements Recurring | Netting Adjustment | Interest rate derivative contracts
Fair value measurements
Trading account assets	-172	-212
Trading account liabilities	-667	-379
Fair Value Measurements Recurring | Netting Adjustment | Commodity derivative contracts
Fair value measurements
Trading account assets	-392	-66
Trading account liabilities	-93	-33
Fair Value Measurements Recurring | Netting Adjustment | Foreign exchange derivative contracts
Fair value measurements
Trading account assets	-63	-18
Trading account liabilities	-24	-11
Fair Value Measurements Recurring | Netting Adjustment | Equity Derivative contracts
Fair value measurements
Trading account assets	-224	-197
Fair Value Measurements Recurring | Netting Adjustment | Interest rate hedging contracts
Fair value measurements
Other assets	-36
Other liabilities	($3)

Fair_Value_Measurement_and_Fai3

Fair Value Measurement and Fair Value of Financial Instruments - Reconciliation of Assets and Liabilities on a Recurring Basis (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Trading Assets
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Asset balance, beginning of period	$271	$136
Total gains (losses) (realized/unrealized) included in income before taxes, assets	61	119
Purchases/additions, assets	4	24
Settlements, assets	-25	-8
Asset balance, end of period	311	271
Changes in unrealized gains (losses) included in income before taxes for assets still held at end of period, assets	61	119
Securities Available for Sale
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Asset balance, beginning of period	2,018	1,499
Total gains (losses) (realized/unrealized) included in other comprehensive income, assets	29	28
Purchases/additions, assets	197	700
Sales, assets		-14
Settlements, assets	-454	-195
Asset balance, end of period	1,790	2,018
Other assets
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Asset balance, beginning of period	1	0
Total gains (losses) (realized/unrealized) included in income before taxes, assets	1
Purchases/additions, assets		1
Asset balance, end of period	2	1
Changes in unrealized gains (losses) included in income before taxes for assets still held at end of period, assets	1
Trading Liabilities
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Liability balance, beginning of period	-264	-136
Total gains (losses) (realized/unrealized) included in income before taxes, assets, liability	-61	-120
Sales, liabilities	-5	-16
Settlements, liabilities	25	8
Liability balance, end of period	-305	-264
Changes in unrealized gains (losses) included in income before taxes for assets still held at end of period, liabilities	-61	-120
Other Liabilities
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Liability balance, beginning of period	-99	-95
Total gains (losses) (realized/unrealized) included in income before taxes, assets, liability	-8	-4
Liability balance, end of period	-107	-99
Changes in unrealized gains (losses) included in income before taxes for assets still held at end of period, liabilities	($8)	($4)

Fair_Value_Measurement_and_Fai4

Fair Value Measurement and Fair Value of Financial Instruments - Level 3 Assets and Liabilities (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities	13,715
Other liabilities	1,889	1,675
Other debt securities, Direct bank purchase bonds
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities	1,741
Other debt securities, Direct bank purchase bonds | Minimum | Return on equity
Significant unobservable inputs, Level 3 assets
Market-required return on capital (as a percent)	8.00%
Probability of default (as a percent)	0.00%
Loss severity (as a percent)	10.00%
Other debt securities, Direct bank purchase bonds | Maximum | Return on equity
Significant unobservable inputs, Level 3 assets
Market-required return on capital (as a percent)	10.00%
Probability of default (as a percent)	25.00%
Loss severity (as a percent)	60.00%
Other debt securities, Direct bank purchase bonds | Weighted Average | Return on equity
Significant unobservable inputs, Level 3 assets
Market-required return on capital (as a percent)	9.90%
Probability of default (as a percent)	0.50%
Loss severity (as a percent)	31.10%
FDIC clawback liability | Minimum | Discounted cash flow
Significant unobservable inputs, Level 3 assets
Probability of default (as a percent)	0.10%
Loss severity (as a percent)	0.00%
FDIC clawback liability | Maximum | Discounted cash flow
Significant unobservable inputs, Level 3 assets
Probability of default (as a percent)	100.00%
Loss severity (as a percent)	100.00%
FDIC clawback liability | Weighted Average | Discounted cash flow
Significant unobservable inputs, Level 3 assets
Probability of default (as a percent)	58.40%
Loss severity (as a percent)	39.10%
Fair Value, Measurements, Recurring
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities	13,724	15,817
Fair Value, Measurements, Recurring | Other debt securities, Direct bank purchase bonds
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities	1,741	1,960
Fair Value, Measurements, Recurring | Level 3
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities	1,790	2,018
Fair Value, Measurements, Recurring | Level 3 | Other debt securities, Direct bank purchase bonds
Significant unobservable inputs, Level 3 assets
Available-for-sale Securities, Debt Securities		1,960
Fair Value, Measurements, Recurring | FDIC clawback liability
Significant unobservable inputs, Level 3 assets
Other liabilities	105

Fair_Value_Measurement_and_Fai5

Fair Value Measurement and Fair Value of Financial Instruments - Assets Measured on Nonrecurring Basis (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Loans:
Impaired loans	$503	$608
Loss Impaired loans	-37	-47
Other assets:
OREO	36	57
Loss on OREO	-6	-11
Loss on Private equity investments		-5
Loss, Total	-43	-63
Fair Value Measurements, Nonrecurring
Loans:
Impaired loans	109	59
Other assets:
OREO	15	21
Total	124	80
Fair Value Measurements, Nonrecurring | Level 3
Loans:
Impaired loans	109	59
Other assets:
OREO	15	21
Total	$124	$80

Fair_Value_Measurement_and_Fai6

Fair Value Measurement and Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Financial Instruments(Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets
Securities held to maturity	$8,412	$6,439
Level 1
Assets
Cash and cash equivalents	5,751	6,203
Level 2
Assets
Securities held to maturity	8,412	6,439
Liabilities
Deposits	86,076	80,228
Commercial paper and other short-term borrowings	2,704	2,563
Long-term debt	7,073	6,709
Level 3
Assets
Loans held for investment, net of allowance for loan losses	77,324	68,132
FDIC indemnification asset	5	95
Other assets	6	3
Off-Balance Sheet Instruments
Commitments to extend credit and standby and commercial letters of credit	269	273
Carrying Amount
Assets
Cash and cash equivalents	5,751	6,203
Securities held to maturity	8,291	6,509
Loans held for investment, net of allowance for loan losses	75,475	66,898
FDIC indemnification asset	52	141
Other assets	7	3
Liabilities
Deposits	86,004	80,101
Commercial paper and other short-term borrowings	2,704	2,563
Long-term debt	6,972	6,547
Off-Balance Sheet Instruments
Commitments to extend credit and standby and commercial letters of credit	269	273
Fair Value
Assets
Cash and cash equivalents	5,751	6,203
Securities held to maturity	8,412	6,439
Loans held for investment, net of allowance for loan losses	77,324	68,132
FDIC indemnification asset	5	95
Other assets	6	3
Liabilities
Deposits	86,076	80,228
Commercial paper and other short-term borrowings	2,704	2,563
Long-term debt	7,073	6,709
Off-Balance Sheet Instruments
Commitments to extend credit and standby and commercial letters of credit	$269	$273

Derivative_Instruments_and_Oth2

Derivative Instruments and Other Financial Instruments Used For Hedging - Notional and Fair Value Amounts (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	$71,679	$64,438
Fair Value, Asset Derivatives	1,799	1,085
Fair Value, Liability Derivatives	1,624	970
Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	61,143	59,953
Fair Value, Asset Derivatives	1,761	1,075
Fair Value, Liability Derivatives	1,617	953
Not designated as hedging instruments | Other risk management
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	286	185
Fair Value, Asset Derivatives	2	2
Fair Value, Liability Derivatives	3	4
Net gain (losses) on derivatives included in other noninterest income	-1	-6
Interest rate contracts | Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	46,944	44,427
Fair Value, Asset Derivatives	933	713
Fair Value, Liability Derivatives	830	609
Interest rate contracts | Cash Flow Hedges | Designated as hedging instrument
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	9,750	4,300
Fair Value, Asset Derivatives	34	8
Fair Value, Liability Derivatives	4	13
Interest rate contracts | Fair Value Hedges | Designated as hedging instrument
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	500	0
Fair Value, Asset Derivatives	2	0
Fair Value, Liability Derivatives	0	0
Commodity contracts | Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	4,741	5,714
Fair Value, Asset Derivatives	422	76
Fair Value, Liability Derivatives	408	61
Foreign exchange contracts | Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	5,661	5,645
Fair Value, Asset Derivatives	106	33
Fair Value, Liability Derivatives	80	29
Equity contracts | Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	3,797	4,027
Fair Value, Asset Derivatives	300	253
Fair Value, Liability Derivatives	299	254
Other contracts | Not designated as hedging instruments | Trading derivatives
Derivative Instruments and Other Financial Instruments
Derivative Notional Amount	$0	$140

Derivative_Instruments_and_Oth3

Derivative Instruments and Other Financial Instruments Used For Hedging - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash flow hedges
Derivative Notional Amount	$71,679	$64,438
Income from accumulated other comprehensive income expected to be reclassified to net interest income	103
Cash Flow Hedges
Cash flow hedges
Weighted average remaining life of the currently active cash flow hedges	3 years 4 months 13 days
Designated as hedging instrument | Cash Flow Hedges | LIBOR indexed loans | Interest rate swaps
Cash flow hedges
Derivative Notional Amount	$9,750

Derivative_Instruments_and_Oth4

Derivative Instruments and Other Financial Instruments Used For Hedging - Derivatives Designated as Cash Flow Hedges (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash Flow Hedges | Interest rate contracts | Noninterest expense | Maximum
Amount and location of net gains and losses
Gain (Loss) Recognized in Income on Derivative Instruments (Ineffective Portion)		$1
Designated as hedging instrument | Fair Value Hedging
Amount and location of net gains and losses
Derivative	2
Hedged Item	-1
Hedge Ineffectiveness	1
Designated as hedging instrument | Fair Value Hedging | Interest rate contracts
Amount and location of net gains and losses
Derivative	2
Hedged Item	-1
Hedge Ineffectiveness	1
Designated as hedging instrument | Cash Flow Hedges
Amount and location of net gains and losses
Amount of Gain (Loss) Recognized in OCI on Derivative Instruments (Effective Portion)	126	29
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	117	43
Gain (Loss) Recognized in Income on Derivative Instruments (Ineffective Portion)	2	0
Designated as hedging instrument | Cash Flow Hedges | Interest rate contracts
Amount and location of net gains and losses
Amount of Gain (Loss) Recognized in OCI on Derivative Instruments (Effective Portion)	126	29
Designated as hedging instrument | Cash Flow Hedges | Interest rate contracts | Interest income
Amount and location of net gains and losses
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	115	44
Designated as hedging instrument | Cash Flow Hedges | Interest rate contracts | Interest expense
Amount and location of net gains and losses
Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	2	-1
Designated as hedging instrument | Cash Flow Hedges | Interest rate contracts | Noninterest expense
Amount and location of net gains and losses
Gain (Loss) Recognized in Income on Derivative Instruments (Ineffective Portion)	2	0
Designated as hedging instrument | Cash Flow Hedges | Interest rate contracts | Noninterest expense | Maximum
Amount and location of net gains and losses
Gain (Loss) Recognized in Income on Derivative Instruments (Ineffective Portion)		$1

Derivative_Instruments_and_Oth5

Derivative Instruments and Other Financial Instruments Used For Hedging - Amount of Net Gains (Losses) for Derivatives Classified as Trading (Details) (Trading Derivatives, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	$67	$50
Interest rate contracts
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	36	30
Equity contracts
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	3	0
Foreign exchange contracts
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	19	18
Commodity contracts
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	8	2
Other contracts
Trading Derivatives
Gain or (Loss) Recognized in Income on Derivative Instruments	$1	$0

Derivative_Instruments_and_Oth6

Derivative Instruments and Other Financial Instruments Used For Hedging - Offsetting of Financial Assets and Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Financial Assets
Gross Amounts of Recognized Assets, Derivative assets	$1,799	$1,085
Gross Amounts Offset in Balance Sheet, Derivative assets	887	493
Net Amounts Presented in Balance Sheet, Derivative assets	912	592
Gross Amounts Not Offset In Balance Sheet, Financial Instruments, Derivative assets	113	79
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Pledged, Derivative assets	0	0
Net Amount, Derivative assets	799	513
Gross Amounts of Recognized Assets, Securities purchased under resale agreements	62	10
Net Amounts Presented in Balance Sheet, Securities purchased under resale agreements	62
Gross Amount Not Offset in Balance Sheet, Financial Instruments, Securities purchased under repurchase agreements	61	10
Net Amount, Securities purchased under repurchase agreements	1	0
Gross Amounts of Recognized Assets, Financial Assets	1,861	1,095
Gross Amounts Offset in Balance Sheet, Financial Assets	887	493
Net Amounts Presented in Balance Sheet, Financial Assets	974	602
Gross Amounts Not Offset In Balance Sheet, Financial Instruments, Financial Assets	174	89
Gross Amounts Not Offset in Balance Sheet, Cash Collateral Pledged, Financial Assets	0	0
Net Amount, Financial Assets	800	513
Financial Liabilities
Gross Amounts of Recognized Liabilities, Derivative liabilities	1,624	970
Gross Amounts Offset in Balance Sheet, Derivative liabilities	787	423
Net Amounts Presented in Balance Sheet, Derivative liabilities	837	547
Gross Amount Not Offset in Balance Sheet, Financial Instruments, Derivative liabilities	162	144
Gross Amount Not Offset in Balance Sheet, Cash Collateral Pledged, Derivative liabilities	0	0
Net Amount, Derivative liabilities	675	403
Gross Amounts of Recognized Liabilities, Securities sold under repurchase agreements	68	8
Net Amounts Presented in Balance Sheet, Securities sold under repurchase agreements	68	8
Gross Amount Not Offset in Balance Sheet, Financial Instruments, Securities sold under repurchase agreements	68	8
Net Amount, Securities sold under repurchase agreements	0	0
Gross Amounts of Recognized Liabilities, Financial Liabilities	1,692	978
Gross Amounts Offset in Balance Sheet, Financial Liabilities	787	423
Net Amounts Presented in Balance Sheet, Financial Liabilities	905	555
Gross Amount Not Offset in Balance Sheet, Financial Instruments, Financial Liabilities	230	152
Gross Amount Not Offset in Balance Sheet, Cash Collateral Pledged, Financial Liabilities	0	0
Net Amount, Financial Liabilities	$675	$403

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income - AOCI and Related Tax Effect (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flow hedge activities:
Unrealized net gains (losses) on hedges arising during the period, Before Tax Amount	$126	$29	$82
Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt, Before Tax Amount	-117	-43	-15
Net change, Before Tax Amount	9	-14	67
Unrealized net gains (losses) on hedges arising during the period, Tax Effect	-50	-11	-32
Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt, Tax Effect	46	17	6
Net change, Tax Effect	-4	6	-26
Unrealized net gains (losses) on hedges arising during the period, Net of Tax	76	18	50
Less: Reclassification adjustment for net (gains) losses on hedges included in interest income for loans and interest expense on long-term debt, Net of Tax	-71	-26	-9
Net change, Net of Tax	5	-8	41
Securities:
Unrealized holding gains (losses) arising during the period on securities available for sale, Before Tax Amount	348	-401	187
Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net, Before Tax Amount	-18	-178	-107
Reclassification of unrealized (gains) losses on held to maturity securities transferred to securities available for sale, Before Tax Amount			301
Less: accretion of fair value adjustment on securities available for sale, Before Tax Amount	-48	-75	-9
Less: accretion of fair value adjustment on held to maturity securities, Before Tax Amount	0	-12	-24
Less: amortization of net unrealized (gains) losses on held to maturity securities, Before Tax Amount	19	-137	90
Net change, Before Tax Amount	301	-803	438
Foreign currency translation adjustment, Before Tax Amount	-11	-7	2
Unrealized holding gains (losses) arising during the period on securities available for sale, Tax Effect	-136	157	-74
Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net, Tax Effect	7	70	42
Reclassification of unrealized (gains) losses on held to maturity securities transferred to securities available for sale, Tax Effect			-118
Less: accretion of fair value adjustment on securities available for sale, Tax Effect	19	30	4
Less: accretion of fair value adjustment on held to maturity securities, Tax Effect	0	5	9
Less: amortization of net unrealized (gains) losses on held to maturity securities, Tax Effect	-8	54	-35
Net change, Tax Effect	-118	316	-172
Foreign currency translation adjustment, Tax Effect	4	3	-1
Unrealized holding gains (losses) arising during the period on securities available for sale, Net of Tax	212	-244	113
Reclassification adjustment for net (gains) losses on securities available for sale included in securities gains, net, Net of Tax	-11	-108	-65
Reclassification of unrealized (gains) losses on held to maturity securities transferred to securities available for sale, Net of Tax			183
Less: accretion of fair value adjustment on securities available for sale, Net of Tax	-29	-45	-5
Less: accretion of fair value adjustment on held to maturity securities, Net of Tax	0	-7	-15
Less: amortization of net unrealized (gains) losses on held to maturity securities, Net of Tax	11	-83	55
Net change, Net of Tax	183	-487	266
Foreign currency translation adjustment, Net of Tax	7	4	-1
Pension and other benefits:
Amortization of transition amount, Before Tax Amount	-17		-1
Recognized net actuarial (gain) loss, Before Tax Amount	62	116	-99
Pension and other benefits arising during the year, Before Tax Amount	-517	526	121
Net change, Before Tax Amount	-472	642	21
Net change in AOCI, Before Tax Amount	-173	-182	486
Amortization of transition amount, Tax Effect	7		1
Recognized net actuarial (gain) loss, Tax Effect	24	46	-39
Pension and other benefits arising during the year, Tax Effect	-203	207	48
Net change, Tax Effect	186	-253	-8
Net change in AOCI, Tax Effect	68	72	-191
Amortization of prior service costs, Net of Tax	-10		0
Recognized net actuarial gain (loss), Net of Tax	38	70	60
Pension and other benefits arising during the year, Net of Tax	-314	319	-73
Net change, Net of Tax	-286	389	-13
Net change in AOCI, Net of Tax	($105)	($110)	$295

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income - Accumulated Other Comprehensive Loss Balances (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning Balance	($624)	($514)	($809)
Accumulated Other Comprehensive Loss, Other comprehensive income before reclassifications	263	-365	199
Accumulated Other Comprehensive Loss, Amounts reclassified from accumulated other comprehensive loss	-368	255	96
Accumulated Other Comprehensive Loss, Ending Balance	-729	-624	-514
Net Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning Balance	16	24	-17
Accumulated Other Comprehensive Loss, Other comprehensive income before reclassifications	76	18	50
Accumulated Other Comprehensive Loss, Amounts reclassified from accumulated other comprehensive loss	-71	-26	-9
Accumulated Other Comprehensive Loss, Ending Balance	21	16	24
Net Unrealized Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning Balance	-328	159	-107
Accumulated Other Comprehensive Loss, Other comprehensive income before reclassifications	194	-379	148
Accumulated Other Comprehensive Loss, Amounts reclassified from accumulated other comprehensive loss	-11	-108	118
Accumulated Other Comprehensive Loss, Ending Balance	-145	-328	159
Foreign Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning Balance	-3	1	0
Accumulated Other Comprehensive Loss, Other comprehensive income before reclassifications	-7	-4	1
Accumulated Other Comprehensive Loss, Amounts reclassified from accumulated other comprehensive loss	0	0	0
Accumulated Other Comprehensive Loss, Ending Balance	-10	-3	1
Pension and Other Benefits Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Loss, Beginning Balance	-309	-698	-685
Accumulated Other Comprehensive Loss, Other comprehensive income before reclassifications	0	0	0
Accumulated Other Comprehensive Loss, Amounts reclassified from accumulated other comprehensive loss	-286	389	-13
Accumulated Other Comprehensive Loss, Ending Balance	($595)	($309)	($698)

Management_Stock_Plans_Bonus_S

Management Stock Plans - Bonus Stock Plans (Details) (Stock Bonus Plan, Restricted Stock Units, USD $)	0 Months Ended							12 Months Ended
	Sep. 15, 2014	Jul. 10, 2014	Apr. 15, 2014	Jul. 15, 2013	Apr. 15, 2013	Jul. 15, 2012	Apr. 15, 2012	Dec. 31, 2014	Dec. 31, 2013
Stock Bonus Plan | Restricted Stock Units
Management Stock Plans
Units Granted	46,552	56,056	9,135,710	78,725	3,656,340	74,175	4,816,795	9,238,318	3,735,065
Fair Value of Stock	$5.80	$5.91	$5.40	$6.67	$6.66	$4.72	$4.78
Vesting Duration	3 years	3 years	3 years	3 years	3 years	3 years	3 years	3 years

Management_Stock_Plans_Rollfor

Management Stock Plans - Rollforward of RSUs under Stock Bonus Plan (Details) (Restricted Stock Units)	0 Months Ended							12 Months Ended
	Sep. 15, 2014	Jul. 10, 2014	Apr. 15, 2014	Jul. 15, 2013	Apr. 15, 2013	Jul. 15, 2012	Apr. 15, 2012	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2014
Stock Bonus Plan
Restricted Stock Units rollforward
Units outstanding, beginning of year								7,851,017	8,857,884
Granted	46,552	56,056	9,135,710	78,725	3,656,340	74,175	4,816,795	9,238,318	3,735,065
Vested								-4,351,084	-4,325,661
Forfeited								-952,075	-416,271
Units outstanding, end of year								15,101,489	7,851,017
HQA Plan
Restricted Stock Units rollforward
Units outstanding, beginning of year										3,315,313
Units outstanding, end of year										3,315,313

Management_Stock_Plans_Compens

Management Stock Plans - Compensation Costs, Tax Benefit and Unrecognized Compensation Costs (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs
Compensation costs	$34	$21	$18
Tax benefit	13	8	7
Unrecognized compensation costs	$42	$27	$26

Employee_Pension_and_Other_Pos2

Employee Pension and Other Postretirement Benefits - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Service Period required for eligibility	1 year
Change in fair value of plan assets
Fair value of plan assets, beginning of year	$2,716	$2,019
Actual return on plan assets	164	391
Employer contributions	100	380
Plan participants' contributions	0	0
Benefits paid	-83	-74
Fair value of plan assets, end of year	2,897	2,716
Pension Benefits | Minimum
Pension Plan and Other Postretirement Benefits Plan
Service Period required for vesting	3 years
Other Benefits
Change in fair value of plan assets
Fair value of plan assets, beginning of year	245	210
Actual return on plan assets	14	37
Employer contributions	13	12
Plan participants' contributions	7	7
Benefits paid	-22	-21
Fair value of plan assets, end of year	$257	$245
Other Benefits | Minimum
Pension Plan and Other Postretirement Benefits Plan
Future cost-sharing changes	25.00%
Other Benefits | Maximum
Pension Plan and Other Postretirement Benefits Plan
Future cost-sharing changes	50.00%

Employee_Pension_and_Other_Pos3

Employee Pension and Other Postretirement Benefits - Asset Allocation (Details)	12 Months Ended
	Dec. 31, 2014
Pension Benefits | Equity securities
Pension Plan and Other Postretirement Benefits Plan
Target plan asset allocation	63.00%
Pension Benefits | Debt Securities
Pension Plan and Other Postretirement Benefits Plan
Target plan asset allocation	25.00%
Pension Benefits | Real estate
Pension Plan and Other Postretirement Benefits Plan
Target plan asset allocation	12.00%
Other Benefits | Equity securities
Pension Plan and Other Postretirement Benefits Plan
Target plan asset allocation	70.00%
Other Benefits | Debt Securities
Pension Plan and Other Postretirement Benefits Plan
Target plan asset allocation	30.00%

Employee_Pension_and_Other_Pos4

Employee Pension and Other Postretirement Benefits - Fair Value Hierarchy of Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	$2,934	$2,747
Accrued dividends and interest receivable	7	4
Net pending trades	-44	-35
Total Plan Assets	2,897	2,716	2,019
Pension Benefits | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1,724	1,639
Pension Benefits | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	912	844
Pension Benefits | Level 3
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	298	264	174
Pension Benefits | Cash and cash equivalents
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	53	28
Pension Benefits | Cash and cash equivalents | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1
Pension Benefits | Cash and cash equivalents | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	52	28
Pension Benefits | U.S. Government securities
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	251	230
Pension Benefits | U.S. Government securities | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	251	230
Pension Benefits | Corporate bonds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	442	364
Pension Benefits | Corporate bonds | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	442	364
Pension Benefits | Equity securities
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	301	233
Pension Benefits | Equity securities | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	295	233
Pension Benefits | Equity securities | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	6
Pension Benefits | Real Estate Funds [Member]
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	270	242
Pension Benefits | Real Estate Funds [Member] | Level 3
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	270	242
Pension Benefits | Limited partnership
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	166	156
Pension Benefits | Limited partnership | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	138	134
Pension Benefits | Limited partnership | Level 3
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	28	22	18
Pension Benefits | Common collective funds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments		60
Pension Benefits | Common collective funds | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments		60
Pension Benefits | Mutual funds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1,422	1,407
Pension Benefits | Mutual funds | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1,422	1,407
Pension Benefits | Other
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	29	27
Pension Benefits | Other | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	6	-1
Pension Benefits | Other | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	23	28
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	264	251
Net pending trades	-7	-6
Total Plan Assets	257	245	210
Other Benefits | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	136	133
Other Benefits | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	128	118
Other Benefits | Cash and cash equivalents
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	3	2
Other Benefits | Cash and cash equivalents | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	3	2
Other Benefits | U.S. Government securities
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	36	33
Other Benefits | U.S. Government securities | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	36	33
Other Benefits | Corporate bonds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	23	19
Other Benefits | Corporate bonds | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	23	19
Other Benefits | Municipal Bonds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1	1
Other Benefits | Municipal Bonds | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	1	1
Other Benefits | Mutual funds
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	136	133
Other Benefits | Mutual funds | Level 1
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	136	133
Other Benefits | Pooled separate account
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	65	63
Other Benefits | Pooled separate account | Level 2
Pension Plan and Other Postretirement Benefits Plan
Total Plan Investments	$65	$63

Employee_Pension_and_Other_Pos5

Employee Pension and Other Postretirement Benefits - Change in Plan Assets, Level 3 (Details) (Pension Benefits, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, end of year	$2,934	$2,747
Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	264	174
Unrealized gains (losses)	26	18
Purchases, issuances, sales, and settlements, net	8	72
Fair value of plan assets, end of year	298	264
Real estate funds | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	242	156
Unrealized gains (losses)	21	18
Purchases, issuances, sales, and settlements, net	7	68
Fair value of plan assets, end of year	270	242
Limited partnership
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, end of year	166	156
Limited partnership | Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, beginning of year	22	18
Unrealized gains (losses)	5	0
Purchases, issuances, sales, and settlements, net	1	4
Fair value of plan assets, end of year	28	22
Other
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets, end of year	$29	$27

Employee_Pension_and_Other_Pos6

Employee Pension and Other Postretirement Benefits - Changes in Benefit Obligation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Increase in projected benefit obligations	$232
Accumulated benefit obligation	2,717	2,046
Change in benefit obligation
Benefit obligation, beginning of year	2,263	2,394
Service cost	75	87
Interest cost	105	99	101
Plan participants' contributions	0	0
Actuarial loss/(gain)	607	-243
Effect of plan amendments	-150
Medicare Part D subsidy	0	0
Benefits paid	-83	-74
Benefit obligation, end of year	2,817	2,263	2,394
Fair value of plan assets, end of year	2,897	2,716	2,019
Over (Under) funded status	80	453
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Increase in projected benefit obligations	35
Change in benefit obligation
Benefit obligation, beginning of year	270	293
Service cost	10	14
Interest cost	11	11	12
Plan participants' contributions	7	7
Actuarial loss/(gain)	42	-34
Effect of plan amendments	-29
Medicare Part D subsidy	1	0
Benefits paid	-22	-21
Benefit obligation, end of year	290	270	293
Fair value of plan assets, end of year	257	245	210
Over (Under) funded status	($33)	($25)

Employee_Pension_and_Other_Pos7

Employee Pension and Other Postretirement Benefits - Changes in AOCI (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan and Other Postretirement Benefits Plan
Net Actuarial (Gain) Loss, Arising during the year	$62	$116	($99)
Transition Assets, Recognized in net income during the year	17		1
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Net Actuarial (Gain) Loss, Balance	467	1,042	1,016
Net Actuarial (Gain) Loss, Arising during the year	636	-468	115
Net Actuarial (Gain) Loss, Recognized in net income during the year	-59	-107	-89
Net Actuarial (Gain) Loss, Balance	1,044	467	1,042
Prior Service Credit, beginning balance	0
Prior Service Credit, Arising during the year	-150
Prior Service Credit, recognized in net income during the year	12
Prior Service Credit, ending balance	-138	0
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Net Actuarial (Gain) Loss, Balance	17	80	90
Net Actuarial (Gain) Loss, Arising during the year	46	-56	-2
Net Actuarial (Gain) Loss, Recognized in net income during the year	-1	-7	-8
Net Actuarial (Gain) Loss, Balance	62	17	80
Prior Service Credit, beginning balance	0
Prior Service Credit, Arising during the year	-28
Prior Service Credit, recognized in net income during the year	5
Prior Service Credit, ending balance	-23	0
Transition Assets, Balance		0	1
Transition Assets, Recognized in net income during the year			-1
Transition Assets, Balance			$0

Employee_Pension_and_Other_Pos8

Employee Pension and Other Postretirement Benefits - AOCI Loss for Pension (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss, Gross	$1,044	$467	$1,042	$1,016
Prior service costs (credits), Gross	-138	0
Pension and other benefits adjustment, Gross	906	467
Net actuarial loss in AOCI, Tax	411	184
Prior service costs (credits) in AOCI, Tax	-54
Pension and other benefits adjustment, Tax	357	184
Net Actuarial (Gain)/Loss, Net of Tax	633	283
Prior service costs (credits), Net of Tax	-84
Amounts to be reclassified from accumulated other comprehensive loss	549	283
Expected cash contribution to Pension Plan in 2014	175
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss, Gross	62	17	80	90
Prior service costs (credits), Gross	-23	0
Pension and other benefits adjustment, Gross	39	17
Net actuarial loss in AOCI, Tax	25	7
Prior service costs (credits) in AOCI, Tax	-9
Pension and other benefits adjustment, Tax	16	7
Net Actuarial (Gain)/Loss, Net of Tax	37	10
Prior service costs (credits), Net of Tax	-14
Amounts to be reclassified from accumulated other comprehensive loss	23	10
Executive Supplemental Benefits Pension Plan
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss, Gross	39	26
Prior service costs (credits), Gross	-2
Pension and other benefits adjustment, Gross	37	26
Net actuarial loss in AOCI, Tax	15	10
Prior service costs (credits) in AOCI, Tax	-1
Pension and other benefits adjustment, Tax	14	10
Net Actuarial (Gain)/Loss, Net of Tax	24	16
Prior service costs (credits), Net of Tax	-1
Amounts to be reclassified from accumulated other comprehensive loss	23	16
Pension and Executive Supplemental Benefits
Pension Plan and Other Postretirement Benefits Plan
Pension and other benefits adjustment, Gross	943	493
Pension and other benefits adjustment, Tax	371	194
Amounts to be reclassified from accumulated other comprehensive loss	$572	$299

Employee_Pension_and_Other_Pos9

Employee Pension and Other Postretirement Benefits - Pension and Post retirement Benefit Payments (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
2015	$92
2016	104
2017	114
2018	123
2019	132
Years 2020-2024	795
Postretirement Benefits
Pension Plan and Other Postretirement Benefits Plan
2015	15
2016	16
2017	17
2018	18
2019	19
Years 2020-2024	101
Medicare Part D Subsidies
Pension Plan and Other Postretirement Benefits Plan
2015	1
2016	1
2017	1
2018	1
2019	1
Years 2020-2024	$6

Recovered_Sheet9

Employee Pension and Other Postretirement Benefits - Weighted Average Assumptions, PV of Benefit Obligations and Net Periodic Benefit Cost (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Discount rate in determining net periodic benefit cost prior to Plan amendments	4.90%	4.20%
Discount rate in determining net periodic benefit cost after Plan amendments	4.50%
Discount rate in determining benefit obligations at year end	3.90%	4.90%
Rate of increase in future compensation levels for determining net periodic benefit cost	4.70%	4.70%
Rate of increase in future compensation levels for determining benefit obligations at year end	4.70%	4.70%
Expected return on plan assets	7.50%	7.50%
Service cost	$81	$87	$77
Interest cost	105	99	101
Expected return on plan assets	-193	-166	-147
Amortization of prior service credit	-12
Recognized net actuarial loss	59	107	89
Total net periodic benefit cost	40	127	120
Service cost associated with transferred employees	6
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Discount rate in determining net periodic benefit cost prior to Plan amendments	4.60%	3.90%
Discount rate in determining net periodic benefit cost after Plan amendments	4.20%
Discount rate in determining benefit obligations at year end	3.80%	4.60%
Expected return on plan assets	7.50%	7.50%
Service cost	10	14	14
Interest cost	11	11	12
Expected return on plan assets	-18	-15	-13
Amortization of prior service credit	-5	0	1
Recognized net actuarial loss	1	7	8
Total net periodic benefit cost	-1	17	22
Superannuation, SERP and ESBP
Pension Plan and Other Postretirement Benefits Plan
Service cost	1	1	2
Interest cost	4	3	2
Recognized net actuarial loss	2	2	2
Total net periodic benefit cost	$7	$6	$6

Recovered_Sheet10

Employee Pension and Other Postretirement Benefits - Periodic Benefit Costs, Forecasted (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2015
Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss	$55
Prior service costs (credits)	0
Amounts to be reclassified from accumulated other comprehensive loss	55
Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss	0
Prior service costs (credits)	0
Amounts to be reclassified from accumulated other comprehensive loss	0
Forecast | Pension Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss		109
Prior service costs (credits)		-18
Amounts to be reclassified from accumulated other comprehensive loss		91
Forecast | Other Benefits
Pension Plan and Other Postretirement Benefits Plan
Net actuarial loss		5
Prior service costs (credits)		-8
Amounts to be reclassified from accumulated other comprehensive loss		($3)

Recovered_Sheet11

Employee Pension and Other Postretirement Benefits - Weighted Average Healthcare Cost Trend Rates (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assumed weighted-average healthcare cost trend rates
Healthcare cost trend rate assumed for next year	7.53%	7.71%	8.31%
Rate to which cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	4.50%	4.50%
Year the rate reaches the ultimate trend rate	2021	2021	2021

Recovered_Sheet12

Employee Pension and Other Postretirement Benefits - Point Percentage Change in Healthcare Cost Trend Rates (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Effect of one-percentage-point change in assumed healthcare cost trend rates
Effect on total of service and interest cost components, One-Percentage- Point Increase	$2
Effect on postretirement benefit obligation, One-Percentage- Point Increase	19
Effect on total of service and interest cost components, One-Percentage- Point Decrease	-2
Effect on postretirement benefit obligation, One-Percentage- Point Decrease	($22)

Recovered_Sheet13

Employee Pension and Other Postretirement Benefits - Executive Supplemental Benefit Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan and Other Postretirement Benefits Plan
Employee pre-tax covered compensation percent	75.00%
Employee after-tax covered compensation percent	10.00%
Combined maximum employee contribution percent	75.00%
Employee pre-tax gross pay for which the employer contributes a match (as a percent)	4.00%
Contribution plan expenses	$37	$32	$29
Executive Supplemental Benefits Pension Plan
Pension Plan and Other Postretirement Benefits Plan
Accrued liability for ESBPs	$98	$85
Matching Range 1
Pension Plan and Other Postretirement Benefits Plan
Company pre-tax compensation match (as a percent)	100.00%
Employee pre-tax gross pay for which the employer contributes a match (as a percent)	3.00%
Matching Range 2
Pension Plan and Other Postretirement Benefits Plan
Company pre-tax compensation match (as a percent)	50.00%
Employee pre-tax gross pay for which the employer contributes a match (as a percent)	2.00%

Other_Noninterest_Expense_Deta

Other Noninterest Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income and Expenses [Abstract]
Software	$94	$83	$70
LIHC investment amortization	89	76	63
Advertising and public relations	39	61	57
Communications	40	45	39
Data processing	32	36	36
Other	159	150	198
Total other noninterest expense	$453	$451	$463

Income_Taxes_Analysis_of_the_E

Income Taxes - Analysis of the Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income tax rate	35.00%	35.00%	35.00%
Net tax effects of:
State income taxes, net of federal income tax benefit	7.00%	5.00%	6.00%
Tax-exempt interest income	-2.00%	-1.00%	-1.00%
Tax credits	-13.00%	-13.00%	-10.00%
Other	-2.00%	-3.00%	-3.00%
Effective tax rate	25.00%	23.00%	27.00%

Income_Taxes_Components_of_Inc

Income Taxes - Components of Income Tax Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Taxes currently payable:
Federal	$82	$79	$93
State	76	43	32
Foreign	13	12	14
Total currently payable	171	134	139
Taxes deferred:
Federal	72	71	62
State	28	-8	20
Foreign	3	-2	-1
Total deferred	103	61	81
Total income tax expense	$274	$195	$220

Income_Taxes_Net_Deferred_Tax_

Income Taxes - Net Deferred Tax Balances (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred tax assets:
Allowance for credit losses	$283	$287
Accrued expense, net	272	216
Unrealized losses on pension and postretirement benefits	389	204
Unrealized net losses on securities available for sale	97	262
Fair value adjustments for valuation of FDIC covered assets	159	183
Other	110	97
Total deferred tax assets	1,310	1,249
Deferred tax liabilities:
Leasing	759	698
Intangible assets	99	105
Pension liabilities	389	363
Other	5	17
Total deferred tax liabilities	1,252	1,183
Net deferred tax asset	$58	$66

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Details) (USD $)	Dec. 31, 2014
Deferred tax assets, carryforwards
Operating loss carry forward	$38,000,000
Tax credit carry forwards	43,000,000
Net valuation allowance	$0

Income_Taxes_Unrecognized_Tax_

Income Taxes - Unrecognized Tax Positions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Changes in unrecognized tax positions
Balance, beginning of year	$16,000,000	$269,000,000	$274,000,000
Gross increases as a result of tax positions taken during prior periods	0	1,000,000	7,000,000
Gross decreases as a result of tax positions taken during prior periods	-10,000,000	-256,000,000	-13,000,000
Gross increases as a result of tax positions taken during current period	2,000,000	2,000,000	1,000,000
Balance, end of year	8,000,000	16,000,000	269,000,000
Unrecognized tax positions disclosures
Unrecognized tax positions that would affect the effective tax rate	7,000,000	12,000,000	113,000,000
Interest and penalties recognized (reversed) as a component of income tax expense	-3,000,000	-12,000,000	-14,000,000
Interest and penalties accrued	$0	$3,000,000	$15,000,000

Regulatory_Capital_Requirement2

Regulatory Capital Requirements (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
MUFG Americas Holdings Corporation
Regulatory Capital Requirements
Total risk-based capital ratio before application of new methodology	10.00%
Tier 1 risk-based capital ratio before application of new methodology	6.00%
Tier 1 capital (to risk-weighted assets), Actual	$12,367	$11,471
Total capital (to risk-weighted assets), Actual	14,246	13,499
Tier 1 Leverage, Actual	12,367	11,471
Tier 1 capital (to risk-weighted assets), ratio, Actual	12.79%	12.41%
Total capital (to risk-weighted assets), ratio, Actual	14.74%	14.61%
Tier 1 leverage, ratio, Actual	11.25%	11.27%
Tier 1 capital (to risk-weighted assets), Minimum Regulatory Requirement	3,867	3,696
Total capital (to risk-weighted assets), Minimum Regulatory Requirement	7,733	7,393
Tier 1 Leverage, Minimum Regulatory Requirement	4,396	4,073
Tier 1 capital (to risk-weighted assets), ratio, Minimum Regulatory Requirement	4.00%	4.00%
Total capital (to risk-weighted assets), ratio, Minimum Regulatory Requirement	8.00%	8.00%
Tier 1 Leverage, ratio, Minimum Regulatory Requirement	4.00%	4.00%
Bank
Regulatory Capital Requirements
Common equity tier 1 capital (to risk-weighted assets), Actual	12,087
Tier 1 capital (to risk-weighted assets), Actual	12,088	11,274
Total capital (to risk-weighted assets), Actual	13,656	12,990
Tier 1 Leverage, Actual	12,088	11,274
Common equity tier 1 capital (to risk-weighted assets), ratio, Actual	13.09%
Tier 1 capital (to risk-weighted assets), ratio, Actual	13.09%	12.94%
Total capital (to risk-weighted assets), ratio, Actual	14.78%	14.91%
Tier 1 leverage, ratio, Actual	11.09%	11.13%
Tier 1 capital (to risk-weighted assets), Minimum Regulatory Requirement	5,080	3,485
Total capital (to risk-weighted assets), Minimum Regulatory Requirement	7,389	6,970
Tier 1 Leverage, Minimum Regulatory Requirement	4,361	4,051
Tier 1 capital (to risk-weighted assets), ratio, Minimum Regulatory Requirement	5.50%	4.00%
Total capital (to risk-weighted assets), ratio, Minimum Regulatory Requirement	8.00%	8.00%
Tier 1 Leverage, ratio, Minimum Regulatory Requirement	4.00%	4.00%
Tier 1 capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	5,542	5,228
Total capital (to risk-weighted assets), To Be Well-Capitalized Under Prompt Corrective Action Provisions	9,237	8,713
Tier 1 Leverage, To Be Well-Capitalized Under Prompt Corrective Action Provisions		$5,063
Tier 1 capital (to risk-weighted assets), ratio, To Be Well-Capitalized Under Prompt Corrective Action Provisions	6.00%	6.00%
Total capital (to risk-weighted assets), ratio, To Be Well-Capitalized Under Prompt Corrective Action Provisions	10.00%	10.00%
Tier 1 Leverage, ratio, To Be Well-Capitalized Under Prompt Corrective Action Provisions		5.00%

Restrictions_on_Cash_and_Due_f1

Restrictions on Cash and Due from Banks, Securities, Loans and Dividends - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restricted Cash and Investments [Abstract]
Required reserve balances	$549,000,000	$398,000,000
Loans pledged as collateral for borrowings	54,200,000,000	50,200,000,000
Federal Reserve Act restricts the amount and the terms of both credit and non-credit transactions, in percentage	10.00%
Aggregate of loan to non-bank affiliate	20.00%
Outstanding on the number of bankers commercial corporation notes payable	366,000,000
Outstanding notes payable to all other non-bank affiliates	$121,000,000

Commitments_Contingencies_and_2

Commitments, Contingencies and Guarantees (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Commitments to extend credit
Commitment, Contingencies and Guarantees disclosures
Commitments	($34,991)
Issued standby and commercial letters of credit
Commitment, Contingencies and Guarantees disclosures
Commitments	-5,836
Maximum term	1 year
Carrying value	4
Other commitments
Commitment, Contingencies and Guarantees disclosures
Commitments	($175)

Commitments_Contingencies_and_3

Commitments, Contingencies and Guarantees - Additional Information (Details) (Financial guarantee, Interest rate swap contracts, USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Financial guarantee | Interest rate swap contracts
Guarantee disclosures
Current exposure to loss	$20
Future exposure to loss	$39

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended				1 Months Ended	3 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2008	Dec. 31, 2013	Jul. 01, 2014	Jun. 30, 2013
Related Party Transaction [Line Items]
Available-for-sale Securities	$13,724,000,000		$15,817,000,000			$15,817,000,000
Increase in retained earnings	-5,000,000	[1]	-9,000,000	-15,000,000
Liabilities	98,463,000,000		91,426,000,000			91,426,000,000
Fees from affiliates	319,000,000		0	0
Salaries and benefits expense	1,785,000,000		1,631,000,000	1,479,000,000
Other expense	2,899,000,000		2,777,000,000	2,583,000,000
Other assets	4,685,000,000		4,854,000,000			4,854,000,000
Other liabilities	1,889,000,000		1,675,000,000			1,675,000,000
Noninterest income	1,123,000,000		876,000,000	818,000,000
BTMU
Related Party Transaction [Line Items]
Other expense	9,000,000		13,000,000	18,000,000
Unsecured revolving credit facility with BTMU					500,000,000
Unsecured revolving credit facility years					3 years
Unsecured revolving credit facility amount outstanding	0
Project Related expenditure	15,000,000		19,000,000	39,000,000
Common equity contribution received						1,200,000,000
Derivative notional amount	634,000,000		735,000,000			735,000,000
Net unrealized losses on derivatives	1,000,000		-7,000,000
Noninterest income	38,000,000		33,000,000	21,000,000
Amount of overdraft balance outstanding	0
BTMU | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Available-for-sale Securities							70,000,000
Employee-related liabilities							30,000,000
Additional paid in capital	31,000,000
Liabilities							9,000,000
BTMU | United States [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Number of U.S. employees							2,300
Bank | Subsidiaries | Floating rate subordinated debt due December 2023
Related Party Transaction [Line Items]
Debt issued								750,000,000
UnionBanCal Corporation
Related Party Transaction [Line Items]
Liabilities	751,000,000		765,000,000			765,000,000
Other expense	4,000,000		4,000,000	0
Other assets	4,000,000		5,000,000			5,000,000
Other liabilities	1,000,000		2,000,000			2,000,000
UnionBanCal Corporation | Subordinated Debt | Floating rate subordinated debt due December 2023
Related Party Transaction [Line Items]
Debt issued			300,000,000			300,000,000
Retained Earnings
Related Party Transaction [Line Items]
Increase in retained earnings	-9,000,000	[1]
BTMU | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Fees from affiliates	319,000,000
Other expense	14,000,000
Other assets	61,000,000
Other liabilities	16,000,000
Support Services [Member] | BTMU | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Fees from affiliates	206,000,000
Salaries and benefits expense	$193,000,000
[1]	For additional information on the capital contribution, refer to Note 21 to these consolidated financial statements.

Business_Segments_Additional_I

Business Segments - Additional Information (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
	segment
Segment Reporting [Abstract]
Reportable business segments	5
Consumer and Business Banking Division [Member] [Member] | California
Business segments
Number of full-service branches	353
Consumer and Business Banking Division [Member] [Member] | Washington and Oregon
Business segments
Number of full-service branches	46
Commercial Banking
Business segments
Number of divisions	5
Commercial Banking | Minimum
Business segments
Corporate customers revenues	15
Commercial Banking | Maximum
Business segments
Corporate customers revenues	2,000
US Corporate Banking | Minimum
Business segments
Corporate customers revenues	2,000

Business_Segments_Schedule_of_

Business Segments - Schedule of Segments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business segments
Net interest income (expense)	$2,862	$2,716	$2,602
Noninterest income	1,123	876	818
Total income	3,985	3,592	3,420
Other expense	2,899	2,777	2,583
(Reversal of) provision for credit losses	6	-29	8
Income before income taxes and including noncontrolling interests	1,080	844	829
Income tax benefit	274	195	220
Net Income including Noncontrolling Interests	806	649	609
Deduct: Net loss from noncontrolling interests	19	18	19
Net Income Attributable to MUAH	825	667	628
Total assets, end of period	113,678	105,894	97,008
Reconciling Items
Business segments
Net interest income (expense)	-394	-350	-350
Noninterest income	-226	-205	-204
Total income	-620	-555	-554
Other expense	-159	-129	-132
(Reversal of) provision for credit losses	-11	-3	4
Income before income taxes and including noncontrolling interests	-450	-423	-426
Income tax benefit	-177	-166	-167
Net Income including Noncontrolling Interests	-273	-257	-259
Net Income Attributable to MUAH	-273	-257	-259
Total assets, end of period	-3,582	-2,679	-1,775
Retail Banking and Wealth Markets | Operating segments
Business segments
Net interest income (expense)	1,385	1,348	1,201
Noninterest income	330	371	336
Total income	1,715	1,719	1,537
Other expense	1,347	1,423	1,294
(Reversal of) provision for credit losses	-7	-35	55
Income before income taxes and including noncontrolling interests	375	331	188
Income tax benefit	148	130	74
Net Income including Noncontrolling Interests	227	201	114
Net Income Attributable to MUAH	227	201	114
Total assets, end of period	37,722	34,421	31,809
Commercial Banking | Operating segments
Business segments
Net interest income (expense)	1,016	913	778
Noninterest income	221	193	208
Total income	1,237	1,106	986
Other expense	440	406	389
(Reversal of) provision for credit losses	21	17	-52
Income before income taxes and including noncontrolling interests	776	683	649
Income tax benefit	188	174	179
Net Income including Noncontrolling Interests	588	509	470
Net Income Attributable to MUAH	588	509	470
Total assets, end of period	38,727	32,661	25,318
US Corporate Banking | Operating segments
Business segments
Net interest income (expense)	173	137	113
Noninterest income	119	81	72
Total income	292	218	185
Other expense	112	54	54
(Reversal of) provision for credit losses	-24	2	21
Income before income taxes and including noncontrolling interests	204	162	110
Income tax benefit	80	64	43
Net Income including Noncontrolling Interests	124	98	67
Net Income Attributable to MUAH	124	98	67
Total assets, end of period	5,130	4,755	3,822
Transaction Banking | Operating segments
Business segments
Net interest income (expense)	442	446	496
Noninterest income	165	160	167
Total income	607	606	663
Other expense	363	356	351
(Reversal of) provision for credit losses	-3	-3	-1
Income before income taxes and including noncontrolling interests	247	253	313
Income tax benefit	97	99	123
Net Income including Noncontrolling Interests	150	154	190
Net Income Attributable to MUAH	150	154	190
Total assets, end of period	1,779	1,574	1,564
Investment Banking & Markets | Operating segments
Business segments
Net interest income (expense)	175	184	174
Noninterest income	357	210	207
Total income	532	394	381
Other expense	166	100	77
(Reversal of) provision for credit losses	35	6	6
Income before income taxes and including noncontrolling interests	331	288	298
Income tax benefit	84	78	86
Net Income including Noncontrolling Interests	247	210	212
Net Income Attributable to MUAH	247	210	212
Total assets, end of period	6,195	5,937	7,137
Other | Operating segments
Business segments
Net interest income (expense)	65	38	190
Noninterest income	157	66	32
Total income	222	104	222
Other expense	630	567	550
(Reversal of) provision for credit losses	-5	-13	-25
Income before income taxes and including noncontrolling interests	-403	-450	-303
Income tax benefit	-146	-184	-118
Net Income including Noncontrolling Interests	-257	-266	-185
Deduct: Net loss from noncontrolling interests	19	18	19
Net Income Attributable to MUAH	-238	-248	-166
Total assets, end of period	$27,707	$29,225	$29,133

Condensed_MUFG_Americas_Holdin2

Condensed MUFG Americas Holdings Corporation Unconsolidated Financial Statements - Balance Sheet (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$1,759,000,000	$1,863,000,000
Other assets	4,685,000,000	4,854,000,000
Total assets	113,678,000,000	105,894,000,000	97,008,000,000
Liabilities and Stockholder's Equity
Long-term debt	6,972,000,000	6,547,000,000
Other liabilities	1,889,000,000	1,675,000,000
Total liabilities	98,463,000,000	91,426,000,000
Stockholder's equity	15,215,000,000	14,468,000,000	12,725,000,000	11,801,000,000
Total liabilities and stockholder's equity	113,678,000,000	105,894,000,000
MUFG Americas Holdings Corporation
Assets
Cash and cash equivalents	328,000,000	191,000,000
Investment in subsidiaries	15,404,000,000	14,784,000,000
Other assets	4,000,000	5,000,000
Total assets	15,736,000,000	14,980,000,000
Liabilities and Stockholder's Equity
Long-term debt	750,000,000	763,000,000
Other liabilities	1,000,000	2,000,000
Total liabilities	751,000,000	765,000,000
Stockholder's equity	14,985,000,000	14,215,000,000
Total liabilities and stockholder's equity	$15,736,000,000	$14,980,000,000

Condensed_MUFG_Americas_Holdin3

Condensed MUFG Americas Holdings Corporation Unconsolidated Financial Statements - Statements of Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income:
Total income	$3,985	$3,592	$3,420
Expense:
Other expense	2,899	2,777	2,583
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	1,080	844	829
Income tax benefit	274	195	220
Equity in undistributed net income (loss) of subsidiaries:
Net Income attributable to MUAH	825	667	628
MUFG Americas Holdings Corporation
Income:
Dividends from bank subsidiary	0	0	950
Interest income on advances to subsidiaries and deposits in bank	0	0	1
Total income	0	0	951
Expense:
Interest expense	21	31	23
Other expense	4	4	0
Total interest expense	25	35	23
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	-25	-35	928
Income tax benefit	-10	-14	-9
Income (loss) before equity in undistributed net income of subsidiaries	-15	-21	937
Equity in undistributed net income (loss) of subsidiaries:
Bank subsidiary	761	625	-403
Nonbank subsidiaries	79	63	94
Net Income attributable to MUAH	$825	$667	$628

Condensed_MUFG_Americas_Holdin4

Condensed MUFG Americas Holdings Corporation Unconsolidated Financial Statements - Statement of Cash Flows (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 income	$825	$667	$628
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Other, net	21	-37	-70
Cash Flows from Investing Activities:
Net cash acquired from (paid for) acquisitions	0	-3,185	53
Cash Flows from Financing Activities:
Capital contribution from BTMU	0	1,200	0
Proceeds from issuance of subordinated loan due to BTMU	0	1,050	0
Other, net	-25	-25	1
Net change in cash and cash equivalents	-452	712	1,296
Cash and cash equivalents at beginning of period	6,203	5,491	4,195
Cash and cash equivalents at end of period	5,751	6,203	5,491
MUFG Americas Holdings Corporation
Cash Flows from Operating Activities:
Net income	825	667	628
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Equity in undistributed net (income) loss of subsidiaries	-840	-688	309
Other, net	1	14	-14
Net cash provided by (used in) operating activities	-14	-7	923
Cash Flows from Investing Activities:
Investments in and advances to subsidiaries	0	-1,700	0
Repayment of investments in and advances to subsidiaries	165	35	650
Net cash acquired from (paid for) acquisitions	0	0	-1,457
Net cash used in investing activities	165	-1,665	-807
Cash Flows from Financing Activities:
Capital contribution from BTMU	0	1,200	0
Proceeds from issuance of subordinated loan due to BTMU	0	300	0
Proceeds from issuance of senior debt	0	0	397
Repayment of subordinated debt	0	-400	0
Repayment of junior subordinated debt	-14	0	0
Other, net	0	0	-2
Net cash provided by (used in) financing activities	-14	1,100	395
Net change in cash and cash equivalents	137	-572	511
Cash and cash equivalents at beginning of period	191	763	252
Cash and cash equivalents at end of period	$328	$191	$763