Other Assets (Details Textuals) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Assets [Line Items]
Prepaid expenses	$ 851,000,000	$ 1,626,000,000
Restricted cash	$ 477,000,000	$ 384,000,000
Amortization period of acquired finite-lived intangible assets	5 years	7 years
Other intangible assets, at amortized cost	$ 796,000,000	$ 854,000,000
Foreign deferred tax liabilities	80,000,000	96,000,000
Other Assets (Textuals) [Abstract]
Goodwill impaired	219,000,000	0
Amortization expense	183,000,000	174,000,000	$ 193,000,000
Tax Credit Investments - Affordable Housing partnerships	578,000,000	522,000,000
Sale of Concur Technologies	0	990,000,000	0
Gain on sale of investments in Concur Technologies	0	744,000,000	$ 0
Carrying amount of Concur Technologies		246,000,000
QAH Tax Credits for equity method losses	53,000,000	47,000,000
Community Reinvestment Act Tax Credit Investments	638,000,000	622,000,000
QAH Investment Commitment	139,000,000
Loss from Affordable Housing Projects Equity Method Investments	50,000,000	$ 48,000,000
Affordable Housing Program Off Balance Sheet Obligation	$ 200,000,000
Earliest Year [Member]
Other Assets [Line Items]
Affordable Housing Tax Credits Commitment Year To Be Paid	2016
Latest Year [Member]
Other Assets [Line Items]
Affordable Housing Tax Credits Commitment Year To Be Paid	2029
Minimum [Member]
Other Assets [Line Items]
Intangible Assets, Useful Life	1 year	5 years
Maximum [Member]
Other Assets [Line Items]
Intangible Assets, Useful Life	22 years	7 years
Coupon and Certain Asset-Backed Securitization Maturities [Member]
Other Assets [Line Items]
Restricted cash	$ 155,000,000	$ 64,000,000
Airline [Member] | Customer Relationships [Member]
Other Assets [Line Items]
Other intangible assets, at amortized cost	255,000,000	340,000,000
Airline [Member] | Delta [Member] | Customer Relationships [Member]
Other Assets [Line Items]
Other intangible assets, at amortized cost	165,000,000	206,000,000
Prepaid Miles And Reward Points [Member] | Airline [Member]
Other Assets [Line Items]
Prepaid expenses	300,000,000	1,100,000,000
Prepaid Miles And Reward Points [Member] | Airline [Member] | Delta [Member]
Other Assets [Line Items]
Prepaid expenses	$ 0	$ 600,000,000