Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Bank Servicing Fees		$ 52	$ 30	$ 114	$ 73
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	267,716		267,716		$ 258,212
Servicing Asset at Fair Value, Amount		1,061		1,061
Mortgage Servicing Rights, Fair Value [Member]
Bank Servicing Fees		92	83	179	166
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		154,500		154,500		148,200
Principal Amount Outstanding of Loans Serviced For Third Parties		125,400		125,400		121,000
Unpaid Principal Balance of Outstanding Underlying MSRs Purchased				8,100	10,300
Unpaid Principal Balance of Outstanding Underlying MSRs Transferred					0
Principal Amount Sold on Loans Serviced for Third Parties				351	407
Servicing Asset at Fair Value, Amount		1,061	1,393	1,061	1,393	1,307	$ 1,206
Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1],[2]	122,646		122,646		117,797
indirect auto loan servicing rights [Member]
Bank Servicing Fees		2	1	4	1
Servicing Asset			13		$ 13
Servicing Asset at Fair Value, Amount		6		6
Consumer Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1],[2]	$ 652		$ 652		$ 807
Proceeds from Securitizations of Consumer Loans			$ 1,000

[1] Excludes $2.5 billion and $1.8 billion of LHFS at June 30, 2016 and December 31, 2015, respectively.

[2] Excludes loans that have completed the foreclosure or short sale process (i.e., involuntary prepayments)