Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		$ 299,181	$ 285,301
Mortgage Servicing Rights, Fair Value [Member]
Fees and Commissions, Mortgage Banking and Servicing	[1]	437	403	$ 366
Principal Amount Outstanding of Loans Serviced For Third Parties		140,801	136,071
Unpaid Principal Balance of Outstanding Underlying MSRs Purchased		7,000	0
Principal Amount Sold on Loans Serviced for Third Parties		1,100	1,100
Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		146,208	139,920
Commercial Mortgage Servicing Rights [Member]
Fees and Commissions, Mortgage Banking and Servicing	[2]	26	22	1
Principal Amount Outstanding of Loans Serviced		34,539	30,054
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		6,399	5,760
Servicing Asset at Amortized Cost		66	65
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		139,809	134,160
Pillar Financial [Member]
Fees and Commissions, Mortgage Banking and Servicing	[2]	13	14	$ 1
Principal Amount Outstanding of Loans Serviced For Third Parties		$ 28,140	$ 24,294

[1] Recognized in Mortgage related income in the Consolidated Statements of Income.

[2] Recognized in Commercial real estate related income in the Consolidated Statements of Income.