Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Assets [Abstract]
Cash and cash equivalents	$ 4,827	$ 8,560	$ 5,753	$ 4,807
Securities borrowed or purchased under resale agreements	19,992		19,747
Other assets	8,927		8,496
Liabilities
Securities loaned or sold under repurchase agreements	25,079		24,616
Commercial paper and other short-term borrowings	3,487		2,360
Other Liabilities	2,383		2,520
Interest and Dividend Income, Operating [Abstract]
Securities borrowed or purchased under resale agreements	63	50
Interest Expense
Commercial paper and other short-term borrowings	8	3
Long-term debt	57	73
Securities loaned or sold under repurchase agreements	59	32
Noninterest Income
Fees from affiliates	219	212
Noninterest Expense
Other Noninterest Expense	120	129
Transferred Entities | Affiliated Entity
Assets [Abstract]
Cash and cash equivalents	105		102
Securities borrowed or purchased under resale agreements	2,386		2,765
Other assets	190		161
Liabilities
Related Party Deposit Liabilities	661		623
Securities loaned or sold under repurchase agreements	597		385
Commercial paper and other short-term borrowings	1,196		1,372
Long-term debt	5,966		6,042
Other Liabilities	124		$ 63
Interest and Dividend Income, Operating [Abstract]
Securities borrowed or purchased under resale agreements	7	6
Interest Expense
Commercial paper and other short-term borrowings	2	6
Long-term debt	28	7
Securities loaned or sold under repurchase agreements	1	0
Noninterest Income
Fees from affiliates	219	212
Other, net	2	0
Noninterest Expense
Other Noninterest Expense	$ 25	$ 24