Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trading assets pledged to various parties	$ 118,200	$ 120,437
Investment securities at fair value	63,038	61,061
Securities purchased under agreement to resell at fair value	4	0
Loans held for investment, allowance	265	238
Intangible assets, accumulated amortization	3,044	2,877
Deposits at fair value	934	442
Securities sold under agreement to repurchase at fair value	658	812
Other secured financings at fair value	8,476	5,245
Borrowings at fair value	$ 61,509	$ 51,184
Common stock, par value (USD per share)	$ 0.01	$ 0.01
Common stock authorized (shares)	3,500,000,000	3,500,000,000
Common stock issued (shares)	2,038,893,979	2,038,893,979
Common stock outstanding (shares)	1,658,805,108	1,699,828,943
Common stock held in treasury (shares)	380,088,871	339,065,036