Shareholders' Equity - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Equity [Abstract]
Net unrealized gains (losses) on cash flow hedges	$ 82		$ (63)
Net unrealized gains on available-for-sale securities portfolio	976		509
Net unrealized (losses) gains related to reclassified available-for-sale securities	(68)		56
Net unrealized gains on available-for-sale securities	908		565
Net unrealized (losses) on available-for-sale securities designated in fair value hedges	(36)		(41)
Net unrealized (losses) gains on hedges of net investments in non-U.S. subsidiaries	(54)		91
Non-credit impairment on held-to-maturity securities previously identified under ASC 320	(2)		(1)
Net unrealized (losses) on retirement plans	(172)		(180)
Foreign currency translation	(837)		(1,356)
Total	$ (111)	$ (876)	$ (985)