Consolidated Statement of Comprehensive Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Foreign currency translation, Taxes	$ (40,000,000)	$ 2,000,000	$ (8,000,000)
Change in net unrealized gains (losses) on available-for-sale securities, Taxes	165,000,000	212,000,000	(134,000,000)
Change in net unrealized gains (losses) on available-for-sale securities designated in fair value hedges, Taxes	1,000,000	6,000,000	9,000,000
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, Taxes	0	1,000,000	2,000,000
Change in net unrealized gains (losses) on cash flow hedges, Taxes	46,000,000	9,000,000	(17,000,000)
Change in unrealized gains (losses) on retirement plans, Taxes	$ 3,000,000	$ (8,000,000)	$ 8,000,000