Other Comprehensive Income (Loss) - Narrative (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Equity [Abstract]
Total comprehensive earnings, net of tax	$ 985	$ 1,152	$ 774	$ 770	$ 519	$ 773	$ 2,911	$ 2,062