Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 367	$ 1,550
Other comprehensive loss:
Net unrealized debt securities gains, net of tax	57	17
Foreign currency translation adjustments, net of tax	(322)	8
Net unrealized pension and other postretirement benefits, net of tax	6	(27)
Other comprehensive loss	(259)	(2)
Comprehensive income	$ 108	$ 1,548