Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 1,237	$ 1,426
Other comprehensive income (loss):
Net unrealized securities gains, net of tax	6	2
Foreign currency translation adjustments, net of tax	316	4
Pension and other postretirement benefit gains	(8)	26
Other comprehensive income (loss)	314	32
Comprehensive income	$ 1,551	$ 1,458