Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 1,634	$ 1,251
Other comprehensive income (loss):
Net unrealized securities (losses) gains, net of tax	(11)	6
Foreign currency translation adjustments, net of tax	30	316
Net unrealized Pension and other postretirement benefits, net of tax	28	(8)
Other comprehensive income (loss)	47	314
Comprehensive income	$ 1,681	$ 1,565