Accumulated Other Comprehensive Loss (Additional Information) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	$ 7	$ 9
Tax benefit (cost) related to unrealized currency translation adjustments other than translation of foreign denominated balance sheets	(19)	4	$ 141
Tax benefit (cost) related to the adjustment for pension and other postretirement benefits	57	(34)	(33)
Cumulative tax benefit related to the adjustment for pension and other postretirement benefits	266	209
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	$ 1	$ 2	$ 5