CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 506	$ 377	$ 981	$ 691
Items related to employee benefit plans:
Change in net actuarial loss, net of $(12), $(13), (24) and $(25) tax	38	39	76	77
Change in net prior service cost, net of $—, $(1), (1) and $(1) tax	1	2	2	3
Reclassification of realized loss on interest rate swaps to net income, net of $(5), $(5), (10) and $(5) tax	16	11	31	16
Unrealized holding loss on interest rate swaps, net of $—, $2, — and $28 tax	0	(8)	0	(88)
Foreign currency translation adjustment, net of $(4), $(4), 3 and $19 tax	80	9	(6)	(230)
Other comprehensive income (loss)	135	53	103	(222)
COMPREHENSIVE INCOME	$ 641	$ 430	$ 1,084	$ 469