CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 270	$ 141	$ 453	$ 250
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments		(21)	25	(46)	34
Fixed price diesel swaps		1	0	1	(1)
Other comprehensive (loss) income		(20)	25	(45)	33
Comprehensive income (loss)	[1]	$ 250	$ 166	$ 408	$ 283

[1] There were no material reclassifications from accumulated other comprehensive loss reflected in other comprehensive income (loss) during 2018 or 2017. There is no tax impact related to the foreign currency translation adjustments, as the earnings are considered permanently reinvested. There were no material taxes associated with other comprehensive income (loss) during 2018 or 2017.