CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 1,174	$ 1,096	$ 1,346
Other comprehensive income (loss):
Foreign currency translation adjustments	[1]	49	(84)	67
Fixed price diesel swaps		2	(2)	0
Other comprehensive (loss) income	[1]	51	(86)	67
Comprehensive income		$ 1,225	$ 1,010	$ 1,413

[1] There were no material reclassifications from accumulated other comprehensive loss reflected in other comprehensive income (loss) during the years ended December 31, 2019, 2018 or 2017. There is no tax impact related to the foreign currency translation adjustments, as the earnings are considered permanently reinvested (see note 14 to the consolidated financial statements for further discussion addressing this determination). There were no material taxes associated with other comprehensive income (loss) during the years ended December 31, 2019, 2018 or 2017.