Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Commitments and Contingencies Disclosure [Abstract]

Schedule of Loss Contingencies by Contingency

The following table summarizes the activity in the Company’s accrued obligations for personal injury claims (in millions):

	Years ended December 31,
	2019			2018			2017
Beginning balance	$	308		$	307		$	367
Accruals / changes in estimates	80			76			(1		)
Payments	(113		)	(75		)	(59		)
Ending balance	$	275		$	308		$	307
Current portion of ending balance	$	75		$	80		$	85

Accrued Obligations for Environmental Matters

The following table summarizes the activity in the Company’s accrued obligations for environmental matters (in millions):

	Years ended December 31,
	2019			2018			2017
Beginning balance	$	298		$	317		$	342
Accruals / changes in estimates	5			—			5
Payments	(21		)	(19		)	(30		)
Ending balance	$	282		$	298		$	317
Current portion of ending balance	$	40		$	40		$	40