Supplemental Cash Flow Information (Tables)

12 Months Ended

Dec. 31, 2017

Supplemental Cash Flow Elements [Abstract]

Schedule of supplemental cash flow information

Supplemental cash flow information is as follows (amounts in millions):

	For the Years Ended December 31,
	2017		2016		2015
Supplemental cash flow information:
Cash paid for income taxes, net of refunds	$	176	$	121	$	20
Cash paid for interest	145		209		193