Fair Value Disclosures (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Estimated Fair Values and Carrying Amounts of Assets and Liabilities

	Level in Fair Value Hierarchy	June 30, 2019				December 31, 2018
		Carrying  Amount		Fair Value		Carrying  Amount		Fair Value
Assets:
Cash and cash equivalents	1	$	288	$	288	$	277	$	277
Restricted cash, current and non-current	1	141		141		136		136
Liabilities:
Total debt and other obligations	2	17,569		18,351		16,682		16,562