CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Cash Flows [Abstract]
Cash flows provided by operating activities	$ 22	$ 119
Cash flows from investing activities
Acquisitions of property and equipment, net of change in related payables	(85)	(72)
Proceeds from the sale and maturity of investments	16	5
Payments to acquire investments	(14)	(16)
Cash flows used in investing activities	(83)	(83)
Cash flows from financing activities
Debt issuance costs and fees	1	0
Repayments of long-term debt and revolving credit facilities	(16)	(54)
Proceeds from Issuance of Common Stock	3	4
Payments Related to Tax Withholding for Share-based Compensation	(12)	(7)
Repayments of Other Debt	(2)	0
Proceeds from Noncontrolling Interests	20	0
Distributions to noncontrolling interest owners	0	(5)
Other	2	0
Cash flows used in financing activities	(6)	(62)
Net decrease in cash, cash equivalents, and restricted cash	(67)	(26)
Cash, cash equivalents, and restricted cash, beginning of period	2,709	4,658
Cash, cash equivalents, and restricted cash, end of period	2,642	4,632
Supplemental Cash Flow Information:
Cash paid for interest	247	75
Cash received for income taxes	(2)	0
Change in accrued capital expenditures	$ (2)	$ (2)