CONSOLIDATED CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Cash flows provided by operating activities	$ 255	$ 22
Cash flows from investing activities
Acquisitions of property and equipment, net of change in related payables	(218)	(85)
Proceeds from the sale and maturity of investments	5	16
Payments to acquire investments	(7)	(14)
Payments for (Proceeds from) Other Investing Activities	2	0
Cash flows used in investing activities	(218)	(83)
Cash flows from financing activities
Debt issuance costs and fees	0	1
Repayments of long-term debt and revolving credit facilities	(116)	(16)
Proceeds from the issuance of common stock	0	3
Taxes paid related to net share settlement of equity awards	(5)	(12)
Financing obligation payments	(5)	(2)
Contributions from noncontrolling interest owners	0	20
Distributions to noncontrolling interest owners	(2)	0
Proceeds from (Payments for) Other Financing Activities	0	2
Cash flows used in financing activities	(128)	(6)
Net decrease in cash, cash equivalents, and restricted cash	(91)	(67)
Cash, cash equivalents, and restricted cash, beginning of period	1,657	2,709
Cash, cash equivalents, and restricted cash, end of period	1,566	2,642
Supplemental Cash Flow Information:
Cash paid for interest	231	247
Cash received/(paid) for income taxes	2	(2)
Change in accrued capital expenditures	$ (7)	$ (2)