Consolidated Condensed Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Cash Flows [Abstract]
Cash flows provided by/(used in) operating activities	$ (20)	$ 255
Cash flows from investing activities
Acquisitions of property and equipment, net of change in related payables	(184)	(218)
Proceeds from the sale and maturity of investments	9	5
Payments to acquire investments	0	(7)
Other	0	2
Cash flows used in investing activities	(175)	(218)
Cash flows from financing activities
Proceeds from long-term debt and revolving credit facilities	1,138	0
Repayments of long-term debt and revolving credit facilities	(16)	(116)
Proceeds from the issuance of common stock	1	0
Taxes paid related to net share settlement of equity awards	(3)	(5)
Financing obligation payments	(3)	(5)
Distributions to noncontrolling interest owners	0	(2)
Cash flows provided by/(used in) financing activities	1,117	(128)
Net increase/(decrease) in cash, cash equivalents, and restricted cash	922	(91)
Cash, cash equivalents, and restricted cash, beginning of period	1,884	1,657
Cash, cash equivalents, and restricted cash, end of period	2,806	1,566
Supplemental Cash Flow Information:
Cash paid for interest	201	231
Cash received/(paid) for income taxes	(1)	2
Non-cash investing and financing activities:
Change in accrued capital expenditures	$ (36)	$ (7)