Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 185	$ 193
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Depreciation, amortization and accretion	399	394
(Gains) losses on retirement of long-term obligations	0	1
Amortization of deferred financing costs and other non-cash interest	1	1
Stock-based compensation expense	37	29
Asset write-down charges	4	6
Deferred income tax (benefit) provision	1	1
Other non-cash adjustments	0	2
Changes in assets and liabilities, excluding the effects of acquisitions:
Increase (decrease) in accrued interest	(50)	(41)
Increase (decrease) in accounts payable	(20)	(5)
Increase (decrease) in other liabilities	2	(7)
Decrease (increase) in receivables	102	(43)
Decrease (increase) in other assets	(8)	(19)
Net cash provided by (used for) operating activities	653	512
Cash flows from investing activities:
Payments for acquisitions, net of cash acquired	(13)	(10)
Capital expenditures	(447)	(480)
Other investing activities, net	(8)	1
Net cash provided by (used for) investing activities	(468)	(489)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	0	996
Principal payments on debt and other long-term obligations	(26)	(25)
Purchases and redemptions of long-term debt	0	(12)
Borrowings under revolving credit facility	1,340	710
Payments under revolving credit facility	(595)	(1,140)
Net issuances (repayments) under commercial paper program	(155)	0
Payments for financing costs	0	(10)
Purchases of Common Stock	(73)	(42)
Dividends/distributions paid on common stock	(513)	(477)
Dividends/distributions paid on preferred stock	(28)	(28)
Net cash provided by (used for) financing activities	(50)	(28)
Net increase (decrease) in cash, cash equivalents, and restricted cash	135	(5)
Cash, cash equivalents and restricted cash at beginning of period	338	413
Cash, cash equivalents and restricted cash at end of period	472	408
Effect of Exchange Rate on Cash and Cash Equivalents [Abstract]
Effect of exchange rate changes	$ (1)	$ 0