Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ 729	$ 458
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Depreciation, amortization and accretion	1,176	1,138
(Gains) losses on retirement of long-term obligations	2	106
Amortization of deferred financing costs and other non-cash interest	1	5
Stock-based compensation expense	91	79
Asset write-down charges	13	18
Deferred income tax (benefit) provision	2	2
Other non-cash adjustments	4	2
Changes in assets and liabilities, excluding the effects of acquisitions:
Increase (decrease) in accrued interest	(38)	(31)
Increase (decrease) in accounts payable	37	31
Increase (decrease) in other liabilities	102	144
Decrease (increase) in receivables	(166)	(74)
Decrease (increase) in other assets	(62)	(103)
Net cash provided by (used for) operating activities	1,891	1,775
Cash flows from investing activities:
Payments for acquisitions, net of cash acquired	(15)	(26)
Capital expenditures	(1,538)	(1,241)
Other investing activities, net	3	(14)
Net cash provided by (used for) investing activities	(1,550)	(1,281)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	1,895	2,743
Principal payments on debt and other long-term obligations	(59)	(76)
Purchases and redemptions of long-term debt	(12)	(2,346)
Borrowings under revolving credit facility	1,585	1,290
Payments under revolving credit facility	(2,270)	(1,465)
Payments for financing costs	(24)	(33)
Net proceeds from issuance of common stock	0	841
Purchases of Common Stock	(44)	(34)
Dividends/distributions paid on common stock	(1,415)	(1,315)
Dividends/distributions paid on preferred stock	(85)	(85)
Net cash provided by (used for) financing activities	(429)	(480)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(88)	14
Cash, cash equivalents and restricted cash at beginning of period	413	440
Cash, cash equivalents, and restricted cash at end of period	325	453
Effect of Exchange Rate on Cash and Cash Equivalents [Abstract]
Effect of exchange rate changes	$ 0	$ (1)