Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows provided from (used by) operating activities:
Net loss	$ (5,911)	$ (643)	$ (1,804)
Adjustments to reconcile net loss to net cash provided from (used by) operating activities:
Depreciation and amortization	1,780	1,954	2,184
(Gain) Loss on early extinguishment of debt	20	(32)	88
Pension settlement costs	57	41	83
Special termination benefits	44		5
Stock-based compensation expense	15	18	14
Amortization of deferred financing costs	30	34	33
Other adjustments		(32)	(14)
Deferred income taxes	(619)	(67)	(1,385)
Goodwill Impairment	5,725	641	2,748
Loss on disposal of Northwest Operations	446
Change in accounts receivable	48	65	122
Change in accounts payable and other liabilities	(122)	(141)	(298)
Change in prepaid expenses, income taxes and other assets	(5)	(26)	74
Net cash provided from operating activities	1,508	1,812	1,850
Cash flows provided from (used by) investing activities:
Capital expenditures - Business operations	(1,226)	(1,192)	(1,154)
Capital expenditures - Integration activities			(34)
Proceeds on sale of assets	88	11	110
Other	4	5	24
Net cash used by investing activities	(1,134)	(1,176)	(1,054)
Cash flows provided from (used by) financing activities:
Long-term debt payments	(2,008)	(2,515)	(1,811)
Proceeds from long-term debt borrowings	1,650	1,840	1,500
Proceeds from revolving debt	949	525
Repayment of revolving debt	(475)	(250)
Financing costs paid	(44)	(43)	(15)
Dividends paid on common stock			(266)
Dividends paid on preferred stock		(107)	(214)
Premium paid to retire debt		(17)	(86)
Finance lease obligation payments	(35)	(36)	(42)
Other	(5)	(5)	(8)
Net cash provided from (used by) financing activities	32	(608)	(942)
Increase (Decrease) in cash, cash equivalents and restricted cash	406	28	(146)
Cash, cash equivalents and restricted cash at January 1,	404	376	522
Cash, cash equivalents and restricted cash at December 31,	810	404	376
Cash paid (received) during the period for:
Interest	1,469	1,507	1,548
Income tax payments (refunds), net	4	4	(51)
Non-cash investing and financing activities:
Financing obligation for contributions of real property to pension plan		37
Reduction of pension obligation		$ 37
Increase (Decrease) in capital expenditures due to changes in accounts payable	$ 13		$ 50