Indebtedness and Credit Agreement - Transactions and Maturity (Details) - USD ($) $ in Thousands													1 Months Ended				3 Months Ended		12 Months Ended
	Feb. 19, 2020	Feb. 05, 2020	Jan. 06, 2020	Oct. 15, 2019	Oct. 11, 2019	Jun. 25, 2018	May 21, 2018	Apr. 29, 2018	Apr. 19, 2018	Apr. 12, 2018	Mar. 29, 2018	Feb. 27, 2018	Nov. 30, 2019	Nov. 30, 2019	Feb. 28, 2018	Jan. 31, 2018	Nov. 30, 2019	Jun. 02, 2018	Feb. 29, 2020	Mar. 02, 2019	Mar. 15, 2019	Dec. 20, 2018	Apr. 28, 2018	Mar. 13, 2018	Mar. 03, 2018
Indebtedness and credit agreements
Gain (loss) on debt retirements, net															$ (8,180)		$ 55,692	$ (554)	$ 55,692	$ (554)
Amount of receivables sold under Receivable Purchase Agreement	$ 501,422
Receipts from sale of receivables	$ 449,949
Interest Rates and Maturities
Annual weighted average rate (as a percent)																			5.70%	5.60%					7.10%
Maturities
2021																			$ 0
2022																			0
2023																			0
2024																			2,253,490
2025 and thereafter																			866,387
Interest rate cap
Indebtedness and credit agreements
Derivative notional amount																			$ 650,000		$ 650,000
Interest rate cap (as a percent)																			2.75%
Continuing operations
Indebtedness and credit agreements
Gain (loss) on debt retirements, net																			$ 55,692	$ (554)
LIBOR | Interest rate cap
Indebtedness and credit agreements
Interest rate cap (as a percent)																					2.75%
Senior Notes 7.70 Percent And 6.875 Percent [Member]
Indebtedness and credit agreements
Notes redeemed and discharged				$ 100,000	$ 84,097
Gain (loss) on debt retirements, net					32,416								$ 18,510
Early redemption of debt					$ 51,300								38,392
6.875% fixed-rate senior notes due December 2028
Indebtedness and credit agreements
Notes redeemed and discharged													$ 39,441
Debt instrument, stated interest rate (as a percent)				6.875%	6.875%								6.875%	6.875%			6.875%		6.875%	6.875%
7.7% notes due February 2027
Indebtedness and credit agreements
Notes redeemed and discharged													$ 18,075	$ 15,000
Gain (loss) on debt retirements, net														$ 4,766
Debt instrument, stated interest rate (as a percent)				7.70%	7.70%								7.70%	7.70%			7.70%		7.70%	7.70%
Early redemption of debt														$ 10,012
9.25% senior notes due March 2020
Indebtedness and credit agreements
Notes redeemed and discharged											$ 3,454
Gain (loss) on debt retirements, net										$ (3,422)
Debt instrument, stated interest rate (as a percent)										9.25%	9.25%	9.25%												9.25%
Percentage of outstanding principal amount redeemed										100.00%	0.38%
9.25% senior notes due March 2020 | Maximum
Indebtedness and credit agreements
Notes redeemed and discharged												$ 900,000
6.75% and 6.125% senior notes
Indebtedness and credit agreements
Notes redeemed and discharged									$ 700,000
6.75% and 6.125% senior notes | Maximum
Indebtedness and credit agreements
Notes redeemed and discharged									$ 700,000
6.75% senior notes due June 2021
Indebtedness and credit agreements
Notes redeemed and discharged						$ 805,169	$ 1,360				$ 3,471
Gain (loss) on debt retirements, net						$ (18,075)	$ (8)
Debt instrument, stated interest rate (as a percent)						6.75%	6.75%		6.75%		6.75%	6.75%
Percentage of outstanding principal amount redeemed											0.43%
6.125% senior notes due April 2023
Indebtedness and credit agreements
Notes redeemed and discharged		$ 600,000					$ 4,759				$ 41,751
Gain (loss) on debt retirements, net							$ (56)
Debt instrument, stated interest rate (as a percent)		6.125%	6.125%				6.125%		6.125%		6.125%	6.125%							6.125%	6.125%		6.125%
Percentage of outstanding principal amount redeemed											2.32%
6.125% senior notes due April 2023 | Continuing operations
Indebtedness and credit agreements
Gain (loss) on debt retirements, net																				$ (498)
Debt instrument, stated interest rate (as a percent)											6.125%
6.125% senior notes due April 2023 | Discontinued operations
Indebtedness and credit agreements
Gain (loss) on debt retirements, net											$ (49)
Debt instrument, stated interest rate (as a percent)											6.125%
6.125% senior notes due April 2023 | Maximum
Indebtedness and credit agreements
Notes redeemed and discharged			$ 600,000
Senior Notes 7.5 Percent [Member]
Indebtedness and credit agreements
Debt instrument, stated interest rate (as a percent)		7.50%	7.50%
Senior secured revolving credit facility due December 2023
Indebtedness and credit agreements
Maximum borrowing capacity																						$ 2,700,000
Senior secured revolving credit facility due January 2020
Indebtedness and credit agreements
Maximum borrowing capacity								$ 2,700,000							$ 3,000,000	$ 3,700,000						$ 2,700,000	$ 3,000,000
Gain (loss) on debt retirements, net								$ (1,091)
Tranche 1 Term Loan (second lien) due August 2020
Indebtedness and credit agreements
Notes redeemed and discharged																470,000
Tranche 2 Term Loan (second lien) due June 2021
Indebtedness and credit agreements
Notes redeemed and discharged																$ 500,000