Indebtedness and Credit Agreement - Transactions and Maturity (Details) - USD ($) $ in Thousands							1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 11, 2019	Jun. 25, 2018	May 21, 2018	Apr. 29, 2018	Apr. 19, 2018	Apr. 12, 2018	Nov. 30, 2019	Nov. 30, 2019	Nov. 30, 2019	Dec. 01, 2018	Oct. 15, 2019	Mar. 15, 2019	Mar. 02, 2019	Dec. 20, 2018	Apr. 28, 2018
Indebtedness and credit agreements
Gain (loss) on debt retirements, net								$ 55,692	$ 55,692	$ (554)
Maturities
2020							$ 0	0	0
2021							0	0	0
2022							0	0	0
2023							0	0	0
2024							3,338,490	3,338,490	3,338,490
thereafter							266,387	$ 266,387	$ 266,387
Interest rate cap
Indebtedness and credit agreements
Derivative notional amount												$ 650,000
LIBOR | Interest rate cap
Indebtedness and credit agreements
Interest rate cap (as a percent)												2.75%
LIBOR | Minimum | 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	$ 84,097
Gain (loss) on debt retirements, net	32,416						18,510
Early redemption of debt	$ 51,300						38,392
Senior Notes 7.70 Percent And 6.875 Percent [Member] | Maximum
Indebtedness and credit agreements
Face amount of debt repurchased											$ 100,000
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%
7.7% notes due February 2027
Indebtedness and credit agreements
Notes redeemed and discharged							$ 18,075
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%
Face amount of debt repurchased							$ 15,000	$ 15,000	$ 15,000
Amount of debt repurchased							$ 10,012	$ 10,012	$ 10,012
9.25% senior notes due March 2020
Indebtedness and credit agreements
Gain (loss) on debt retirements, net						$ (3,422)
Debt instrument, stated interest rate (as a percent)						9.25%
Percentage of outstanding principal amount redeemed						100.00%
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
Gain (loss) on debt retirements, net		$ (18,075)	$ (8)
Debt instrument, stated interest rate (as a percent)		6.75%	6.75%		6.75%
6.125% senior notes due April 2023
Indebtedness and credit agreements
Notes redeemed and discharged			$ 4,759
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%
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			$ 2,700,000	$ 2,700,000	$ 2,700,000						$ 3,000,000
Gain (loss) on debt retirements, net				$ (1,091)