Fair Value Measurements (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Carrying Value | Other current assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 280	$ 275
Carrying Value | Derivative Liability | Level 2 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	(39,086)	(23,237)
Carrying Value | Term debt | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of term debt	(264,250)	(721,875)
Carrying Value | 2024 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(450,000)	(450,000)
Carrying Value | 2025 senior notes | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(1,000,000)	0
Carrying Value | 2027 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(500,000)	(500,000)
Carrying Value | 2028 senior notes | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(300,000)	0
Carrying Value | 2029 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(500,000)	(500,000)
Fair Value | Other current assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	280	275
Fair Value | Derivative Liability | Level 2 | Interest rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability	(39,086)	(23,237)
Fair Value | Term debt | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of term debt	(253,680)	(725,484)
Fair Value | 2024 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(451,125)	(462,375)
Fair Value | 2025 senior notes | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(1,043,750)	0
Fair Value | 2027 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(507,500)	(535,000)
Fair Value | 2028 senior notes | Long-Term Debt | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	(318,000)	0
Fair Value | 2029 senior notes | Long-Term Debt | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of notes	$ (505,625)	$ (539,375)