Fair Value Measurements - Carrying Values and Estimated Fair Values of Financial Instruments (Details) - Level 2 - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt	$ 2,175,000	$ 2,175,000
Estimated Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total debt	1,992,879	2,181,750
Term Loan, Secured Due April 2024 | Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Term loan	975,000	975,000
Term Loan, Secured Due April 2024 | Estimated Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Term loan	972,563	975,000
6.875% Notes, Unsecured, Due April 2022, Issued 2017 | Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	700,000	700,000
6.875% Notes, Unsecured, Due April 2022, Issued 2017 | Estimated Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	610,316	701,750
7.125% Notes, Unsecured, Due April 2025, Issued 2017 | Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	500,000	500,000
7.125% Notes, Unsecured, Due April 2025, Issued 2017 | Estimated Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Notes payable	$ 410,000	$ 505,000