Long-Term Obligations - August 2018 Refinancing - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended
Aug. 09, 2018	Aug. 31, 2018
Senior Notes - Due 2026 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Face amount	$ 500,000
Debt instrument interest rate	6.625%
Debt instrument maturity date	Aug. 31, 2026
Debt cost incurred		$ 2,270
Debt costs capitalized		6,230
Senior Notes - Due 2023 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Aug. 31, 2023
Write off of deferred financing costs		29
Debt costs capitalized		986
Senior Notes - Due 2023 [Member] \| Senior Notes [Member] \| Loans and Notes Payable [Member]
Debt Instrument [Line Items]
Debt repayments	$ 90,000
Term Loan Credit Agreement [Member] \| Secured Debt [Member]
Debt Instrument [Line Items]
Debt repayments	$ 400,000
Deferred financing costs and original issuance discount		1,824
Term Loan Credit Agreement [Member] \| Secured Debt [Member] \| Other Expense [Member]
Debt Instrument [Line Items]
Write off of deferred financing costs		$ 968

Face (par) amount of debt instrument at time of issuance.

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