Debt - Schedule of Maturities of Long-Term Debt (Detail) $ in Thousands	Dec. 31, 2017 USD ($)
Debt Disclosure [Abstract]
2018	$ 1,125
2019	1,154
2020	205,392
2021	0
2022	11,200
Thereafter	700,000
Subtotal	918,871
Less unamortized debt issuance costs	(5,672)
Total outstanding debt	$ 913,199

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after accumulated amortization, of debt discount (premium).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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