Long-Term Debt Obligations - Schedule of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Debt Disclosure [Abstract]
Contractual interest coupon	$ 10,359	$ 10,548
Amortization of debt issuance costs	1,470	1,615
Amortization of debt discounts	28,074	29,859
Total	$ 39,903	$ 42,022

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

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Amount of amortization expense attributable to debt issuance costs.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs.

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