Borrowings - Components of Long-term Borrowings (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Less: unamortized discount and debt issuance costs	$ (1,423)	$ (3,247)
Total borrowings, net	306,567	304,743
Less: current portion of long-term borrowings, net	306,567
Long-term borrowings, net	0	304,743
Exchangeable Senior Notes [Member] \| 5.0% Exchangeable Senior Notes due March 2021 [Member]
Debt Instrument [Line Items]
Long-term borrowings	83,740	83,740
Senior Notes [Member] \| 6.625% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Long-term borrowings	$ 224,250	$ 224,250

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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