Debt, Inventory Financing Facilities, Finance Leases and Other Financing Obligations - Schedule of Convertible Senior Notes Balances (Detail) - Convertible Senior Notes due 2025 [Member] - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Aug. 15, 2019
Liability:
Principal	$ 350,000,000	$ 350,000,000	$ 300,000,000
Less: debt discount and issuance costs, net of accumulated accretion	(56,531,000)	(65,164,000)
Net carrying amount	293,469,000	284,836,000
Equity, net of deferred tax	$ 44,731,000	$ 44,731,000