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Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Valuation Allowances for Deferred Tax Assets [Member] |  |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Year | $ 213,847 | $ 193,987 | $ 159,540
Charged (Credited) to Statement of Operation | 123,977 | 19,860 | 34,447
Charged to Other Accounts - Liabilities and Equity | 0 | 0 | 0
Deductions, Net | 0 | 0 | 0
Balance at End of Year | 337,824 | 213,847 | 193,987
Valuation Allowance for Rebates and Discounts [Member] |  |  |
Valuation And Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Year | 1,102 | 0 |
Charged (Credited) to Statement of Operation | 16,497 | 1,102 |
Charged to Other Accounts - Liabilities and Equity | (14,867) | 0 |
Deductions, Net | (2,184) | 0 |
Balance at End of Year | $ 548 | $ 1,102 | $ 0

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- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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