Income Taxes - Schedule of Net NOL and Other Tax Attribute Carryforwards (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)
U.S. [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 159,895
Tax-effected NOL carryforwards	16,298
Valuation allowance	(6,193)
Net deferred tax asset - NOL carryforwards	$ 10,105
Expiration periods	2029
Expiration periods	indefinite
Foreign [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 528,567
Tax-effected NOL carryforwards	133,703
Valuation allowance	(30,784)
Net deferred tax asset - NOL carryforwards	$ 102,919
Expiration periods	indefinite

The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

Name:	us-gaap_OperatingLossCarryforwardsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant