Income Taxes - Schedule of Net NOL Carryforwards (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
U.S. [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 192,358
Tax-effected NOL carryforwards	22,960
Valuation allowance	(6,212)
Net deferred tax asset - NOL carryforwards	$ 16,748
Expiration periods	2027
Expiration periods	indefinite
Luxembourg [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 9,946
Tax-effected NOL carryforwards	2,481
Valuation allowance	$ (2,481)
Expiration periods	2034
Expiration periods	indefinite
Germany [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 1,426
Tax-effected NOL carryforwards	226
Valuation allowance	$ (226)
Expiration periods	Indefinite
U.K. [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 5,416
Tax-effected NOL carryforwards	921
Valuation allowance	$ (921)
Expiration periods	Indefinite
Australia [Member]
Income Taxes [Line Items]
Gross NOL carryforwards	$ 12,939
Tax-effected NOL carryforwards	1,941
Net deferred tax asset - NOL carryforwards	$ 1,941
Expiration periods	Indefinite