Income Taxes - Schedule of Changes in Balance of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021		Mar. 31, 2020
Income Tax Contingency [Line Items]
Beginning balance		$ 27,016
Decrease -Lapse of statute of limitations		(5,171)	[1]	$ (5,981)
Increases		39
Foreign currency translation	[2]	338
Ending balance		22,222
Unrecognized Tax Benefits [Member]
Income Tax Contingency [Line Items]
Beginning balance		21,850
Decrease -Lapse of statute of limitations	[1]	(3,559)
Foreign currency translation	[2]	273
Ending balance		18,564
Interest And Penalties [Member]
Income Tax Contingency [Line Items]
Beginning balance		5,166
Decrease -Lapse of statute of limitations	[1]	(1,612)
Increases		39
Foreign currency translation	[2]	65
Ending balance		$ 3,658

[1] Recorded as an income tax benefit of $5,171 during the three months ended March 31, 2021, along with an equal and offsetting amount recorded in other losses, net, to recognize a reduction in the indemnification asset. During the three months ended March 31, 2020, an income tax benefit of $5,981 was recorded along with an equal and offsetting amount in other losses, net.

[2] The gross unrecognized tax benefits were accrued in British pounds sterling.