Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Valuation Allowance [Line Items]
Income tax (benefit) expense	$ (6,422)		$ (1,076)	$ (2,967)	$ 1,425
Settlement agreement	5,500
Decrease from uncertain tax positions				700
Decrease in income tax penalties and interest expense, uncertain tax positions				500
Decrease from prior uncertain tax positions				100
Decrease in income tax penalties and interest expense, prior uncertain tax positions				400
Reduction from lapse of statute of limitations				200
Goodwill acquired		$ 2,600
UNITED KINGDOM
Valuation Allowance [Line Items]
Deferred tax asset, valuation allowance	1,200			1,200
SWEDEN
Valuation Allowance [Line Items]
Deferred tax asset, valuation allowance	$ 2,000			$ 2,000