Receivables and Allowance for Doubtful Accounts - Schedule of Activity in Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Allowance For Doubtful Accounts Receivable Rollforward
Allowance for doubtful accounts receivables, Beginning balance		$ 36,649	[1]	$ 27,130	[1]	$ 40,164
Adjustment for adoption of new accounting guidance				7,575
Bad debt expense, net of reversals		3,807		3,991		(5,080)
Charge-offs, foreign currency translation and other adjustments		(6,499)		(2,047)		(7,954)
Allowance for doubtful accounts receivables, Ending balance	[1]	$ 33,957		$ 36,649		$ 27,130

[1] The allowance for doubtful accounts balances are substantially all related to M&A and Restructuring fee receivables that include reimbursable expense receivables.