Receivables and Allowance for Doubtful Accounts - Additional Information (Detail) - USD ($)	Sep. 30, 2022		Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	[1]	Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables	$ 103,695,000			$ 123,189,000
Allowance for doubtful accounts receivables	15,320,000	[1]	$ 30,271,000	33,957,000	$ 37,292,000		$ 36,244,000	$ 36,649,000
Customers and other	169,268,000			136,345,000
Aggregate carrying amount of receivables excluding financing fees and customer loans	517,527,000			560,391,000
Customer and Other Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customers and other	119,173,000			122,229,000
Financing Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts receivables	$ 0			$ 0

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