Fair Value of Financial Assets and Liabilities - Changes in Level 3 Liabilities Measured at Fair Value on Recurring Basis (Detail) - Level 3 - Accounts Payable Accrued and Other Liabilities - Contingent Consideration - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 32,975	$ 35,107	$ 39,791	$ 42,159
Total realized and unrealized (gains) losses included in Net income (loss)	74	1,541	2,013	1,173
Unrealized (gains) losses included in Other comprehensive income (loss)	0	0	0	67
Purchases/ Issuances	0	0	0	2,959
Sales/ Settlements	(5,565)	(133)	(14,320)	(9,843)
Closing Balance	27,484	36,515	27,484	36,515
Net income (loss) on Level 3 Assets/ Liabilities Outstanding	74	1,541	2,013	1,173
Other comprehensive income (loss) on Level 3 Assets / Liabilities Outstanding	$ 0	$ 0	$ 0	$ 67