Annual report pursuant to Section 13 and 15(d)

Investments and Fair Value Measurements - Schedule of Changes in Fair Value of Estimated Contingent Consideration (Detail)

v3.20.4
Investments and Fair Value Measurements - Schedule of Changes in Fair Value of Estimated Contingent Consideration (Detail) - Level 3 - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]    
Balance at January 1, 2019 $ 15,921 $ 755
Additions to estimated contingent consideration   15,417
Payments of contingent consideration (741) (425)
Non-cash changes in fair value of estimated contingent consideration 1,222 174
Balance at December 31, 2019 $ 16,402 $ 15,921