Fair Value Measurements - Reconciliation of Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Details) - Contingent consideration - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 43,000	$ 55,900	$ 42,400	$ 63,800
Change in fair value	500	12,200	1,100	4,300
Settlements	(4,500)	(15,000)	(4,500)	(15,000)
Balance at end of period	$ 39,000	$ 53,100	$ 39,000	$ 53,100