Fair Value Measurements - Contingent Consideration Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Contingent consideration liabilities measured at fair value
Balance at beginning of period	$ 12,485
Balance at end of period	8,267
Fair value | Level 3
Contingent consideration liabilities measured at fair value
Balance at beginning of period	12,485
Fair value adjustments included in operating expenses	(4,218)
Balance at end of period	$ 8,267