Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Total assets	$ 328,195	$ 2,899
Liabilities:
Total liabilities	0	557
Money market funds
Assets:
Money market funds	328,195	2,899
Contingent earn-out
Liabilities:
Contingent earn-out	0	557
Level 1
Assets:
Total assets	328,195	2,899
Liabilities:
Total liabilities	0	0
Level 1 | Money market funds
Assets:
Money market funds	328,195	2,899
Level 1 | Contingent earn-out
Liabilities:
Contingent earn-out	0	0
Level 2
Assets:
Total assets	0	0
Liabilities:
Total liabilities	0	0
Level 2 | Money market funds
Assets:
Money market funds	0	0
Level 2 | Contingent earn-out
Liabilities:
Contingent earn-out	0	0
Level 3
Assets:
Total assets	0	0
Liabilities:
Total liabilities	0	557
Level 3 | Money market funds
Assets:
Money market funds	0	0
Level 3 | Contingent earn-out
Liabilities:
Contingent earn-out	$ 0	$ 0