Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Cash and cash equivalents	$ 109,559	$ 91,436
Marketable Securities		23,280
Cash
Assets
Cash and cash equivalents	39,309	44,616
Money market funds
Assets
Cash and cash equivalents	70,250	46,820
Domestic corporate debt securities
Assets
Marketable Securities		18,285
Domestic corporate commercial paper
Assets
Marketable Securities		4,995
Recurring basis
Assets
Cash and cash equivalents	109,559	91,436
Marketable Securities		23,280
Recurring basis | Cash
Assets
Cash and cash equivalents	39,309	44,616
Recurring basis | Money market funds
Assets
Cash and cash equivalents	70,250	46,820
Recurring basis | Domestic corporate debt securities
Assets
Marketable Securities		18,285
Recurring basis | Domestic corporate commercial paper
Assets
Marketable Securities		4,995
Recurring basis | Level 1
Assets
Cash and cash equivalents	109,559	91,436
Marketable Securities		0
Recurring basis | Level 1 | Cash
Assets
Cash and cash equivalents	39,309	44,616
Recurring basis | Level 1 | Money market funds
Assets
Cash and cash equivalents	70,250	46,820
Recurring basis | Level 1 | Domestic corporate debt securities
Assets
Marketable Securities		0
Recurring basis | Level 1 | Domestic corporate commercial paper
Assets
Marketable Securities		0
Recurring basis | Level 2
Assets
Cash and cash equivalents	0	0
Marketable Securities		23,280
Recurring basis | Level 2 | Cash
Assets
Cash and cash equivalents	0	0
Recurring basis | Level 2 | Money market funds
Assets
Cash and cash equivalents	0	0
Recurring basis | Level 2 | Domestic corporate debt securities
Assets
Marketable Securities		18,285
Recurring basis | Level 2 | Domestic corporate commercial paper
Assets
Marketable Securities		4,995
Recurring basis | Level 3
Assets
Cash and cash equivalents	0	0
Marketable Securities		0
Recurring basis | Level 3 | Cash
Assets
Cash and cash equivalents	0	0
Recurring basis | Level 3 | Money market funds
Assets
Cash and cash equivalents	$ 0	0
Recurring basis | Level 3 | Domestic corporate debt securities
Assets
Marketable Securities		0
Recurring basis | Level 3 | Domestic corporate commercial paper
Assets
Marketable Securities		$ 0