Significant Accounting Policies - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) segment shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2022 USD ($)
Property, Plant and Equipment [Line Items]
Number of operating segments | segment	1
Deferred offering costs	$ 0	$ 2,792
Impairment of property and equipment, net	0	0	$ 0
Capitalized computer software	3,400	1,700
Advertising expense	1,300	600	400
Stock-based compensation expense	32,727	5,380	4,826
Accounting Standards Update 2016-02 | Subsequent Event
Property, Plant and Equipment [Line Items]
Operating lease, right-of-use asset				$ 18,000
Total lease rental payment				$ 20,000
Capitalized software
Property, Plant and Equipment [Line Items]
Capitalized software amortization	600	$ 300	$ 100
Internal use software, expected amortization, year one	600
Internal use software, expected amortization, year two	300
Internal use software, expected amortization, year three	$ 100
Accounts Receivable | Customer Concentration Risk | Largest Customer
Property, Plant and Equipment [Line Items]
Concentration risk		11.00%
Revenue Benchmark | Customer Concentration Risk | Largest Customer
Property, Plant and Equipment [Line Items]
Concentration risk	18.00%	21.00%	11.00%
Outstanding stock options
Property, Plant and Equipment [Line Items]
Vesting period (in years)	4 years
Dividend yield	0.00%	0.00%	0.00%
Outstanding restricted stock units
Property, Plant and Equipment [Line Items]
Vesting period (in years)	4 years
Outstanding SARs
Property, Plant and Equipment [Line Items]
Stock-based compensation expense	$ 2,800
Outstanding SARs | Common Class B
Property, Plant and Equipment [Line Items]
Issuance of common stock upon settlement of SARs (in shares) | shares	1,642,570