Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue		$ 886,093	$ 779,796	$ 486,920
Cost of revenue		653,983	635,693	367,496
Gross profit		232,110	144,103	119,424
Operating expenses
Technology and development		84,297	69,765	53,797
Marketing		54,881	76,710	44,061
General and administrative(1)	[1]	92,140	76,874	65,500
Total operating expenses		231,318	223,349	163,358
Income (loss) from operations		792	(79,246)	(43,934)
Interest income		2,074	7,146	5,416
Interest expense		(19,495)	(8,928)	(3,681)
Other income (loss), net		(1,898)	223	221
Net loss		(18,527)	(80,805)	(41,978)
Temporary Equity, Dividends, Adjustment		(4,454)	0	0
Net loss attributable to common stock—basic		(22,981)	(80,805)	(41,978)
Net loss attributable to common stock—diluted		$ (22,981)	$ (80,805)	$ (41,978)
Net loss per share attributable to common stock—basic and diluted (in dollars per share)		$ (0.23)	$ (0.88)	$ (0.49)
Weighted average shares of common stock—basic and diluted (in shares)		98,574,529	91,583,533	85,669,039
Net loss		$ (22,981)	$ (80,805)	$ (41,978)
Other comprehensive income
Foreign currency translation adjustments		(3)	33	0
Unrealized gain on available-for-sale securities		172	9	0
Other Comprehensive Income (Loss), Tax		169	42	0
Total comprehensive loss		(18,358)	(80,763)	(41,978)
Service
Revenue		674,345	539,288	441,927
Cost of revenue		437,484	390,504	320,883
Product
Revenue		211,748	240,508	44,993
Cost of revenue		$ 216,499	$ 245,189	$ 46,613

[1] (1) Includes direct and incremental costs related to COVID-19 of $7,864, which are partially offset by $1,348 in employee retention credits allowed under the CARES Act, for the year ended December 31, 2020.