Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Summary of Reconciliation of Denominator Used in Calculation of Basic and Diluted Loss Per Share

A reconciliation of the denominator used in the calculation of basic and diluted loss per share is as follows:

	Year Ended December 31,
	2021			2020			2019
	(in thousands, except per share amounts)
Net loss	$	(77,837	)	$	(85,031	)	$	(53,746	)
Weighted-average common shares outstanding—basic		46,891			44,757			42,025
Dilutive effect of share equivalents resulting from stock    options, RSUs, ESPP, Warrants and the Conversion Options		—			—			—
Weighted-average common shares outstanding-diluted		46,891			44,757			42,025
Net loss per common share, basic and diluted	$	(1.66	)	$	(1.90	)	$	(1.28	)

Schedule of Potentially Dilutive Common Stock Equivalents

The following table contains all potentially dilutive common stock equivalents.

	Year Ended December 31,
	2021		2020		2019
	(in thousands)
Options to purchase common shares		584		1,020		1,489
RSUs		1,239		1,561		1,207
Conversion Option of the 2022 Notes and Warrants		1,326		1,873		3,104
Conversion Option of the 2025 Notes		1,020		318		—
ESPP		13		21		2

Schedule of Roll Forward of Company's Allowance for Doubtful Accounts

The following is a roll-forward of the Company’s allowance for doubtful accounts (in thousands):

	Balance Beginning of Period		Charged to Statement of Operations		Deductions  (1)			Balance at End of Period
Allowance for doubtful accounts
Year ended December 31, 2021	$	1,993	$	6,144	$	(6,369	)	$	1,768
Year ended December 31, 2020	$	1,584	$	8,501	$	(8,092	)	$	1,993
Year ended December 31, 2019	$	1,317	$	7,895	$	(7,628	)	$	1,584

(1) Deductions include actual accounts written-off, net of recoveries. 

Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash

The following table provides a reconciliation of the cash, cash equivalents and restricted cash within the consolidated balance sheets that sum to the total of the same such amounts shown in the statement of cash flows for the year ended December 31, 2021 and 2020.

	December 31, 2021		December 31, 2020
	(in thousands)
Cash and cash equivalents	$	377,013	$	378,123
Restricted cash, included in other assets		3,029		3,029
Total cash, cash equivalents, and restricted cash	$	380,042	$	381,152

Schedule of Property Plant and Equipment Useful Life

Depreciation is recorded over the following estimated useful lives:

	Estimated Useful Life
Employee related computer equipment	2 - 3 years
Computer equipment and purchased software	3 years
Furniture and fixtures	5 years
Internal use software	5 years
Leasehold improvements	Lesser of lease term or useful life

Summary of Capitalized Software Development Costs, Exclusive of those Costs Recorded within Property and Equipment

Capitalized software development costs, exclusive of those costs recorded within property and equipment, consisted of the following:

	December 31, 2021			December 31, 2020
	(in thousands)
Gross capitalized software development costs	$	122,592		$	85,630
Accumulated amortization		(82,734	)		(60,687	)
Capitalized software development costs, net	$	39,858		$	24,943