Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020	Dec. 31, 2019	Jun. 30, 2019	Feb. 28, 2018
Debt Instrument [Line Items]
Allowance for credit loss, contract balances	$ 300,000			$ 0
Provision for expected credit losses, contract balances	200,000
Writeoffs, contract balances	0
Unbilled receivables	4,000,000.0			4,300,000
Allowance reserve	400,000			0
Provision for expected credit losses, accounts receivable	300,000
Writeoffs, accounts receivable	100,000
Allowance for credit losses, sales credits	500,000			$ 500,000
Capitalized costs	0	$ 0
Amortization of capitalized software development costs	200,000	200,000
Advertising costs	200,000	300,000
Unrecognized Tax Benefits	10,700,000
Amount of unrecognized tax benefits, reasonably possible to be resolved	$ 10,000,000.0
Warrant strike price (usd per share)						$ 78.75
Convertible Senior Notes Due February 2023 | Convertible Debt
Debt Instrument [Line Items]
Principal amount						$ 230,000,000.0
Conversion price (usd per share)						$ 57.38
Convertible Senior Notes Due June 2026 | Convertible Debt
Debt Instrument [Line Items]
Principal amount					$ 316,300,000
Conversion price (usd per share)	$ 88.61				$ 88.61
Initial cap price (in usd per share)	$ 139.00				$ 139.00
Software and Software Development Costs
Debt Instrument [Line Items]
Capitalized costs	$ 300,000	0
Amortization of capitalized software development costs	$ 0	$ 0
Accounting Standards Update 2016-13
Debt Instrument [Line Items]
Allowance for credit loss, contract balances			$ 100,000
Allowance reserve			$ 200,000