Property and Equipment - Capitalized Software Development Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Capitalized internal use software development costs	$ 29,700	$ 25,300	$ 21,500
Stock-based compensation capitalized in software development costs	7,777	5,706	4,176
Amortization of capitalized software development costs	17,104	13,024	8,407
Cost of revenue
Property, Plant and Equipment [Line Items]
Amortization of capitalized software development costs	9,546	6,898	4,788
Research and development
Property, Plant and Equipment [Line Items]
Amortization of capitalized software development costs	7,345	5,437	$ 3,619
General and administrative
Property, Plant and Equipment [Line Items]
Amortization of capitalized software development costs	$ 213	$ 689