Capitalized Software Development Costs - Summary of Capitalized Software Development Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Capitalized Computer Software Net [Line Items]
Gross carrying amount	$ 45,677	$ 36,899
Accumulated amortization	(32,784)	(26,894)
Net carrying amount	12,893	10,005
Capitalized Software Development costs
Capitalized Computer Software Net [Line Items]
Gross carrying amount	$ 45,677	$ 36,899
Amortization period	3 years	3 years
Accumulated amortization	$ (32,784)	$ (26,894)
Net carrying amount	$ 12,893	$ 10,005