Capitalized Software Development Costs, Net - Summary of Capitalized Software Development Costs, Net (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Capitalized Computer Software Net [Line Items]
Gross carrying amount	$ 45,832	$ 45,677
Accumulated amortization	(31,982)	(32,784)
Net carrying amount	13,850	12,893
Capitalized Software Development Costs
Capitalized Computer Software Net [Line Items]
Gross carrying amount	$ 45,832	$ 45,677
Amortization period	3 years	3 years
Accumulated amortization	$ (31,982)	$ (32,784)
Net carrying amount	$ 13,850	$ 12,893