Long-Lived Assets - Summary of Carrying Values of Client Contract Cost Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Capitalized Contract Cost [Line Items]
Gross Carrying Amount	$ 82,272	$ 80,340
Accumulated Amortization	(31,526)	(43,051)
Net Amount	50,746	37,289
Client contract incentives
Capitalized Contract Cost [Line Items]
Gross Carrying Amount	4,626	28,366
Accumulated Amortization	(1,612)	(20,833)
Net Amount	3,014	7,533
Capitalized costs
Capitalized Contract Cost [Line Items]
Gross Carrying Amount	68,085	44,469
Accumulated Amortization	(26,482)	(20,230)
Net Amount	41,603	24,239
Capitalized commission fees
Capitalized Contract Cost [Line Items]
Gross Carrying Amount	9,561	7,505
Accumulated Amortization	(3,432)	(1,988)
Net Amount	$ 6,129	$ 5,517