Accrued Expenses and Other Current Liabilities - Summary of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued expenses	$ 48,797	$ 44,711
Derivative instruments	928	3,204
Client liabilities	6,493	6,933
Other current liabilities	8,789	9,321
Accrued expenses and other current liabilities	$ 65,007	$ 64,169