Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Deposits	$ 17,485	$ 6,641
Accrued IT and software licensing costs	3,359	2,261
Accrued taxes and insurance premiums	4,160	2,697
Accrued facilities rental and lease exit costs	2,271	1,673
Accrued interest	308	705
Accrued professional services	1,828	1,318
Accrued dividends	2,639
Contingent liabilities from acquisitions	2,323
Other accrued expenses and current liabilities	4,699	2,277
Total accrued expenses and other current liabilities	$ 39,072	$ 17,572