Accrued Liabilities and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Payroll and other employee related costs	$ 19,014	$ 16,431
Professional services, consulting and other vendor fees	17,461	15,674
Unrecognized tax benefits	1,913	4,924
Sales commissions	6,239	5,259
Contingent earn-out (Note 8)	2,372	0
Restructuring Reserve	977	2,338	$ 2,551
Other	2,686	3,385
Total	$ 50,662	$ 48,011