Property and Equipment, net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Owned Assets:
Owned assets, gross	$ 209,260	$ 207,318
Less: Accumulated depreciation and amortization	(143,553)	(141,059)
Owned assets, net	65,707	66,259
Assets under capital leases:
Capital leased assets, gross	1,501	1,818
Less: Accumulated depreciation and amortization	(1,096)	(1,320)
Assets under capital leases, net	405	498
Property and equipment, net	66,112	66,757
Network equipment and computers
Owned Assets:
Owned assets, gross	77,183	77,587
Software
Owned Assets:
Owned assets, gross	63,827	59,325
Leasehold improvements
Owned Assets:
Owned assets, gross	37,506	38,857
Assets under capital leases:
Capital leased assets, gross	812	941
Office furniture and equipment
Owned Assets:
Owned assets, gross	19,823	19,667
Assets under capital leases:
Capital leased assets, gross	77	167
Motor vehicles
Owned Assets:
Owned assets, gross	597	638
Assets under capital leases:
Capital leased assets, gross	$ 612	710
Buildings
Owned Assets:
Estimated useful lives	30 years
Owned assets, gross	$ 1,162	1,245
Land
Owned Assets:
Owned assets, gross	760	815
Capital work in progress
Owned Assets:
Owned assets, gross	$ 8,402	$ 9,184
Minimum | Network equipment and computers
Owned Assets:
Estimated useful lives	3 years
Minimum | Software
Owned Assets:
Estimated useful lives	3 years
Minimum | Leasehold improvements
Owned Assets:
Estimated useful lives	3 years
Minimum | Office furniture and equipment
Owned Assets:
Estimated useful lives	3 years
Minimum | Motor vehicles
Owned Assets:
Estimated useful lives	2 years
Maximum | Network equipment and computers
Owned Assets:
Estimated useful lives	5 years
Maximum | Software
Owned Assets:
Estimated useful lives	5 years
Maximum | Leasehold improvements
Owned Assets:
Estimated useful lives	8 years
Maximum | Office furniture and equipment
Owned Assets:
Estimated useful lives	8 years
Maximum | Motor vehicles
Owned Assets:
Estimated useful lives	5 years