Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Owned Assets:
Owned assets, gross	$ 164,097	$ 143,517
Less: Accumulated depreciation and amortization	(115,568)	(96,079)
Owned Assets, net	48,529	47,438
Assets under capital leases:
Capital leased assets, gross	1,797	1,819
Less: Accumulated depreciation and amortization	(1,297)	(1,266)
Assets under capital leases, net	500	553
Property, Plant and Equipment, net	49,029	47,991
Network equipment, computers and software
Owned Assets:
Owned assets, gross	$ 109,998	95,245
Network equipment, computers and software | Minimum
Owned Assets:
Estimated useful life (in years)	3 years
Network equipment, computers and software | Maximum
Owned Assets:
Estimated useful life (in years)	5 years
Leasehold improvements
Owned Assets:
Owned assets, gross	$ 31,192	28,603
Assets under capital leases:
Capital leased assets, gross	$ 854	877
Leasehold improvements | Minimum
Owned Assets:
Estimated useful life (in years)	3 years
Leasehold improvements | Maximum
Owned Assets:
Estimated useful life (in years)	8 years
Office furniture and equipment
Owned Assets:
Owned assets, gross	$ 15,426	14,000
Assets under capital leases:
Capital leased assets, gross	$ 133	136
Office furniture and equipment | Minimum
Owned Assets:
Estimated useful life (in years)	3 years
Office furniture and equipment | Maximum
Owned Assets:
Estimated useful life (in years)	8 years
Motor vehicles
Owned Assets:
Owned assets, gross	$ 580	540
Assets under capital leases:
Capital leased assets, gross	$ 810	806
Motor vehicles | Minimum
Owned Assets:
Estimated useful life (in years)	2 years
Motor vehicles | Maximum
Owned Assets:
Estimated useful life (in years)	5 years
Buildings
Owned Assets:
Owned assets, gross	$ 1,171	1,202
Estimated useful life (in years)	30 years
Land
Owned Assets:
Owned assets, gross	$ 766	787
Capital work in progress
Owned Assets:
Owned assets, gross	$ 4,964	$ 3,140