Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Owned Assets:
Owned assets, gross	$ 207,318	$ 164,097
Less: Accumulated depreciation and amortization	(141,059)	(115,568)
Owned assets, net	66,259	48,529
Assets under capital leases:
Assets under capital leases, gross	1,818	1,797
Less: Accumulated depreciation	(1,320)	(1,297)
Assets under capital leases, net	498	500
Property and Equipment, net	66,757	49,029
Network equipment and computers
Owned Assets:
Owned assets, gross	$ 77,587	65,381
Network equipment and computers \| Minimum
Owned Assets:
Estimated useful life	3 years
Network equipment and computers \| Maximum
Owned Assets:
Estimated useful life	5 years
Software
Owned Assets:
Owned assets, gross	$ 59,325	44,617
Software \| Minimum
Owned Assets:
Estimated useful life	3 years
Software \| Maximum
Owned Assets:
Estimated useful life	5 years
Leasehold improvements
Owned Assets:
Owned assets, gross	$ 38,857	31,192
Assets under capital leases:
Assets under capital leases, gross	$ 941	854
Leasehold improvements \| Minimum
Owned Assets:
Estimated useful life	3 years
Leasehold improvements \| Maximum
Owned Assets:
Estimated useful life	8 years
Office furniture and equipment
Owned Assets:
Owned assets, gross	$ 19,667	15,426
Assets under capital leases:
Assets under capital leases, gross	$ 167	133
Office furniture and equipment \| Minimum
Owned Assets:
Estimated useful life	3 years
Office furniture and equipment \| Maximum
Owned Assets:
Estimated useful life	8 years
Motor vehicles
Owned Assets:
Owned assets, gross	$ 638	580
Assets under capital leases:
Assets under capital leases, gross	$ 710	810
Motor vehicles \| Minimum
Owned Assets:
Estimated useful life	2 years
Motor vehicles \| Maximum
Owned Assets:
Estimated useful life	5 years
Buildings
Owned Assets:
Estimated useful life	30 years
Owned assets, gross	$ 1,245	1,171
Land
Owned Assets:
Owned assets, gross	815	766
Capital work in progress
Owned Assets:
Owned assets, gross	$ 9,184	$ 4,964

Cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land or leased assets).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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