Basis of Presentation - Statement of Operating Illustrating effect of Immaterial Revisions (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating expenses:
Cost of service revenue (exclusive of items shown below)	$ 56,365	$ 46,470	$ 164,615	$ 138,030
Cost of equipment revenue (exclusive of items shown below)	10,527	9,813	36,752	29,605
Engineering, design and development	25,835	23,375	72,201	60,807
Sales and marketing	14,874	14,601	46,366	39,678
General and administrative	21,661	21,487	65,038	63,096
Depreciation and amortization	26,779	22,224	76,042	61,814
Total operating expenses	$ 156,041	137,970	$ 461,014	393,030
As Reported [Member]
Operating expenses:
Cost of service revenue (exclusive of items shown below)		45,477		135,406
Cost of equipment revenue (exclusive of items shown below)		9,744		29,375
Engineering, design and development		21,367		55,732
Sales and marketing		12,345		34,051
General and administrative		26,813		76,652
Depreciation and amortization		22,224		61,814
Total operating expenses		137,970		393,030
Revisions [Member] | Incentive Compensation Expense [Member]
Operating expenses:
Cost of service revenue (exclusive of items shown below)		677		1,795
Cost of equipment revenue (exclusive of items shown below)		40		165
Engineering, design and development		1,162		3,291
Sales and marketing		1,036		2,733
General and administrative		(2,915)		(7,984)
Revisions [Member] | Stock Based Compensation Expense [Member]
Operating expenses:
Cost of service revenue (exclusive of items shown below)		316		829
Cost of equipment revenue (exclusive of items shown below)		29		65
Engineering, design and development		846		1,784
Sales and marketing		1,220		2,894
General and administrative		$ (2,411)		$ (5,572)