Satellite Network and Other Equipment - Summary of Satellite Network and Other Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	$ 299,027	$ 286,434
Less: accumulated depreciation and amortization	(87,361)	(70,593)
Satellite network and other equipment, net	211,666	215,841
Land [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	381	381
Satellite Network [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	232,928	231,782
Capitalized Software [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	39,215	30,758
Computer Hardware [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	5,044	4,707
Other [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	7,902	7,522
Assets under Construction [Member]
Property Plant And Equipment [Line Items]
Satellite network and other equipment, gross	$ 13,557	$ 11,284