Summary of Significant Accounting Principles - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) Customer	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Customer	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Accounting Policies [Abstract]
Equity method investments	$ 0		$ 0		$ 0
Guarantee or other funding obligations under equity method investment	0		0		$ 0
Losses from equity method investment	$ 0	$ 0	$ 0	$ 0
Number of customers with revenues greater than 10% | Customer	0		0
Impairment loss - satellite network	$ 12,748,000		$ 12,748,000
Typical warranty coverage period on product sales			1 year