Condensed Consolidated Statements of Operations and Comprehensive Income (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Revenue:    
Services $ 75,424 $ 73,430
Subscriber equipment 16,540 20,157
Engineering and support services 5,043 4,445
Total revenue 97,007 98,032
Operating expenses:    
Cost of services (exclusive of depreciation and amortization) 14,882 14,203
Cost of subscriber equipment 10,647 13,912
Research and development 4,126 2,121
Selling, general and administrative 20,524 19,186
Depreciation and amortization 13,355 20,266
Total operating expenses 63,534 69,688
Operating income 33,473 28,344
Other income (expense):    
Interest income, net 1,237 637
Undrawn credit facility fees (917) (1,499)
Other expense, net (214) (350)
Total other income (expense) 106 (1,212)
Income before income taxes 33,579 27,132
Provision for income taxes (12,560) (10,589)
Net income 21,019 16,543
Net income attributable to common stockholders 17,160 14,793
Weighted average shares outstanding - basic (in shares) 94,527 77,082
Weighted average shares outstanding - diluted (in shares) 122,313 87,711
Net income attributable to common stockholders per share - basic (in dollars per share) $ 0.18 $ 0.19
Net income attributable to common stockholders per share - diluted (in dollars per share) $ 0.17 $ 0.19
Comprehensive income:    
Net income 21,019 16,543
Foreign currency translation adjustments, net of tax (1,401) 156
Unrealized gain on marketable securities, net of tax 61 60
Comprehensive income 19,679 16,759
Series A Preferred Stock [Member]    
Other income (expense):    
Dividends, Preferred Stock, Total 1,750 1,750
Series B Preferred Stock [Member]    
Other income (expense):    
Dividends, Preferred Stock, Total $ 2,109 $ 0