Unaudited Condensed Consolidated Statements of Comprehensive Income (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Revenues:    
Services revenue $ 139,814 $ 179,044
Product revenue, net 35,012 37,139
Total revenues 174,826 216,183
Cost of revenues:    
Services cost of revenue 34,941 71,293
Product cost of revenue 24,100 25,029
Total cost of revenues 59,041 96,322
Engineering and technology 5,217 4,135
Sales and marketing 54,196 55,836
General and administrative 10,409 8,632
Depreciation 1,138 1,058
Amortization of intangible assets 6,118 5,584
Total operating expenses 136,119 171,567
Operating income 38,707 44,616
Other loss, net (3,726) (4,069)
Income before income taxes 34,981 40,547
Income tax expense (11,881) (14,560)
Net income 23,100 25,987
Net income per share:    
Basic, USD per share $ 0.56 $ 0.62
Diluted, USD per share $ 0.55 $ 0.58
Weighted average shares outstanding:    
Basic, Shares 40,987 42,162
Diluted, Shares 41,899 44,521
Other comprehensive income (loss):    
Net income 23,100 25,987
Unrealized gain (loss) on available-for-sale investments, net of tax (73) 14
Reclassification adjustment for realized loss on available-for-sale investments, net of tax, included in net income 41 0
Other comprehensive income (loss) (32) 14
Comprehensive income $ 23,068 $ 26,001