Consolidated Statements of Operations (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Operating Expenses [Abstract]    
Revenue $ 61,215,000 $ 69,161,000
Cost of revenue 28,408,000 36,353,000
Gross profit 32,807,000 32,808,000
Research and development 8,207,000 6,779,000
General and administrative 15,829,000 14,259,000
Sales and marketing 17,401,000 13,656,000
Total operating expenses 41,437,000 34,694,000
Operating loss (8,630,000) (1,886,000)
Interest income 36,000 31,000
Interest expense (3,193,000) (4,489,000)
Other income, net 5,000 265,000
Interest and other expense, net (3,152,000) (4,193,000)
Loss before income taxes (11,782,000) (6,079,000)
Income tax expense (52,000) (65,000)
Net loss $ (11,834,000) $ (6,144,000)
Net loss per share basic and diluted $ (0.21) $ (0.11)
Weighted-average number of shares used in calculating net loss per share 56,496,648 55,089,028