Net Income (Loss) Per Share Attributable to Common Stockholders (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Apr. 24, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	704,000	10,833,000	23,206,000
Preferred Stock Dividends, Income Statement Impact	$ 0	$ 1,116	$ 4,244
Chango
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 18,200			$ 18,200
Business Combination, Contingent Consideration, Threshold Trading Days to Determine Number of Shares	10 days
Contingent consideration, shares issued	971,481
Contingent Consideration, Shares Released From Escrow	126,098
Business Combination, Contingent Consideration, Shares Held in Escrow				126,098
Business Combination, Contingent Consideration, Stock Price Trigger				$ 18.77
iSocket
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	$ 9,600
Business Combination, Contingent Consideration, Threshold Trading Days to Determine Number of Shares	10 days
Contingent consideration, shares issued	585,170
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	8,113,000	8,360,000
Unvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	1,750,000	0
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	845,000	0
Shares held in escrow
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	125,000	0
Contingent Consideration Issued In Acquisitions [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	704,000	0	0
Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	0	14,410,000
Conversion of preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share attributable to common stockholders	0	0	436,000