Net Income (Loss) Per Share (Narrative) (Details) - shares	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share	0	10,114,000
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	0	7,348,000
Unvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share	0	1,691,000
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share	0	950,000
Shares held in escrow
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded from net income (loss) per share	0	125,000
iSocket
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Business Combination, Contingent Consideration, Shares Issued			585,170
Pro Forma [Member] | iSocket
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Business Combination, Contingent Consideration, Shares Issued		532,487