Income (Loss) per Share (Narrative) (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,357,154	12,471,789	4,510,729	12,471,789
Antidilutive Securities Excluded from Computation of Earnings Per Share, Exercise Price of Excluded Securities	$ 29.31		$ 19.84
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		877,665		877,665
Employee Stock Purchase Plan (ESPP)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		165,167		165,167