Net Income (Loss) Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	13,275,612	13,049,014
Stock appreciation rights
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	2,350,368	2,123,770
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	87,026	87,026
Convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	10,838,218	10,838,218