Summary of Significant Accounting Policies - Net loss per common share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Outstanding Stock options
Weighted-average anti-dilutive shares related to:
Antidilutive securities excluded from computation of earnings per share (in shares)	6,826,000	2,690,000	6,880,000	4,341,000
Restricted stock awards
Weighted-average anti-dilutive shares related to:
Antidilutive securities excluded from computation of earnings per share (in shares)	1,500,000	457,000	1,052,000	547,000
Performance-based restricted stock awards, M356
Weighted-average anti-dilutive shares related to:
Antidilutive securities excluded from computation of earnings per share (in shares)			1,439,985