Equity-Based Compensation - Activity Related to Plans (Details) $ in Millions	1 Months Ended		9 Months Ended
	May 31, 2017 shares	Feb. 28, 2017 shares	Sep. 30, 2017 USD ($) plan shares
Equity compensation plans
Number of equity compensation plans | plan			4
Stock Options
Stock Options
Outstanding (in shares)			3,113,178
Granted (in shares)			1,022,517
Exercised (in shares)			(90,696)
Expired or terminated (in shares)			(386,164)
Outstanding (in shares)			3,658,835
Restricted Stock Units
Restricted Stock Units
Outstanding (in shares)			936,954
Granted (in shares)			814,776
Vested (in shares)			(407,799)
Expired or terminated (in shares)			(192,557)
Outstanding (in shares)			1,151,374
2007 Equity Plan
Equity compensation plans
Additional common stock for issuance (in shares)	2,485,000
2007 Equity Plan | Stock Options
Stock Options
Outstanding (in shares)			2,158,822
Granted (in shares)			931,417
Exercised (in shares)			(90,696)
Expired or terminated (in shares)			(306,070)
Outstanding (in shares)			2,693,473
2007 Equity Plan | Restricted Stock Units
Restricted Stock Units
Outstanding (in shares)			773,804
Granted (in shares)			790,476
Vested (in shares)			(349,306)
Expired or terminated (in shares)			(181,986)
Outstanding (in shares)			1,032,988
2007 Equity Plan | Performance Restricted Stock Units (RSUs)
Restricted Stock Units
Granted (in shares)		191,250
Award vesting period		3 years
Maximum shares of common stock that may be issued			162,750
Fair value, performance- based RSUs | $			$ 3.2
Compensation expense, period for recognition			3 years
2000 Equity Plan | Stock Options
Stock Options
Outstanding (in shares)			5,200
Granted (in shares)			0
Exercised (in shares)			0
Expired or terminated (in shares)			0
Outstanding (in shares)			5,200
2000 Equity Plan | Restricted Stock Units
Restricted Stock Units
Outstanding (in shares)			0
Granted (in shares)			0
Vested (in shares)			0
Expired or terminated (in shares)			0
Outstanding (in shares)			0
2013 Lumara Equity Plan | Stock Options
Stock Options
Outstanding (in shares)			134,181
Granted (in shares)			0
Exercised (in shares)			0
Expired or terminated (in shares)			(7,969)
Outstanding (in shares)			126,212
2013 Lumara Equity Plan | Restricted Stock Units
Restricted Stock Units
Outstanding (in shares)			27,694
Granted (in shares)			0
Vested (in shares)			(12,831)
Expired or terminated (in shares)			(752)
Outstanding (in shares)			14,111
Inducement Grants | Stock Options
Stock Options
Outstanding (in shares)			814,975
Granted (in shares)			91,100
Exercised (in shares)			0
Expired or terminated (in shares)			(72,125)
Outstanding (in shares)			833,950
Inducement Grants | Restricted Stock Units
Restricted Stock Units
Outstanding (in shares)			135,456
Granted (in shares)			24,300
Vested (in shares)			(45,662)
Expired or terminated (in shares)			(9,819)
Outstanding (in shares)			104,275