Stock Incentive Plans (Summary of Restricted Common Stock and Performance-Based Restricted Stock Unit Activity) (Details)	6 Months Ended
	Jun. 30, 2016 $ / shares shares
Restricted Common Stock
Number of Shares
Unvested at the beginning of the period (in shares) | shares	374,817
Granted (in shares) | shares	685,872
Vested (in shares) | shares	(30,350)
Forfeited (in shares) | shares	(6,580)
Expired (in shares) | shares	(65,000)
Unvested at the end of the period (in shares) | shares	958,759
Weighted Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share) | $ / shares	$ 12.68
Granted (in dollars per share) | $ / shares	15.06
Vested (in dollars per share) | $ / shares	(9.72)
Forfeited (in dollars per share) | $ / shares	(13.81)
Expired (in dollars per share) | $ / shares	(13.23)
Unvested at the end of the period (in dollars per share) | $ / shares	$ 14.43
Restricted Stock Units
Number of Shares
Unvested at the beginning of the period (in shares) | shares	751,500
Granted (in shares) | shares	0
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(7,500)
Expired (in shares) | shares	0
Unvested at the end of the period (in shares) | shares	744,000
Weighted Average Grant Date Fair Value
Unvested at the beginning of the period (in dollars per share) | $ / shares	$ 12.41
Granted (in dollars per share) | $ / shares	0.00
Vested (in dollars per share) | $ / shares	(0.00)
Forfeited (in dollars per share) | $ / shares	(12.43)
Expired (in dollars per share) | $ / shares	(0.00)
Unvested at the end of the period (in dollars per share) | $ / shares	$ 12.41