Stockholders' Equity (Tables)

6 Months Ended

Jun. 30, 2015

Equity [Abstract]

Summary of Allocated Stock-based Compensation Expense

The Company’s stock-based compensation expense is allocated between research and development and selling, general and administrative as follows:

	Three months ended,		Six months ended,
Stock-based compensation expense	June 30, 2015	June 30, 2014	June 30, 2015	June 30, 2014
Research and Development	$1.1	$ —	$1.9	$ —
Selling, General and Administrative	$3.1	$0.4	$5.7	$2.5

Weighted Average for Key Assumptions Used in Determining Fair Value of Options Granted

The weighted average for key assumptions used in determining the fair value of options granted during the six months ended June 30, 2015 follows:

Expected price volatility	72.82% -73.33%
Risk-free interest rate	1.44%
Weighted average expected life in years	6 years
Dividend yield	—

Summary of Option Activity

Option activity during the six months ended June 30, 2015 was as follows:

	Number of Shares			Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
Outstanding at January 1, 2015		3,196,100		$	4.32
Granted		271,614			10.23
Exercised		(75,050	)		4.04
Forfeitures		(114,237	)		12.57
Outstanding at June 30, 2015		3,278,427		$	5.44	$	10,769

Summary of Restricted Stock Activity

Restricted stock activity during the six months ended June 30, 2015 was as follows:

	Number of Restricted Shares			Weighted Average Fair Market Value Per RSU
Outstanding at January 1, 2015		2,849,076		$	6.08
Granted:
Executive officers		2,102,615			14.63
Directors		—			—
Vested		(712,677	)		14.23
Forfeitures		(65,853	)		11.69
Outstanding at June 30, 2015		4,173,161		$	10.25