Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-Based Compensation, Activity

Information with respect to the number and weighted average exercise price of stock options under the 2006 Plan, 2010 Restated Plan and Inducement Plan is summarized as follows:

	Shares (in thousands)		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2014	2,112		$	21.22
Granted	1,080		$	12.36
Exercised	(96	)	$	14.94
Cancelled/Forfeited	(382	)	$	22.19
Outstanding at December 31, 2015	2,714		$	17.78	7.5	$	2,549
Exercisable at December 31, 2015	1,504		$	19.92	6.3	$	537
Vested and unvested expected to vest at December 31, 2015	2,707		$	17.77	7.5	$	2,548

Schedule of Share-based Compensation, Additional Information

The intrinsic values for stock options above represent the aggregate value of the total pre-tax intrinsic value based upon a common stock price of $14.74 at December 31, 2015, and the contractual exercise prices.

	Years Ended December 31,
	2015		2014		2013
Stock Options and Restricted Stock Units
Weighted-average grant date fair value	$	8.37	$	18.58	$	12.43
Aggregate intrinsic value of options exercised	$	330,000	$	297,000	$	370,000
Total fair value of shares vested	$	7,028,000	$	8,231,000	$	4,895,000

Assumptions used in the Black-Scholes Option-Pricing Model

The assumptions used in the Black-Scholes option-pricing model are as follows:

	Year Ended December 31,
	2015	2014	2013
Stock Options
Risk free interest rate	1.5% to 1.9%	1.6% to 2.0%	0.8% to 1.8%
Expected term	5.1 to 6.1 years	5.1 to 6.1 years	5.0 to 6.1 years
Expected volatility	76.7 to 79.2%	79.7 to 84.9%	82.8 to 87.9%
Expected dividend yield	—%	—%	—%
Employee Stock Purchase Plan
Risk free interest rate	0.1% to 0.5%	0.1%	0.1%
Expected term	0.5 to 1.0 years	0.5 to 1.0 years	0.5 to 1.0 years
Expected volatility	67.4% to 77.8%	65.0% to 83.2%	74.3% to 125.6%
Expected dividend yield	—%	—%	—%

Stock-Based Compensation Expense

The Company recognized stock-based compensation expense in continuing operations as follows (in thousands):

	Year Ended December 31,
	2015		2014		2013
Cost of sales	$	390	$	467	$	333
Research and development	1,266		1,236		1,138
Selling, general and administrative	5,285		5,833		6,715
Total	$	6,941	$	7,536	$	8,186