Stock Options and Stock-based Employee Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Stock Options and Stock-based Employee Compensation [Abstract]

Stock options and restricted stock units (RSUs) outstanding and available for future issuance

Stock options and restricted stock units (RSUs) outstanding and available for future issuance are as follows:

	December 31,
	2014		2013
Stock Options and RSUs Outstanding
2011 Plan		6,113		4,919
2007 Plan		257		258
1998 Plan		182		251
Total Outstanding		6,552		5,428
Available for Future Grants under 2011 Plan		6,667		2,894

Summary of stock option activity

A summary of activity under our long-term incentive plans is presented below:

(in thousands, except for weighted-average data)
Stock Options	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In Yrs)
Outstanding at January 1, 2014		5,428		$	6.51
Granted		1,786			2.39
Exercised		(17	)		1.83
Forfeited or expired		(663	)		15.57
Outstanding at December 31, 2014		6,534		$	4.50		7.3
Exercisable at December 31, 2014		3,599		$	6.23		6.3

(in thousands, except for weighted-average data)
Restricted Stock Units	Shares			Weighted- Average Grant Date Fair Value
Unvested at January 1, 2014		19		$	1.69
Awarded		36		$	1.71
Vested		(36	)	$	1.70
Unvested at December 31, 2014		19		$	1.71

Employee stock-based compensation

Stock-based compensation expense was classified as follows:

	December 31,
(in thousands)	2014		2013		2012
Research and development	$	1,014	$	784	$	487
Selling, general and administrative		1,927		1,426		1,924
Total	$	2,941	$	2,210	$	2,411

Weighted-average assumptions in estimating fair value of options

The risk-free interest rates are based upon the U.S. Treasury yield curve in effect at the time of the grant.

	December 31,
	2014		2013		2012
Weighted average expected volatility		100%		109%		111%
Weighted average expected term	5.4 years		4.7 years		4.6 years
Weighted average risk-free interest rate		1.65%		0.73%		0.74%
Expected dividends		–		–		–