Share-Based Payments (Tables)

6 Months Ended

Jun. 30, 2013

Share-Based Payments

Schedule of weighted average assumptions

	Weighted Average Assumptions
	Stock Options				Employee Stock Purchase Plan
	For the Three Months Ended June 30, 2013		For the Three Months Ended June 30, 2012		For the Three Months Ended June 30, 2013		For the Three Months Ended June 30, 2012
Expected volatility	64	%	70	%	62	%	65	%
Expected dividends	—		—		—		—
Expected life (years)	5.1		5.7		0.5		0.5
Risk-free interest rate	1.7	%	1.1	%	0.1	%	0.1	%

	Weighted Average Assumptions
	Stock Options				Employee Stock Purchase Plan
	For the Six Months Ended June 30, 2013		For the Six Months Ended June 30, 2012		For the Six Months Ended June 30, 2013		For the SixMonths Ended June 30, 2012
Expected volatility	62	%	66	%	64	%	66	%
Expected dividends	—		—		—		—
Expected life (years)	6.0		6.3		0.5		0.5
Risk-free interest rate	1.4	%	1.3	%	0.1	%	0.1	%

Summarized information about time-based or performance-based vesting schedules

A summary of the status of nonvested shares of restricted stock as of June 30, 2013 and the changes during the six months then ended are presented below (in thousands, except fair values):

	Number of Shares		Weighted Average Grant Date Fair Value
Nonvested at January 1, 2013	1,137		$	14.61
Granted	146		12.58
Vested	(83	)	14.48
Forfeited	(31	)	14.59
Nonvested at June 30, 2013	1,169		$	14.37

Schedule of nonvested shares of restricted stock

Vesting Schedule	Nonvested Shares
Time-based	322
Performance-based	847
Nonvested at June 30, 2013	1,169