Stock-Based Compensation

9 Months Ended

Sep. 30, 2011

Stock-Based Compensation [Abstract]

Stock-Based Compensation

Note 5: Stock-Based Compensation

On March 9, 2009, the Board of Directors approved an amendment and restatement of the 2005 Stock Incentive Plan ("2005 Plan"), which was originally adopted on March 30, 2005, for Board members, employees, officers, and executives of, and consultants and advisors to, the Company. The amendment and restatement of the 2005 Plan increased by 2,000,000 shares the maximum number of shares of the Company's common stock that may be issued or be subject to awards under the plan, established a new 10-year term for the plan and made certain other amendments. The 2005 Plan amendment was approved by the Company's stockholders on June 9, 2009. The 2005 Plan provides for the granting of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units and performance-based awards to eligible individuals. As amended, the 2005 Plan allows the granting of an aggregate of 3,500,000 shares of the Company's common stock for awards, plus the number of shares of stock that were available for future awards under the prior 1999 Equity Participation Plan ("1999 Plan"). In addition, shares subject to options granted under either the 1999 Plan or the 2005 Plan that terminate or expire without being exercised will become available for grant under the 2005 Plan. The benefit provided under these plans is compensation subject to authoritative guidance for stock-based compensation.

In accordance with authoritative guidance for stock-based compensation, compensation expense is recognized only for those shares expected to vest, based on the Company's historical experience and future expectations. Total compensation expense during the three months ended September 30, 2011 and 2010 was $2.4 million and $1.5 million, respectively. Total compensation expense during the nine months ended September 30, 2011 and 2010 was $6.0 million and $4.8 million, respectively.

The Company's stock-based compensation arrangements are described below:

Stock Options

The 2005 Plan permits the granting of stock options to certain employees and directors of the Company. Option awards are generally granted with an exercise price equal to the market price of the Company's stock at the date of issuance. They generally vest over three to five years of continuous service, and have ten-year contractual terms.

The Company uses the Black-Scholes option-pricing model to determine the fair-value of stock-based awards. All options are amortized ratably over the requisite service periods of the awards, which are generally the vesting periods.

The fair value for options granted was estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions:

	Nine Months Ended September 30,
	2011			2010
Weighted average fair value of options granted	$	13.26		$	9.70
Risk free interest rate		2.0	%		2.3	%
Dividend yield		0.0	%		0.0	%
Volatility factor of the expected market price of the Company's common stock		61.0	%		62.0	%
Weighted-average expected life of options		5 Years			5 Years

Unrecognized compensation cost related to stock options as of September 30, 2011, was $3.4 million. The weighted-average remaining expense period, based on the unamortized value of these outstanding stock options, was approximately 1.9 years.

A summary of the Company's stock option activity as of September 30, 2011, and changes during the nine months ended, is presented below:

	Number of Shares			Option Price Per Share		Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2010		2,437,062		$	0.51 – $20.09	$	10.74
Granted		209,000			24.65		24.65
Cancelled/forfeited		(36,498	)		2.89 – 17.90		11.50
Exercised		(409,956	)		0.51 – 17.90		5.66
Outstanding at September 30, 2011		2,199,608		$	0.51 –$24.65	$	12.99	$	20,065
Exercisable at September 30, 2011		1,292,613		$	0.51 –$20.09	$	11.42	$	13,479

The total intrinsic value of options exercised during the nine months ended September 30, 2011 and 2010 was $10.2 million and $4.9 million, respectively. As of September 30, 2011, the weighted-average remaining contractual life of options outstanding and options exercisable was 6.0 years and 4.5 years, respectively.

Non-Vested Shares

Under the Company's 2005 Plan, employees, officers, executives and directors of, and consultants and advisors to, the Company are eligible to receive restricted stock units and restricted stock awards. In accordance with the authoritative guidance, the fair value of these non-vested shares is equal to the closing sale price of the Company's common stock on the date of issuance. The total number of these awards expected to vest is adjusted by estimated forfeiture rates. As of September 30, 2011, 37,662 of the non-vested shares are expected to vest over approximately one to two years based upon the achievement of certain performance goals ("Performance-Based Awards"). The fair value of the Performance-Based Awards is expensed over the expected vesting period, net of estimated forfeitures. If performance goals are not expected to be met, the compensation expense previously recognized would be reversed. No reversals of compensation expense related to the Performance-Based Awards have been made as of September 30, 2011. The remaining 608,658 non-vested shares are not performance-based, and will vest over approximately one to three years of continuous service.

A summary of the status of the Company's restricted stock units as of September 30, 2011, and changes during the nine months ended, is presented below:

	Non-Vested Shares			Weighted Average Grant Date Fair Value
Non-vested at December 31, 2010		614,370		$	13.08
Awarded		294,344		$	25.09
Vested		(228,557	)	$	13.16
Cancelled/forfeited		(33,837	)	$	17.04
Non-vested at September 30, 2011		646,320		$	18.31

Unrecognized compensation expense related to non-vested shares as of September 30, 2011, was $6.9 million. The weighted-average remaining expense period, based on the unamortized value of these outstanding non-vested shares, was approximately 2.1 years. The fair value of restricted stock units and restricted stock awards vested during the nine months ended September 30, 2011 and 2010 was $6.0 million and $4.8 million, respectively.