Stock-Based Compensation

3 Months Ended

Mar. 31, 2013

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

Stock-Based Compensation

Stock-Based Compensation

The Company recorded approximately $4.6 million and $3.1 million of stock-based compensation expense for the three months ended March 31, 2013 and March 31, 2012, respectively, in each case, related to options, restricted stock or the Company's 2010 employee stock purchase plan (the 2010 ESPP). As of March 31, 2013, there was approximately $25.9 million of total unrecognized compensation costs related to non-vested stock-based employee compensation arrangements granted under the Company's equity compensation plans. The Company expects to recognize those costs over a weighted average period of 1.42 years.

During the three months ended March 31, 2013, the Company issued a total of 1,687,043 shares of its common stock upon the exercise of stock options, pursuant to restricted stock grants and pursuant to purchases under the 2010 ESPP. During the three months ended March 31, 2012, the Company issued a total of 590,704 shares of its common stock upon the exercise of stock options, pursuant to restricted stock grants and pursuant to purchases under the 2010 ESPP. Cash received from the exercise of stock options and purchases through the 2010 ESPP during the three months ended March 31, 2013 and March 31, 2012 was approximately $29.7 million and $3.9 million, respectively, and is included within the financing activities section of the consolidated statements of cash flows.

At March 31, 2013, there were an aggregate of 1,380,070 shares of common stock reserved for future issuance under the 2010 ESPP and for future grants under the Company's amended and restated 2004 stock incentive plan.