Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

11. Stock-Based Compensation

In fiscal 2009, the stockholders of the Company approved the 2009 Stock Incentive Plan (the “2009 Plan”) and the 2009 Employee Stock Purchase Plan (the “2009 Purchase Plan”). In fiscal 2017, the stockholders of the Company approved amendments to both the 2009 Plan and the 2009 Purchase Plan. These amendments authorized additional shares of common stock for issuance, to comply with changes in applicable law, improve the Company’s corporate governance and to implement other best practices.

Stock-based compensation costs are based on the fair values on the date of grant for stock awards and stock options and on the date of enrollment for the employee stock purchase plans. The fair values of stock awards (such as RSUs, performance stock units (PSUs) and restricted stock awards (RSAs)) are estimated based on their intrinsic values. The fair values of MSUs are estimated using a Monte Carlo simulation. The fair values of stock options and employee stock purchase plans are estimated using the Black-Scholes option-pricing model.

The following table presents details of stock-based compensation costs recognized in the Condensed Consolidated Statements of Income (in thousands):

	Three Months Ended
	March 31, 2018		April 1, 2017
Cost of revenues	$	296	$	258
Research and development	5,769		5,246
Selling, general and administrative	6,127		4,982
	12,192		10,486
Income tax benefit	5,219		5,282
	$	6,973	$	5,204

The Company had approximately $93.8 million of total unrecognized compensation costs related to granted stock options and awards as of March 31, 2018 that are expected to be recognized over a weighted-average period of approximately 2.3 years. There were no significant stock-based compensation costs capitalized into assets in any of the periods presented.