Stock-based Compensation Expense

3 Months Ended

Mar. 31, 2013

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

Stock-based Compensation Expense

Stock-based Compensation Expense

The Company issues stock options, restricted stock and restricted stock units with service conditions, which are generally the vesting periods of the awards. The Company also has issued, to certain members of senior management, restricted stock and restricted stock units that vest upon the earlier of the satisfaction of (i) a performance condition or (ii) a service condition, and stock options that vest upon the earlier of the satisfaction of (a) performance conditions or (b) a service condition. In addition, the Company issues shares pursuant to an employee stock purchase plan ("ESPP").

The effect of stock-based compensation expense during the three months ended March 31, 2013 and 2012 was as follows:

	Three Months Ended March 31,
	2013			2012
	(in thousands)
Stock-based compensation expense by type of award:
Stock options	$	19,674		$	18,222
Restricted stock and restricted stock units	9,378			7,286
ESPP share issuances	2,522			2,430
Less stock-based compensation expense capitalized to inventories	(299		)	(250		)
Total stock-based compensation expense included in costs and expenses	$	31,275		$	27,688
Stock-based compensation expense by line item:
Research and development expenses	$	19,349		$	17,204
Sales, general and administrative expenses	11,926			10,484
Total stock-based compensation expense included in costs and expenses	$	31,275		$	27,688

The following table sets forth the Company's unrecognized stock-based compensation expense, net of estimated forfeitures, as of March 31, 2013 by type of award and the weighted-average period over which that expense is expected to be recognized:

	As of March 31, 2013
	Unrecognized Expense, Net of Estimated Forfeitures	Weighted-average Recognition Period
	(in thousands)	(in years)
Type of award:
Stock options	$187,456	2.90
Restricted stock and restricted stock units	86,795	2.58
ESPP share issuances	3,091	0.49

The following table summarizes information about stock options outstanding and exercisable at March 31, 2013:

	Options Outstanding			Options Exercisable
Range of Exercise Prices	Number Outstanding	Weighted-average Remaining Contractual Life	Weighted-average Exercise Price	Number Exercisable	Weighted-average Exercise Price
	(in thousands)	(in years)	(per share)	(in thousands)	(per share)
$ 9.07–$20.00	887	3.05	$15.33	887	$15.33
$20.01–$30.00	1,394	6.13	$29.32	1,052	$29.14
$30.01–$40.00	11,913	6.61	$36.11	7,905	$35.41
$40.01–$50.00	5,333	9.53	$46.34	341	$47.41
$50.01–$60.00	2,268	8.46	$53.44	926	$54.03
$60.01–$64.30	53	8.92	$63.31	11	$63.23