Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Total Compensation Cost from Share-Based Payments

The Company’s statement of operations included total compensation cost from share-based payments for the years ended December 31, as follows:

In thousands	2011		2010		2009
Compensation cost from:
Stock options	$	2,893	$	1,879	$	3,068
Stock and stock units		4,601		2,834		1,096
Purchases of common stock at a discount		181		123		191
	$	7,675	$	4,836	$	4,355
Compensation cost included in:
Research and development expenses	$	3,782	$	2,444	$	2,123
General and administrative expenses		3,893		2,392		2,232
	$	7,675	$	4,836	$	4,355

Summary of Information About Stock Options

The following table summarizes information about stock options as of and for the years ended December 31, 2011, 2010 and 2009:

In thousands, except per share amounts	2011		2010		2009
Weighted average fair value of options granted, per share	$	5.80	$	2.43	$	1.03
Total cash received from exercises of stock options		4,648		418		206
Total intrinsic value of stock options exercised		5,169		331		271

Weighted-Average Assumptions of Fair Value of Options Granted

The weighted average fair value of options granted in the years ended December 31, 2011, 2010 and 2009, reflect the following weighted-average assumptions:

	2011		2010		2009
Expected life of options granted (in years)	7.48		6.75		7.04
Expected volatility	74.77	%	78.54	%	70.68	%
Risk-free rate	2.53	%	2.57	%	2.75	%
Expected dividends	0	%	0	%	0	%

Summary of Stock-Based Activity

Stock option activity under the Company’s stock plans for the year ended December 31, 2011 was as follows:

	Number of Shares		Weighted Average Exercise Price Per Share
Options outstanding, January 1, 2011		7,177,191	$	4.42
Granted		1,599,519	$	8.05
Forfeited		225,295	$	4.16
Exercised		1,170,086	$	4.40
Options outstanding, December 31, 2011		7,381,329	$	5.22

Summary of Stock Options Outstanding

The following table summarizes information about stock options outstanding as of December 31, 2011:

	Options Outstanding		Options Exercisable		Options Vested and Expected To Vest
Number of options		7,381,329		5,055,872		7,066,555
Weighted average exercise price per share	$	5.22	$	4.84	$	5.21
Aggregate intrinsic value (in 000’s)	$	51,878	$	37,468	$	49,717
Weighted average remaining contractual term	5.52 years		4.07 years		5.38 years

Stock and Stock Units Grants [Member]

Summary of Stock-Based Activity

Stock and stock unit activity under the Company’s stock plans for the year ended December 31, 2011 was as follows:

	Number of Shares		Weighted Average Grant Date Fair Value
Outstanding, January 1, 2011		2,779,300	$	2.83
Granted		1,255,681	$	7.43
Forfeited		115,632	$	4.05
Vested or restrictions lapsed		1,134,323	$	3.69
Outstanding, December 31, 2011		2,785,026	$	4.51