Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total	$ 5,581	$ 3,675	$ 9,917	$ 7,289
Research and Development Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total	3,048	2,108	5,485	4,178
Selling, General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total	$ 2,533	$ 1,567	$ 4,432	$ 3,111