Summary Of Significant Accounting Policies Summary Of Significant Accounting Policies (Schedule of Non-Cash ESOP and 401(k) expense by operation statement classification) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Employee Stock Ownership Plan And 401 K Compensation Expense	$ 7,698	$ 4,238
General and Administrative Expense [Member]
Summary Of Significant Accounting Policies [Line Items]
Employee Stock Ownership Plan And 401 K Compensation Expense	4,383	2,536
Research and Development Expense [Member]
Summary Of Significant Accounting Policies [Line Items]
Employee Stock Ownership Plan And 401 K Compensation Expense	$ 3,315	$ 1,702