Summary Of Significant Accounting Policies (Schedule Of Non-Cash ESOP And 401(k) Expense By Operating Statement Classification) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Summary Of Significant Accounting Policies [Line Items]
Non-cash ESOP and 401(k) expenses	$ 4,333	$ 4,021	$ 12,915	$ 15,631
Selling, General And Administrative Expenses [Member]
Summary Of Significant Accounting Policies [Line Items]
Non-cash ESOP and 401(k) expenses	2,569	2,403	7,633	8,860
Research And Development Expenses [Member]
Summary Of Significant Accounting Policies [Line Items]
Non-cash ESOP and 401(k) expenses	$ 1,764	$ 1,618	$ 5,282	$ 6,771