Summary Of Significant Accounting Policies (Allowance For Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Summary Of Significant Accounting Policies [Abstract]
Beginning allowance for doubtful accounts balance	$ 3,674	$ 14,299
Amount charged (credited) to costs and expenses, net	(1,693)	(442)	4,356
Other net decreases	(835)	(10,183)
Ending allowance for doubtful accounts balance	$ 1,146	$ 3,674	$ 14,299