Receivables (Schedule Of Allowance For Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 2,372	$ 1,044	$ 1,307
Charged to costs and expenses	(86)	2,096	373
Amounts written off	(760)	(768)	(636)
Balance at end of period	$ 1,526	$ 2,372	$ 1,044