Schedule Of Allowance For Uncollectible Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Balance at beginning of period	$ 6,103	$ 9,774	$ 6,951
Additions charged to expense	2,869	6,908	6,358
Additions charged to other accounts	0	0	0
Write-offs net of recoveries	(2,976)	(10,579)	(3,535)
Balance at end of period	$ 5,996	$ 6,103	$ 9,774