Income Taxes (Schedule Of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Liabilities, Net, Classification [Abstract]
Gross assets	$ 2,012	$ 1,151
Gross liabilities	0	(1)
Current deferred income tax assets and liabilities	2,012	1,150
Valuation allowance	0	0
Current deferred income taxes	2,012	1,150
Gross assets	63,129	63,374
Gross liabilities	(149,708)	(148,540)
Long term deferred income tax assets and liabilities	(86,579)	(85,166)
Valuation allowance	(6,879)	(8,585)
Long term deferred income taxes	(93,458)	(93,751)
Net deferred income tax liability	$ (91,446)	$ (92,601)