Discontinued Operations And Other Dispositions (Summary Of Discontinued Operations Presented In Consolidated Statements Of Income And Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Discontinued Operations And Other Dispositions [Abstract]
Operating revenues	$ 1,729	$ 9,916	$ 6,640	$ 17,625
Total operating expenses	778	7,702	5,542	15,346
Operating income	951	2,214	1,098	2,279
Gain on sale	(326)		(17,699)
Loss on sale	2,736		2,986
Other expense, net	91	562	444	1,149
Income from discontinued operations before income taxes	(1,550)	1,652	15,367	1,130
Provision for income taxes	(368)	657	6,303	430
(Loss) Income from discontinued operations	$ (1,182)	$ 995	$ 9,064	$ 700