Acquisitions and Divestitures (Estimated Fair Values Of The Assets Acquired And Liabilities Assumed) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Acquisitions and Divestitures [Abstract]
Business acquisition, cost of acquired entity, purchase price	$ 296,000,000		$ 296,000,000
Business acquisition, purchase price allocation, assets acquired	468,900,000		468,900,000
Business acquisition, purchase price allocation, property, plant and equipment	454,500,000		454,500,000
Business acquisition, purchase price allocation, liabilities assumed	(172,900,000)		(172,900,000)
Business acquisition, purchase price allocation, deferred taxes asset (liability), net, noncurrent	(150,800,000)		(150,800,000)
Business combination, acquisition related costs	$ 1,190,000	$ 0	$ 2,173,000	$ 0