Pension Plans and Other Postretirement Employee Benefits (Narrative) (Details) (USD $)	6 Months Ended		12 Months Ended	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2012	Jun. 30, 2012 Qualified Salaried Pension Plan [Member]	Jun. 30, 2012 Qualified Hourly Pension Plan [Member]	Jun. 30, 2012 Qualified Non-Represented Pension Plan [Member]	Jun. 30, 2012 Non-Qualified Supplemental Pension Plans [Member]	Jun. 30, 2012 Discretionary Funding [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum Funding Requirement			$ 9,700,000
Pension Contributions	21,630,000	9,400,000
Contributions				$ 9,300,000	$ 6,800,000	$ 5,500,000	$ 900,000	$ 11,900,000