Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Summary of Changes in the Fair Value of the Plans' Level 3 Assest) (Details) (Hedge Funds [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Hedge Funds [Member]
Asset balance	$ 45,693	$ 42,940	$ 44,201
Purchases, sales, issuances, settlements, net	0	0
Unrealized gain (losses) relating to assets still held at the reporting date	$ 2,753	$ (1,261)