Postretirement Benefits Other Than Pensions (Narrative) (Details) (Postretirement Benefits [Member], USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service costs, before tax	$ (794,000)	$ (225,000)
Unrecognized prior service costs, net of tax	(483,000)	(138,000)
Unrecognized actuarial losses, before tax	(2,800,000)	(4,200,000)
Unrecognized actuarial losses, net of tax	(1,700,000)	(2,600,000)
Prior service costs expected to be recognized next fiscal year	26,000
Prior service costs expected to be recognized next fiscal year, net of tax	16,000
Actuarial losses expected to be recognized next fiscal year	129,000
Actuarial losses expected to be recognized next fiscal year, net of tax	79,000
Unfunded portion of the liability	(32,508,000)	(17,551,000)
Accrued postretirement liability, current	2,800,000
Postretirement health care plans, expected contribution in 2012	$ 2,800,000