Retirement Plans (Asset Allocation Policy Ranges) (Details)	12 Months Ended
	Dec. 31, 2012
Equities
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range minimum	25.00%
Asset allocation policy range maximum	75.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range minimum	10.00%
Asset allocation policy range maximum	50.00%
Cash
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range minimum	0.00%
Asset allocation policy range maximum	15.00%
Other asset classes
Defined Benefit Plan Disclosure [Line Items]
Asset allocation policy range minimum	0.00%
Asset allocation policy range maximum	20.00%