Benefit Plans Benefit Plans - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.21%	5.04%
Rate of compensation increase	3.25%	3.25%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	5.04%	5.83%
Expected long-term return on plan assets	8.25%	8.50%
Rate of compensation increase	3.25%	3.25%
Other Benefits [Member]
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rate	4.21%	5.04%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rate	5.04%	5.83%