Retirement Benefits and Trusteed Assets (Details 4) (Pension Plans, Defined Benefit [Member])	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Pension Plans, Defined Benefit [Member]
Assumptions Used to Determin Projected Benefit Obligations and Net Pension Costs [Line Items]
Discount rate	4.15%	5.00%	5.50%
Rate of compensation increase	4.20%	4.20%	4.00%
Discount Rate	5.00%	5.50%	5.90%
Rate of compensation increase	4.20%	4.00%	4.00%
Expected long-term rate of return on plan assets	8.25%	8.50%	8.75%