Retirement Benefits - Assumptions Used In Calculations (Details)	6 Months Ended
	Jun. 30, 2012
Pension Plans Defined Benefit [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost [Abstract]
Expected return on plan assets	7.50%
Discount rate	4.74%
Discount rate from acquisition entity	4.27%
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost [Abstract]
Expected return on plan assets	6.68%
Discount rate	4.80%
Discount rate from acquisition entity	4.28%