Employee Benefits Schedule of Allocation of Plan Assets (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Actual [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	68.00%	68.00%
Debt Securities	32.00%	32.00%
Total	100.00%	100.00%
Actual [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	61.00%	46.00%
Debt Securities	39.00%	54.00%
Total	100.00%	100.00%
Actual [Member] | Non Qualified Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	30.00%	42.00%
Debt Securities	7.00%	5.00%
Insurance contracts	63.00%	53.00%
Total	100.00%	100.00%
Target [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	67.00%	67.00%
Debt Securities	33.00%	33.00%
Total	100.00%	100.00%
Target [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	72.00%	47.00%
Debt Securities	28.00%	53.00%
Total	100.00%	100.00%
Target [Member] | Non Qualified Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Equity Securities	23.00%	42.00%
Debt Securities	14.00%	7.00%
Insurance contracts	63.00%	51.00%
Total	100.00%	100.00%