Retirement, Other Postretirement Benefits, and Defined Contribution Plans (Details 6)	Dec. 31, 2011	Dec. 31, 2010
Actuarial Assumptions Used in Determining Pension and Other Postretirement Benefit Obligation
Weighted-average rate of increase in future compensation levels	4.23%	4.23%
Qualified Pension [Member] | Maximum [Member]
Actuarial Assumptions Used in Determining Pension and Other Postretirement Benefit Obligation
Weighted-average discount rate:	5.20%	5.70%
Qualified Pension [Member] | Minimum [Member]
Actuarial Assumptions Used in Determining Pension and Other Postretirement Benefit Obligation
Weighted-average discount rate:	5.10%	5.60%
Non Qualified Pension [Member]
Actuarial Assumptions Used in Determining Pension and Other Postretirement Benefit Obligation
Weighted-average discount rate:	4.40%	4.90%
Other Postretirement Trusts [Member]
Actuarial Assumptions Used in Determining Pension and Other Postretirement Benefit Obligation
Weighted-average discount rate:	5.10%	5.50%