Employee Benefits (Target Allocations - Other Postretirment Benefit Plans) (Details) (Other Postretirement Benefit Plans, Defined Benefit)	12 Months Ended
Dec. 31, 2011
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Equity securities	65.00%
Fixed income	30.00%
Alternative investments	5.00%
Total	100.00%

Target allocation percentage of investments in equity securities to total plan assets presented on a weighted-average basis as of the measurement date of the latest statement of financial position.

No definition available.

Name:	us-gaap_DefinedBenefitPlanTargetAllocationPercentageOfAssetsEquitySecurities
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration