Retirement Benefits (Narrative) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Anticipated additional contribution for pension plans and other postretirement benefit plans in 2011	$ 3.7
Pension Plans [Member]
Expected contribution for next fiscal year		7.9
Actual contributions	4.8
Other Postretirement Benefit Plans [Member]
Expected contribution for next fiscal year		1.0
Actual contributions	$ 0.4

The employer's best estimate, as soon as it can be reasonably determined, of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position. Estimated contributions may be presented in the aggregate combining (1) contributions required by funding regulations or laws, (2) discretionary contributions, and (3) noncash contributions.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph g

Name:	us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsInNextFiscalYear
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant