Acquisitions and Dispositions (Narrative) (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2012 business	Oct. 02, 2011 business	Oct. 02, 2011 business	Sep. 30, 2012 Education [Member] business	Sep. 30, 2012 Other Businesses [Member] business
Business Acquisition [Line Items]
Number of businesses acquired	0	0	4	3	1

The number of businesses acquired by the entity during the period.

No definition available.

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration