Segment Information (Details 1) (USD $) In Millions	Dec. 31, 2010	Dec. 31, 2009
Segment information (Details) [Abstract]
Total assets	$ 10,557.8	$ 11,931.2
DISC OP [Member]
Balance sheet information about reportable segments
Total Assets, by segment	0	36.4
PBM [Member]
Balance sheet information about reportable segments
Total Assets, by segment	10,155.1	11,629.1
EM [Member]
Balance sheet information about reportable segments
Total Assets, by segment	$ 402.7	$ 265.7

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Concepts (CON)

-Number 6

-Paragraph 25

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 18

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 7

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