Business Combinations (Details) (USD $)	0 Months Ended	1 Months Ended
Dec. 14, 2011	Sep. 01, 2011	Sep. 10, 2010	Sep. 30, 2011
Business Combinations [Abstract]
Value of acquired buisness	$ 3,300,000,000
Authorized repurchase of Company common stock	$ 1,600,000,000	$ 500,000,000	$ 250,000,000	$ 500,000,000

The amount authorized by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration