v2.3.0.15

Common Stock Repurchase Program (Narrative) (Details) (Class A Common Stock [Member], USD $) In Millions	0 Months Ended	1 Months Ended		12 Months Ended
	Jul. 26, 2011 Additional Stock Approved [Member]	Jul. 31, 2010 Additional Stock Approved [Member]	Nov. 30, 2009	Sep. 30, 2011
Equity, Class Of Treasury Stock [Line Items]
Stock authorized for repurchase	$ 250.0	$ 300.0	$ 250.0	$ 800.0

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

Name:	us-gaap_EquityClassOfTreasuryStockLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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

+ Details

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