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