| Fair Value Measurements (Changes in Level 3 Securities) (Details) (USD $) In Thousands | 3 Months Ended | |
|---|---|---|
| Sep. 30, 2011 | Sep. 30, 2010 | |
| Changes in Level 3 Securities | ||
| Beginning aggregate fair value of Level 3 securities | $ 0 | $ 16,825 | 
| Net settlements | 0 | (16,825) | 
| Ending aggregate fair value of Level 3 securities | $ 0 | $ 0 | 
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. 
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- Definition This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3). Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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