Summary of Significant Accounting Policies Fair Value Measurements Policy Additional Information (Details) (Fair Value, Inputs, Level 1 [Member], USD $) In Thousands | Sep. 30, 2011 |
|---|---|
Fair Value, Inputs, Level 1 [Member] | |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |
| Assets, Fair Value Disclosure | $ 0 |
| Liabilities, Fair Value Disclosure | $ 0 |