Commitments and Contingencies, Legal Proceedings (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011 issuers
Loss Contingencies [Line Items]
Number of other issuers included in IPO lawsuit allegations	300
Estimated Incremental Tax Liability Excluding Interest And Penalties Related to PNOD	$ 92
Estimated incremental tax liability excluding interest and penalties related to NOPA	$ 807

Estimated Incremental Tax Liability Excluding Interest And Penalties Related to Preliminary Notice Of Deficiency

No definition available.

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