Summary Of Significant Accounting Policies (Fair Value Of The Equity Index Put Options) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011 contracts	Dec. 31, 2010
Option Indexed to Issuer's Equity [Line Items]
Equity index put option liability	$ 69,729	$ 58,467
Equity index put option contracts sold	7
Equity Index Put Option Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Option Indexed to Issuer's Equity [Line Items]
Equity index put option liability	$ 69,729	$ 58,467