Other	3 Months Ended
Mar. 31, 2012
Other [Abstract]
Other Items Disclosure	Debt At March 31, 2012, short-term debt consisted of $372.2 million of securities lending transactions. Regarding activity relative to our long-term debt, during the three months ended March 31, 2012, we made principal payments of $15.0 million and $2.5 million on our senior secured non-recourse floating rate notes issued by Northwind Holdings, LLC and Tailwind Holdings, LLC, respectively. Income Tax At March 31, 2012, we had a liability of $82.5 million for unrecognized tax benefits, all of which is associated with deferred tax assets. The interest expense and penalties related to unrecognized tax expense in our consolidated statements of income was $0.5 million and $1.2 million for the three months ended March 31, 2012 and 2011, respectively. During 2010, the Internal Revenue Service (IRS) completed its examination of tax years 2005 and 2006 and issued its revenue agent's report (RAR) in December 2010. In January 2011, we filed a protest to the RAR with respect to all significant adverse proposed adjustments. Although we have not yet reached a final settlement with the IRS for these years, it is reasonably possible that this appeal will be resolved in whole or in part within 12 months and that statutes of limitations may expire in multiple jurisdictions within the same period. As a result, it is reasonably possible that our liability for unrecognized tax benefits could decrease within 12 months by $0 million to $66.0 million. We believe sufficient provision has been made for all uncertain tax provisions and that any adjustments by tax authorities with respect to such positions would not have a material adverse effect on our financial position, liquidity, or results of operations.

Debt

At March 31, 2012, short-term debt consisted of $372.2 million of securities lending transactions. Regarding activity relative to our long-term debt, during the three months ended March 31, 2012, we made principal payments of $15.0 million and $2.5 million on our senior secured non-recourse floating rate notes issued by Northwind Holdings, LLC and Tailwind Holdings, LLC, respectively.

Income Tax

At March 31, 2012, we had a liability of $82.5 million for unrecognized tax benefits, all of which is associated with deferred tax assets. The interest expense and penalties related to unrecognized tax expense in our consolidated statements of income was $0.5 million and $1.2 million for the three months ended March 31, 2012 and 2011, respectively.

During 2010, the Internal Revenue Service (IRS) completed its examination of tax years 2005 and 2006 and issued its revenue agent's report (RAR) in December 2010. In January 2011, we filed a protest to the RAR with respect to all significant adverse proposed adjustments. Although we have not yet reached a final settlement with the IRS for these years, it is reasonably possible that this appeal will be resolved in whole or in part within 12 months and that statutes of limitations may expire in multiple jurisdictions within the same period. As a result, it is reasonably possible that our liability for unrecognized tax benefits could decrease within 12 months by $0 million to $66.0 million. We believe sufficient provision has been made for all uncertain tax provisions and that any adjustments by tax authorities with respect to such positions would not have a material adverse effect on our financial position, liquidity, or results of operations.