This element represents the total of accruals as of the date of the statement of financial position for interest recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties for a tax position claimed or expected to be claimed by the entity, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

+ References+ Details

This element represents the total of interest expense recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties in the period in which the entity claims or expects to claim a tax position, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

+ References+ Details

Income Taxes, Additional Disclosures (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Range of potential change in unrecognized tax benefits due to closure of state income tax audits and expiration of statutes of limitations within the next year	$ 4.9
Net accrued interest and penalties, total	12.8	15.6
Accrued interest and penalties related to unrecognized income tax benefits	$ (2.2)	$ (2.6)	$ 3.0
Federal
Income Tax Disclosure [Abstract]
Open tax years by major tax jurisdiction	2009
State
Income Tax Disclosure [Abstract]
Open tax years by major tax jurisdiction	2008