Income Taxes Net Operating Loss Carryforwards (Details) (USD $) In Millions, unless otherwise specified			12 Months Ended
Dec. 31, 2012 Internal Revenue Service (IRS) [Member]	Sep. 30, 2012 State and Local Jurisdiction [Member]	Dec. 31, 2012 Current year [Member] NumberStates	Dec. 31, 2011 Current year [Member] NumberStates	Dec. 31, 2011 amended 2006-2008 [Member] NumberStates	Dec. 31, 2011 true-up 2010 [Member] NumberStates	Dec. 31, 2010 amended 07-08, 09 true-up [Member] NumberStates
State tax expense (ones)			1	2	1	2	1
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration	$ 116.5	$ 111.3

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

No definition available.

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant