Income Taxes Income taxes (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | ||
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Mar. 31, 2011
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Dec. 31, 2011
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Dec. 31, 2010
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Dec. 31, 2012
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Operating Loss Carryforwards [Line Items] | ||||
Tax Credit Carryforward, Federal | $ 41 | |||
Tax Credit Carryforward, State | 14 | |||
Deferred Tax Assets, Valuation Allowance | 0 | |||
Valuation Allowance, Deferred Tax Asset, Change in Amount | (2) | |||
Unrecognized Tax Benefits | 0 | 2 | 0 | |
Unrecognized Tax Benefits, Interest on Income Taxes Expense | 1 | |||
Unrecognized Tax Benefits, Income Tax Penalties Expense | 0 | |||
Unrecognized Tax Benefits, Decreases Resulting from Current Period Tax Positions | $ 2 |
X | ||||||||||
- Definition
The amount of the federal tax credit carryforward, berfore tax effects, available to reduce future taxable income under enacted tax laws. No definition available.
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- Definition
The amount of the state tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. No definition available.
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- Definition
Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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X | ||||||||||
- Definition
The gross amount of decreases in unrecognized tax benefits resulting from tax positions that have been or will be taken in the tax return for the current period, excluding amounts pertaining to examined tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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X | ||||||||||
- Definition
This element represents the recognized expense for 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 or, if not recognizing the expense in the period in which the tax return was initially filed, the expense is generally recognized in the period in which the enterprise's judgment about meeting the minimum statutory threshold changes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This element represents 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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X | ||||||||||
- Definition
The amount of the change in the period in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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