Income Taxes Income Tax Expense (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Current Federal Tax Expense (Benefit)	$ 1,190us-gaap_CurrentFederalTaxExpenseBenefit	$ 1,346us-gaap_CurrentFederalTaxExpenseBenefit	$ 1,204us-gaap_CurrentFederalTaxExpenseBenefit
Current State and Local Tax Expense (Benefit)	169	206	141
Current Income Tax Expense (Benefit)	1,359us-gaap_CurrentIncomeTaxExpenseBenefit	1,552us-gaap_CurrentIncomeTaxExpenseBenefit	1,345us-gaap_CurrentIncomeTaxExpenseBenefit
Deferred Federal Income Tax Expense (Benefit)	852	609	591
Deferred State and Local Income Tax Expense (Benefit)	89	(26)	69
Deferred Income Tax Expense (Benefit)	941us-gaap_DeferredIncomeTaxExpenseBenefit	583us-gaap_DeferredIncomeTaxExpenseBenefit	660us-gaap_DeferredIncomeTaxExpenseBenefit
Income Tax Expense (Benefit), Continuing Operations	$ 2,300us-gaap_IncomeTaxExpenseBenefit	$ 2,135us-gaap_IncomeTaxExpenseBenefit	$ 2,005us-gaap_IncomeTaxExpenseBenefit

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.