v3.3.1.900
Income Taxes (Federal Statutory) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Federal tax at statutory rate $ 4,680 $ 4,363 $ 3,890
State income taxes, net of federal benefit 326 329 319
Foreign income taxes, net of federal credit 13 0 15
Nontaxable income attributable to noncontrolling interests (69) (62) (103)
Other adjustments (79) (114) (313)
Income tax expense 4,959 3,873 3,980
Uncertain And Effectively Settled Tax Positions, Net [Member]      
Other adjustments 15 (408) 58
Accrued Interest On Uncertain And Effectively Settled Tax Positions Net [Member]      
Other adjustments $ 73 $ (235) $ 114