XML 196 R104.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Deferred tax balances (Details) - USD ($)
$ in Millions
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Deferred tax assets and liabilities        
Net deferred tax liability $ (5,622) $ (6,692) $ (8,378) $ (10,731)
Net operating losses and tax carry forwards        
Deferred tax assets and liabilities        
Deferred tax asset 3,014 3,267 3,100  
Employee benefits        
Deferred tax assets and liabilities        
Deferred tax asset 1,153 1,257 1,251  
Other temporary non-deductible provisions or tax deductions        
Deferred tax assets and liabilities        
Deferred tax asset 6,344 5,862 6,279  
Deferred tax liability (2,746) (2,126) (1,795)  
Differences in depreciations        
Deferred tax assets and liabilities        
Deferred tax liability $ (13,387) $ (14,952) $ (17,213)