Schedule II - Condensed Financial Information, Balance Sheets (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Dec. 31, 2013
Assets        
Cash and cash equivalents $ 2,620 $ 1,420 $ 2,276 $ 2,795
Other assets 2,985 2,683    
Total assets 58,122 55,896    
Liabilities:        
Short-term debt 999 147    
Long-term debt, carrying value 5,062 5,005    
Total liabilities 47,081 45,017    
Shareholders Equity:        
Common stock (shares issued, 296; authorized, 600) 74 74    
Additional paid-in capital 2,823 2,769    
Accumulated other comprehensive loss (934) (936)    
Retained earnings 10,635 10,289    
Less treasury stock, at cost (1,656) (1,422)    
Total shareholders' equity 10,942 10,774    
Total liabilities and equity $ 58,122 $ 55,896