XML 45 R31.htm IDEA: XBRL DOCUMENT v3.7.0.1
Commitments and Contingencies (Environmental) (Details)
$ in Millions
Mar. 31, 2017
USD ($)
Superfund_Sites
Dec. 31, 2016
USD ($)
Accrual for Environmental Loss Contingencies Disclosure [Abstract]    
Accrual for Environmental Loss Contingencies $ 49 $ 50
Superfund Sites [Member]    
Accrual for Environmental Loss Contingencies Disclosure [Abstract]    
Number of superfund sites | Superfund_Sites 8  
Accrual for site contingency $ 4