XML 111 R92.htm IDEA: XBRL DOCUMENT v3.6.0.2
Components of Net Periodic Postretirement Health Care Costs (Detail) - Postretirement Benefit Plans - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]      
Service cost $ 12 $ 15 $ 13
Interest cost 20 22 22
Net loss from experience differences 10 13 5
Prior service credit [1] (20) (7) (10)
Net periodic benefit cost $ 22 $ 43 $ 30
[1] For the year ended December 31, 2016, amortization of prior service credit includes $9 million of curtailment gain related to a change in the eligibility requirement.