Amounts Recognized in Other Comprehensive Income (Loss) Related to Postretirement Benefit Plans, Net of Tax (Parenthetical) (Detail) - USD ($) $ in Millions |
12 Months Ended | ||||
|---|---|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Accumulated Other Comprehensive Income (Loss) [Line Items] | |||||
| Net prior service (credit) and cost - Recognition of Previously Deferred Amounts | $ (239) | $ (259) | $ (100) | ||
| Recognition of net prior service credits from divestiture of IS&GS segment | [1] | 134 | |||
| Discontinued Operations | Information Systems & Global Solutions | |||||
| Accumulated Other Comprehensive Income (Loss) [Line Items] | |||||
| Net prior service (credit) and cost - Recognition of Previously Deferred Amounts | 9 | $ 16 | $ 11 | ||
| Recognition of net prior service credits from divestiture of IS&GS segment | $ 134 | ||||
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