Other Comprehensive Income (Loss) - Changes in AOCI balance by Component (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Other Comprehensive Income (Loss)
Income Before Reclassifications	$ 1
Amounts Reclassified to Net Earnings	8
Tax (Expense) Benefit	(1)
Reclassification of Stranded Tax Effects	(107)
Total Other Comprehensive Income	(99)
Pension and Other Post-Employment Benefits
Other Comprehensive Income (Loss)
Beginning balance	(440)
Income Before Reclassifications	0
Amounts Reclassified to Net Earnings	10
Tax (Expense) Benefit	(2)
Reclassification of Stranded Tax Effects	(108)
Total Other Comprehensive Income	(100)
Ending balance	(540)
Other
Other Comprehensive Income (Loss)
Beginning balance	(46)
Income Before Reclassifications	1
Amounts Reclassified to Net Earnings	(2)
Tax (Expense) Benefit	1
Reclassification of Stranded Tax Effects	1
Total Other Comprehensive Income	1
Ending balance	(45)
Accumulated Other Comprehensive Income (Loss)
Other Comprehensive Income (Loss)
Beginning balance	(486)
Ending balance	$ (585)