Consolidated Statements of Comprehensive Income $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Retained Earnings (Accumulated Deficit)	$ 50,644	$ 55,941
Net (loss)/earnings	(636)	10,460	$ 8,458
Currency translation adjustments	(27)	(86)	128
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax of ($1), $1, and ($5)	1	2	1
Derivative instruments:
Unrealized (loss)/gain arising during period, net of tax of $13, $40, and ($66)	(48)	(146)	119
Reclassification adjustment for loss included in net earnings, net of tax of ($7), ($8), and ($28)	26	30	52
Total derivative instruments, net of tax	(22)	(116)	171
Defined benefit pension plans & other postretirement benefits:
Net actuarial (loss)/gain arising during the period, net of tax of $405, ($105), and $248	(1,413)	384	(495)
Amortization of actuarial losses included in net periodic pension cost, net of tax of ($133), ($242), and ($272)	464	878	542
Settlements and curtailments included in net income, net of tax of $0, ($2), and $0		(8)
Pension and postretirement benefit/(cost) related to our equity method investments, net of tax ($5), ($6), and $5	17	22	(11)
Amortization of prior service credits included in net periodic pension cost, net of tax of $25, $39, and $59	(89)	(143)	(117)
Prior service (credit)/cost arising during the period, net of tax of $0, ($94), and ($14)	(1)	341	28
Total defined benefit pension plans & other postretirement benefits, net of tax	(1,022)	1,490	(53)
Other comprehensive (loss)/income, net of tax	(1,070)	1,290	247
Comprehensive loss related to noncontrolling interests	(41)	(21)	(2)
Comprehensive (loss)/income, net of tax	$ (1,747)	$ 11,729	$ 8,703