Income Taxes (Significant Components Of Deferred Tax Assets Net Of Deferred Tax Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Inventory and long-term contract methods of income recognition		$ (5,422)	$ (6,459)
Pension benefits		3,344	3,565
Fixed assets, intangibles and goodwill (net of valuation allowance of $16 and $16)		(1,616)	(1,253)
Retiree health care benefits		1,124	1,304
Other employee benefits		873	847
Accrued expenses and reserves		411	334
Customer and commercial financing		(309)	(369)
Net operating loss, credit and capital loss carryovers (net of valuation allowance of $77 and $53)	[1]	258	299
Other		(115)	(135)
Net deferred tax (liabilities)/assets	[2]	1,452	1,867
Deferred tax asset for net operating loss and credit carryovers each year through December 31, 2035		244
Deferred tax asset for net operating loss and credit carryovers indefinitely		14
Deferred tax assets related to Accumulated other comprehensive loss		4,275	4,636
Valuation Allowance - Fixed assets, intangibles, and goodwill deferred tax assets		93	69
Valuation Allowance - Net operating loss, credit and capital loss carryovers		77	53
Valuation Allowance, Property Plant and Equipment, Intangibles and Goodwill [Member]
Valuation Allowance [Line Items]
Valuation Allowance - Fixed assets, intangibles, and goodwill deferred tax assets		$ 16	$ 16

[1] Of the deferred tax asset for net operating loss and credit carryovers, $244 expires on or before December 31, 2037 and $14 may be carried over indefinitely.

[2] Included in the net deferred tax (liabilities)/assets as of December 31, 2018 and 2017 are deferred tax assets in the amounts of $4,275 and $4,636 related to Accumulated other comprehensive loss.