Recast 2017 and 2016 Financial Information (Details 1) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 1,579				$ 11,225				$ 1,579	$ 11,225	$ 2,541	$ 2,319
Revenues	8,156	$ 8,085	$ 7,119	$ 6,735	6,552	$ 6,569	$ 6,473	$ 6,410	30,095	26,004	24,706
General and Administrative Expense									3,011	2,712	2,632
Operating Income (Loss)	943	1,172	817	848	672	829	864	853	3,780	3,218	3,277
Interest and Debt Expense									562	360	301
Net FAS (non-service) pension benefit									1,049	699	611
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									130	136	44
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									3,742	4,229	2,681
Income Tax Expense (Benefit)									513	1,360	638
Net Income (Loss) Attributable to Parent	$ 356	$ 1,244	$ 789	$ 840	$ 672	$ 750	$ 677	$ 770	$ 3,229	$ 2,869	$ 2,043
Earnings Per Share, Basic	$ 2.07	$ 7.15	$ 4.52	$ 4.82	$ 3.86	$ 4.31	$ 3.88	$ 4.41	$ 18.59	$ 16.45	$ 11.42
Weighted Average Number of Shares Outstanding, Basic	171,800,000	174,100,000	174,500,000	174,300,000	174,200,000	174,200,000	174,500,000	174,800,000	173,700,000	174,400,000	178,900,000
Earnings Per Share, Diluted	$ 2.06	$ 7.11	$ 4.50	$ 4.79	$ 3.83	$ 4.28	$ 3.86	$ 4.37	$ 18.49	$ 16.34	$ 11.32
Weighted Average Number of Shares Outstanding, Diluted	172,600,000	174,900,000	175,400,000	175,400,000	175,500,000	175,300,000	175,500,000	176,100,000	174,600,000	175,600,000	180,500,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax									$ 60	$ 44	$ 62
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax									(8)	(4)	(50)
Other, net									(6)	2	(1)
Other comprehensive loss, net of tax									(74)	(46)	(113)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									3,155	2,823	1,930
Accounts receivable, net	$ 1,448				$ 1,054				1,448	1,054
Unbilled receivables, net	5,026				3,465				5,026	3,465
Inventoried costs, net	654				398				654	398
Other Assets, Current	973				445				973	445
Assets, Current	9,680				16,587				9,680	16,587
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017	6,372				4,225				6,372	4,225
Goodwill	18,672				12,455				18,672	12,455	12,450
Intangible assets, net	1,372				52				1,372	52
Deferred tax assets	94				447				94	447
Other non-current assets	1,463				1,362				1,463	1,362
Assets	37,653				35,128				37,653	35,128
Accounts Payable, Current	2,182				1,661				2,182	1,661
Employee-related Liabilities, Current	1,676				1,382				1,676	1,382
Customer Advances, Current	1,917				1,761				1,917	1,761
Other Liabilities, Current	2,499				2,288				2,499	2,288
Liabilities, Current	8,274				7,092				8,274	7,092
Long-term Debt and Capital Lease Obligations	13,883				14,399				13,883	14,399
Liability, Defined Benefit Plan, Noncurrent	5,755				5,511				5,755	5,511
Other Liabilities, Noncurrent	1,446				994				1,446	994
Liabilities	29,466				27,996				29,466	27,996
Preferred Stock, Value, Issued	0				0				0	0
Common Stock, Value, Issued	171				174				171	174
Paid-in capital	0				44				0	44
Retained Earnings (Accumulated Deficit)	8,068				6,913				8,068	6,913
Accumulated Other Comprehensive Income (Loss), Net of Tax	(52)				1				(52)	1
Stockholders' Equity Attributable to Parent	8,187				7,132				8,187	7,132	5,363
Liabilities and Equity	37,653				35,128				37,653	35,128
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					11,225					11,225
Revenues										25,803	24,508
General and Administrative Expense										2,655	2,584
Operating Income (Loss)										3,299	3,193
Interest and Debt Expense										360	301
Net FAS (non-service) pension benefit										0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										110	31
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										3,049	2,923
Income Tax Expense (Benefit)										1,034	723
Net Income (Loss) Attributable to Parent										$ 2,015	$ 2,200
Earnings Per Share, Basic										$ 11.55	$ 12.30
Weighted Average Number of Shares Outstanding, Basic										174,400,000	178,900,000
Earnings Per Share, Diluted										$ 11.47	$ 12.19
Weighted Average Number of Shares Outstanding, Diluted										175,600,000	180,500,000
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 830	$ 175
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										(4)	(50)
Other, net										2	(1)
Other comprehensive loss, net of tax										828	(226)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										2,843	1,974
Accounts receivable, net					829					829
Unbilled receivables, net					3,147					3,147
Inventoried costs, net					780					780
Other Assets, Current					368					368
Assets, Current					16,349					16,349
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					4,225					4,225
Goodwill					12,455					12,455
Intangible assets, net					52					52
Deferred tax assets					475					475
Other non-current assets					1,361					1,361
Assets					34,917					34,917
Accounts Payable, Current					1,661					1,661
Employee-related Liabilities, Current					1,382					1,382
Customer Advances, Current					1,617					1,617
Other Liabilities, Current					2,305					2,305
Liabilities, Current					6,965					6,965
Long-term Debt and Capital Lease Obligations					14,399					14,399
Liability, Defined Benefit Plan, Noncurrent					5,511					5,511
Other Liabilities, Noncurrent					994					994
Liabilities					27,869					27,869
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					174					174
Paid-in capital					44					44
Retained Earnings (Accumulated Deficit)					11,548					11,548
Accumulated Other Comprehensive Income (Loss), Net of Tax					(4,718)					(4,718)
Stockholders' Equity Attributable to Parent					7,048					7,048	5,259
Liabilities and Equity					34,917					34,917
Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] | Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					0					0
Revenues	0	$ 0	$ 0	$ 0	0	$ 0	$ 0	$ 0		0
General and Administrative Expense										0	0
Operating Income (Loss)	23	(6)	(6)	(6)	(32)	(8)	(9)	(9)	5	(58)	8
Interest and Debt Expense									0	0	0
Net FAS (non-service) pension benefit									535	743	752
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit									(655)	536	(950)
Other Nonoperating Income (Expense)									(2)	12	16
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									(117)	1,233	(174)
Income Tax Expense (Benefit)									(24)	359	(61)
Net Income (Loss) Attributable to Parent	$ (394)	$ 100	$ 100	$ 101	$ 525	$ 107	$ 122	$ 120	$ (93)	$ 874	$ (113)
Earnings Per Share, Basic	$ (2.29)	$ 0.58	$ 0.57	$ 0.58	$ 3.01	$ 0.62	$ 0.70	$ 0.69	$ (0.53)	$ 5.01	$ (0.63)
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted	$ (2.28)	$ 0.57	$ 0.57	$ 0.58	$ 2.99	$ 0.61	$ 0.70	$ 0.68	$ (0.54)	$ 4.98	$ (0.63)
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ (874)	$ 113
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax									$ 93	(874)	113
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										0	0
Accounts receivable, net					$ 0					0
Unbilled receivables, net					0					0
Inventoried costs, net					0					0
Other Assets, Current					0					0
Assets, Current					0					0
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					0					0
Goodwill					0					0
Intangible assets, net					0					0
Deferred tax assets					0					0
Other non-current assets					0					0
Assets					0					0
Accounts Payable, Current					0					0
Employee-related Liabilities, Current					0					0
Customer Advances, Current					0					0
Other Liabilities, Current					0					0
Liabilities, Current					0					0
Long-term Debt and Capital Lease Obligations					0					0
Liability, Defined Benefit Plan, Noncurrent					0					0
Other Liabilities, Noncurrent					0					0
Liabilities					0					0
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					0					0
Paid-in capital					0					0
Retained Earnings (Accumulated Deficit)	$ (5,897)				(4,719)				(5,897)	(4,719)
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 5,897				4,719				5,897	4,719
Stockholders' Equity Attributable to Parent					0					0	0
Liabilities and Equity					0					0
Accounting Standards Update 2014-09 [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value					0					0
Revenues										201	198
General and Administrative Expense										57	48
Operating Income (Loss)										(53)	(68)
Interest and Debt Expense										0	0
Net FAS (non-service) pension benefit										0	0
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										(53)	(68)
Income Tax Expense (Benefit)										(33)	(24)
Net Income (Loss) Attributable to Parent										$ (20)	$ (44)
Earnings Per Share, Basic										$ (0.11)	$ (0.25)
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted										$ (0.11)	$ (0.24)
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 0	$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax										0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										(20)	(44)
Accounts receivable, net					225					225
Unbilled receivables, net					318					318
Inventoried costs, net					(382)					(382)
Other Assets, Current					77					77
Assets, Current					238					238
Property, plant and equipment, net of accumulated depreciation of $5,369 for 2018 and $5,066 for 2017					0					0
Goodwill					0					0
Intangible assets, net					0					0
Deferred tax assets					(28)					(28)
Other non-current assets					1					1
Assets					211					211
Accounts Payable, Current					0					0
Employee-related Liabilities, Current					0					0
Customer Advances, Current					144					144
Other Liabilities, Current					(17)					(17)
Liabilities, Current					127					127
Long-term Debt and Capital Lease Obligations					0					0
Liability, Defined Benefit Plan, Noncurrent					0					0
Other Liabilities, Noncurrent					0					0
Liabilities					127					127
Preferred Stock, Value, Issued					0					0
Common Stock, Value, Issued					0					0
Paid-in capital					0					0
Retained Earnings (Accumulated Deficit)					84					84
Accumulated Other Comprehensive Income (Loss), Net of Tax					0					0
Stockholders' Equity Attributable to Parent					84					84	104
Liabilities and Equity					$ 211					211
Accounting Standards Update 2017-07 [Domain] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
General and Administrative Expense										0	0
Operating Income (Loss)										30	144
Interest and Debt Expense										0	0
Net FAS (non-service) pension benefit										(44)	(141)
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit										0	0
Other Nonoperating Income (Expense)										14	(3)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										0	0
Income Tax Expense (Benefit)										0	0
Net Income (Loss) Attributable to Parent										$ 0	$ 0
Earnings Per Share, Basic										$ 0.00	$ 0.00
Weighted Average Number of Shares Outstanding, Basic										0.00	0
Earnings Per Share, Diluted										$ 0.00	$ 0.00
Weighted Average Number of Shares Outstanding, Diluted										0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax										$ 0	$ 0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax										0	0
Other, net										0	0
Other comprehensive loss, net of tax										0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent										0	0
Product [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues									20,469	16,364	15,080
Cost of Goods and Services Sold									15,785	12,527	11,197
Product [Member] | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										16,038	14,738
Cost of Goods and Services Sold										12,271	11,002
Product [Member] | Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] | Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										35	(5)
Product [Member] | Accounting Standards Update 2014-09 [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										326	342
Cost of Goods and Services Sold										239	286
Product [Member] | Accounting Standards Update 2017-07 [Domain] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										(18)	(86)
Service [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues									9,626	9,640	9,626
Cost of Goods and Services Sold									$ 7,519	7,547	7,600
Service [Member] | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										9,765	9,770
Cost of Goods and Services Sold										7,578	7,729
Service [Member] | Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] | Adjustments for Change in Accounting Principle [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										23	(3)
Service [Member] | Accounting Standards Update 2014-09 [Member] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										(125)	(144)
Cost of Goods and Services Sold										(42)	(68)
Service [Member] | Accounting Standards Update 2017-07 [Domain] | Adjustments for New Accounting Pronouncement [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues										0	0
Cost of Goods and Services Sold										$ (12)	$ (58)