Impact of Adoption of New Standards Impact of Adoption of New Standards (Schedule of Accounting Changes) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Sales of products		$ 20,820	$ 19,367
Sales of services		2,562	2,594
Revenues		23,382	21,961
Cost of Goods Sold		(16,816)	(16,062)
Cost of Services		(1,992)	(1,998)
Financial Services Costs		(16)	(13)
Cost of Revenue		(18,824)	(18,073)
Gross Profit		4,558	3,888
Income from operating investments, net		74	81
General and Administrative Expense		(997)	(929)
Research and Development Expense		(764)	(836)
(Gain)/Loss on dispositions, net		(4)	(2)
Earnings from operations		2,875	2,206
Other income, net		66	26
Interest and Debt Expense		(102)	(87)
Earnings before income taxes		2,839	2,145
Income tax expense		(362)	(566)
Net earnings		$ 2,477	$ 1,579
Earnings Per Share, Basic		$ 4.19	$ 2.57
Earnings Per Share, Diluted		$ 4.15	$ 2.54
Assets [Abstract]
Short-term and other investments		$ 656		$ 1,179
Accounts receivable, net		2,802		2,894
Unbilled receivables, net		9,822		8,194
Current portion of customer financing, net		244		309
Inventories		61,303		61,388
Other current assets		2,481		2,417
Assets, Current		86,543		85,194
Customer financing, net		2,753		2,756
Property, plant and equipment, net		12,628		12,672
Goodwill		5,558		5,559
Acquired intangible assets, net		2,525		2,573
Deferred income taxes		325		321
Investments		1,248		1,260
Other assets, net of accumulated amortization		1,969		2,027
Assets		113,549		112,362
Liabilities and equity
Accounts payable		12,613		12,202
Accrued liabilities		10,983		13,069
Advances and billings in excess of related costs
Advances and progress billings		49,955		48,042
Short-term debt and current portion of long-term debt		1,981		1,335
Total current liabilities		75,532		74,648
Deferred income taxes		2,001		2,188
Accrued retiree health care		5,494		5,545
Accrued pension plan liability, net		16,279		16,471
Other long-term liabilities		2,474		2,015
Long-term debt		10,471		9,782
Common stock		5,061		5,061
Additional paid-in capital		6,624		6,804
Treasury stock, at cost		46,396		43,454
Retained earnings		52,095		49,618
Accumulated other comprehensive loss	[1]	(16,162)	$ (13,415)	(16,373)	$ (13,623)
Total shareholders’ equity		1,222		1,656
Noncontrolling interests		76		57
Total equity		1,298	1,323	1,713	1,917
Total liabilities and equity		113,549		112,362
Cash flows - operation activities:
Net earnings		2,477	1,579
Non-cash items -
Share-based plans expense		45	50
Depreciation and amortization		501	468
Asset Impairment Charges		20	23
Customer financing valuation (benefit)/expense		(1)	7
Gain on dispositions, net		4	2
Other charges and credits, net		60	58
Changes in assets and liabilities -
Accounts receivable		92	(264)
Unbilled receivables		(1,628)	(568)
Advances and progress billings		1,917	1,375
Inventories		283	(1,491)
Other current assets		(103)	(117)
Accounts payable		591	616
Accrued liabilities		(1,337)	(282)
Advances and billings in excess of related costs
Income taxes receivable, payable and deferred		348	552
Other long-term liabilities		(243)	(72)
Pension and other postretirement plans		(50)	10
Customer financing, net		44	231
Other		124	(75)
Net Cash Provided by (Used in) Operating Activities		3,136	2,098
Cash flows - investing activities:
Payments to Acquire Property, Plant, and Equipment		(394)	(466)
Property, plant and equipment reductions		27	9
Payments to Acquire Investments		(249)	(605)
Proceeds from investments		752	803
Other		3	(1)
Net Cash Provided by (Used in) Investing Activities		119	(260)
Cash flows - financing activities:
New borrowings		2,687	872
Debt repayments		(1,371)	(34)
Stock options exercised		51	174
Employee taxes on certain share-based payment arrangements		(226)	(107)
Common shares repurchased		(3,000)	(2,500)
Dividends paid		(1,006)	(868)
Net cash used by financing activities		(2,845)	(2,463)
Effect of exchange rate changes on cash and cash equivalents, including restricted		8	20
Net increase/(decrease) in cash & cash equivalents, including restricted		418	(605)
Cash & cash equivalents, including restricted, at beginning of year		8,887	8,869	8,869
Cash & cash equivalents, including restricted, at end of period		9,305	8,264	8,887	8,869
Restricted Cash and Cash Equivalents	[2]	(70)	(74)	(74)
Cash and cash equivalents at end of period		9,235	8,190	8,813
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		1,298	1,323	1,713	1,917
Common Stock [Member]
Liabilities and equity
Common stock				5,061
Total equity		5,061	5,061	5,061	5,061
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		5,061	5,061	5,061	5,061
Additional Paid-In Capital [Member]
Liabilities and equity
Additional paid-in capital				6,804
Total equity		6,624	4,604	6,804	4,762
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		6,624	4,604	6,804	4,762
Treasury Stock [Member]
Liabilities and equity
Treasury stock, at cost				(43,454)
Total equity		(46,396)	(38,320)	(43,454)	(36,097)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		(46,396)	(38,320)	(43,454)	(36,097)
Retained Earnings [Member]
Income Statement [Abstract]
Net earnings		2,477	1,579
Liabilities and equity
Total equity		52,095	43,333	49,618	41,754
Cash flows - operation activities:
Net earnings		2,477	1,579
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		52,095	43,333	49,618	41,754
Accumulated Other Comprehensive Loss [Member]
Liabilities and equity
Total equity		(16,162)	(13,415)	(16,373)	(13,623)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		(16,162)	(13,415)	(16,373)	(13,623)
Non-Controlling Interest [Member]
Liabilities and equity
Noncontrolling interests				57
Total equity		76	60	57	60
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity		$ 76	60	57	60
Scenario, Previously Reported [Member]
Income Statement [Abstract]
Sales of products			18,512
Sales of services			2,464
Revenues			20,976
Cost of Goods Sold			(15,363)
Cost of Services			(1,888)
Cost of Revenue			(17,264)
Gross Profit			3,712
General and Administrative Expense			(933)
Research and Development Expense			(838)
Earnings from operations			2,024
Other income, net			22
Earnings before income taxes			1,959
Income tax expense			(508)
Net earnings			$ 1,451
Earnings Per Share, Basic			$ 2.36
Earnings Per Share, Diluted			$ 2.34
Assets [Abstract]
Accounts receivable, net				10,516
Unbilled receivables, net
Inventories				44,344
Other current assets
Assets, Current				65,161
Customer financing, net				2,740
Deferred income taxes				341
Assets				92,333
Liabilities and equity
Accrued liabilities				15,292
Advances and billings in excess of related costs				27,440
Advances and progress billings
Total current liabilities				56,269
Deferred income taxes				1,839
Total shareholders’ equity				355
Total equity				412	877
Total liabilities and equity				92,333
Cash flows - operation activities:
Net earnings			$ 1,451
Non-cash items -
Depreciation and amortization			471
Other charges and credits, net			52
Changes in assets and liabilities -
Accounts receivable			(769)
Unbilled receivables
Advances and progress billings
Inventories			(31)
Other current assets
Accrued liabilities			(613)
Advances and billings in excess of related costs			249
Income taxes receivable, payable and deferred			495
Customer financing, net			232
Net Cash Provided by (Used in) Operating Activities			2,094
Cash flows - investing activities:
Other			(3)
Net Cash Provided by (Used in) Investing Activities			(262)
Cash flows - financing activities:
Net increase/(decrease) in cash & cash equivalents, including restricted			(611)
Cash & cash equivalents, including restricted, at beginning of year			8,801	8,801
Cash & cash equivalents, including restricted, at end of period			8,190		8,801
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity				412	877
Scenario, Previously Reported [Member] | Retained Earnings [Member]
Liabilities and equity
Retained earnings				45,320
Total equity					40,714
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity					40,714
Scenario, Previously Reported [Member] | Accumulated Other Comprehensive Loss [Member]
Liabilities and equity
Total equity				(13,376)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity				(13,376)
Scenario, Restated [Member]
Liabilities and equity
Total equity				1,713	1,917
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity				1,713	1,917
Scenario, Restated [Member] | Retained Earnings [Member]
Liabilities and equity
Retained earnings				49,618
Total equity					41,754
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity					41,754
Scenario, Restated [Member] | Accumulated Other Comprehensive Loss [Member]
Liabilities and equity
Accumulated other comprehensive loss				(16,373)
Adjustments for New Accounting Pronouncement [Member]
Income Statement [Abstract]
Sales of products			855
Sales of services			130
Revenues			985
Cost of Goods Sold			(699)
Cost of Services			(110)
Cost of Revenue			(809)
Gross Profit			176
General and Administrative Expense			4
Research and Development Expense			2
Earnings from operations			182
Other income, net			4
Earnings before income taxes			186
Income tax expense			(58)
Net earnings			$ 128
Earnings Per Share, Basic			$ 0.21
Earnings Per Share, Diluted			$ 0.20
Assets [Abstract]
Accounts receivable, net				(7,622)
Unbilled receivables, net				8,194
Inventories				17,044
Other current assets				2,417
Assets, Current				20,033
Customer financing, net				16
Deferred income taxes				(20)
Assets				20,029
Liabilities and equity
Accrued liabilities				(2,223)
Advances and billings in excess of related costs				(27,440)
Advances and progress billings				48,042
Total current liabilities				18,379
Deferred income taxes				349
Retained earnings				4,298
Accumulated other comprehensive loss				(2,997)
Total shareholders’ equity				1,301
Total equity				1,301
Total liabilities and equity				20,029
Cash flows - operation activities:
Net earnings			$ 128
Non-cash items -
Depreciation and amortization			(3)
Other charges and credits, net			6
Changes in assets and liabilities -
Accounts receivable			505
Unbilled receivables			(568)
Advances and progress billings			1,375
Inventories			(1,460)
Other current assets			(117)
Accrued liabilities			331
Advances and billings in excess of related costs			(249)
Income taxes receivable, payable and deferred			57
Customer financing, net			(1)
Net Cash Provided by (Used in) Operating Activities			4
Cash flows - investing activities:
Other			2
Net Cash Provided by (Used in) Investing Activities			2
Cash flows - financing activities:
Net increase/(decrease) in cash & cash equivalents, including restricted			6
Cash & cash equivalents, including restricted, at beginning of year			68	68
Cash & cash equivalents, including restricted, at end of period			$ 74		68
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total equity				1,301
Accounting Standards Update 2014-09 [Member]
Income Statement [Abstract]
Net earnings				261	139
Cash flows - operation activities:
Net earnings				261	139
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption				1,301	139	$ 901
Accounting Standards Update 2014-09 [Member] | Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption				1,301		$ 901
Accounting Standards Update 2018-02 [Member]
Liabilities and equity
Retained earnings				2,997
Accumulated other comprehensive loss				(2,997)
Fiscal Year 2016 [Member] | Accounting Standards Update 2014-09 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption					$ 139
Fiscal Year 2017 [Member] | Accounting Standards Update 2014-09 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 261

[1] Net of tax.

[2] Reflects amounts restricted in support of our workers’ compensation programs, employee benefit programs, and insurance premiums.