Revenue Recognition Revenue Recognition (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Mar. 31, 2018	Jan. 01, 2018	Mar. 31, 2017	Dec. 31, 2016
Inventory Costs in Excess of Average Cost Per Unit	$ 0		$ 0		$ 438,000,000
Capitalized Contract Cost, Gross							$ 700,000,000
Previously Recognized Customer Funding to Contract Liability							850,000,000
Revenues	16,705,000,000	$ 15,280,000,000	31,947,000,000	$ 29,095,000,000
Research and development	589,000,000	619,000,000	1,143,000,000	1,205,000,000
Selling, general and administrative	1,759,000,000	1,590,000,000	3,470,000,000	3,127,000,000
Total costs and expenses	14,770,000,000	13,373,000,000	28,315,000,000	25,632,000,000
Other income, net	941,000,000	257,000,000	1,172,000,000	845,000,000
Operating profit	2,876,000,000	2,164,000,000	4,804,000,000	4,308,000,000
Non-service pension cost (benefit)	(192,000,000)	(126,000,000)	(383,000,000)	(249,000,000)
Interest expense, net	234,000,000	226,000,000	463,000,000	439,000,000
Income from operations before income taxes	2,834,000,000	2,064,000,000	4,724,000,000	4,118,000,000
Income tax expense	695,000,000	532,000,000	1,217,000,000	1,118,000,000
Net Income from operations	2,139,000,000	1,532,000,000	3,507,000,000	3,000,000,000
Less: Noncontrolling interest in subsidiaries' earnings from operations	91,000,000	93,000,000	162,000,000	175,000,000
Net income attributable to common shareowners	2,048,000,000	1,439,000,000	3,345,000,000	2,825,000,000
Accounts receivable, net	11,973,000,000		11,973,000,000		12,595,000,000
Inventories and contracts in progress, net	8,979,000,000		8,979,000,000		9,881,000,000
Contract with Customer, Asset, Net, Current	3,273,000,000		3,273,000,000		0
Other assets, current	1,263,000,000		1,263,000,000		1,397,000,000
Future income tax benefits	1,626,000,000		1,626,000,000		1,723,000,000
Intangible assets, net	15,739,000,000		15,739,000,000		15,883,000,000
Other assets	7,071,000,000		7,071,000,000		5,988,000,000
Accrued liabilities	8,730,000,000		8,730,000,000		12,316,000,000
Contract with Customer, Liability, Current	(5,652,000,000)		(5,652,000,000)		0
Other long-term liabilities	13,190,000,000		13,190,000,000		12,952,000,000
Noncontrolling interest	1,982,000,000	1,713,000,000	1,982,000,000	1,713,000,000	1,811,000,000	$ 1,958,000,000		$ 1,678,000,000	$ 1,590,000,000
Retained earnings	57,027,000,000		57,027,000,000		55,242,000,000
Contract with Customer, Asset, Reclassified to Receivable	(14,401,000,000)
Revenue, Remaining Performance Obligation, Amount	$ 103,400,000,000		$ 103,400,000,000
Revenue, Remaining Performance Obligations, to be recognized within 24 months	45.00%		45.00%
Contract Asset and Liability [Abstract]
Contract with Customer, Asset, Net, Current	$ 3,273,000,000		$ 3,273,000,000		0
Contract with Customer, Asset, Net, Noncurrent	1,015,000,000		1,015,000,000
Contract with Customer, Asset, Net	4,288,000,000		4,288,000,000
Contract with Customer, Liability, Current	(5,652,000,000)		(5,652,000,000)		0
Contract with Customer, Liability, Noncurrent	(4,838,000,000)		(4,838,000,000)
Contract with Customer, Liability	(10,490,000,000)		(10,490,000,000)
Contract with Customer, Net	(6,202,000,000)		(6,202,000,000)				(6,365,000,000)
Contract with Customer, Liability, Revenue Recognized	12,701,000,000				$ 1,728,000,000
Product [Member]
Revenues	11,520,000,000	10,661,000,000	21,778,000,000	20,298,000,000
Cost of Goods and Services Sold	9,154,000,000	7,957,000,000	17,170,000,000	15,268,000,000
Service [Member]
Revenues	5,185,000,000	4,619,000,000	10,169,000,000	8,797,000,000
Cost of Goods and Services Sold	3,268,000,000	$ 3,207,000,000	6,532,000,000	$ 6,032,000,000
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Satisfied Portion of the Performance Obligation of CIP							220,000,000
Inventory Costs in Excess of Average Cost Per Unit							438,000,000
Revenues	184,000,000		406,000,000
Research and development	(18,000,000)		(37,000,000)
Selling, general and administrative	0		0
Total costs and expenses	201,000,000		408,000,000
Other income, net	(2,000,000)		(3,000,000)
Operating profit	(19,000,000)		(5,000,000)
Non-service pension cost (benefit)	0		0
Interest expense, net	0		0
Income from operations before income taxes	(19,000,000)		(5,000,000)
Income tax expense	(5,000,000)		(1,000,000)
Net Income from operations	(14,000,000)		(4,000,000)
Less: Noncontrolling interest in subsidiaries' earnings from operations	4,000,000		6,000,000
Net income attributable to common shareowners	(18,000,000)		(10,000,000)
Accounts receivable, net	1,459,000,000		1,459,000,000
Inventories and contracts in progress, net	2,114,000,000		2,114,000,000
Contract with Customer, Asset, Net, Current	3,273,000,000		3,273,000,000
Other assets, current	13,000,000		13,000,000
Future income tax benefits	26,000,000		26,000,000
Intangible assets, net	68,000,000		68,000,000
Other assets	973,000,000		973,000,000
Accrued liabilities	5,557,000,000		5,557,000,000
Contract with Customer, Liability, Current	(5,652,000,000)		(5,652,000,000)
Other long-term liabilities	1,010,000,000		1,010,000,000
Noncontrolling interest	5,000,000		5,000,000
Retained earnings	(490,000,000)		(490,000,000)				$ 480,000,000
Contract Asset and Liability [Abstract]
Contract with Customer, Asset, Net, Current	3,273,000,000		3,273,000,000
Contract with Customer, Liability, Current	(5,652,000,000)		(5,652,000,000)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Product [Member]
Revenues	114,000,000		205,000,000
Cost of Goods and Services Sold	179,000,000		309,000,000
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Service [Member]
Revenues	70,000,000		201,000,000
Cost of Goods and Services Sold	40,000,000		136,000,000
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenues	16,521,000,000		31,541,000,000
Research and development	607,000,000		1,180,000,000
Selling, general and administrative	1,759,000,000		3,470,000,000
Total costs and expenses	14,569,000,000		27,907,000,000
Other income, net	943,000,000		1,175,000,000
Operating profit	2,895,000,000		4,809,000,000
Non-service pension cost (benefit)	(192,000,000)		(383,000,000)
Interest expense, net	234,000,000		463,000,000
Income from operations before income taxes	2,853,000,000		4,729,000,000
Income tax expense	700,000,000		1,218,000,000
Net Income from operations	2,153,000,000		3,511,000,000
Less: Noncontrolling interest in subsidiaries' earnings from operations	87,000,000		156,000,000
Net income attributable to common shareowners	2,066,000,000		3,355,000,000
Accounts receivable, net	13,432,000,000		13,432,000,000
Inventories and contracts in progress, net	11,093,000,000		11,093,000,000
Contract with Customer, Asset, Net, Current	0		0
Other assets, current	1,276,000,000		1,276,000,000
Future income tax benefits	1,600,000,000		1,600,000,000
Intangible assets, net	15,807,000,000		15,807,000,000
Other assets	6,098,000,000		6,098,000,000
Accrued liabilities	14,287,000,000		14,287,000,000
Contract with Customer, Liability, Current	0		0
Other long-term liabilities	12,180,000,000		12,180,000,000
Noncontrolling interest	1,977,000,000		1,977,000,000
Retained earnings	57,517,000,000		57,517,000,000
Contract Asset and Liability [Abstract]
Contract with Customer, Asset, Net, Current	0		0
Contract with Customer, Liability, Current	0		0
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product [Member]
Revenues	11,406,000,000		21,573,000,000
Cost of Goods and Services Sold	8,975,000,000		16,861,000,000
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Service [Member]
Revenues	5,115,000,000		9,968,000,000
Cost of Goods and Services Sold	$ 3,228,000,000		$ 6,396,000,000