Consolidated Statement of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net income (loss) from continuing operations		$ (2,928)	$ 3,731	$ 1,406
Adjustments to reconcile income from continuing operations to net cash flows provided by operating activities of continuing operations:
Depreciation and amortization		4,156	2,708	1,896
Deferred income tax (benefit) provision		(99)	38	763
Stock compensation cost		330	268	169
Net periodic pension and other postretirement (income) expense		(413)	(566)	(392)
Goodwill impairment charge		3,183	0	0
Change in:
Accounts receivables		1,318	88	(1,147)
Contract assets		63	(679)	(651)
Inventory		412	(1,267)	(417)
Other current assets		(445)	(984)	(645)
Accounts payable and accrued liabilities		(1,666)	1,111	2,738
Contract liabilities		1,129	1,234	325
Global pension contributions		(1,025)	(55)	(79)
Canadian Government Settlement		0	(38)	(429)
Other operating activities, net		319	232	(867)
Net cash flows provided by operating activities from continuing operations		4,334	5,821	2,670
Investing Activities:
Capital expenditures		(1,795)	(1,868)	(1,467)
Increase in customer financing assets		(280)	(787)	(988)
Decrease in customer financing assets		368	128	604
Investments in businesses (Note 2)		(419)	(9)	(15,039)
Cash acquired in Raytheon Merger		3,208	0	0
Dispositions of businesses (Note 2)		2,556	134	74
Increase in collaboration intangible assets		(172)	(351)	(400)
Receipts (payments) from settlements of derivative contracts		(32)	342	140
Other investing activities, net		(91)	(265)	(183)
Net cash flows provided by (used in) investing activities from continuing operations		3,343	(2,676)	(17,259)
Financing Activities:
Issuance of long-term debt		2,004	(19)	13,337
Distribution from discontinued operation		17,207	0	0
Repayment of long-term debt		(16,082)	(2,693)	(2,520)
(Decrease) increase in short-term borrowings, net		(2,041)	896	(370)
Proceeds from Common Stock issued under employee stock plans		15	27	36
Dividends paid on Common Stock		(2,732)	(2,442)	(2,170)
Repurchase of Common Stock		(47)	(151)	(325)
Net transfer (to) from discontinued operations		(2,033)	2,387	3,979
Other financing activities, net		(151)	82	242
Net cash flows provided by (used in) financing activities of continuing operations		(3,860)	(1,913)	12,209
Discontinued Operations:
Net cash (used in) provided by operating activities		(728)	3,062	3,652
Net cash (used in) provided by investing activities		(241)	(416)	286
Net cash used in financing activities		(1,414)	(2,651)	(4,244)
Net cash flows used in discontinued operations		(2,383)	(5)	(306)
Effect of foreign exchange rate changes on cash and cash equivalents from continuing operations		54	1	(6)
Effect of foreign exchange rate changes on cash and cash equivalents from discontinued operations		(76)	(20)	(114)
Net increase (decrease) in cash, cash equivalents and restricted cash		1,412	1,208	(2,806)
Cash, cash equivalents and restricted cash, beginning of year		4,961	3,731	6,118
Cash, cash equivalents and restricted cash within assets related to discontinued operations, beginning of year		2,459	2,481	2,900
Cash, cash equivalents and restricted cash, end of year		8,832	7,420	6,212
Less: Restricted cash, included in Other assets		30	24	38
Less: Cash, cash equivalents and restricted cash for discontinued operations		0	2,459	2,481
Cash and cash equivalents, end of year		8,802	4,937	3,693
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of amounts capitalized	[1]	1,628	1,801	1,027
Income taxes paid, net of refunds	[1]	$ 1,716	$ 1,768	$ 1,714

[1] (1)    Amounts are inclusive of continuing operations and discontinued operations payments.