Condensed Consolidated Statements Of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Sales and service revenues
Sales and service revenues	$ 2,314	$ 2,219	$ 6,604	$ 6,487
Cost of sales and service revenues
Income (loss) from operating investments, net	6	6	19	15
General and administrative expenses	220	209	648	564
Operating income (loss)	222	214	494	550
Other income (expense)
Interest expense	(27)	(18)	(68)	(52)
Non-operating retirement benefit (expense)	29	3	89	8
Other, net	2	(1)	(8)	5
Earnings (loss) before income taxes	226	198	507	511
Federal and foreign income taxes	4	44	60	111
Net earnings (loss)	$ 222	$ 154	$ 447	$ 400
Basic earnings (loss) per share (in dollars per share)	$ 5.47	$ 3.74	$ 11.01	$ 9.66
Weighted-average common shares outstanding (in shares)	40.6	41.2	40.6	41.4
Diluted earnings (loss) per share	$ 5.45	$ 3.74	$ 10.98	$ 9.66
Weighted-average diluted shares outstanding (in shares)	40.7	41.2	40.7	41.4
Dividends declared per share	$ 1.03	$ 0.86	$ 3.09	$ 2.58
Other comprehensive income (loss)
Change in unamortized benefit plan costs	$ 24	$ 25	$ 70	$ 74
Other	1	1		1
Tax benefit (expense) for items of other comprehensive income	(6)	(7)	(18)	(19)
Other comprehensive income (loss), net of tax	19	19	52	56
Comprehensive income (loss)	241	173	499	456
Product [Member]
Sales and service revenues
Sales and service revenues	1,699	1,545	4,743	4,555
Cost of sales and service revenues
Cost of sales and service revenues	1,388	1,246	3,931	3,754
Service [Member]
Sales and service revenues
Sales and service revenues	615	674	1,861	1,932
Cost of sales and service revenues
Cost of sales and service revenues	$ 490	$ 556	$ 1,550	$ 1,634