Business segment information - Schedule of Business Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025	Jun. 30, 2025
Segment Reporting Information [Line Items]
Net sales	$ 5,486	$ 4,960	$ 15,744	$ 14,607
Other segment items	4,204	3,808	11,995	11,300
Segment operating income	1,229	1,108	3,594	3,158
Corporate general and administrative expenses	884	785	2,594	2,416
Interest expense	99	96	306	310
Other expense (income), net	11	17	65	(188)
Income before income taxes	1,119	995	3,223	3,036
Assets	30,679		30,679		$ 29,494
Property Additions	103	88	286	304
Depreciation	87	86	264	263
Amortization	148	136	436	414
Diversified Industrial
Segment Reporting Information [Line Items]
Net sales	3,672	3,389	10,583	10,098
Aerospace Systems
Segment Reporting Information [Line Items]
Net sales	1,814	1,571	5,161	4,509
Investment in a joint venture	225		225		226
Operating Segments
Segment Reporting Information [Line Items]
Segment operating income	1,282	1,152	3,749	3,307
Operating Segments | Diversified Industrial
Segment Reporting Information [Line Items]
Net sales	3,672	3,389	10,583	10,098
Other segment items	2,847	2,610	8,145	7,825
Segment operating income	825	779	2,438	2,273
Assets	17,042		17,042		15,953
Property Additions	80	59	223	233
Depreciation	60	55	178	170
Amortization	71	61	208	189
Operating Segments | Aerospace Systems
Segment Reporting Information [Line Items]
Net sales	1,814	1,571	5,161	4,509
Other segment items	1,357	1,198	3,850	3,475
Segment operating income	457	373	1,311	1,034
Assets	12,228		12,228		12,218
Property Additions	22	18	56	53
Depreciation	25	28	78	84
Amortization	77	75	228	225
Corporate
Segment Reporting Information [Line Items]
Corporate general and administrative expenses	53	44	155	149
Assets	1,409		1,409		$ 1,323
Property Additions	1	11	7	18
Depreciation	2	3	8	9
Amortization	$ 0	$ 0	$ 0	$ 0