Business segment data - Narrative (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Sales	$ 302,089	$ 276,203	$ 245,579
Sales, Service and Leasing Revenues [Member]
Segment Reporting Information [Line Items]
Sales	$ 165,000	$ 151,000	$ 132,300
United States [Member] | Geographic Concentration [Member] | Sales, Service and Leasing Revenues [Member]
Segment Reporting Information [Line Items]
Concentration percentage	86.00%	85.00%	86.00%
United States [Member] | Geographic Concentration [Member] | Property, Plant and Equipment and Equipment Held for Lease [Member]
Segment Reporting Information [Line Items]
Concentration percentage	90.00%
Railroad, Utilities and Energy [Member]
Segment Reporting Information [Line Items]
Sales	$ 52,149	$ 48,229	$ 41,833
Railroad, Utilities and Energy [Member] | United States [Member] | Geographic Concentration [Member] | Revenues [Member]
Segment Reporting Information [Line Items]
Concentration percentage	96.00%	96.00%	96.00%