Segment Information - Capital Expenditure by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jul. 02, 2023	Jun. 30, 2024	Jul. 02, 2023
Segment Reporting Information [Line Items]
Consolidated capital expenditures	$ 22,655	$ 30,515	$ 53,154	$ 53,752
Operating Segments | U.S. Gas
Segment Reporting Information [Line Items]
Consolidated capital expenditures	9,931	14,824	24,209	29,730
Operating Segments | Canadian Gas
Segment Reporting Information [Line Items]
Consolidated capital expenditures	2,292	2,324	5,282	4,159
Operating Segments | Union Electric
Segment Reporting Information [Line Items]
Consolidated capital expenditures	7,544	10,280	11,737	14,818
Operating Segments | Non-Union Electric
Segment Reporting Information [Line Items]
Consolidated capital expenditures	925	2,003	5,622	2,533
Other
Segment Reporting Information [Line Items]
Consolidated capital expenditures	$ 1,963	$ 1,084	$ 6,304	$ 2,512