Supplemental Cash Flow Information (Disclosure of supplemental cash flow information) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022
Changes in Operating Assets and Liabilities, Net of Divestitures
Accounts receivable	$ (7,930)	$ 1,094	$ (405)	$ (3,651)
Inventories	1,043	(3,542)	(9,893)	(22,100)
Accounts payable and accrued liabilities	(18,586)	(14,350)	(11,362)	1,896
Other operating assets and liabilities	(6,235)	5,920	(4,192)	2,204
Changes in operating assets and liabilities, total	(31,708)	(10,878)	(25,852)	(21,651)
Non-Cash Investing and Financing Activities
Change in additions to property, plant and equipment included in accounts payable and accrued liabilities	(266)	421	(1,058)	(5,131)
Change in accrued dividends on preferred stock included in accounts payable and accrued liabilities	0	0	(304)	0
Change in proceeds receivable from sale of Sunflower	$ 0	$ 0	$ 385	$ 0