REPORTABLE SEGMENTS (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) customer segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Segment results
Number of segments | segment	2
Total Operating Revenue	$ 3,421.8	$ 3,094.6	$ 4,343.0
Operating costs:
Direct cargo expense	980.1	946.2	1,003.8
Vessel operating expense	610.5	580.4	703.6
Operating overhead	329.1	297.7	301.2
Direct operating costs	493.1	504.2	663.7
Depreciation and amortization	153.1	142.2	139.2
Total operating costs	2,565.9	2,470.7	2,811.5
Loss (Income) from SSAT	1.0	(2.2)	(83.1)
General and administrative	303.6	283.3	261.0
Total Costs and Expenses	2,870.5	2,751.8	2,989.4
Total Operating Income	551.3	342.8	1,353.6
Interest income	48.3	36.0	8.2
Interest expense	(7.5)	(12.2)	(18.0)
Other income (expense), net	7.3	6.4	8.5
Income before Taxes	599.4	373.0	1,352.3
Income taxes	(123.0)	(75.9)	(288.4)
Net Income	476.4	297.1	1,063.9
Capital Expenditure	310.1	248.4	209.3
Capital expenditures included in accounts payable, accruals and other liabilities	7.9	10.8	5.5
Operating segments
Segment results
Total Operating Revenue	3,421.8	3,094.6	4,343.0
Intersegment Eliminations
Segment results
Total Operating Revenue	245.8	208.7	270.9
Ocean Transportation
Operating costs:
Direct cargo expense	980.1	946.2	1,003.8
Vessel operating expense	610.5	580.4	703.6
Operating overhead	329.1	297.7	301.2
Depreciation and amortization	141.1	130.6	131.1
Total operating costs	2,060.8	1,954.9	2,139.7
Loss (Income) from SSAT	1.0	(2.2)	(83.1)
General and administrative	247.0	229.5	206.8
Total Costs and Expenses	2,308.8	2,182.2	2,263.4
Total Operating Income	500.9	294.8	1,281.2
Capital Expenditure	298.9	240.2	190.9
Dry-docking amortization	$ 27.2	25.3	24.9
Ocean Transportation | Revenue | Serves customers
Operating costs:
Transportation customers | customer	10
Concentration percentage	18.00%
Ocean Transportation | Operating segments
Segment results
Total Operating Revenue	$ 2,809.7	2,477.0	3,544.6
Ocean Transportation | Intersegment Eliminations
Segment results
Total Operating Revenue	92.8	76.5	93.6
Logistics
Operating costs:
Direct operating costs	493.1	504.2	663.7
Depreciation and amortization	12.0	11.6	8.1
Total operating costs	505.1	515.8	671.8
General and administrative	56.6	53.8	54.2
Total Costs and Expenses	561.7	569.6	726.0
Total Operating Income	50.4	48.0	72.4
Capital Expenditure	$ 11.2	8.2	18.4
Logistics | Revenue | Serves customers
Operating costs:
Transportation customers | customer	10
Concentration percentage	17.00%
Logistics | Operating segments
Segment results
Total Operating Revenue	$ 612.1	617.6	798.4
Logistics | Intersegment Eliminations
Segment results
Total Operating Revenue	$ 153.0	$ 132.2	$ 177.3