INVESTMENT IN SSAT (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Sep. 16, 2022
Investments in affiliates
Investment in SSAT	$ 81.2	$ 58.7
Financial information for equity method investment
Company's share of net income	83.1	56.3	$ 26.3
Distributions Received	47.3	46.9	55.4
Total Current assets	759.6	704.5
Total Non-current assets	3,570.4	2,988.6
Total Assets	4,330.0	3,693.1
Total Current liabilities	581.6	612.4
Total Non-current liabilities	1,451.5	1,413.3
Total Liabilities and Shareholders' Equity	4,330.0	3,693.1
SSAT Terminals Oakland | SSAT
Investments in affiliates
Investment in SSAT, interest acquired (as a percent)				20.00%
SSAT
Investments in affiliates
Increase in investment in SSAT			2.2
Equity method investment decrease in investment in subsidiary	15.5
Equity method investment decrease in deferred tax assets in subsidiary	3.9
Equity method investment decrease in retained earnings in subsidiary	11.6
Ocean Transportation | SSAT
Financial information for equity method investment
Total Current assets	324.7	343.4
Total Non-current assets	1,436.0	1,239.7
Total Assets	1,760.7	1,583.1
Total Current liabilities	342.1	302.7
Total Non-current liabilities	1,199.5	1,125.5
Equity	219.1	154.9
Total Liabilities and Shareholders' Equity	1,760.7	1,583.1
Operating revenue	1,466.9	1,297.5	1,091.6
Operating costs and expenses	1,168.8	1,113.8	1,003.2
Operating Income	298.1	183.7	88.4
Net Income	$ 249.6	161.7	76.6
Ocean Transportation | SSAT
Investments in affiliates
Ownership interest accounted in the related party terminal joint venture (as a percent)	35.00%
Cost of services from transactions with unconsolidated affiliate	$ 308.3	284.9	251.6
Accounts payable and accrued liabilities	43.6	38.8
Financial information for equity method investment
Company's share of net income	$ 83.1	$ 56.3	$ 26.3