Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenue:
Total Operating Revenue	$ 704.8	$ 1,165.5
Costs and Expenses:
Operating costs	(597.5)	(703.7)
(Loss) Income from SSAT	(1.8)	34.0
Selling, general and administrative	(66.8)	(63.2)
Total Costs and Expenses	(666.1)	(732.9)
Operating Income	38.7	432.6
Interest income	8.2
Interest expense	(4.5)	(4.8)
Other income (expense), net	1.8	2.0
Income before Taxes	44.2	429.8
Income taxes	(10.2)	(90.6)
Net Income	34.0	339.2
Other Comprehensive Income (Loss), Net of Income Taxes:
Net Income	34.0	339.2
Other Comprehensive Income (Loss):
Amortization of prior service cost	(0.7)	(0.9)
Amortization of net loss (gain)	(0.1)	0.8
Other	1.4	0.3
Total Other Comprehensive Income (Loss), Net of Income Taxes	0.6	0.2
Comprehensive Income	$ 34.6	$ 339.4
Basic Earnings Per Share (in dollars per share)	$ 0.94	$ 8.29
Diluted Earnings Per Share (in dollars per share)	$ 0.94	$ 8.23
Weighted Average Number of Shares Outstanding:
Basic (in shares)	36.1	40.9
Diluted (in shares)	36.3	41.2
Ocean. Transportation.
Operating Revenue:
Total Operating Revenue	$ 551.0	$ 943.9
Logistics.
Operating Revenue:
Total Operating Revenue	$ 153.8	$ 221.6