Consolidated Statements of Income and Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Revenue:
Ocean Transportation	$ 1,278.4	$ 1,229.4	$ 1,189.8
Logistics	435.8	407.8	370.2
Total Operating Revenue	1,714.2	1,637.2	1,560.0
Costs and Expenses:
Operating costs	1,433.5	1,402.3	1,338.1
Equity in (income) loss of terminal joint venture	(6.6)	2.0	(3.2)
Selling, general and administrative	147.3	132.6	119.8
Separation costs			8.6
Total costs and expenses	1,574.2	1,536.9	1,463.3
Operating Income	140.0	100.3	96.7
Interest expense	(17.3)	(14.4)	(11.7)
Income before income taxes	122.7	85.9	85.0
Income tax expense	(51.9)	(32.2)	(33.0)
Income (Loss) from Continuing Operations Attributable to Parent, Total	70.8	53.7	52.0
Loss From Discontinued Operations (net of income taxes)	0	0	(6.1)
Net Income	70.8	53.7	45.9
Other Comprehensive Income (Loss), Net of Income Taxes:
Net Income	70.8	53.7	45.9
Other Comprehensive Income (Loss):
Net (loss) gain in prior service cost	(31.4)	18.7	(4.6)
Amortization of prior service cost included in net periodic pension cost	(1.3)	(1.3)	(1.4)
Amortization of net loss included in net periodic pension cost	2.5	4.7	4.8
Foreign currency translation adjustment	0.4	(0.1)
Other comprehensive income from discontinued operations			0.7
Total Other Comprehensive (Loss) Income	(29.8)	22.0	(0.5)
Comprehensive Income	$ 41.0	$ 75.7	$ 45.4
Basic Earnings (Loss) Per Share:
Continuing operations (in dollars per share)	$ 1.65	$ 1.26	$ 1.23
Discontinued operations (in dollars per share)			$ (0.14)
Earnings Per Share, Basic, Total	$ 1.65	$ 1.26	$ 1.09
Diluted Earnings (Loss) Per Share:
Continuing operations (in dollars per share)	$ 1.63	$ 1.25	$ 1.22
Discontinued operations (in dollars per share)			$ (0.14)
Earnings Per Share, Diluted, Total	$ 1.63	$ 1.25	$ 1.08
Weighted Average Number of Shares Outstanding:
Basic (in shares)	43.0	42.7	42.3
Diluted (in shares)	43.4	43.1	42.7