Condensed Consolidated Statements of Income and Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Operating Revenue:
Ocean transportation	$ 310.0	$ 299.5	$ 609.9	$ 579.0
Logistics	106.6	94.7	201.4	181.3
Total operating revenue	416.6	394.2	811.3	760.3
Costs and Expenses:
Operating costs	344.9	329.0	687.7	659.0
Equity in loss (income) of terminal joint venture	0.8	(1.6)	0.6	(2.4)
Selling, general and administrative	34.4	28.5	67.8	56.8
Separation costs		5.8		8.3
Operating costs and expenses	380.1	361.7	756.1	721.7
Operating Income	36.5	32.5	55.2	38.6
Interest expense	(3.6)	(1.9)	(7.3)	(3.9)
Income from Continuing Operations Before Income Taxes	32.9	30.6	47.9	34.7
Income tax expense	12.8	15.3	18.7	17.4
Income From Continuing Operations	20.1	15.3	29.2	17.3
Loss From Discontinued Operations (net of income taxes)	0	(7.5)	0	(6.1)
Net Income	20.1	7.8	29.2	11.2
Other Comprehensive Income, Net of Tax:
Net Income	20.1	7.8	29.2	11.2
Defined benefit pension plans:
Net loss and prior service cost	(0.8)	(1.1)	(0.8)	(1.1)
Less: amortization of prior service cost included in net periodic pension cost	(0.4)	(0.7)	(0.7)	(0.5)
Less: amortization of net loss included in net periodic pension cost	0.9	1.4	2.3	2.2
Foreign currency translation adjustment	(0.4)		(0.2)
Other Comprehensive Income	(0.7)	(0.4)	0.6	0.6
Comprehensive Income	$ 19.4	$ 7.4	$ 29.8	$ 11.8
Basic Earnings Per Share:
Continuing operations (in dollars per share)	$ 0.47	$ 0.36	$ 0.68	$ 0.41
Discontinued operations (in dollars per share)		$ (0.18)		$ (0.14)
Net income (in dollars per share)	$ 0.47	$ 0.18	$ 0.68	$ 0.27
Diluted Earnings Per Share:
Continuing operations (in dollars per share)	$ 0.47	$ 0.36	$ 0.68	$ 0.41
Discontinued operations (in dollars per share)		$ (0.18)		$ (0.15)
Net income (in dollars per share)	$ 0.47	$ 0.18	$ 0.68	$ 0.26
Weighted Average Number of Shares Outstanding:
Basic (in shares)	42.7	42.3	42.7	42.1
Diluted (in shares)	43.0	42.8	43.0	42.5
Cash Dividends Per Share (in dollars per share)	$ 0.15	$ 0.315	$ 0.30	$ 0.63