Condensed Consolidated Statements of Income and Comprehensive Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating Revenue:
Ocean transportation	$ 299.9	$ 279.5
Logistic services	94.8	86.6
Total operating revenue	394.7	366.1
Costs and Expenses:
Operating costs	342.8	329.7
Equity in income of terminal joint venture	(0.2)	(0.8)
Selling, general and administrative	33.4	28.6
Separation costs		2.5
Operating costs and expenses	376.0	360.0
Operating Income	18.7	6.1
Interest expense	(3.7)	(2.0)
Income from Continuing Operations Before Income Taxes	15.0	4.1
Income tax expense	5.9	2.1
Income From Continuing Operations	9.1	2.0
Income From Discontinued Operations (net of income taxes)		1.8
Net Income	9.1	3.8
Other Comprehensive Income, Net of Tax:
Net Income	9.1	3.8
Defined benefit pension plans:
Less: amortization of prior service cost included in net periodic pension cost	(0.3)	0.1
Less: amortization of net loss included in net periodic pension cost	1.4	0.8
Foreign currency translation adjustment	0.2
Other Comprehensive income from Discontinued Operations		0.8
Other Comprehensive Income	1.3	1.7
Comprehensive Income	$ 10.4	$ 5.5
Basic Earnings Per Share:
Continuing operations (in dollars per share)	$ 0.21	$ 0.05
Discontinued operations (in dollars per share)		$ 0.04
Net income (in dollars per share)	$ 0.21	$ 0.09
Diluted Earnings Per Share:
Continuing operations (in dollars per share)	$ 0.21	$ 0.05
Discontinued operations (in dollars per share)		$ 0.04
Net income (in dollars per share)	$ 0.21	$ 0.09
Weighted Average Number of Shares Outstanding:
Basic (in shares)	42.6	41.9
Diluted (in shares)	43.0	42.3
Cash Dividends Per Share (in dollars per share)	$ 0.15	$ 0.315