Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Revenue:
Ocean Transportation	$ 398.0	$ 444.8	$ 1,135.0	$ 1,097.0
Logistics	102.4	99.5	287.3	293.1
Total Operating Revenue	500.4	544.3	1,422.3	1,390.1
Costs and Expenses:
Operating costs	411.4	424.8	1,177.7	1,107.5
Equity in income of related party Terminal Joint Venture	(3.6)	(4.5)	(9.2)	(13.1)
Selling, general and administrative	46.4	52.2	136.9	145.3
Total Costs and Expenses	454.2	472.5	1,305.4	1,239.7
Operating Income	46.2	71.8	116.9	150.4
Interest expense	(6.0)	(4.7)	(17.4)	(13.6)
Income before Income Taxes	40.2	67.1	99.5	136.8
Income tax expense	(15.2)	(25.6)	(38.4)	(60.4)
Net Income	25.0	41.5	61.1	76.4
Other Comprehensive Income (Loss), Net of Income Taxes:
Net Income	25.0	41.5	61.1	76.4
Other Comprehensive Income (Loss):
Net gain (loss) in prior service cost			0.7	(0.2)
Amortization of prior service cost included in net periodic pension cost	(0.3)	(0.4)	(0.9)	(1.0)
Amortization of net loss included in net periodic pension cost	0.9	1.1	3.0	3.4
Foreign currency translation and other adjustments	0.6	0.9	0.5	1.6
Total Other Comprehensive Income	1.2	1.6	3.3	3.8
Comprehensive Income	$ 26.2	$ 43.1	$ 64.4	$ 80.2
Basic Earnings Per-Share:
Basic Earnings Per-Share (in dollars per share)	$ 0.58	$ 0.95	$ 1.42	$ 1.76
Diluted Earnings Per-Share:
Diluted Earnings Per-Share (in dollars per share)	$ 0.58	$ 0.94	$ 1.40	$ 1.74
Weighted Average Number of Shares Outstanding:
Basic (in shares)	42.8	43.5	43.1	43.5
Diluted (in shares)	43.2	44.0	43.5	44.0
Dividends
Cash Dividends Per-Share	$ 0.19	$ 0.18	$ 0.55	$ 0.52