Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounts Receivable [Abstract]
Accruals for revenues earned included in accounts receivable	$ 153,661,000	$ 84,453,000
Receivables from insurance companies to cover claims in excess included in accounts receivable	$ 66,588,000	88,182,000
Drydocking on Ocean-Going Vessels [Abstract]
Period in which recertification of ocean going vessels occur twice	5 years
Recognized amortization of major maintenance costs	$ 21,207,000	19,869,000	$ 22,126,000
Capitalized interest excluded from interest expense	1,731,000	2,974,000	3,026,000
Goodwill [Abstract]
Impairment of goodwill	0	0
Gross carrying value of goodwill	947,502,000	615,598,000
Accumulated amortization	15,566,000	15,566,000
Accumulated impairment losses	1,901,000	1,901,000
Net goodwill	935,135,000	598,131,000
Other Intangibles [Abstract]
Intangible assets gross carrying amounts	315,983,000	158,634,000
Intangible assets accumulated amortization	83,175,000	71,328,000
Intangible assets net carrying amount	232,808,000	87,306,000
Intangible liabilities gross carrying value	7,437,000	5,759,000
Intangible liabilities accumulated amortization	4,751,000	3,949,000
Intangible liabilities net carrying amount	2,686,000	1,810,000
Amortization of intangible assets	11,296,000	8,467,000	8,526,000
Intangible Assets and liabilities, Estimated Amortization Expense, Fiscal Year Maturity [Abstract]
2018	17,760,000
2019	17,395,000
2020	17,617,000
2021	17,171,000
2022	$ 16,971,000
Weighted average amortization period for intangible assets and liabilities	15 years
Accrued Insurance [Abstract]
Accrued insurance liabilities	$ 26,195,000	23,085,000	23,737,000
Minimum [Member]
Drydocking on Ocean-Going Vessels [Abstract]
Period of amortization of shipyard costs	30 months
Maximum [Member]
Drydocking on Ocean-Going Vessels [Abstract]
Period of amortization of shipyard costs	60 months
Marine Transportation Equipment [Member] | Minimum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	5 years
Marine Transportation Equipment [Member] | Maximum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	40 years
Buildings [Member] | Minimum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	10 years
Buildings [Member] | Maximum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	40 years
Other Equipment [Member] | Minimum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	2 years
Other Equipment [Member] | Maximum [Member]
Property, Maintenance and Repairs [Abstract]
Estimated useful lives of the individual assets	10 years
Marine Transportation Segment [Member]
Goodwill [Abstract]
Net goodwill	$ 387,504,000	382,227,000
Marine Transportation Segment [Member] | Minimum [Member]
Revenue Recognition [Abstract]
Range of term contracts	1 year
Marine Transportation Segment [Member] | Maximum [Member]
Revenue Recognition [Abstract]
Range of term contracts	5 years
Distribution and Services Segment [Member]
Goodwill [Abstract]
Net goodwill	$ 547,631,000	215,904,000
ASU 2016-09 [Member]
Accounting Standards [Abstract]
Cumulative effect on retained earnings		(8,486,000)
Effect of change on operating activities and financing activities		1,756,000	$ 2,975,000
ASU 2015-17 [Member]
Accounting Standards [Abstract]
Reclassification of deferred income taxes		$ 13,604,000
ASU 2014-09 [Member]
Accounting Standards [Abstract]
Cumulative effect on retained earnings	$ (10,000,000)