Summary of Significant Accounting Policies, Goodwill and Other Intangibles (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Abstract]
Impairment of goodwill	$ 0	$ 2,702,000	$ 0
Gross carrying value of goodwill	973,995,000	973,995,000
Accumulated amortization	15,566,000	15,566,000
Accumulated impairment losses	4,603,000	4,603,000
Net goodwill	953,826,000	953,826,000
Other Intangibles [Abstract]
Intangible assets gross carrying amounts	332,656,000	326,984,000
Intangible assets accumulated amortization	121,974,000	102,787,000
Intangible assets net carrying amount	210,682,000	224,197,000
Intangible liabilities gross carrying value	13,860,000	18,323,000
Intangible liabilities accumulated amortization	7,956,000	8,652,000
Intangible liabilities net carrying amount	5,904,000	9,671,000
Amortization of intangible assets	15,040,000	16,760,000	$ 11,296,000
Intangible Assets and liabilities, Estimated Amortization Expense, Fiscal Year Maturity [Abstract]
2020	16,358,000
2021	17,392,000
2022	16,989,000
2023	17,527,000
2024	$ 18,092,000
Weighted average amortization period for intangible assets and liabilities	13 years
Marine Transportation Segment [Member]
Goodwill [Abstract]
Net goodwill	$ 405,575,000	405,575,000
Distribution and Services Segment [Member]
Goodwill [Abstract]
Net goodwill	$ 548,251,000	$ 548,251,000