Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies [Abstract]

Changes in Goodwill

Goodwill. The excess of the purchase price over the fair value of identifiable net assets acquired in transactions accounted for as a purchase is included in goodwill. The Company conducted its annual goodwill impairment tests at November 30, 2020, 2019 and 2018.  The Company also conducted an interim goodwill impairment test at March 31, 2020.  Refer to Note 7, Impairments and other charges for more information. The Company will continue to conduct goodwill impairment tests as of November 30 of subsequent years, or whenever events or circumstances indicate that interim impairment testing is necessary. The amount of goodwill impairment, if any, is typically measured based on projected discounted future operating cash flows using an appropriate discount rate.  The following table summarizes the changes in goodwill (in thousands):

	Marine Transportation			Distribution and Services			Total
Balance at December 31, 2017 (gross)	$	403,376		$	549,226		$	952,602
Accumulated impairment and amortization		(15,872	)		(1,595	)		(17,467	)
Balance at December 31, 2017		387,504			547,631			935,135
Impairment		(2,702	)		—			(2,702	)
Higman acquisition		4,657			—			4,657
Targa acquisition		16,116			—			16,116
Other		—			620			620
Balance at December 31, 2018 (gross)		424,149			549,846			973,995
Accumulated impairment and amortization		(18,574	)		(1,595	)		(20,169	)
Balance at December 31, 2018	$	405,575		$	548,251		$	953,826
Balance at December 31, 2019 (gross)	$	424,149		$	549,846		$	973,995
Accumulated impairment and amortization		(18,574	)		(1,595	)		(20,169	)
Balance at December 31, 2019		405,575			548,251			953,826
Impairment		—			(387,970	)		(387,970	)
Savage acquisition		81,635			—			81,635
Convoy acquisition		—			10,309			10,309
Balance at December 31, 2020 (gross)		505,784			560,155			1,065,939
Accumulated impairment and amortization		(18,574	)		(389,565	)		(408,139	)
Balance at December 31, 2020	$	487,210		$	170,590		$	657,800

Other Intangible Assets and Other Intangible Liabilities

Other Intangibles. Other intangibles include assets for favorable contracts and customer relationships, distributorship and dealership agreements, trade names and non-compete agreements and liabilities for unfavorable leases and contracts. The following table summarizes the balances of other intangible assets and other intangible liabilities (in thousands):

	December 31,
	2020			2019
Other intangible assets – gross	$	203,217		$	332,656
Accumulated amortization		(134,238	)		(121,974	)
Other intangible assets – net	$	68,979		$	210,682
Other intangible liabilities – gross	$	13,860		$	13,860
Accumulated amortization		(10,960	)		(7,956	)
Other intangible liabilities – net	$	2,900		$	5,904