Martin Midstream Partners (MMLP) 10-Q 11 May 20 2020 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 11, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	000-50056
Entity Registrant Name	MARTIN MIDSTREAM PARTNERS L.P.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	05-0527861
Entity Address, Address Line One	4200 Stone Road
Entity Address, City or Town	Kilgore
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75662
City Area Code	903
Local Phone Number	983-6200
Title of each class	Common Units representing limited partnership interests
Trading Symbol(s)	MMLP
Name of each exchange on which registered	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		38,852,507
Entity Central Index Key	0001176334
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONSOLIDATED AND CONDENSED BALA

CONSOLIDATED AND CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets
Cash	$ 68	$ 2,856
Accounts and other receivables, less allowance for doubtful accounts of $498 and $532, respectively	59,073	87,254
Inventories	46,830	62,540
Due from affiliates	15,100	17,829
Fair value of derivatives	2	0
Other current assets	6,396	5,833
Assets held for sale	0	5,052
Total current assets	127,469	181,364
Property, plant and equipment, at cost	893,619	884,728
Accumulated depreciation	(479,301)	(467,531)
Property, plant and equipment, net	414,318	417,197
Goodwill	17,705	17,705
Right-of-use assets	25,771	23,901
Deferred income taxes, net	23,136	23,422
Other assets, net	3,800	3,567
Total assets	612,199	667,156
Liabilities and Partners’ Capital (Deficit)
Current installments of long-term debt and finance lease obligations	369,238	6,758
Trade and other accounts payable	52,713	64,802
Product exchange payables	4,772	4,322
Due to affiliates	1,304	1,470
Income taxes payable	605	472
Fair value of derivatives	0	667
Other accrued liabilities	20,282	28,789
Total current liabilities	448,914	107,280
Long-term debt, net	165,543	569,788
Finance lease obligations	526	717
Operating lease liabilities	17,810	16,656
Other long-term obligations	8,907	8,911
Total liabilities	641,700	703,352
Commitments and contingencies
Partners’ capital (deficit)	(29,501)	(36,196)
Total partners’ capital (deficit)	(29,501)	(36,196)
Total liabilities and partners' capital (deficit)	$ 612,199	$ 667,156

CONSOLIDATED AND CONDENSED BA_2

CONSOLIDATED AND CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 498	$ 532

CONSOLIDATED AND CONDENSED STAT

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenues		$ 198,883	$ 240,033
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		108,810	152,757
Expenses:
Operating expenses	[1]	51,282	51,849
Selling, general and administrative	[1]	10,462	10,200
Depreciation and amortization		15,239	14,901
Total costs and expenses		185,793	229,707
Other operating income (loss), net		2,510	(720)
Operating income		15,600	9,606
Other income (expense):
Interest expense, net		(9,925)	(13,671)
Gain on retirement of senior unsecured notes		3,484	0
Other, net		3	3
Total other expense		(6,438)	(13,668)
Net income (loss) before taxes		9,162	(4,062)
Income tax expense		(347)	(696)
Income (loss) from continuing operations		8,815	(4,758)
Income from discontinued operations, net of income taxes		0	1,102
Net income (loss)		8,815	(3,656)
Less general partner's interest in net (income) loss		(176)	73
Less (income) loss allocable to unvested restricted units		(55)	2
Limited partners' interest in net income (loss)		8,584	(3,581)
Terminalling and storage
Revenues:
Revenues	[1]	20,474	23,104
Transportation
Revenues:
Revenues	[1]	38,941	37,795
Sulfur services
Revenues:
Revenues		2,915	2,859
Product sales
Revenues:
Revenues	[1]	136,553	176,275
Natural gas liquids
Revenues:
Revenues		82,211	116,474
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	69,835	106,190
Sulfur services
Revenues:
Revenues		25,408	28,734
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	15,295	19,696
Terminalling and storage
Revenues:
Revenues		28,934	31,067
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	$ 23,680	$ 26,871
[1]	Related Party Transactions Included Above Three Months Ended March 31, 2020 2019 Revenues:* Terminalling and storage $ 15,874 $ 18,972 Transportation 5,894 5,643 Product Sales 92 421 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Sulfur services 2,767 2,574 Terminalling and storage 5,777 5,909 Expenses: Operating expenses 21,771 22,536 Selling, general and administrative 8,312 8,535

CONSOLIDATED AND CONDENSED ST_2

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - Allocation of Net Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Limited partner interest:
Continuing operations	$ 8,584	$ (4,660)
Discontinued operations	0	1,079
Limited partners’ interest in net income (loss)	8,584	(3,581)
General partner interest:
Continuing operations	176	(95)
Discontinued operations	0	22
General partner interest in net income (loss)	$ 176	$ (73)
Basic:
Continuing operations (in dollars per share)	$ 0.22	$ (0.12)
Discontinued operations (in dollars per share)	0	0.03
Net income (loss) per unit attributable to limited partners, Basic (in dollars per share)	$ 0.22	$ (0.09)
Weighted average limited partner units - basic (in shares)	38,640,862	38,681,925
Diluted:
Continuing operations (in dollars per share)	$ 0.22	$ (0.12)
Discontinued operations (in dollars per share)	0	0.03
Net income (loss) per unit attributable to limited partners, Diluted (in dollars per share)	$ 0.22	$ (0.09)
Weighted average limited partner units - diluted (in shares)	38,644,467	38,681,925

CONSOLIDATED AND CONDENSED ST_3

CONSOLIDATED AND CONDENSED STATEMENTS OF OPERATIONS - Related Party Transactions - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Revenues:
Revenues		$ 198,883	$ 240,033
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		108,810	152,757
Expenses:
Operating expenses		21,771	22,536
Selling, general and administrative		8,312	8,535
Terminalling and storage
Revenues:
Revenues	[1]	20,474	23,104
Transportation
Revenues:
Revenues	[1]	38,941	37,795
Product Sales
Revenues:
Revenues	[1]	136,553	176,275
Sulfur services
Revenues:
Revenues		25,408	28,734
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	15,295	19,696
Terminalling and storage
Revenues:
Revenues		28,934	31,067
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold	[1]	23,680	26,871
Related Party
Expenses:
Operating expenses		21,771	22,536
Related Party | Terminalling and storage
Revenues:
Revenues		15,874	18,972
Related Party | Transportation
Revenues:
Revenues		5,894	5,643
Related Party | Product Sales
Revenues:
Revenues		92	421
Related Party | Sulfur services
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		2,767	2,574
Related Party | Terminalling and storage
Cost of products sold: (excluding depreciation and amortization)
Cost of products sold		$ 5,777	$ 5,909
[1]	Related Party Transactions Included Above Three Months Ended March 31, 2020 2019 Revenues:* Terminalling and storage $ 15,874 $ 18,972 Transportation 5,894 5,643 Product Sales 92 421 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Sulfur services 2,767 2,574 Terminalling and storage 5,777 5,909 Expenses: Operating expenses 21,771 22,536 Selling, general and administrative 8,312 8,535

CONSOLIDATED AND CONDENSED ST_4

CONSOLIDATED AND CONDENSED STATEMENTS OF CAPITAL (DEFICIT) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Increase (Decrease) in Partners' Capital
Beginning balance	$ (36,196)	$ 288,432
Net (loss) income	8,815	(3,656)
Issuance of restricted units	0	0
Forfeiture of restricted units	0	0
Cash distributions	(2,457)	(19,613)
Unit-based compensation	346	352
Purchase of treasury units	(9)	(392)
Excess purchase price over carrying value of acquired assets		(102,393)
Deferred taxes on acquired assets and liabilities		24,781
Contribution to parent		(23,720)
Ending balance	(29,501)	163,791
Common Limited
Increase (Decrease) in Partners' Capital
Beginning balance	$ (38,342)	$ 258,085
Beginning balance (in shares)	38,863,389	39,032,237
Net (loss) income	$ 8,639	$ (3,583)
Issuance of restricted units (in shares)	81,000	16,944
Forfeiture of restricted units (in shares)	(84,134)	(118,087)
Cash distributions	$ (2,408)	$ (19,221)
Unit-based compensation	346	352
Purchase of treasury units	$ (9)	$ (392)
Purchase of treasury units (in shares)	(7,748)	(31,504)
Excess purchase price over carrying value of acquired assets		$ (102,393)
Deferred taxes on acquired assets and liabilities		24,781
Ending balance	$ (31,774)	$ 157,629
Ending balance (in shares)	38,852,507	38,899,590
General Partner
Increase (Decrease) in Partners' Capital
Beginning balance	$ 2,146	$ 6,627
Net (loss) income	176	(73)
Cash distributions	(49)	(392)
Ending balance	2,273	6,162
Parent Net Investment
Increase (Decrease) in Partners' Capital
Beginning balance	0	23,720
Contribution to parent		(23,720)
Ending balance	$ 0	$ 0

CONSOLIDATED AND CONDENSED ST_5

CONSOLIDATED AND CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 8,815	$ (3,656)
Less: (Income) from discontinued operations, net of income taxes	0	(1,102)
Net income (loss) from continuing operations	8,815	(4,758)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	15,239	14,901
Amortization and write-off of deferred debt issuance costs	492	895
Amortization of premium on notes payable	(77)	(77)
Deferred income tax expense	286	369
Loss on sale of property, plant and equipment, net	190	720
Gain on retirement of senior unsecured notes	(3,484)	0
Derivative (income) loss	(33)	239
Net cash paid for commodity derivatives	(636)	(385)
Unit-based compensation	346	352
Change in current assets and liabilities, excluding effects of acquisitions and dispositions:
Accounts and other receivables	26,413	13,451
Product exchange receivables	0	(15)
Inventories	15,710	15,235
Due from affiliates	2,729	(7,384)
Other current assets	(1,413)	(102)
Trade and other accounts payable	(10,440)	10,881
Product exchange payables	450	1,930
Due to affiliates	(166)	1,154
Income taxes payable	133	544
Other accrued liabilities	(9,118)	(11,177)
Change in other non-current assets and liabilities	(547)	(1,351)
Net cash provided by continuing operating activities	44,889	35,422
Net cash provided by discontinued operating activities	0	5,181
Net cash provided by operating activities	44,889	40,603
Cash flows from investing activities:
Payments for property, plant and equipment	(12,260)	(6,637)
Acquisitions	0	(23,720)
Payments for plant turnaround costs	(150)	(3,827)
Proceeds from involuntary conversion of property, plant and equipment	1,768	0
Proceeds from sale of property, plant and equipment	4,347	574
Net cash used in continuing investing activities	(6,295)	(33,610)
Net cash used in discontinued investing activities	0	(336)
Net cash used in investing activities	(6,295)	(33,946)
Cash flows from financing activities:
Payments of long-term debt and finance lease obligations	(114,724)	(89,255)
Proceeds from long-term debt	76,000	205,000
Purchase of treasury units	(9)	(392)
Payment of debt issuance costs	(192)	(77)
Excess purchase price over carrying value of acquired assets	0	(102,393)
Cash distributions paid	(2,457)	(19,613)
Net cash used in financing activities	(41,382)	(6,730)
Net decrease in cash	(2,788)	(73)
Cash at beginning of period	2,856	300
Cash at end of period	68	227
Non-cash additions to property, plant and equipment	$ 2,142	$ 2,001

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	3 Months Ended
	Mar. 31, 2020
Accounting Policies [Abstract]
Nature of Operations and Basis of Presentation	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Martin Midstream Partners L.P. (the "Partnership") is a publicly traded limited partnership with a diverse set of operations focused primarily in the United States ("U.S.") Gulf Coast region. Its four primary business lines include: terminalling, processing, storage and packaging services for petroleum products and by-products including the refining of naphthenic crude oil; land and marine transportation services for petroleum products and by-products, chemicals, and specialty products; sulfur and sulfur-based products processing, manufacturing, marketing and distribution; and natural gas liquids marketing, distribution, and transportation services. The Partnership’s unaudited consolidated and condensed financial statements have been prepared in accordance with the requirements of Form 10-Q and U.S. Generally Accepted Accounting Principles ("U.S. GAAP") for interim financial reporting. Accordingly, these financial statements have been condensed and do not include all of the information and footnotes required by U.S. GAAP for annual audited financial statements of the type contained in the Partnership’s annual reports on Form 10-K. In the opinion of the management of the Partnership’s general partner, all adjustments and elimination of significant intercompany balances necessary for a fair presentation of the Partnership’s financial position, results of operations, and cash flows for the periods shown have been made. All such adjustments are of a normal recurring nature. Results for such interim periods are not necessarily indicative of the results of operations for the full year. These financial statements should be read in conjunction with the Partnership’s audited consolidated financial statements and notes thereto included in the Partnership’s annual report on Form 10-K for the year ended December 31, 2019, filed with the Securities and Exchange Commission (the "SEC") on February 14, 2020. Management has made a number of estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities to prepare these consolidated and condensed financial statements in conformity with U.S. GAAP. Actual results could differ from those estimates. Divestiture of Natural Gas Storage Assets. On June 28, 2019, the Partnership completed the sale of its membership interests in Arcadia Gas Storage, LLC, Cadeville Gas Storage LLC, Monroe Gas Storage Company, LLC and Perryville Gas Storage LLC (the "Natural Gas Storage Assets") to Hartree Cardinal Gas, LLC ("Hartree"), a subsidiary of Hartree Bulk Storage, LLC. The Natural Gas Storage Assets consist of approximately 50 billion cubic feet of working capacity located in northern Louisiana and Mississippi. In consideration of the sale of the Natural Gas Storage Assets, the Partnership received cash proceeds of $210,067 after transaction fees and expenses. The net proceeds were used to reduce outstanding borrowings under the Partnership's revolving credit facility. The Partnership concluded the disposition represented a strategic shift which had a major effect on its financial results going forward. As a result, the Partnership has presented the results of operations and cash flows relating to the Natural Gas Storage Assets as discontinued operations for the three months ended March 31, 2019. See Note 3 for more information. Impact of COVID-19 Pandemic. A novel strain of coronavirus (“COVID-19”) surfaced in late 2019 and has spread around the world, including to the United States. In March 2020, the World Health Organization declared COVID-19 a pandemic. Due to the economic impacts of the COVID-19 pandemic, the markets have experienced a decline in oil prices in response to oil demand concerns. These concerns have been further exacerbated by the price war among members of the Organization of Petroleum Exporting Countries and other non-OPEC producer nations during the first quarter 2020 and global storage considerations. Travel restrictions and stay-at-home orders implemented by governments in many regions and countries across the globe, including the United States, have greatly impacted the demand for refined products resulting in a significant reduction in refinery utilization. The COVID-19 pandemic has impacted the Partnership's 2020 performance to date, and the Partnership expects to continue to experience the impacts of COVID-19 throughout the remainder of 2020 as a result of continued reduction in refined product demand across the industries the Partnership serves. The extent to which the duration and severity of the pandemic impacts our business, results of operations, and financial condition, will depend on future developments, which are highly uncertain and cannot be predicted at this time. Accordingly, it is possible that the impact of the COVID-19 pandemic could have a material adverse effect on the Partnership's results of operations, financial position and cash flows for the year ended December 31, 2020, including the recoverability of long-lived assets and goodwill, the valuation of inventory, and the amount of expected credit losses. Management considered the impact of the COVID-19 pandemic on the assumptions and estimates used in the preparation of the financial statements. Management identified triggering events requiring the performance of impairment testing of long-lived assets and goodwill related to both the performance the Partnership's unit price during the first quarter of 2020 and certain of the Partnership's businesses that are sensitive to reductions in refined product demand and refinery utilization. As a result, the Partnership recorded impairment charges of $4.4 million related to long-lived assets. See Note 3 for more information. No impairments were identified related to goodwill. A sustained reduction in refinery demand and utilization could lead to future asset impairments as well as adversely affect access to capital and financing to be able to meet future obligations. Management also assessed the extent to which the current macroeconomic events brought about by COVID-19 and significant declines in refined product demand impacted the valuation of expected credit losses on accounts receivable and certain inventory items or resulted in modifications to any significant contracts. Ultimately the results of these assessments did not have a material impact on the Partnership's results as of March 31, 2020.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2020
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS During the first quarter of 2020, the Partnership adopted Accounting Standards Update (“ASU”) 2016-13, "Financial Instruments - Credit Losses," which required the Partnership to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaced the existing incurred loss model and is applicable to the measurement of credit losses on financial assets, including trade receivables. Adoption of the new standard did not have a material impact on the Partnership’s consolidated financial statements.

Divestitures and Discontinued O

Divestitures and Discontinued Operations	3 Months Ended
	Mar. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
Divestitures and Discontinued Operations	DIVESTITURES AND DISCONTINUED OPERATIONS Divestiture of Natural Gas Storage Assets. On June 28, 2019, the Partnership completed the sale of the Natural Gas Storage Assets to Hartree, a subsidiary of Hartree Bulk Storage, LLC. The Natural Gas Storage Assets consist of approximately 50 billion cubic feet of working capacity located in northern Louisiana and Mississippi. In consideration of the sale of these assets, the Partnership received cash proceeds of $210,067 after transaction fees and expenses. The net proceeds were used to reduce outstanding borrowings under the Partnership's revolving credit facility. The Partnership has concluded the disposition represents a strategic shift and will have a major effect on its financial results going forward. As a result, the Partnership has presented the results of operations and cash flows relating to the Natural Gas Storage Assets as discontinued operations for the three months ended March 31, 2019. The operating results, which are included in income from discontinued operations, were as follows: Three Months Ended March 31, 2019 Total revenues $ 10,934 Total costs and expenses and other, net, excluding depreciation and amortization (5,751 ) Depreciation and amortization (4,081 ) Income from discontinued operations before income taxes 1,102 Income tax expense — Income from discontinued operations, net of income taxes $ 1,102 Long-Lived Assets Held for Sale At December 31, 2019, certain terminalling and storage and transportation assets met the criteria to be classified as held for sale in accordance with ASC 360-10 and are presented at the lower of the assets' carrying amount or fair value less cost to sell by segment in current assets in the table below. These assets are considered non-core assets to the Partnership's operations and did not qualify for discontinued operations presentation under the guidance of ASC 205-20. March 31, 2020 December 31, 2019 Terminalling and storage $ — $ 3,552 Transportation — 1,500 Assets held for sale $ — $ 5,052 In the first quarter of 2020, the Partnership identified a triggering event related to a decline in the fair value related to the assets classified as held for sale at December 31, 2019. As a result, an impairment charge of $3,052 and $1,300

Revenue

Revenue	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE The following table disaggregates our revenue by major source: Three Months Ended March 31, 2020 2019 Terminalling and storage segment Lubricant product sales $ 28,934 $ 31,067 Throughput and storage 20,474 23,104 $ 49,408 $ 54,171 Natural gas liquids segment Natural gas liquids product sales $ 82,211 $ 116,474 $ 82,211 $ 116,474 Sulfur services segment Sulfur product sales $ 6,481 $ 9,952 Fertilizer product sales 18,927 18,782 Sulfur services 2,915 2,859 $ 28,323 $ 31,593 Transportation segment Land transportation $ 24,234 $ 24,119 Inland transportation 13,706 12,477 Offshore transportation 1,001 1,199 $ 38,941 $ 37,795 Revenue is measured based on a consideration specified in a contract with a customer and excludes amounts collected on behalf of third parties where the Partnership is acting as an agent. The Partnership recognizes revenue when the Partnership satisfies a performance obligation, which typically occurs when the Partnership transfers control over a product to a customer or as the Partnership delivers a service. The following is a description of the principal activities - separated by reportable segments - from which the Partnership generates revenue. Terminalling and Storage Segment Revenue is recognized for storage contracts based on the contracted monthly tank fixed fee. For throughput contracts, revenue is recognized based on the volume moved through the Partnership’s terminals at the contracted rate. For the Partnership’s tolling agreement, revenue is recognized based on the contracted monthly reservation fee and throughput volumes moved through the facility. When lubricants and drilling fluids are sold by truck or rail, revenue is recognized when title is transferred, which is either upon delivering product to the customer or when the product leaves the Partnership's facility, depending on the specific terms of the contract. Delivery of product is invoiced as the transaction occurs and is generally paid within a month. Throughput and storage revenue in the table above includes non-cancelable revenue arrangements that are under the scope of ASC 842, whereby the Partnership has committed certain Terminalling and Storage assets in exchange for a minimum fee. Natural Gas Liquids Segment NGL distribution revenue is recognized when product is delivered by truck, rail, or pipeline to the Partnership's NGL customers. Revenue is recognized on title transfer of the product to the customer. Delivery of product is invoiced as the transaction occurs and is generally paid within a month. Sulfur Services Segment Revenue from sulfur and fertilizer product sales is recognized when the customer takes title to the product. Delivery of product is invoiced as the transaction occurs and is generally paid within a month. Revenue from sulfur services is recognized as services are performed during each monthly period. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Transportation Segment Revenue related to land transportation is recognized for line hauls based on a mileage rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. Revenue related to marine transportation is recognized for time charters based on a per day rate. For contracted trips, revenue is recognized upon completion of the particular trip. The performance of the service is invoiced as the transaction occurs and is generally paid within a month. The table includes estimated minimum revenue expected to be recognized in the future related to performance obligations that are unsatisfied at the end of the reporting period. The Partnership applies the practical expedient in ASC 606-10-50-14(a) and does not disclose information about remaining performance obligations that have original expected durations of one year or less. 2020 2021 2022 2023 2024 Thereafter Total Terminalling and storage Throughput and storage $ 34,599 $ 43,273 $ 40,394 $ 41,605 $ 42,854 $ 338,339 $ 541,064 Sulfur services Sulfur product sales 4,236 5,366 3,220 2,175 975 975 16,947 Total $ 38,835 $ 48,639 $ 43,614 $ 43,780 $ 43,829 $ 339,314 $ 558,011

Inventories

Inventories	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Components of inventories at March 31, 2020 and December 31, 2019 were as follows: March 31, 2020 December 31, 2019 Natural gas liquids $ 3,687 $ 19,097 Sulfur 4,443 4,586 Fertilizer 14,549 15,852 Lubricants 20,126 18,925 Other 4,025 4,080 $ 46,830 $ 62,540

Debt

Debt	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Debt	DEBT At March 31, 2020 and December 31, 2019 , long-term debt consisted of the following: March 31, December 31, $400,000 Revolving credit facility at variable interest rate (3.93% 1 weighted average at March 31, 2020), due August 2023 4 secured by substantially all of the Partnership’s assets, including, without limitation, inventory, accounts receivable, vessels, equipment, fixed assets and the interests in the Partnership’s operating subsidiaries, net of unamortized debt issuance costs of $4,457 and $4,586, respectively 2 $ 165,543 $ 196,414 $400,000 Senior notes, 7.25% interest, net of unamortized debt issuance costs of $599 and $770, respectively, including unamortized premium of $267 and $344, respectively, issued $250,000 February 2013 and $150,000 April 2014, $26,200 repurchased during 2015, $9,344 repurchased during 2020, due February 2021, unsecured 2,3,4,5 364,124 373,374 Total 529,667 569,788 Less: current portion (364,124 ) — Total long-term debt, net of current portion $ 165,543 $ 569,788 Current installments of finance lease obligations $ 5,114 $ 6,758 Finance lease obligations 526 717 Total finance lease obligations $ 5,640 $ 7,475 1 Interest rate fluctuates based on the LIBOR rate plus an applicable margin set on the date of each advance. The margin above LIBOR is set every three months. Indebtedness under the credit facility bears interest at LIBOR plus an applicable margin or the base prime rate plus an applicable margin. All amounts outstanding at March 31, 2020 and December 31, 2019 were at LIBOR plus an applicable margin. The applicable margin for revolving loans that are LIBOR loans ranges from 2.25% to 3.50% and the applicable margin for revolving loans that are base prime rate loans ranges from 1.25% to 2.50% . The applicable margin for existing LIBOR borrowings at March 31, 2020 is 3.25% . The credit facility contains various covenants which limit the Partnership’s ability to make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management Corporation (the "Omnibus Agreement"). The Partnership is permitted to make quarterly distributions so long as no event of default exists. 2 The Partnership is in compliance with all debt covenants as of March 31, 2020 and December 31, 2019 , respectively. 3 The 2021 indenture restricts the Partnership’s ability to sell assets; pay distributions or repurchase units or redeem or repurchase subordinated debt; make investments; incur or guarantee additional indebtedness or issue preferred units; and consolidate, merge or transfer all or substantially all of its assets. 4 As of March 31, 2020, the Partnership’s 7.25% senior unsecured notes due 2021 (the "2021 Notes") were due within twelve months and have therefore been presented as a current liability on the Consolidated and Condensed Balance Sheets at March 31, 2020. The Partnership's amended revolving credit facility includes a provision which accelerates the maturity date to August 19, 2020 if the 2021 Notes are not refinanced in a manner not prohibited by the facility. If the Partnership is unable to refinance the 2021 Notes and is unable to repay the outstanding borrowings under its revolving credit facility on August 19, 2020, the Partnership's ability to meet its obligations would be adversely affected. Failure to comply with this provision, if not waived, would result in an event of default under the Partnership's revolving credit facility, the potential acceleration of outstanding debt thereunder, and the potential foreclosure on the collateral securing such debt, and could cause a cross-default under other agreements, which could also result in the acceleration of those obligations by the counterparties to those agreements. The Partnership, with support from the Board of Directors, is actively pursuing a variety of strategic alternatives to strengthen the balance sheet and address near term maturities and accordingly, announced on April 6, 2020, the hiring of Stephens Inc. as a financial advisor to assist in the process. Pending the successful implementation of the refinancing, the conditions described above have raised substantial doubt about the Partnership’s ability to continue as a going concern. The Partnership’s management is engaged in ongoing communication with credit providers and presently believes the measures being taken will enable the Partnership to successfully refinance the 2021 Notes and comply with covenants under its revolving credit facility, although no assurance can be given. 5 In March 2020, the Partnership repurchased on the open market an aggregate $9,344 of the 2021 Notes. These transactions resulted in a gain on retirement of $3,484 . The Partnership paid cash interest, net of capitalized interest, in the amount of $16,736 and $19,363 for the three months ended March 31, 2020 and 2019 , respectively. Capitalized interest was $4 and $2 for the three months ended March 31, 2020 and 2019

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	LEASES The Partnership has numerous operating leases primarily for terminal facilities and transportation and other equipment. The leases generally provide that all expenses related to the equipment are to be paid by the lessee. Operating lease Right-of-Use ("ROU") assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. Because most of the Partnership's leases do not provide an implicit rate of return, the Partnership uses its imputed collateralized rate based on the information available at commencement date in determining the present value of lease payments. The estimated rate is based on a risk-free rate plus a risk-adjusted margin. Our leases have remaining lease terms of 1 year to 17 years , some of which include options to extend the leases for up to 5 years , and some of which include options to terminate the leases within 1 year . The Partnership includes extension periods and excludes termination periods from its lease term if, at commencement, it is reasonably likely that the Partnership will exercise the option. The components of lease expense for the three months ended March 31, 2020 and 2019 were as follows: Three Months Ended March 31, 2020 2019 Operating lease cost $ 6,296 $ 5,177 Finance lease cost: Amortization of right-of-use assets 589 622 Interest on lease liabilities 110 183 Short-term lease cost 3,423 2,551 Total lease cost $ 10,418 $ 8,533 Supplemental balance sheet information related to leases was as follows: Three Months Ended March 31, 2020 2019 Operating Leases Operating lease right-of-use assets $ 25,771 $ 23,901 Current portion of operating lease liabilities included in "Other accrued liabilities" $ 8,358 $ 7,722 Operating lease liabilities 17,810 16,656 Total operating lease liabilities $ 26,168 $ 24,378 Finance Leases Property, plant and equipment, at cost $ 13,163 $ 14,058 Accumulated depreciation (3,634 ) (1,888 ) Property, plant and equipment, net $ 9,529 $ 12,170 Current installments of finance lease obligations $ 5,114 $ 5,540 Finance lease obligations 526 4,886 Total finance lease obligations $ 5,640 $ 10,426 The Partnership’s future minimum lease obligations as of March 31, 2020 consist of the following: Operating Leases Finance Leases Year 1 $ 9,519 $ 5,307 Year 2 7,113 336 Year 3 4,379 213 Year 4 1,978 — Year 5 1,115 — Thereafter 6,564 — Total $ 30,668 $ 5,856 Less amounts representing interest costs (4,500 ) (216 ) Total lease liability $ 26,168 $ 5,640 The Partnership has non-cancelable revenue arrangements that are under the scope of ASC 842 whereby we have committed certain terminalling and storage assets in exchange for a minimum fee. Future minimum revenues the Partnership expects to receive under these non-cancelable arrangements as of March 31, 2020 are as follows: 2020 - $14,386 ; 2021 - $14,019 ; 2022 - $13,004 ; 2023 - $12,609 ; 2024 - $12,609 ; subsequent years - $49,414 .
Leases	LEASES The Partnership has numerous operating leases primarily for terminal facilities and transportation and other equipment. The leases generally provide that all expenses related to the equipment are to be paid by the lessee. Operating lease Right-of-Use ("ROU") assets and operating lease liabilities are recognized based on the present value of lease payments over the lease term at commencement date. Because most of the Partnership's leases do not provide an implicit rate of return, the Partnership uses its imputed collateralized rate based on the information available at commencement date in determining the present value of lease payments. The estimated rate is based on a risk-free rate plus a risk-adjusted margin. Our leases have remaining lease terms of 1 year to 17 years , some of which include options to extend the leases for up to 5 years , and some of which include options to terminate the leases within 1 year . The Partnership includes extension periods and excludes termination periods from its lease term if, at commencement, it is reasonably likely that the Partnership will exercise the option. The components of lease expense for the three months ended March 31, 2020 and 2019 were as follows: Three Months Ended March 31, 2020 2019 Operating lease cost $ 6,296 $ 5,177 Finance lease cost: Amortization of right-of-use assets 589 622 Interest on lease liabilities 110 183 Short-term lease cost 3,423 2,551 Total lease cost $ 10,418 $ 8,533 Supplemental balance sheet information related to leases was as follows: Three Months Ended March 31, 2020 2019 Operating Leases Operating lease right-of-use assets $ 25,771 $ 23,901 Current portion of operating lease liabilities included in "Other accrued liabilities" $ 8,358 $ 7,722 Operating lease liabilities 17,810 16,656 Total operating lease liabilities $ 26,168 $ 24,378 Finance Leases Property, plant and equipment, at cost $ 13,163 $ 14,058 Accumulated depreciation (3,634 ) (1,888 ) Property, plant and equipment, net $ 9,529 $ 12,170 Current installments of finance lease obligations $ 5,114 $ 5,540 Finance lease obligations 526 4,886 Total finance lease obligations $ 5,640 $ 10,426 The Partnership’s future minimum lease obligations as of March 31, 2020 consist of the following: Operating Leases Finance Leases Year 1 $ 9,519 $ 5,307 Year 2 7,113 336 Year 3 4,379 213 Year 4 1,978 — Year 5 1,115 — Thereafter 6,564 — Total $ 30,668 $ 5,856 Less amounts representing interest costs (4,500 ) (216 ) Total lease liability $ 26,168 $ 5,640 The Partnership has non-cancelable revenue arrangements that are under the scope of ASC 842 whereby we have committed certain terminalling and storage assets in exchange for a minimum fee. Future minimum revenues the Partnership expects to receive under these non-cancelable arrangements as of March 31, 2020 are as follows: 2020 - $14,386 ; 2021 - $14,019 ; 2022 - $13,004 ; 2023 - $12,609 ; 2024 - $12,609 ; subsequent years - $49,414 .

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	3 Months Ended
	Mar. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Supplemental Balance Sheet Information	SUPPLEMENTAL BALANCE SHEET INFORMATION Components of "Other accrued liabilities" were as follows: March 31, 2020 December 31, 2019 Accrued interest $ 3,538 $ 10,761 Asset retirement obligations — 25 Property and other taxes payable 2,803 5,411 Accrued payroll 3,944 3,011 Operating lease liabilities 8,358 7,722 Other 1,639 1,859 $ 20,282 $ 28,789 The schedule below summarizes the changes in our asset retirement obligations: March 31, 2020 Beginning asset retirement obligations $ 8,936 Additions to asset retirement obligations 379 Accretion expense 102 Liabilities settled (510 ) Ending asset retirement obligations 8,907 Current portion of asset retirement obligations 1 — Long-term portion of asset retirement obligations 2 $ 8,907 1 The current portion of asset retirement obligations is included in "Other accrued liabilities" on the Partnership's Consolidated and Condensed Balance Sheets. 2 The non-current portion of asset retirement obligations is included in "Other long-term obligations" on the Partnership's Consolidated and Condensed Balance Sheets.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES The Partnership’s revenues and cost of products sold are materially impacted by changes in NGL prices. Additionally, the Partnership's results of operations are materially impacted by changes in interest rates. In an effort to manage its exposure to these risks, the Partnership periodically enters into various derivative instruments, including commodity and interest rate hedges. All derivatives and hedging instruments are non-hedge derivatives and are included on the balance sheet as an asset or a liability measured at fair value and changes in fair value are recognized as gains and losses in earnings of the periods in which they occur. (a) Commodity Derivative Instruments The Partnership from time to time has used derivatives to manage the risk of commodity price fluctuation. Commodity risk is the adverse effect on the value of a liability or future purchase that results from a change in commodity price. The Partnership monitors and manages the commodity market risk associated with potential commodity risk exposure. In addition, the Partnership has focused on utilizing counterparties for these transactions whose financial condition is appropriate for the credit risk involved in each specific transaction. The Partnership has entered into hedging transactions as of March 31, 2020 to protect a portion of its commodity price risk exposure. These hedging arrangements are in the form of swaps for NGLs. At March 31, 2020 , the Partnership has instruments totaling a gross notional quantity of 25,000 barrels settling during the month of April 2020. At December 31, 2019 , the Partnership had instruments totaling a gross notional quantity of 452,000 barrels settling during the period from January 31, 2020 through February 29, 2020. These instruments settle against the applicable pricing source for each grade and location. (b) Interest Rate Derivative Instruments The Partnership is exposed to market risks associated with interest rates. Market risk is the adverse effect on the value of a financial instrument that results from a change in interest rates. We minimize this market risk by establishing and monitoring parameters that limit the types and degree of market risk that may be undertaken. From time to time, the Partnership enters into interest rate swaps to manage interest rate risk associated with the Partnership’s variable rate credit facility and its 2021 Notes. At March 31, 2020 and December 31, 2019 , the Partnership did not have any outstanding interest rate derivative instruments. For information regarding gains and losses on interest rate derivative instruments, see "Tabular Presentation of Gains and Losses on Derivative Instruments" below. (c) Tabular Presentation of Gains and Losses on Derivative Instruments The following table summarizes the fair value and classification of the Partnership’s derivative instruments in its Consolidated and Condensed Balance Sheets: Fair Values of Derivative Instruments in the Consolidated and Condensed Balance Sheets Derivative Assets Derivative Liabilities Fair Values Fair Values Balance Sheet Location March 31, 2020 December 31, 2019 Balance Sheet Location March 31, 2020 December 31, 2019 Derivatives not designated as hedging instruments: Current: Commodity contracts Fair value of derivatives $ 2 $ — Fair value of derivatives $ — $ 667 Total derivatives not designated as hedging instruments $ 2 $ — $ — $ 667 Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Three Months Ended March 31, 2020 and 2019 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2020 2019 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ 33 $ (239 ) Total effect of derivatives not designated as hedging instruments $ 33 $ (239 )

Partners' Capital

Partners' Capital	3 Months Ended
	Mar. 31, 2020
Partners' Capital Notes [Abstract]
Partners' Capital	PARTNERS' CAPITAL As of March 31, 2020 , Partners’ capital consisted of 38,852,507 common limited partner units, representing a 98% partnership interest, and a 2% general partner interest. Martin Resource Management Corporation, through subsidiaries, owns 6,114,532 of the Partnership's common limited partner units representing approximately 15.7% of the Partnership's outstanding common limited partner units. Martin Midstream GP LLC ("MMGP"), the Partnership's general partner, owns the 2% general partnership interest. Martin Resource Management Corporation controls the Partnership's general partner, by virtue of its 51% voting interest in MMGP Holdings, LLC ("Holdings"), the sole member of the Partnership's general partner. The partnership agreement of the Partnership (the "Partnership Agreement") contains specific provisions for the allocation of net income and losses to each of the partners for purposes of maintaining their respective partner capital accounts. Incentive Distribution Rights MMGP holds a 2% general partner interest and certain incentive distribution rights ("IDRs") in the Partnership. IDRs are a separate class of non-voting limited partner interest that may be transferred or sold by the general partner under the terms of the Partnership Agreement, and represent the right to receive an increasing percentage of cash distributions after the minimum quarterly distribution and any cumulative arrearages on common units once certain target distribution levels have been achieved. The Partnership is required to distribute all of its available cash from operating surplus, as defined in the Partnership Agreement. The general partner was allocated no incentive distributions during the three months ended March 31, 2020 and 2019. The target distribution levels entitle the general partner to receive 2% of quarterly cash distributions from the minimum of $0.50 per unit up to $0.55 per unit, 15% of quarterly cash distributions in excess of $0.55 per unit until all unitholders have received $0.625 per unit, 25% of quarterly cash distributions in excess of $0.625 per unit until all unitholders have received $0.75 per unit and 50% of quarterly cash distributions in excess of $0.75 per unit. Distributions of Available Cash The Partnership distributes all of its available cash (as defined in the Partnership Agreement) within 45 days after the end of each quarter to unitholders of record and to the general partner. Available cash is generally defined as all cash and cash equivalents of the Partnership on hand at the end of each quarter less the amount of cash reserves its general partner determines in its reasonable discretion is necessary or appropriate to: (i) provide for the proper conduct of the Partnership’s business; (ii) comply with applicable law, any debt instruments or other agreements; or (iii) provide funds for distributions to unitholders and the general partner for any one or more of the next four quarters, plus all cash on the date of determination of available cash for the quarter resulting from working capital borrowings made after the end of the quarter. Net Income per Unit The Partnership follows the provisions of the FASB ASC 260-10 related to earnings per share, which addresses the application of the two-class method in determining income per unit for master limited partnerships having multiple classes of securities that may participate in partnership distributions accounted for as equity distributions. Undistributed earnings are allocated to the general partner and limited partners utilizing the contractual terms of the Partnership Agreement. Distributions to the general partner pursuant to the IDRs are limited to available cash that will be distributed as defined in the Partnership Agreement. Accordingly, the Partnership does not allocate undistributed earnings to the general partner for the IDRs because the general partner's share of available cash is the maximum amount that the general partner would be contractually entitled to receive if all earnings for the period were distributed. When current period distributions are in excess of earnings, the excess distributions for the period are to be allocated to the general partner and limited partners based on their respective sharing of income and losses specified in the Partnership Agreement. Additionally, as required under FASB ASC 260-10-45-61A, unvested share-based payments that entitle employees to receive non-forfeitable distributions are considered participating securities, as defined in FASB ASC 260-10-20, for earnings per unit calculations. For purposes of computing diluted net income per unit, the Partnership uses the more dilutive of the two-class and if-converted methods. Under the if-converted method, the weighted-average number of subordinated units outstanding for the period is added to the weighted-average number of common units outstanding for purposes of computing basic net income per unit and the resulting amount is compared to the diluted net income per unit computed using the two-class method. The following is a reconciliation of net income from continuing operations and net income from discontinued operations allocated to the general partner and limited partners for purposes of calculating net income attributable to limited partners per unit: Three Months Ended March 31, 2020 2019 Continuing operations: Income (loss) from continuing operations $ 8,815 $ (4,758 ) Less general partner’s interest in net income (loss): Distributions payable on behalf of general partner interest 49 256 General partner interest in undistributed income (loss) 127 (351 ) Less income (loss) allocable to unvested restricted units 55 (3 ) Limited partners’ interest in net income (loss) $ 8,584 $ (4,660 ) Three Months Ended March 31, 2020 2019 Discontinued operations: Income from discontinued operations $ — $ 1,102 Less general partner’s interest in net income (loss): Distributions payable on behalf of general partner interest — (59 ) General partner interest in undistributed income — 81 Less income allocable to unvested restricted units — 1 Limited partners’ interest in net income $ — $ 1,079 The Partnership allocates the general partner's share of earnings between continuing and discontinued operations as a proportion of net income from continuing and discontinued operations to total net income. The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented: Three Months Ended March 31, 2020 2019 Basic weighted average limited partner units outstanding 38,640,862 38,681,925 Dilutive effect of restricted units issued 3,605 — Total weighted average limited partner diluted units outstanding 38,644,467 38,681,925 All outstanding units were included in the computation of diluted earnings per unit and weighted based on the number of days such units were outstanding during the periods presented. All common unit equivalents were antidilutive for the three months ended March 31, 2019 because the limited partners were allocated a net loss in this period.

Unit Based Awards

Unit Based Awards	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Unit Based Awards	UNIT BASED AWARDS The Partnership recognizes compensation cost related to unit-based awards to both employees and non-employees in its consolidated and condensed financial statements in accordance with certain provisions of ASC 718. Amounts recognized in selling, general, and administrative expense in the consolidated and condensed financial statements with respect to these plans are as follows: Three Months Ended March 31, 2020 2019 Employees $ 301 $ 329 Non-employee directors 45 23 Total unit-based compensation expense $ 346 $ 352 All of the Partnership's outstanding awards at March 31, 2020 met the criteria to be treated under equity classification. Long-Term Incentive Plans The Partnership's general partner has a long-term incentive plan for employees and directors of the general partner and its affiliates who perform services for the Partnership. On May 26, 2017, the unitholders of the Partnership approved the Martin Midstream Partners L.P. 2017 Restricted Unit Plan (the "2017 LTIP"). The plan currently permits the grant of awards covering an aggregate of 3,000,000 common units, all of which can be awarded in the form of restricted units. The plan is administered by the compensation committee of the general partner’s board of directors (the "Compensation Committee"). A restricted unit is a unit that is granted to grantees with certain vesting restrictions, which may be time-based and/or performance-based. Once these restrictions lapse, the grantee is entitled to full ownership of the unit without restrictions. The Compensation Committee may determine to make grants under the plan containing such terms as the Compensation Committee shall determine under the plan. With respect to time-based restricted units ("TBRU's"), the Compensation Committee will determine the time period over which restricted units granted to employees and directors will vest. The Compensation Committee may also award a percentage of restricted units with vesting requirements based upon the achievement of specified pre-established performance targets ("Performance Based Restricted Units" or "PBRU's"). The performance targets may include, but are not limited to, the following: revenue and income measures, cash flow measures, net income before interest expense and income tax expense ("EBIT"), net income before interest expense, income tax expense, and depreciation and amortization ("EBITDA"), distribution coverage metrics, expense measures, liquidity measures, market measures, corporate sustainability metrics, and other measures related to acquisitions, dispositions, operational objectives and succession planning objectives. PBRU's are earned only upon our achievement of an objective performance measure for the performance period. PBRU's which vest are payable in common units. Unvested units granted under the 2017 LTIP may or may not participate in cash distributions depending on the terms of each individual award agreement. The restricted units issued to directors generally vest in equal annual installments over a four -year period. Restricted units issued to employees generally vest in equal annual installments over three years of service. In February 2020, the Partnership issued 27,000 TBRU's to each of the Partnership's three independent directors under the 2017 LTIP. These restricted common units vest in equal installments of 6,750 units on January 24, 2021, 2022, 2023, and 2024. On March 1, 2018, the Partnership issued 301,550 TBRU's and 317,925 PBRU's to certain employees of Martin Resource Management Corporation. The TBRU's vest in equal installments over a three-year service period. The PBRU's will vest at the conclusion of a three-year performance period based on certain performance targets. In addition, the PBRU's awarded on March 1, 2018 that are achieved will only vest if the grantee is employed by Martin Resource Management Corporation on March 31, 2021. As of March 31, 2020 , the Partnership is unable to ascertain if certain performance conditions will be achieved and, as such, has not recognized compensation expense for the vesting of the units. The Partnership will record compensation expense for the vested portion of the units once the achievement of the performance condition is deemed probable. The restricted units are valued at their fair value at the date of grant which is equal to the market value of common units on such date. A summary of the restricted unit activity for the three months ended March 31, 2020 is provided below: Number of Units Weighted Average Grant-Date Fair Value Per Unit Non-vested, beginning of period 379,019 $ 13.91 Granted (TBRU) 81,000 $ 2.53 Vested (101,128 ) $ 13.95 Forfeited (84,134 ) $ 13.90 Non-Vested, end of period 274,757 $ 10.54 Aggregate intrinsic value, end of period $ 302 A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the three months ended March 31, 2020 and 2019 is provided below: Three Months Ended March 31, 2020 2019 Aggregate intrinsic value of units vested $ 151 $ 1,351 Fair value of units vested 1,427 1,551 As of March 31, 2020 , there was $1,613 of unrecognized compensation cost related to non-vested restricted units. That cost is expected to be recognized over a weighted-average period of 1.51 years.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS As of March 31, 2020 , Martin Resource Management Corporation owns 6,114,532 of the Partnership’s common units representing approximately 15.7% of the Partnership’s outstanding limited partner units. Martin Resource Management Corporation controls the Partnership's general partner by virtue of its 51% voting interest in Holdings, the sole member of the Partnership's general partner. The Partnership’s general partner, MMGP, owns a 2% general partner interest in the Partnership and the Partnership’s IDRs. The Partnership’s general partner’s ability, as general partner, to manage and operate the Partnership, and Martin Resource Management Corporation’s ownership as of March 31, 2020 , effectively gives Martin Resource Management Corporation the ability to veto some of the Partnership’s actions and to control the Partnership’s management. The following is a description of the Partnership’s material related party agreements and transactions: Omnibus Agreement Omnibus Agreement . The Partnership and its general partner are parties to the Omnibus Agreement dated November 1, 2002, with Martin Resource Management Corporation that governs, among other things, potential competition and indemnification obligations among the parties to the agreement, related party transactions, the provision of general administration and support services by Martin Resource Management Corporation and the Partnership’s use of certain Martin Resource Management Corporation trade names and trademarks. The Omnibus Agreement was amended on November 25, 2009, to include processing crude oil into finished products including naphthenic lubricants, distillates, asphalt and other intermediate cuts. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management Corporation. Non-Competition Provisions . Martin Resource Management Corporation has agreed for so long as it controls the general partner of the Partnership, not to engage in the business of: • providing terminalling and storage services for petroleum products and by-products including the refining, blending and packaging of finished lubricants; • providing land and marine transportation of petroleum products, by-products, and chemicals; • distributing NGLs; and • manufacturing and selling sulfur-based fertilizer products and other sulfur-related products. This restriction does not apply to: • the ownership and/or operation on the Partnership’s behalf of any asset or group of assets owned by it or its affiliates; • any business operated by Martin Resource Management Corporation, including the following: ◦ distributing fuel oil, marine fuel and other liquids; ◦ providing marine bunkering and other shore-based marine services in Texas, Louisiana, Mississippi, Alabama, and Florida; ◦ operating a crude oil gathering business in Stephens, Arkansas; ◦ providing crude oil gathering, refining, and marketing services of base oils, asphalt, and distillate products in Smackover, Arkansas; ◦ providing crude oil marketing and transportation from the well head to the end market; ◦ operating an environmental consulting company; ◦ supplying employees and services for the operation of the Partnership's business; and ◦ operating, solely for our account, the asphalt facilities in each of Hondo, South Houston and Port Neches, Texas and Omaha, Nebraska. • any business that Martin Resource Management Corporation acquires or constructs that has a fair market value of less than $5,000 ; • any business that Martin Resource Management Corporation acquires or constructs that has a fair market value of $5,000 or more if the Partnership has been offered the opportunity to purchase the business for fair market value and the Partnership declines to do so with the concurrence of the conflicts committee of the board of directors of the general partner of the Partnership (the "Conflicts Committee"); and • any business that Martin Resource Management Corporation acquires or constructs where a portion of such business includes a restricted business and the fair market value of the restricted business is $5,000 or more and represents less than 20% of the aggregate value of the entire business to be acquired or constructed; provided that, following completion of the acquisition or construction, the Partnership will be provided the opportunity to purchase the restricted business. Services. Under the Omnibus Agreement, Martin Resource Management Corporation provides the Partnership with corporate staff, support services, and administrative services necessary to operate the Partnership’s business. The Omnibus Agreement requires the Partnership to reimburse Martin Resource Management Corporation for all direct expenses it incurs or payments it makes on the Partnership’s behalf or in connection with the operation of the Partnership’s business. There is no monetary limitation on the amount the Partnership is required to reimburse Martin Resource Management Corporation for direct expenses. In addition to the direct expenses, under the Omnibus Agreement, the Partnership is required to reimburse Martin Resource Management Corporation for indirect general and administrative and corporate overhead expenses. Effective January 1, 2020, through December 31, 2020, the Conflicts Committee approved an annual reimbursement amount for indirect expenses of $16,410 . The Partnership reimbursed Martin Resource Management Corporation for $4,103 and $4,164 of indirect expenses for the three months ended March 31, 2020 and 2019 , respectively. The Conflicts Committee will review and approve future adjustments in the reimbursement amount for indirect expenses, if any, annually. These indirect expenses are intended to cover the centralized corporate functions Martin Resource Management Corporation provides to the Partnership, such as accounting, treasury, clerical, engineering, legal, billing, information technology, administration of insurance, general office expenses and employee benefit plans and other general corporate overhead functions the Partnership shares with Martin Resource Management Corporation retained businesses. The provisions of the Omnibus Agreement regarding Martin Resource Management Corporation’s services will terminate if Martin Resource Management Corporation ceases to control the general partner of the Partnership. Related Party Transactions . The Omnibus Agreement prohibits the Partnership from entering into any material agreement with Martin Resource Management Corporation without the prior approval of the Conflicts Committee. For purposes of the Omnibus Agreement, the term "material agreements" means any agreement between the Partnership and Martin Resource Management Corporation that requires aggregate annual payments in excess of the then-applicable agreed upon reimbursable amount of indirect general and administrative expenses. Please read "Services" above. License Provisions. Under the Omnibus Agreement, Martin Resource Management Corporation has granted the Partnership a nontransferable, nonexclusive, royalty-free right and license to use certain of its trade names and marks, as well as the trade names and marks used by some of its affiliates. Amendment and Termination. The Omnibus Agreement may be amended by written agreement of the parties; provided, however, that it may not be amended without the approval of the Conflicts Committee if such amendment would adversely affect the unitholders. The Omnibus Agreement was first amended on November 25, 2009, to permit the Partnership to provide refining services to Martin Resource Management Corporation. The Omnibus Agreement was amended further on October 1, 2012, to permit the Partnership to provide certain lubricant packaging products and services to Martin Resource Management Corporation. Such amendments were approved by the Conflicts Committee. The Omnibus Agreement, other than the indemnification provisions and the provisions limiting the amount for which the Partnership will reimburse Martin Resource Management Corporation for general and administrative services performed on its behalf, will terminate if the Partnership is no longer an affiliate of Martin Resource Management Corporation. Master Transportation Services Agreement Master Transportation Agreement. Martin Transport, Inc. ("MTI"), a wholly owned subsidiary of the Partnership, is a party to a master transportation services agreement effective January 1, 2019, with certain wholly owned subsidiaries of Martin Resource Management Corporation. Under the agreement, MTI agreed to transport Martin Resource Management Corporation's petroleum products and by-products. Term and Pricing. The agreement will continue unless either party terminates the agreement by giving at least 30 days' written notice to the other party. These rates are subject to any adjustments which are mutually agreed upon or in accordance with a price index. Additionally, shipping charges are also subject to fuel surcharges determined on a weekly basis in accordance with the U.S. Department of Energy’s national diesel price list. Indemnification. MTI has agreed to indemnify Martin Resource Management Corporation against all claims arising out of the negligence or willful misconduct of MTI and its officers, employees, agents, representatives and subcontractors. Martin Resource Management Corporation has agreed to indemnify MTI against all claims arising out of the negligence or willful misconduct of Martin Resource Management Corporation and its officers, employees, agents, representatives and subcontractors. In the event a claim is the result of the joint negligence or misconduct of MTI and Martin Resource Management Corporation, indemnification obligations will be shared in proportion to each party’s allocable share of such joint negligence or misconduct. Marine Agreements Marine Transportation Agreement. The Partnership is a party to a marine transportation agreement effective January 1, 2006, as amended, under which the Partnership provides marine transportation services to Martin Resource Management Corporation on a spot-contract basis at applicable market rates. Effective each January 1, this agreement automatically renews for consecutive one year periods unless either party terminates the agreement by giving written notice to the other party at least 60 days prior to the expiration of the then applicable term. The fees the Partnership charges Martin Resource Management Corporation are based on applicable market rates. Marine Fuel. The Partnership is a party to an agreement with Martin Resource Management Corporation dated November 1, 2002, under which Martin Resource Management Corporation provides the Partnership with marine fuel from its locations in the Gulf of Mexico at a fixed rate in excess of the Platt’s U.S. Gulf Coast Index for #2 Fuel Oil. Under this agreement, the Partnership agreed to purchase all of its marine fuel requirements that occur in the areas serviced by Martin Resource Management Corporation. Terminal Services Agreements Diesel Fuel Terminal Services Agreement. Effective January 1, 2016, the Partnership entered into a second amended and restated terminalling services agreement under which the Partnership provides terminal services to Martin Resource Management Corporation for marine fuel distribution. At such time, the per-gallon throughput fee the Partnership charged under this agreement was increased when compared to the previous agreement and may be adjusted annually based on a price index. This agreement was further amended on January 1, 2017, October 1, 2017, and April 1, 2019 to modify its minimum throughput requirements and throughput fees. The term of this agreement is currently evergreen and it will continue on a month to month basis until terminated by either party by giving 60 days’ written notice. Miscellaneous Terminal Services Agreements. The Partnership is currently party to several terminal services agreements and from time to time the Partnership may enter into other terminal service agreements for the purpose of providing terminal services to related parties. Individually, each of these agreements is immaterial but when considered in the aggregate they could be deemed material. These agreements are throughput based with a minimum volume commitment. Generally, the fees due under these agreements are adjusted annually based on a price index. Other Agreements Cross Tolling Agreement. The Partnership is a party to an amended and restated tolling agreement with Cross Oil Refining and Marketing, Inc. ("Cross") dated October 28, 2014, under which the Partnership processes crude oil into finished products, including naphthenic lubricants, distillates, asphalt and other intermediate cuts for Cross. The tolling agreement expires November 25, 2031. Under this tolling agreement, Cross agreed to process a minimum of 6,500 barrels per day of crude oil at the facility at a fixed price per barrel. Any additional barrels are processed at a modified price per barrel. In addition, Cross agreed to pay a monthly reservation fee and a periodic fuel surcharge fee based on certain parameters specified in the tolling agreement. Further, certain capital improvements, to the extent requested by Cross, are reimbursed through a capital recovery fee. As of December 31, 2019, annual capital recovery fee reimbursement of $2,088 expired. An additional $2,586 of capital recovery fee reimbursement will expire on December 31, 2020. All of these fees (other than the fuel surcharge and capital recovery fee) are subject to escalation annually based upon the greater of 3% or the increase in the Consumer Price Index for a specified annual period. In addition, on the third, sixth and ninth anniversaries of the agreement, the parties can negotiate an upward or downward adjustment in the fees subject to their mutual agreement. Also, the Partnership renegotiated a crude transportation contract set to expire in the first half of 2022 resulting in a reduction in revenue of $2,145 annually beginning January 1, 2020. Other Miscellaneous Agreements. From time to time the Partnership enters into other miscellaneous agreements with Martin Resource Management Corporation for the provision of other services or the purchase of other goods. The tables below summarize the related party transactions that are included in the related financial statement captions on the face of the Partnership’s Consolidated and Condensed Statements of Operations. The revenues, costs and expenses reflected in these tables are tabulations of the related party transactions that are recorded in the corresponding captions of the consolidated and condensed financial statements and do not reflect a statement of profits and losses for related party transactions. The impact of related party revenues from sales of products and services is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Revenues: Terminalling and storage $ 15,874 $ 18,972 Transportation 5,894 5,643 Product sales: Sulfur services 19 7 Terminalling and storage 73 414 92 421 $ 21,860 $ 25,036 The impact of related party cost of products sold is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Cost of products sold: Sulfur services $ 2,767 $ 2,574 Terminalling and storage 5,777 5,909 $ 8,544 $ 8,483 The impact of related party operating expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Operating expenses: Transportation $ 15,553 $ 14,980 Natural gas liquids 497 2,025 Sulfur services 1,146 924 Terminalling and storage 4,575 4,607 $ 21,771 $ 22,536 The impact of related party selling, general and administrative expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Selling, general and administrative: Transportation $ 1,839 $ 1,728 Natural gas liquids 704 1,189 Sulfur services 743 716 Terminalling and storage 838 717 Indirect, including overhead allocation 4,188 4,185 $ 8,312 $ 8,535

Business Segments

Business Segments	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Business Segments	BUSINESS SEGMENTS The Partnership has four reportable segments: terminalling and storage, transportation, sulfur services and natural gas liquids. The Partnership’s reportable segments are strategic business units that offer different products and services. The operating income of these segments is reviewed by the chief operating decision maker to assess performance and make business decisions. The accounting policies of the operating segments are the same as those described in Note 2 in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2019 , filed with the SEC on February 14, 2020. The Partnership evaluates the performance of its reportable segments based on operating income. There is no allocation of administrative expenses or interest expense. Three Months Ended March 31, 2020 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 51,134 $ (1,726 ) $ 49,408 $ 7,456 $ 758 $ 3,745 Transportation 45,174 (6,233 ) 38,941 4,280 (5,021 ) 3,926 Sulfur services 28,336 (13 ) 28,323 2,894 13,858 2,985 Natural gas liquids 82,215 (4 ) 82,211 609 10,377 105 Indirect selling, general and administrative — — — — (4,372 ) — Total $ 206,859 $ (7,976 ) $ 198,883 $ 15,239 $ 15,600 $ 10,761 Three Months Ended March 31, 2019 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 55,892 $ (1,721 ) $ 54,171 $ 7,837 $ 4,815 $ 5,345 Transportation 45,186 (7,391 ) 37,795 3,570 (3,880 ) 2,461 Sulfur services 31,593 — 31,593 2,868 6,380 2,206 Natural gas liquids 116,474 — 116,474 626 6,858 287 Indirect selling, general and administrative — — — — (4,567 ) — Total $ 249,145 $ (9,112 ) $ 240,033 $ 14,901 $ 9,606 $ 10,299 The Partnership's assets by reportable segment as of March 31, 2020 and December 31, 2019 , are as follows: March 31, 2020 December 31, 2019 Total assets: Terminalling and storage $ 288,915 $ 292,136 Transportation 170,274 170,045 Sulfur services 112,709 110,780 Natural gas liquids 40,301 94,195 Total assets $ 612,199 $ 667,156

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITTMENTS AND CONTINGENCIES Contingencies From time to time, the Partnership is subject to various claims and legal actions arising in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on the Partnership. On December 31, 2015, the Partnership received a demand from a customer in its lubricants packaging business for defense and indemnity in connection with lawsuits filed against it in various United States District Courts, which generally allege that the customer engaged in unlawful and deceptive business practices in connection with its marketing and advertising of its private label motor oil. The Partnership disputes that it has any obligation to defend or indemnify the customer for its conduct. Accordingly, on January 7, 2016, the Partnership filed a Complaint for Declaratory Judgment in the Chancery Court of Davidson County, Tennessee requesting a judicial determination that the Partnership does not owe the customer the demanded defense and indemnity obligations. The lawsuits against the customer have been transferred to the United States District Court for the Western District of Missouri for consolidated pretrial proceedings. On March 1, 2017, at the request of the parties, the Chancery Court of Davidson County, Tennessee administratively closed the Partnership's lawsuit pending rulings in the United States District Court for the Western District of Missouri. In the event that either party moves the Chancery Court of Davidson County, Tennessee to reopen the case, we expect the Court would grant such motion and reopen the case. Further, the same customer has made a claim under the Partnership’s insurance policy. The insurer has denied the claim. However, in the event that the customer is successful in pursuing the claim, such action would negatively impact the Partnership because the Partnership has certain reimbursement obligations it would owe the insurance company. If the case is reopened or the insurance claim by the customer is successful, we are currently unable to determine the exposure we may have in this matter, if any.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that reflect the entity's own assumptions and are not corroborated by market data. Assets and liabilities measured at fair value on a recurring basis are summarized below: Level 2 March 31, 2020 December 31, 2019 Commodity derivative contracts, net $ 2 $ (667 ) The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument: • Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments. • Current and noncurrent portion of long-term debt: The carrying amount of the revolving credit facility approximates fair value due to the debt having a variable interest rate and is in Level 2. The Partnership has not had any indicators which represent a change in the market spread associated with its variable interest rate debt. The estimated fair value of the 2021 Notes is considered Level 1, as the fair value is based on quoted market prices in active markets. March 31, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 2021 Notes $ 364,124 $ 146,825 $ 373,374 $ 343,470

Condensed Consolidated Financia

Condensed Consolidated Financial Information	3 Months Ended
	Mar. 31, 2020
Consolidating Financial Statements [Abstract]
Condensed Consolidated Financial Information	CONDENSED CONSOLIDATED FINANCIAL INFORMATION The Partnership's operations are conducted by its operating subsidiaries as it has no independent assets or operations. Martin Operating Partnership L.P. (the "Operating Partnership"), the Partnership’s wholly-owned subsidiary, and the Partnership's other operating subsidiaries have issued in the past, and may issue in the future, unconditional guarantees of senior or subordinated debt securities of the Partnership. The guarantees that have been issued are full, irrevocable and unconditional

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Three Months Ended March 31, 2020 2019 Provision for income taxes $ 347 $ 696 The operations of a partnership are generally not subject to income taxes, except for Texas margin tax, because its income is taxed directly to its partners. MTI is subject to income taxes due to its corporate structure. Total income tax expense of $347 , related to the operation of the subsidiary, for the three months ended March 31, 2020 , resulted in an effective income tax rate of 32.17% . Total income tax expense of $448 , related to the operation of the subsidiary, for the three months ended March 31, 2019 , resulted in an effective income tax rate of 24.79% . The increase in the effective income tax rate for income taxes during the three months ended March 31, 2020 , compared to the three months ended March 31, 2019 , is primarily due to an increase in permanent differences and a decrease in income before income taxes. The decrease in the provision for income taxes during the three months ended March 31, 2020 , compared to the similar period in 2019 , was primarily due to the impact of a decrease in income before income taxes in the current period. The Coronavirus Aid, Relief, and Economic Security ("CARES") Act was enacted on March 27, 2020, in response to the market volatility and instability resulting from the COVID-19 pandemic, and includes changes to various income tax provisions including, but not limited to, providing for a five-year carryback of net operating losses generated in taxable years beginning after December 31, 2017, and before January 1, 2021, suspension of the 80% taxable income limitation for net operating losses generated after December 31, 2017, and before January 1, 2021, and relaxation of the limitation of adjusted taxable income as determined under Internal Revenue Code Section 163(j) from 30% to 50% when determining the deduction for business interest expense for 2019 and 2020. Since, prior to its acquisition by the Partnership, MTI was a Qualified Subchapter S subsidiary ("QSub") of Martin Resource Management Corporation, it is precluded from carrying back net operating losses to its QSub taxable years. The other applicable provisions of the CARES Act have no material impact on the annual effective tax rate ("AETR"), deferred taxes, or valuation allowances. A current federal income tax expense (benefit) of $133 and $297 , related to the operation of the subsidiary, were recorded for the three months ended March 31, 2020 and 2019 , respectively. A current state income tax expense (benefit) of $(72) and $(218) , related to the operation of the subsidiary, were recorded for the three months ended March 31, 2020 and 2019 , respectively With respect to MTI, income taxes are accounted for under the asset and liability method pursuant to the provisions of ASC 740 related to income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A deferred tax expense related to the MTI temporary differences of $286 and $369 was recorded for the three months ended March 31, 2020 and 2019, respectively. A deferred tax asset of $23,136 and $23,422 , related to the cumulative book and tax temporary differences, existed at March 31, 2020 and December 31, 2019 , respectively. All income tax positions taken for all open years are more likely than not to be sustained based upon their technical merit under applicable tax laws.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Quarterly Distribution. On April 22, 2020, the Partnership declared a quarterly cash distribution of $0.0625 per common unit for the first quarter of 2020, or $0.25

New Accounting Pronouncements (

New Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2020
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS During the first quarter of 2020, the Partnership adopted Accounting Standards Update (“ASU”) 2016-13, "Financial Instruments - Credit Losses," which required the Partnership to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaced the existing incurred loss model and is applicable to the measurement of credit losses on financial assets, including trade receivables. Adoption of the new standard did not have a material impact on the Partnership’s consolidated financial statements.
Fair Value Measurements	The Partnership uses a valuation framework based upon inputs that market participants use in pricing certain assets and liabilities. These inputs are classified into two categories: observable inputs and unobservable inputs. Observable inputs represent market data obtained from independent sources. Unobservable inputs represent the Partnership's own market assumptions. Unobservable inputs are used only if observable inputs are unavailable or not reasonably available without undue cost and effort. The two types of inputs are further prioritized into the following hierarchy: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that reflect the entity's own assumptions and are not corroborated by market data.
Fair Value of Financial Instruments	The Partnership is required to disclose estimated fair values for its financial instruments. Fair value estimates are set forth below for these financial instruments. The following methods and assumptions were used to estimate the fair value of each class of financial instrument: • Accounts and other receivables, trade and other accounts payable, accrued interest payable, other accrued liabilities, income taxes payable and due from/to affiliates: The carrying amounts approximate fair value due to the short maturity and highly liquid nature of these instruments, and as such these have been excluded from the table below. There is negligible credit risk associated with these instruments. • Current and noncurrent portion of long-term debt: The carrying amount of the revolving credit facility approximates fair value due to the debt having a variable interest rate and is in Level 2. The Partnership has not had any indicators which represent a change in the market spread associated with its variable interest rate debt. The estimated fair value of the 2021 Notes is considered Level 1, as the fair value is based on quoted market prices in active markets.

Divestitures and Discontinued_2

Divestitures and Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2020
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	The operating results, which are included in income from discontinued operations, were as follows: Three Months Ended March 31, 2019 Total revenues $ 10,934 Total costs and expenses and other, net, excluding depreciation and amortization (5,751 ) Depreciation and amortization (4,081 ) Income from discontinued operations before income taxes 1,102 Income tax expense — Income from discontinued operations, net of income taxes $ 1,102
Disclosure of Long Lived Assets Held-for-sale	At December 31, 2019, certain terminalling and storage and transportation assets met the criteria to be classified as held for sale in accordance with ASC 360-10 and are presented at the lower of the assets' carrying amount or fair value less cost to sell by segment in current assets in the table below. These assets are considered non-core assets to the Partnership's operations and did not qualify for discontinued operations presentation under the guidance of ASC 205-20. March 31, 2020 December 31, 2019 Terminalling and storage $ — $ 3,552 Transportation — 1,500 Assets held for sale $ — $ 5,052

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table disaggregates our revenue by major source: Three Months Ended March 31, 2020 2019 Terminalling and storage segment Lubricant product sales $ 28,934 $ 31,067 Throughput and storage 20,474 23,104 $ 49,408 $ 54,171 Natural gas liquids segment Natural gas liquids product sales $ 82,211 $ 116,474 $ 82,211 $ 116,474 Sulfur services segment Sulfur product sales $ 6,481 $ 9,952 Fertilizer product sales 18,927 18,782 Sulfur services 2,915 2,859 $ 28,323 $ 31,593 Transportation segment Land transportation $ 24,234 $ 24,119 Inland transportation 13,706 12,477 Offshore transportation 1,001 1,199 $ 38,941 $ 37,795
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The table includes estimated minimum revenue expected to be recognized in the future related to performance obligations that are unsatisfied at the end of the reporting period. The Partnership applies the practical expedient in ASC 606-10-50-14(a) and does not disclose information about remaining performance obligations that have original expected durations of one year or less. 2020 2021 2022 2023 2024 Thereafter Total Terminalling and storage Throughput and storage $ 34,599 $ 43,273 $ 40,394 $ 41,605 $ 42,854 $ 338,339 $ 541,064 Sulfur services Sulfur product sales 4,236 5,366 3,220 2,175 975 975 16,947 Total $ 38,835 $ 48,639 $ 43,614 $ 43,780 $ 43,829 $ 339,314 $ 558,011

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2020
Inventory Disclosure [Abstract]
Components of Inventory	Components of inventories at March 31, 2020 and December 31, 2019 were as follows: March 31, 2020 December 31, 2019 Natural gas liquids $ 3,687 $ 19,097 Sulfur 4,443 4,586 Fertilizer 14,549 15,852 Lubricants 20,126 18,925 Other 4,025 4,080 $ 46,830 $ 62,540

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	At March 31, 2020 and December 31, 2019 , long-term debt consisted of the following: March 31, December 31, $400,000 Revolving credit facility at variable interest rate (3.93% 1 weighted average at March 31, 2020), due August 2023 4 secured by substantially all of the Partnership’s assets, including, without limitation, inventory, accounts receivable, vessels, equipment, fixed assets and the interests in the Partnership’s operating subsidiaries, net of unamortized debt issuance costs of $4,457 and $4,586, respectively 2 $ 165,543 $ 196,414 $400,000 Senior notes, 7.25% interest, net of unamortized debt issuance costs of $599 and $770, respectively, including unamortized premium of $267 and $344, respectively, issued $250,000 February 2013 and $150,000 April 2014, $26,200 repurchased during 2015, $9,344 repurchased during 2020, due February 2021, unsecured 2,3,4,5 364,124 373,374 Total 529,667 569,788 Less: current portion (364,124 ) — Total long-term debt, net of current portion $ 165,543 $ 569,788 Current installments of finance lease obligations $ 5,114 $ 6,758 Finance lease obligations 526 717 Total finance lease obligations $ 5,640 $ 7,475 1 Interest rate fluctuates based on the LIBOR rate plus an applicable margin set on the date of each advance. The margin above LIBOR is set every three months. Indebtedness under the credit facility bears interest at LIBOR plus an applicable margin or the base prime rate plus an applicable margin. All amounts outstanding at March 31, 2020 and December 31, 2019 were at LIBOR plus an applicable margin. The applicable margin for revolving loans that are LIBOR loans ranges from 2.25% to 3.50% and the applicable margin for revolving loans that are base prime rate loans ranges from 1.25% to 2.50% . The applicable margin for existing LIBOR borrowings at March 31, 2020 is 3.25% . The credit facility contains various covenants which limit the Partnership’s ability to make certain investments and acquisitions; enter into certain agreements; incur indebtedness; sell assets; and make certain amendments to the Partnership's omnibus agreement with Martin Resource Management Corporation (the "Omnibus Agreement"). The Partnership is permitted to make quarterly distributions so long as no event of default exists. 2 The Partnership is in compliance with all debt covenants as of March 31, 2020 and December 31, 2019 , respectively. 3 The 2021 indenture restricts the Partnership’s ability to sell assets; pay distributions or repurchase units or redeem or repurchase subordinated debt; make investments; incur or guarantee additional indebtedness or issue preferred units; and consolidate, merge or transfer all or substantially all of its assets. 4 As of March 31, 2020, the Partnership’s 7.25% senior unsecured notes due 2021 (the "2021 Notes") were due within twelve months and have therefore been presented as a current liability on the Consolidated and Condensed Balance Sheets at March 31, 2020. The Partnership's amended revolving credit facility includes a provision which accelerates the maturity date to August 19, 2020 if the 2021 Notes are not refinanced in a manner not prohibited by the facility. If the Partnership is unable to refinance the 2021 Notes and is unable to repay the outstanding borrowings under its revolving credit facility on August 19, 2020, the Partnership's ability to meet its obligations would be adversely affected. Failure to comply with this provision, if not waived, would result in an event of default under the Partnership's revolving credit facility, the potential acceleration of outstanding debt thereunder, and the potential foreclosure on the collateral securing such debt, and could cause a cross-default under other agreements, which could also result in the acceleration of those obligations by the counterparties to those agreements. The Partnership, with support from the Board of Directors, is actively pursuing a variety of strategic alternatives to strengthen the balance sheet and address near term maturities and accordingly, announced on April 6, 2020, the hiring of Stephens Inc. as a financial advisor to assist in the process. Pending the successful implementation of the refinancing, the conditions described above have raised substantial doubt about the Partnership’s ability to continue as a going concern. The Partnership’s management is engaged in ongoing communication with credit providers and presently believes the measures being taken will enable the Partnership to successfully refinance the 2021 Notes and comply with covenants under its revolving credit facility, although no assurance can be given. 5 In March 2020, the Partnership repurchased on the open market an aggregate $9,344 of the 2021 Notes. These transactions resulted in a gain on retirement of $3,484 .

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Components of Lease Expense	The components of lease expense for the three months ended March 31, 2020 and 2019 were as follows: Three Months Ended March 31, 2020 2019 Operating lease cost $ 6,296 $ 5,177 Finance lease cost: Amortization of right-of-use assets 589 622 Interest on lease liabilities 110 183 Short-term lease cost 3,423 2,551 Total lease cost $ 10,418 $ 8,533
Schedule of Supplemental Balance Sheet Information	Supplemental balance sheet information related to leases was as follows: Three Months Ended March 31, 2020 2019 Operating Leases Operating lease right-of-use assets $ 25,771 $ 23,901 Current portion of operating lease liabilities included in "Other accrued liabilities" $ 8,358 $ 7,722 Operating lease liabilities 17,810 16,656 Total operating lease liabilities $ 26,168 $ 24,378 Finance Leases Property, plant and equipment, at cost $ 13,163 $ 14,058 Accumulated depreciation (3,634 ) (1,888 ) Property, plant and equipment, net $ 9,529 $ 12,170 Current installments of finance lease obligations $ 5,114 $ 5,540 Finance lease obligations 526 4,886 Total finance lease obligations $ 5,640 $ 10,426
Schedule of Future Minimum Lease Obligations, Finance Lease	The Partnership’s future minimum lease obligations as of March 31, 2020 consist of the following: Operating Leases Finance Leases Year 1 $ 9,519 $ 5,307 Year 2 7,113 336 Year 3 4,379 213 Year 4 1,978 — Year 5 1,115 — Thereafter 6,564 — Total $ 30,668 $ 5,856 Less amounts representing interest costs (4,500 ) (216 ) Total lease liability $ 26,168 $ 5,640
Schedule of Future Minimum Lease Obligations, Operating Leases	The Partnership’s future minimum lease obligations as of March 31, 2020 consist of the following: Operating Leases Finance Leases Year 1 $ 9,519 $ 5,307 Year 2 7,113 336 Year 3 4,379 213 Year 4 1,978 — Year 5 1,115 — Thereafter 6,564 — Total $ 30,668 $ 5,856 Less amounts representing interest costs (4,500 ) (216 ) Total lease liability $ 26,168 $ 5,640

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	3 Months Ended
	Mar. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Schedule of Other Accrued Liabilities	Components of "Other accrued liabilities" were as follows: March 31, 2020 December 31, 2019 Accrued interest $ 3,538 $ 10,761 Asset retirement obligations — 25 Property and other taxes payable 2,803 5,411 Accrued payroll 3,944 3,011 Operating lease liabilities 8,358 7,722 Other 1,639 1,859 $ 20,282 $ 28,789
Schedule of Asset Retirement Obligations	The schedule below summarizes the changes in our asset retirement obligations: March 31, 2020 Beginning asset retirement obligations $ 8,936 Additions to asset retirement obligations 379 Accretion expense 102 Liabilities settled (510 ) Ending asset retirement obligations 8,907 Current portion of asset retirement obligations 1 — Long-term portion of asset retirement obligations 2 $ 8,907 1 The current portion of asset retirement obligations is included in "Other accrued liabilities" on the Partnership's Consolidated and Condensed Balance Sheets. 2 The non-current portion of asset retirement obligations is included in "Other long-term obligations" on the Partnership's Consolidated and Condensed Balance Sheets.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Effect of Derivative Instruments on the Consolidated Balance Sheets	The following table summarizes the fair value and classification of the Partnership’s derivative instruments in its Consolidated and Condensed Balance Sheets: Fair Values of Derivative Instruments in the Consolidated and Condensed Balance Sheets Derivative Assets Derivative Liabilities Fair Values Fair Values Balance Sheet Location March 31, 2020 December 31, 2019 Balance Sheet Location March 31, 2020 December 31, 2019 Derivatives not designated as hedging instruments: Current: Commodity contracts Fair value of derivatives $ 2 $ — Fair value of derivatives $ — $ 667 Total derivatives not designated as hedging instruments $ 2 $ — $ — $ 667
Effect of Derivative Instruments on the Consolidated Statement of Operations	Effect of Derivative Instruments on the Consolidated and Condensed Statements of Operations For the Three Months Ended March 31, 2020 and 2019 Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives 2020 2019 Derivatives not designated as hedging instruments: Commodity contracts Cost of products sold $ 33 $ (239 ) Total effect of derivatives not designated as hedging instruments $ 33 $ (239 )

Partners' Capital (Tables)

Partners' Capital (Tables)	3 Months Ended
	Mar. 31, 2020
Partners' Capital Notes [Abstract]
Reconciliation of Net Income to Partners Interest in Net Income	The following is a reconciliation of net income from continuing operations and net income from discontinued operations allocated to the general partner and limited partners for purposes of calculating net income attributable to limited partners per unit: Three Months Ended March 31, 2020 2019 Continuing operations: Income (loss) from continuing operations $ 8,815 $ (4,758 ) Less general partner’s interest in net income (loss): Distributions payable on behalf of general partner interest 49 256 General partner interest in undistributed income (loss) 127 (351 ) Less income (loss) allocable to unvested restricted units 55 (3 ) Limited partners’ interest in net income (loss) $ 8,584 $ (4,660 ) Three Months Ended March 31, 2020 2019 Discontinued operations: Income from discontinued operations $ — $ 1,102 Less general partner’s interest in net income (loss): Distributions payable on behalf of general partner interest — (59 ) General partner interest in undistributed income — 81 Less income allocable to unvested restricted units — 1 Limited partners’ interest in net income $ — $ 1,079 The following are the unit amounts used to compute the basic and diluted earnings per limited partner unit for the periods presented: Three Months Ended March 31, 2020 2019 Basic weighted average limited partner units outstanding 38,640,862 38,681,925 Dilutive effect of restricted units issued 3,605 — Total weighted average limited partner diluted units outstanding 38,644,467 38,681,925

Unit Based Awards (Tables)

Unit Based Awards (Tables)	3 Months Ended
	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Compensation Costs Related to Unit Based Plan	Amounts recognized in selling, general, and administrative expense in the consolidated and condensed financial statements with respect to these plans are as follows: Three Months Ended March 31, 2020 2019 Employees $ 301 $ 329 Non-employee directors 45 23 Total unit-based compensation expense $ 346 $ 352
Summary of Restricted Unit Activity	A summary of the restricted unit activity for the three months ended March 31, 2020 is provided below: Number of Units Weighted Average Grant-Date Fair Value Per Unit Non-vested, beginning of period 379,019 $ 13.91 Granted (TBRU) 81,000 $ 2.53 Vested (101,128 ) $ 13.95 Forfeited (84,134 ) $ 13.90 Non-Vested, end of period 274,757 $ 10.54 Aggregate intrinsic value, end of period $ 302
Summary of Aggregate Intrinsic Value and Fair Value of Units Vested	A summary of the restricted units’ aggregate intrinsic value (market value at vesting date) and fair value of units vested (market value at date of grant) during the three months ended March 31, 2020 and 2019 is provided below: Three Months Ended March 31, 2020 2019 Aggregate intrinsic value of units vested $ 151 $ 1,351 Fair value of units vested 1,427 1,551

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2020
Related Party Transactions [Abstract]
The Impact of Related Party Transactions	The impact of related party revenues from sales of products and services is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Revenues: Terminalling and storage $ 15,874 $ 18,972 Transportation 5,894 5,643 Product sales: Sulfur services 19 7 Terminalling and storage 73 414 92 421 $ 21,860 $ 25,036 The impact of related party cost of products sold is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Cost of products sold: Sulfur services $ 2,767 $ 2,574 Terminalling and storage 5,777 5,909 $ 8,544 $ 8,483 The impact of related party operating expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Operating expenses: Transportation $ 15,553 $ 14,980 Natural gas liquids 497 2,025 Sulfur services 1,146 924 Terminalling and storage 4,575 4,607 $ 21,771 $ 22,536 The impact of related party selling, general and administrative expenses is reflected in the consolidated and condensed financial statements as follows: Three Months Ended March 31, 2020 2019 Selling, general and administrative: Transportation $ 1,839 $ 1,728 Natural gas liquids 704 1,189 Sulfur services 743 716 Terminalling and storage 838 717 Indirect, including overhead allocation 4,188 4,185 $ 8,312 $ 8,535

Business Segments (Tables)

Business Segments (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Reporting by Segment	Three Months Ended March 31, 2020 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 51,134 $ (1,726 ) $ 49,408 $ 7,456 $ 758 $ 3,745 Transportation 45,174 (6,233 ) 38,941 4,280 (5,021 ) 3,926 Sulfur services 28,336 (13 ) 28,323 2,894 13,858 2,985 Natural gas liquids 82,215 (4 ) 82,211 609 10,377 105 Indirect selling, general and administrative — — — — (4,372 ) — Total $ 206,859 $ (7,976 ) $ 198,883 $ 15,239 $ 15,600 $ 10,761 Three Months Ended March 31, 2019 Operating Revenues Intersegment Revenues Eliminations Operating Revenues after Eliminations Depreciation and Amortization Operating Income (Loss) after Eliminations Capital Expenditures and Plant Turnaround Costs Terminalling and storage $ 55,892 $ (1,721 ) $ 54,171 $ 7,837 $ 4,815 $ 5,345 Transportation 45,186 (7,391 ) 37,795 3,570 (3,880 ) 2,461 Sulfur services 31,593 — 31,593 2,868 6,380 2,206 Natural gas liquids 116,474 — 116,474 626 6,858 287 Indirect selling, general and administrative — — — — (4,567 ) — Total $ 249,145 $ (9,112 ) $ 240,033 $ 14,901 $ 9,606 $ 10,299
Assets by Segment	The Partnership's assets by reportable segment as of March 31, 2020 and December 31, 2019 , are as follows: March 31, 2020 December 31, 2019 Total assets: Terminalling and storage $ 288,915 $ 292,136 Transportation 170,274 170,045 Sulfur services 112,709 110,780 Natural gas liquids 40,301 94,195 Total assets $ 612,199 $ 667,156

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are summarized below: Level 2 March 31, 2020 December 31, 2019 Commodity derivative contracts, net $ 2 $ (667 ) March 31, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value 2021 Notes $ 364,124 $ 146,825 $ 373,374 $ 343,470

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense	Three Months Ended March 31, 2020 2019 Provision for income taxes $ 347 $ 696

Nature of Operations and Basi_2

Nature of Operations and Basis of Presentation (Details) $ in Thousands, ft³ in Billions	3 Months Ended
	Mar. 31, 2020USD ($)segment	Jun. 28, 2019USD ($)ft³
Error Corrections and Prior Period Adjustments Restatement
Number of primary business lines | segment	4
Impairment of long lived assets	$ 4,400
Discontinued Operations, Disposed of by Sale | Natural Gas Storage Assets
Error Corrections and Prior Period Adjustments Restatement
Natural gas storage (in cubic feet) | ft³		50
Proceeds from sale of assets		$ 210,067

Divestitures and Discontinued_3

Divestitures and Discontinued Operations - Narratives (Details) $ in Thousands, ft³ in Billions	3 Months Ended
	Mar. 31, 2020USD ($)	Jun. 28, 2019USD ($)ft³
Terminalling and storage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets classified as held for sale	$ 3,052
Transportation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets classified as held for sale	$ 1,300
Discontinued Operations, Disposed of by Sale | Natural Gas Storage Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Natural gas storage (in cubic feet) | ft³		50
Proceeds from sale of assets		$ 210,067

Divestitures and Discontinued_4

Divestitures and Discontinued Operations - Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income from discontinued operations, net of income taxes	$ 0	$ 1,102
Natural Gas Storage Assets | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		10,934
Total costs and expenses and other, net, excluding depreciation and amortization		(5,751)
Depreciation and amortization		(4,081)
Income from discontinued operations before income taxes		1,102
Income tax expense		0
Income from discontinued operations, net of income taxes		$ 1,102

Divestitures and Discontinued_5

Divestitures and Discontinued Operations - Long-Lived Assets Held-for-Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0	$ 5,052
Terminalling and storage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	0	3,552
Transportation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0	$ 1,500

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues		$ 198,883	$ 240,033
Lubricant product sales
Disaggregation of Revenue [Line Items]
Revenues		28,934	31,067
Throughput and storage
Disaggregation of Revenue [Line Items]
Revenues	[1]	20,474	23,104
Natural gas liquids product sales
Disaggregation of Revenue [Line Items]
Revenues		82,211	116,474
Sulfur services
Disaggregation of Revenue [Line Items]
Revenues		2,915	2,859
Terminalling and storage segment
Disaggregation of Revenue [Line Items]
Revenues		49,408	54,171
Terminalling and storage segment | Lubricant product sales
Disaggregation of Revenue [Line Items]
Revenues		28,934	31,067
Terminalling and storage segment | Throughput and storage
Disaggregation of Revenue [Line Items]
Revenues		20,474	23,104
Natural gas liquids segment
Disaggregation of Revenue [Line Items]
Revenues		82,211	116,474
Natural gas liquids segment | Natural gas liquids product sales
Disaggregation of Revenue [Line Items]
Revenues		82,211	116,474
Sulfur services segment
Disaggregation of Revenue [Line Items]
Revenues		28,323	31,593
Sulfur services segment | Sulfur product sales
Disaggregation of Revenue [Line Items]
Revenues		6,481	9,952
Sulfur services segment | Fertilizer product sales
Disaggregation of Revenue [Line Items]
Revenues		18,927	18,782
Sulfur services segment | Sulfur services
Disaggregation of Revenue [Line Items]
Revenues		2,915	2,859
Transportation segment
Disaggregation of Revenue [Line Items]
Revenues		38,941	37,795
Transportation segment | Land transportation
Disaggregation of Revenue [Line Items]
Revenues		24,234	24,119
Transportation segment | Inland transportation
Disaggregation of Revenue [Line Items]
Revenues		13,706	12,477
Transportation segment | Offshore transportation
Disaggregation of Revenue [Line Items]
Revenues		$ 1,001	$ 1,199
[1]	Related Party Transactions Included Above Three Months Ended March 31, 2020 2019 Revenues:* Terminalling and storage $ 15,874 $ 18,972 Transportation 5,894 5,643 Product Sales 92 421 Costs and expenses:* Cost of products sold: (excluding depreciation and amortization) Sulfur services 2,767 2,574 Terminalling and storage 5,777 5,909 Expenses: Operating expenses 21,771 22,536 Selling, general and administrative 8,312 8,535

Revenue - Estimated Revenue Exp

Revenue - Estimated Revenue Expected to be Recognized in Future (Details) $ in Thousands	Mar. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 558,011
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 38,835
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 48,639
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 43,614
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 43,780
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 43,829
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 339,314
Revenue, remaining performance obligation, expected timing of satisfaction, period
Terminalling and storage segment | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 541,064
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 34,599
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 43,273
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 40,394
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 41,605
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 42,854
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Terminalling and storage segment | Terminalling and storage | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 338,339
Revenue, remaining performance obligation, expected timing of satisfaction, period
Sulfur services segment | Sulfur product sales
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 16,947
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 4,236
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 5,366
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 3,220
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 2,175
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 975
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Sulfur services segment | Sulfur product sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 975
Revenue, remaining performance obligation, expected timing of satisfaction, period

Revenue - Estimated Revenue E_2

Revenue - Estimated Revenue Expected to be Recognized in Future Total (Details) $ in Thousands	Mar. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 558,011
Terminalling and storage | Terminalling and storage
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	541,064
Sulfur services segment | Sulfur product sales
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, remaining performance obligation	$ 16,947

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Natural gas liquids	$ 3,687	$ 19,097
Sulfur	4,443	4,586
Fertilizer	14,549	15,852
Lubricants	20,126	18,925
Other	4,025	4,080
Inventories	$ 46,830	$ 62,540

Debt (Details)

Debt (Details) - USD ($)	1 Months Ended	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2015	Apr. 30, 2014	Feb. 28, 2013
Debt Instrument
Total long-term debt	$ 529,667,000	$ 529,667,000		$ 569,788,000
Less: current portion	(364,124,000)	(364,124,000)		0
Total long-term debt, net of current portion	165,543,000	165,543,000		569,788,000
Current installments of long-term debt and finance lease obligations	5,114,000	5,114,000	$ 5,540,000	6,758,000
Finance lease obligations	526,000	526,000	4,886,000	717,000
Total finance lease obligations	5,640,000	5,640,000	10,426,000	7,475,000
Gain on retirement of senior unsecured notes		3,484,000	$ 0
Revolving Loan Facility
Debt Instrument
Total long-term debt	165,543,000	165,543,000		196,414,000
Face amount	$ 400,000,000	$ 400,000,000
Weighted average interest rate	3.93%	3.93%
Unamortized debt issuance costs	$ 4,457,000	$ 4,457,000		4,586,000
Revolving Loan Facility | LIBOR
Debt Instrument
Applicable margins		3.25%
Revolving Loan Facility | LIBOR | Minimum
Debt Instrument
Applicable margins		2.25%
Revolving Loan Facility | LIBOR | Maximum
Debt Instrument
Applicable margins		3.50%
Revolving Loan Facility | Prime Rate | Minimum
Debt Instrument
Applicable margins		1.25%
Revolving Loan Facility | Prime Rate | Maximum
Debt Instrument
Applicable margins		2.50%
Senior Notes | Senior Notes 7.25%
Debt Instrument
Total long-term debt	364,124,000	$ 364,124,000		373,374,000
Face amount	400,000,000	400,000,000				$ 150,000,000	$ 250,000,000
Unamortized debt issuance costs	$ 599,000	$ 599,000		770,000
Stated interest rate	7.25%	7.25%
Unamortized premium	$ 267,000	$ 267,000		$ 344,000
Repurchase amount	9,344,000	$ 9,344,000			$ 26,200,000
Gain on retirement of senior unsecured notes	$ 3,484,000

Debt - Narratives (Details)

Debt - Narratives (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Debt Disclosure [Abstract]
Cash paid for interest	$ 16,736	$ 19,363
Capitalized interest	$ 4	$ 2

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease termination term	1 year
Non-cancelable revenue arrangements, future minimum revenues, 2020	$ 14,386
Non-cancelable revenue arrangements, future minimum revenues, 2021	14,019
Non-cancelable revenue arrangements, future minimum revenues, 2022	13,004
Non-cancelable revenue arrangements, future minimum revenues, 2023	12,609
Non-cancelable revenue arrangements, future minimum revenues, 2024	12,609
Non-cancelable revenue arrangements, future minimum revenues, subsequent years	$ 49,414
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease term	1 year
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease term	17 years
Lease renewal term	5 years

Leases - Lease Costs (Details)

Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease cost	$ 6,296	$ 5,177
Finance lease cost:
Amortization of right-of-use assets	589	622
Interest on lease liabilities	110	183
Short-term lease cost	3,423	2,551
Total lease cost	$ 10,418	$ 8,533

Leases - Balance Sheet Informat

Leases - Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Operating Leases
Operating lease right-of-use assets	$ 25,771	$ 23,901	$ 23,901
Current portion of operating lease liabilities included in Other accrued liabilities	8,358	7,722	7,722
Operating lease liabilities	17,810	16,656	16,656
Total operating lease liabilities	26,168		24,378
Finance Leases
Property, plant and equipment, at cost	13,163		14,058
Accumulated depreciation	(3,634)		(1,888)
Property, plant and equipment, net	9,529		12,170
Current installments of finance lease obligations	5,114	6,758	5,540
Finance lease obligations	526	717	4,886
Total finance lease obligations	$ 5,640	$ 7,475	$ 10,426

Leases - Future Minimum Lease O

Leases - Future Minimum Lease Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Operating Leases
Year 1	$ 9,519
Year 2	7,113
Year 3	4,379
Year 4	1,978
Year 5	1,115
Thereafter	6,564
Total	30,668
Less amounts representing interest costs	(4,500)
Total lease liability	26,168		$ 24,378
Finance Leases
Year 1	5,307
Year 2	336
Year 3	213
Year 4	0
Year 5	0
Thereafter	0
Total	5,856
Less amounts representing interest costs	(216)
Total lease liability	$ 5,640	$ 7,475	$ 10,426

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Accrued interest	$ 3,538	$ 10,761
Asset retirement obligations	0	25
Property and other taxes payable	2,803	5,411
Accrued payroll	3,944	3,011
Operating lease liabilities	8,358	7,722	$ 7,722
Other	1,639	1,859
Total other accrued liabilities	$ 20,282	$ 28,789

Supplemental Balance Sheet In_4

Supplemental Balance Sheet Information - Asset Retirement Obligations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis
Beginning asset retirement obligations	$ 8,936
Additions to asset retirement obligations	379
Accretion expense	102
Liabilities settled	(510)
Ending asset retirement obligations	8,907
Current portion of asset retirement obligations	0	$ (25)
Long-term portion of asset retirement obligations	$ 8,907

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Narrative (Details) - bbl bbl in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Commodity contracts
Derivatives, Fair Value
Notional quantity (in bbl)	25	452

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Balance Sheet Derivatives (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value
Derivative Assets	$ 2	$ 0
Derivative Liabilities	0	667
Commodity contracts | Fair value of derivatives
Derivatives, Fair Value
Derivative Assets	2	0
Derivative Liabilities	$ 0	$ 667

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Statement of Operations Derivatives (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ 33	$ (239)
Commodity contracts | Cost of products sold
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in Income on Derivatives	$ 33	$ (239)

Partners' Capital - Narrative (

Partners' Capital - Narrative (Details)	3 Months Ended
	Mar. 31, 2020shares
Limited Partners' Capital Account
Common limited partner units (in shares)	38,852,507
Martin Resource Management Corporation | Martin Resource Management
Limited Partners' Capital Account
Voting interest percentage	51.00%
Martin Resource Management
Limited Partners' Capital Account
Common limited partner units (in shares)	6,114,532
Voting interest percentage	15.70%
Martin Resource Management Corporation
Limited Partners' Capital Account
Ownership interest (percentage)	98.00%
MMGP LLC
Limited Partners' Capital Account
General partner interest percentage	2.00%
MMGP LLC | Martin Resource Management
Limited Partners' Capital Account
Ownership interest (percentage)	15.70%
General partner interest percentage	2.00%

Partners' Capital - Incentive D

Partners' Capital - Incentive Distribution Rights and Distributions of Available Cash (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Limited Partners' Capital Account
Distribution period	45 days
MMGP
Limited Partners' Capital Account
Incentive distribution	$ 0	$ 0
MMGP | Target Level 1
Limited Partners' Capital Account
Target cash distribution, percent	2.00%
MMGP | Target Level 2
Limited Partners' Capital Account
Target cash distribution, percent	15.00%
Target cash distribution (USD per share)	$ 0.625
MMGP | Target Level 3
Limited Partners' Capital Account
Target cash distribution, percent	25.00%
Target cash distribution (USD per share)	$ 0.75
MMGP | Target Level 4
Limited Partners' Capital Account
Target cash distribution, percent	50.00%
Minimum | MMGP | Target Level 1
Limited Partners' Capital Account
Target cash distribution (USD per share)	$ 0.50
Minimum | MMGP | Target Level 2
Limited Partners' Capital Account
Target cash distribution (USD per share)	0.55
Minimum | MMGP | Target Level 3
Limited Partners' Capital Account
Target cash distribution (USD per share)	0.625
Minimum | MMGP | Target Level 4
Limited Partners' Capital Account
Target cash distribution (USD per share)	0.75
Maximum | MMGP | Target Level 1
Limited Partners' Capital Account
Target cash distribution (USD per share)	$ 0.55
Martin Operating Partnership L.P. | MMGP
Limited Partners' Capital Account
General partner interest percentage	2.00%

Partners' Capital - Net Income

Partners' Capital - Net Income Per Unit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Schedule of Reconciliation of Net Income from Continuing and Discontinuing Operations [Line Items]
Income (loss) from continuing operations	$ 8,815	$ (4,758)
Income from discontinued operations	0	1,102
Less general partner’s interest in net income (loss):
Less income (loss) allocable to unvested restricted units	55	(2)
Limited partners’ interest in net income (loss)	$ 8,584	$ (3,581)
Basic weighted average limited partner units outstanding (in shares)	38,640,862	38,681,925
Dilutive effect of restricted units issued (in shares)	3,605	0
Total weighted average limited partner diluted units outstanding (in shares)	38,644,467	38,681,925
Continuing operations
Less general partner’s interest in net income (loss):
Distributions payable on behalf of general partner interest	$ (49)	$ (256)
General partner interest in undistributed income (loss)	127	(351)
Less income (loss) allocable to unvested restricted units	55	(3)
Limited partners’ interest in net income (loss)	8,584	(4,660)
Discontinued operations
Less general partner’s interest in net income (loss):
Distributions payable on behalf of general partner interest	0	(59)
General partner interest in undistributed income (loss)	0	81
Less income (loss) allocable to unvested restricted units	0	1
Limited partners’ interest in net income (loss)	$ 0	$ 1,079

Unit Based Awards - Schedule of

Unit Based Awards - Schedule of Compensation Costs (Details) - Selling, General and Administrative Expenses - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 346	$ 352
Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	301	329
Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unit-based compensation expense	$ 45	$ 23

Unit Based Awards - Narrative (

Unit Based Awards - Narrative (Details) $ in Thousands	Jan. 24, 2023shares	Jan. 24, 2022shares	Jan. 24, 2021shares	Mar. 01, 2018shares	Feb. 29, 2020directorshares	Mar. 31, 2020USD ($)shares	May 26, 2017shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)							3,000,000
Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of units (in shares)						101,128
Unrecognized compensation cost related to non-vested restricted units | $						$ 1,613
Weighted average period for recognition (in years)						1 year 6 months 3 days
Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						3 years
Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						4 years
Time Based Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						3 years
Granted, number of units (in shares)						81,000
Number of independent directors receiving grants | director					3
Time Based Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)				301,550
Time Based Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)					27,000
Performance Based Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)						3 years
Performance Based Restricted Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, number of units (in shares)				317,925
Scenario, Forecast | Time Based Restricted Units | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested, number of units (in shares)	6,750	6,750	6,750

Unit Based Awards - Restricted

Unit Based Awards - Restricted Unit Activity (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)$ / sharesshares
Restricted Units
Number of Units
Non-vested, beginning of period, number of units (in shares) | shares	379,019
Vested, number of units (in shares) | shares	(101,128)
Forfeited, number of units (in shares) | shares	(84,134)
Non-vested, end of period, number of units (in shares) | shares	274,757
Weighted Average Grant-Date Fair Value Per Unit
Non-vested, beginning of period, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 13.91
Vested, weighted average grant-date fair value per unit (USD per share) | $ / shares	13.95
Forfeited, weighted average grant-date fair value per unit (USD per share) | $ / shares	13.90
Non-vested, end of period, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 10.54
Aggregate intrinsic value, end of period | $	$ 302
Time Based Restricted Units
Number of Units
Granted, number of units (in shares) | shares	81,000
Weighted Average Grant-Date Fair Value Per Unit
Granted, weighted average grant-date fair value per unit (USD per share) | $ / shares	$ 2.53

Unit Based Awards - Intrinsic a

Unit Based Awards - Intrinsic and Fair Value (Details) - Restricted Units - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of units vested	$ 151	$ 1,351
Fair value of units vested	$ 1,427	$ 1,551

Related Party Transactions - Na

Related Party Transactions - Narrative (Details)	3 Months Ended
	Mar. 31, 2020shares
MMGP LLC
Related Party Transaction
General partner interest percentage	2.00%
Martin Resource Management
Related Party Transaction
Common limited partner units (in shares)	6,114,532
Voting interest percentage	15.70%
Martin Resource Management | Martin Resource Management | MMGP Holdings, LLC
Related Party Transaction
General partner interest percentage	51.00%
Martin Resource Management | MMGP LLC
Related Party Transaction
General partner interest percentage	2.00%

Related Party Transactions - Om

Related Party Transactions - Omnibus Agreement (Details) - Omnibus Agreement - Martin Resource Management - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Related Party Transaction
Noncompete restriction threshold	$ 5,000,000
Noncompete restriction ownership option opportunity threshold minimum	5,000,000
Noncompete restriction ownership option opportunity threshold minimum with equity limitation	$ 5,000,000
Equity limitation on ownership restriction percentage	20.00%
Approved annual reimbursements for indirect expenses			$ 16,410,000
Indirect expenses reimbursed	$ 4,103,000	$ 4,164,000

Related Party Transactions - Ma

Related Party Transactions - Master Transportation Services Agreement (Details)	3 Months Ended
	Mar. 31, 2020
Master Transportation Services Agreement | Martin Resource Management
Related Party Transaction
Termination written notice, minimum (in days)	30 days

Related Party Transactions - _2

Related Party Transactions - Marine Agreements (Details) - Marine Transportation Agreement - Martin Resource Management	3 Months Ended
	Mar. 31, 2020
Related Party Transaction
Automatic consecutive term renewal period (in years)	1 year
Termination written notice, minimum (in days)	60 days

Related Party Transactions - Te

Related Party Transactions - Terminal Services Agreements (Details)	3 Months Ended
	Mar. 31, 2020
Terminal Services Agreements | Martin Resource Management
Related Party Transaction
Termination written notice, minimum (in days)	60 days

Related Party Transactions - Ot

Related Party Transactions - Other Agreements (Details) - Martin Resource Management - Cross Tolling Agreement $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Mar. 31, 2020bbl	Dec. 31, 2019USD ($)
Related Party Transaction
Production minimum per day (in bbl) | bbl		6,500
Capital recovery fee reimbursement, expired			$ 2,088
Annual escalation benchmark percentage		3.00%
Scenario, Forecast
Related Party Transaction
Capital recovery fee reimbursement, expired	$ 2,586
Annual revenue decrease from contract expiration	$ 2,145

Related Party Transactions - Sc

Related Party Transactions - Schedule of the Impact of Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Operating expenses	$ 21,771	$ 22,536
Related Party
Revenues:
Revenue from related parties	21,860	25,036
Cost of products sold:
Cost of products sold	8,544	8,483
Operating expenses:
Operating expenses	21,771	22,536
Selling, general and administrative:
Selling, general and administrative	8,312	8,535
Related Party | Indirect, including overhead allocation
Selling, general and administrative:
Selling, general and administrative	4,188	4,185
Related Party | Product sales
Revenues:
Revenue from related parties	92	421
Related Party | Terminalling and storage
Operating expenses:
Operating expenses	4,575	4,607
Related Party | Terminalling and storage | Operating segments
Selling, general and administrative:
Selling, general and administrative	838	717
Related Party | Terminalling and storage | Terminalling and storage
Revenues:
Revenue from related parties	15,874	18,972
Related Party | Terminalling and storage | Terminalling and storage
Revenues:
Revenue from related parties	73	414
Cost of products sold:
Cost of products sold	5,777	5,909
Related Party | Transportation
Operating expenses:
Operating expenses	15,553	14,980
Related Party | Transportation | Operating segments
Selling, general and administrative:
Selling, general and administrative	1,839	1,728
Related Party | Transportation | Transportation
Revenues:
Revenue from related parties	5,894	5,643
Related Party | Natural gas liquids
Operating expenses:
Operating expenses	497	2,025
Related Party | Natural gas liquids | Operating segments
Selling, general and administrative:
Selling, general and administrative	704	1,189
Related Party | Sulfur services
Operating expenses:
Operating expenses	1,146	924
Related Party | Sulfur services | Operating segments
Selling, general and administrative:
Selling, general and administrative	743	716
Related Party | Sulfur services | Sulfur services
Revenues:
Revenue from related parties	19	7
Cost of products sold:
Cost of products sold	$ 2,767	$ 2,574

Business Segments - Narratives

Business Segments - Narratives (Details)	3 Months Ended
	Mar. 31, 2020segment
Business Combinations [Abstract]
Number of reportable segments	4

Business Segments - Income Stat

Business Segments - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Total revenue	$ 198,883	$ 240,033
Depreciation and Amortization	15,239	14,901
Operating Income (Loss) after Eliminations	15,600	9,606
Capital Expenditures and Plant Turnaround Costs	10,761	10,299
Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	49,408	54,171
Depreciation and Amortization	7,456	7,837
Operating Income (Loss) after Eliminations	758	4,815
Capital Expenditures and Plant Turnaround Costs	3,745	5,345
Transportation
Segment Reporting Information [Line Items]
Total revenue	38,941	37,795
Depreciation and Amortization	4,280	3,570
Operating Income (Loss) after Eliminations	(5,021)	(3,880)
Capital Expenditures and Plant Turnaround Costs	3,926	2,461
Sulfur services
Segment Reporting Information [Line Items]
Total revenue	28,323	31,593
Depreciation and Amortization	2,894	2,868
Operating Income (Loss) after Eliminations	13,858	6,380
Capital Expenditures and Plant Turnaround Costs	2,985	2,206
Natural gas liquids
Segment Reporting Information [Line Items]
Total revenue	82,211	116,474
Depreciation and Amortization	609	626
Operating Income (Loss) after Eliminations	10,377	6,858
Capital Expenditures and Plant Turnaround Costs	105	287
Operating Revenues
Segment Reporting Information [Line Items]
Total revenue	206,859	249,145
Operating Revenues | Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	51,134	55,892
Operating Revenues | Transportation
Segment Reporting Information [Line Items]
Total revenue	45,174	45,186
Operating Revenues | Sulfur services
Segment Reporting Information [Line Items]
Total revenue	28,336	31,593
Operating Revenues | Natural gas liquids
Segment Reporting Information [Line Items]
Total revenue	82,215	116,474
Intersegment Revenues Eliminations
Segment Reporting Information [Line Items]
Total revenue	(7,976)	(9,112)
Intersegment Revenues Eliminations | Terminalling and storage
Segment Reporting Information [Line Items]
Total revenue	(1,726)	(1,721)
Intersegment Revenues Eliminations | Transportation
Segment Reporting Information [Line Items]
Total revenue	(6,233)	(7,391)
Intersegment Revenues Eliminations | Sulfur services
Segment Reporting Information [Line Items]
Total revenue	(13)	0
Intersegment Revenues Eliminations | Natural gas liquids
Segment Reporting Information [Line Items]
Total revenue	(4)	0
Indirect selling, general and administrative
Segment Reporting Information [Line Items]
Depreciation and Amortization	0	0
Operating Income (Loss) after Eliminations	(4,372)	(4,567)
Capital Expenditures and Plant Turnaround Costs	$ 0	$ 0

Business Segments - Balance She

Business Segments - Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Total assets:
Total assets	$ 612,199	$ 667,156
Terminalling and storage
Total assets:
Total assets	288,915	292,136
Transportation
Total assets:
Total assets	170,274	170,045
Sulfur services
Total assets:
Total assets	112,709	110,780
Natural gas liquids
Total assets:
Total assets	$ 40,301	$ 94,195

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Recurring | Level 2 | Commodity Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative contracts, net	$ 2
Commodity derivative contracts, net		$ (667)
Nonrecurring | 2021 Notes | Carrying Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2021 Notes	364,124	373,374
Nonrecurring | 2021 Notes | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2021 Notes	$ 146,825	$ 343,470

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income taxes	$ 347	$ 696

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Income Tax Contingency
Income tax expense	$ 347	$ 696
Effective income tax rate (percentage)	32.17%	24.79%
Current federal income tax expense	$ 133	$ 297
State income tax expense (benefit)	(72)	(218)
Deferred income tax expense	286	369
Deferred tax asset	23,136		$ 23,422
Martin Transport Inc
Income Tax Contingency
Income tax expense	$ 347	$ 448

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event	Apr. 22, 2020$ / shares
Subsequent Event [Line Items]
Dividends declared (USD per share)	$ 0.0625
Estimated annualized dividends (USD per share)	$ 0.25