CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL - USD ($) $ in Thousands		3 Months Ended						12 Months Ended
		Dec. 31, 2019	Mar. 31, 2019		Dec. 31, 2018		Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	[2]		$ 288,432	[1]			$ 322,481	$ 288,432	[1]	$ 322,481		$ 331,060
Net income (loss)		$ 6,642	$ (3,656)		$ 2,582		$ 15,036	(174,946)		55,655	[3],[4]	19,916	[3],[4]
Issuance of common units, net								(289)		(118)		51,056
Issuance of restricted units												0
Forfeiture of restricted units								0		0		0
General partner contribution												1,098
Cash distributions								(49,093)		(78,441)		(76,938)
Deemed contribution from Martin Resource Management Corporation										(12,070)		(2,405)
Reimbursement of excess purchase price over carrying value of acquired assets												1,125
Excess carrying value of the assets over the purchase price paid by Martin Resource Management												(7,887)
Excess purchase price over carrying value of acquired assets								(102,393)		(26)
Deferred taxes on acquired assets and liabilities								24,781
Unit-based compensation								1,424		1,224		650
Purchase of treasury units								(392)		(273)		(4)
Contribution to parent								(23,720)
Ending balance		$ (36,196)			$ 288,432	[1],[2]		$ (36,196)		$ 288,432	[1],[2]	$ 322,481	[2]
Common | Common
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)	[2]		39,032,237				38,444,612	39,032,237		38,444,612		35,452,062
Beginning balance	[2]		$ 258,085				$ 290,927	$ 258,085		$ 290,927		$ 304,594
Net income (loss)								(171,447)		43,223		$ 16,792
Issuance of common units, net (in shares)												2,990,000
Issuance of common units, net								$ (289)		$ (118)		$ 51,056
Issuance of restricted units (in shares)												12,000
Forfeiture of restricted units (in shares)								(154,288)		(27,000)		(9,250)
Cash distributions								$ (48,111)		$ (76,872)		$ (75,399)
Reimbursement of excess purchase price over carrying value of acquired assets												1,125
Excess carrying value of the assets over the purchase price paid by Martin Resource Management												(7,887)
Excess purchase price over carrying value of acquired assets								(102,393)		(26)
Deferred taxes on acquired assets and liabilities								24,781
Unit-based compensation								$ 1,424		$ 1,224		$ 650
Purchase of treasury units (in shares)								(31,504)		(18,800)		(200)
Purchase of treasury units								$ (392)		$ (273)		$ (4)
Ending balance (in shares)		38,863,389			39,032,237	[2]		38,863,389		39,032,237	[2]	38,444,612	[2]
Ending balance		$ (38,342)			$ 258,085	[2]		$ (38,342)		$ 258,085	[2]	$ 290,927	[2]
General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	[2]		6,627				7,314	6,627		7,314		7,412
Net income (loss)								(3,499)		882		343
General partner contribution												1,098
Cash distributions								(982)		(1,569)		(1,539)
Ending balance		2,146			6,627	[2]		2,146		6,627	[2]	7,314	[2]
Time Based Restricted Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of restricted units								$ 0		$ 0
Time Based Restricted Units | Common | Common
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of restricted units (in shares)								16,944		315,500
Performance Based Restricted Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of restricted units										$ 0
Performance Based Restricted Units | Common | Common
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of restricted units (in shares)										317,925
Parent Net Investment
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance	[2]		$ 23,720				$ 24,240	$ 23,720		$ 24,240		19,054
Net income (loss)										11,550		2,781
Deemed contribution from Martin Resource Management Corporation										(12,070)
Contribution to parent								(23,720)
Ending balance		$ 0			$ 23,720	[2]		$ 0		$ 23,720	[2]	$ 24,240	[2]

[1] Financial information has been revised to include results attributable to MTI acquired from Martin Resource Management Corporation. See Note 2 – Significant Accounting Policies and Practices.

[2] Financial information has been revised to include results attributable to MTI acquired from Martin Resource Management Corporation. See Note 2 – Significant Accounting Policies and Practices.

[3] Financial information has been revised to include results attributable to MTI acquired from Martin Resource Management Corporation. See Note 2 – Significant Accounting Policies and Practices.

[4] Financial information has been revised to include results attributable to MTI acquired from Martin Resource Management Corporation. See Note 2 – Significant Accounting Policies and Practices.