Net Income Per Common Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 01, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Class A convertible preferred units issued (in shares)	22,411,728								22,411,728
Net Income Attributable to Genesis Energy L.P.	$ 15,512	$ 6,312	$ 33,733	$ 27,090	$ 22,118	$ 32,101	$ 23,727	$ 35,303	$ 82,647	$ 113,249	$ 422,528
Less: Accumulated distributions attributable to Class A Convertible Preferred Units									(21,995)	0	0
Net Income Available to Common Unitholders									$ 60,652	$ 113,249	$ 422,528
Weighted Average Outstanding Units (in units)									121,546,000	113,433,000	103,004,000
Basic and Diluted (in dollars per unit)									$ 0.50	$ 1.00	$ 4.10
Private Placement [Member] | Convertible Preferred Stock [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Class A convertible preferred units issued (in shares)	22,411,728								22,411,728			22,249,494
Alkali Business [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Basic and Diluted (in dollars per unit)									$ 0.50	$ 1.00	$ 4.10