Acquisition (Schedule of Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
As reported net income per unit (in dollars per share)	$ (0.05)	$ 0.28	$ (0.12)	$ 0.50
Alkali Business
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Revenues		$ 608,000		$ 1,214,100
Net Income Attributable to Genesis Energy, L.P.		45,435		81,925
Net Income Available to Common Unitholders		$ 28,670		$ 48,753
As reported net income per unit (in dollars per share)		$ 0.28		$ 0.50
Pro forma net income per unit (in dollars per share)		$ 0.23		$ 0.40