Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Goodwill [Line Items]
Goodwill impairment	$ 0		$ 0	$ 42,000	$ 0
Goodwill	23,105		$ 63,934	23,105	$ 63,934	$ 63,934
Plant Nutrient
Goodwill [Line Items]
Goodwill impairment				42,000
Goodwill	17,767			17,767		$ 59,767
Plant Nutrient | Wholesale
Goodwill [Line Items]
Goodwill impairment		$ 42,000
Goodwill	$ 17,100			$ 17,100