Goodwill and Other Intangible Assets (Textual) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill		$ 6,024,000	$ 6,024,000	$ 63,934,000	$ 63,934,000
Goodwill impairment		0	59,081,000	0
Amortization expense for intangible assets		19,100,000	18,100,000	16,800,000
Expected future annual amortization expense of intangibles in 2019		19,500,000
Expected future annual amortization expense of intangibles in 2020		17,700,000
Expected future annual amortization expense of intangibles in 2021		16,400,000
Expected future annual amortization expense of intangibles in 2022		14,400,000
Expected future annual amortization expense of intangibles in 2023		12,900,000
Grain
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill		1,171,000		0	0
Goodwill, accumulated impairment loss		46,400,000
Goodwill impairment			0
Plant Nutrient
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill		686,000	686,000	$ 59,767,000	$ 59,767,000
Goodwill, accumulated impairment loss		$ 68,900,000
Goodwill impairment			59,081,000
Plant Nutrient | Wholesale
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Goodwill impairment	$ 42,000,000.0		$ 17,100,000
Long-term earnings growth percentage used to determine impairment or reporting unit			2.00%
Weighted average cost of capital percentage used to determine impairment or reporting unit			10.40%