Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Amortized intangible assets
Amortized intangible assets ,Original Cost	$ 40,859	$ 20,220
Amortized intangible assets, Accumulated Amortization	14,798	10,105
Finite-Lived Intangible Assets, Net, Total	26,061	10,115
Rail | Acquired customer list
Amortized intangible assets
Amortized intangible assets ,Original Cost	3,462	3,462
Amortized intangible assets, Accumulated Amortization	3,362	3,331
Finite-Lived Intangible Assets, Net, Total	100	131
Rail | Lease intangible
Amortized intangible assets
Amortized intangible assets ,Original Cost	2,410	2,222
Amortized intangible assets, Accumulated Amortization	1,778	1,433
Finite-Lived Intangible Assets, Net, Total	632	789
Plant Nutrient | Acquired customer list
Amortized intangible assets
Amortized intangible assets ,Original Cost	9,596	4,096
Amortized intangible assets, Accumulated Amortization	2,071	1,098
Finite-Lived Intangible Assets, Net, Total	7,525	2,998
Plant Nutrient | Acquired non-compete agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	2,119	1,319
Amortized intangible assets, Accumulated Amortization	1,219	847
Finite-Lived Intangible Assets, Net, Total	900	472
Plant Nutrient | Acquired marketing agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	1,607	1,607
Amortized intangible assets, Accumulated Amortization	1,029	825
Finite-Lived Intangible Assets, Net, Total	578	782
Plant Nutrient | Acquired supply agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	4,846	4,846
Amortized intangible assets, Accumulated Amortization	1,959	1,443
Finite-Lived Intangible Assets, Net, Total	2,887	3,403
Plant Nutrient | Trademarks and Technology
Amortized intangible assets
Amortized intangible assets ,Original Cost	3,300
Amortized intangible assets, Accumulated Amortization	495
Finite-Lived Intangible Assets, Net, Total	2,805
Grain | Acquired customer list
Amortized intangible assets
Amortized intangible assets ,Original Cost	8,450	1,250
Amortized intangible assets, Accumulated Amortization	717	433
Finite-Lived Intangible Assets, Net, Total	7,733	817
Grain | Acquired non-compete agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	175	175
Amortized intangible assets, Accumulated Amortization	81	46
Finite-Lived Intangible Assets, Net, Total	94	129
Grain | Acquired supply agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	340
Amortized intangible assets, Accumulated Amortization	0
Finite-Lived Intangible Assets, Net, Total	340
Grain | Acquired grower agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	300	300
Amortized intangible assets, Accumulated Amortization	275	175
Finite-Lived Intangible Assets, Net, Total	25	125
Turf & Specialty | Acquired customer list
Amortized intangible assets
Amortized intangible assets ,Original Cost	600
Amortized intangible assets, Accumulated Amortization	10
Finite-Lived Intangible Assets, Net, Total	590
Turf & Specialty | Acquired non-compete agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	100
Amortized intangible assets, Accumulated Amortization	2
Finite-Lived Intangible Assets, Net, Total	98
Ethanol | Acquired non-compete agreement
Amortized intangible assets
Amortized intangible assets ,Original Cost	250
Amortized intangible assets, Accumulated Amortization	84
Finite-Lived Intangible Assets, Net, Total	166
Ethanol | Lease intangible
Amortized intangible assets
Amortized intangible assets ,Original Cost	2,123
Amortized intangible assets, Accumulated Amortization	1,230
Finite-Lived Intangible Assets, Net, Total	893
Various | Patents and other
Amortized intangible assets
Amortized intangible assets ,Original Cost	1,181	943
Amortized intangible assets, Accumulated Amortization	486	474
Finite-Lived Intangible Assets, Net, Total	$ 695	$ 469