Inventories (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014 bu	Dec. 31, 2013 bu	Jun. 30, 2013 bu
Inventory, Net [Abstract]
Grain	$ 290,595	$ 432,893	$ 303,018
Ethanol and by-products	16,798	14,453	17,966
Agricultural fertilizer and supplies	64,971	100,593	71,226
Lawn and garden fertilizer and corncob products	30,151	39,960	23,434
Retail merchandise	25,180	22,505	25,389
Railcar repair parts	5,107	4,312	3,293
Other	194	207	197
Total inventories	$ 432,996	$ 614,923	$ 444,523
Bushels of grain held in storage and excluded from inventory calculations	3,700,000	13,300,000	2,500,000