Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014 bu	Dec. 31, 2013 bu	Sep. 30, 2013 bu
Inventory, Net [Abstract]
Grain	$ 227,014	$ 432,893	$ 264,104
Ethanol and by-products	9,696	14,453	11,178
Agricultural fertilizer and supplies	90,907	100,593	94,035
Lawn and garden fertilizer and corncob products	37,666	39,960	29,364
Retail merchandise	25,647	22,505	25,716
Railcar repair parts	5,336	4,312	4,421
Other	198	207	199
Total inventories	$ 396,464	$ 614,923	$ 429,017
Bushels of grain held in storage and excluded from inventory calculations	2,000,000	13,300,000	4,700,000