Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2011	Mar. 31, 2011 Segments	Sep. 30, 2010	Sep. 30, 2011 Person Segments	Sep. 30, 2010
Segment Reporting Information [Line Items]
Revenues from external customers	$ 938,660		$ 706,825	$ 3,278,501	$ 2,239,822
Inter-segment sales	4,653		2,223	14,968	10,551
Equity in earnings (loss) of affiliates	9,731		(1,096)	29,489	15,476
Other income (loss), net	1,217		3,561	5,541	9,096
Interest expense	5,711		4,625	20,609	13,923
Operating income (loss) (a)	15,409		1,832	113,674	63,234
Net (income) loss attributable to the noncontrolling interest	(306)		1,026	(1,245)	25
Income (loss) before income taxes	15,715		806	114,919	63,209
Segment Information (Textuals) [Abstract]
Number of reportable segments		2		6
Grain [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	538,723		388,981	1,973,820	1,151,984
Inter-segment sales	1			3	2
Equity in earnings (loss) of affiliates	6,459		1,538	18,117	6,869
Other income (loss), net	652		664	1,754	1,918
Interest expense	2,674		1,952	11,373	4,183
Operating income (loss) (a)	8,313		3,220	59,955	28,791
Income (loss) before income taxes	8,313		3,220	59,955	28,791
Ethanol [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	179,331		109,264	476,783	340,830
Equity in earnings (loss) of affiliates	3,270		(2,635)	11,366	8,602
Other income (loss), net	38		45	133	88
Interest expense	194		468	880	920
Operating income (loss) (a)	4,443		(764)	16,844	14,003
Net (income) loss attributable to the noncontrolling interest	(306)		1,026	(1,245)	25
Income (loss) before income taxes	4,749		(1,790)	18,089	13,978
Rail [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	24,067		22,314	82,478	72,639
Inter-segment sales	111		144	486	445
Other income (loss), net	604		1,782	2,198	4,090
Interest expense	1,614		1,279	4,572	3,923
Operating income (loss) (a)	1,123		85	7,432	1,225
Income (loss) before income taxes	1,123		85	7,432	1,225
Plant Nutrient [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	137,637		129,109	521,109	460,671
Inter-segment sales	4,224		1,828	12,830	8,820
Equity in earnings (loss) of affiliates	2		1	6	5
Other income (loss), net	282		233	541	866
Interest expense	940		1,065	2,756	3,331
Operating income (loss) (a)	6,622		1,462	35,813	21,198
Income (loss) before income taxes	6,622		1,462	35,813	21,198
Turf and Specialty [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	23,051		23,156	111,872	105,971
Inter-segment sales	317		251	1,649	1,284
Other income (loss), net	167		244	716	1,038
Interest expense	273		337	1,094	1,379
Operating income (loss) (a)	(1,245)		(291)	3,811	4,859
Income (loss) before income taxes	(1,245)		(291)	3,811	4,859
Retail [Member]
Segment Reporting Information [Line Items]
Revenues from external customers	35,851		34,001	112,439	107,727
Other income (loss), net	130		128	430	404
Interest expense	238		312	705	868
Operating income (loss) (a)	(1,233)		(1,651)	(2,020)	(2,400)
Income (loss) before income taxes	(1,233)		(1,651)	(2,020)	(2,400)
Other [Member]
Segment Reporting Information [Line Items]
Other income (loss), net	(656)		465	(231)	692
Interest expense	(222)		(788)	(771)	(681)
Operating income (loss) (a)	(2,614)		(229)	(8,161)	(4,442)
Income (loss) before income taxes	$ (2,614)		$ (229)	$ (8,161)	$ (4,442)