Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Sales and merchandising revenues	$ 1,584,266		$ 1,181,374	$ 1,566,964	$ 1,271,970	$ 1,680,641		$ 1,138,402	$ 1,315,834	$ 1,137,133	$ 5,604,574		$ 5,272,010		$ 4,576,331
Inter-segment sales											20,220		19,516		19,184
Interest expense (income)											20,860		22,155		25,256
Equity in earnings of affiliates, net											68,705		16,487		41,450
Other income, net											14,876		14,725		7,922
Income (loss) before income taxes											149,513		120,133		147,878
Identifiable assets	2,273,556					2,182,304					2,273,556		2,182,304		1,734,123
Capital expenditures											46,786		69,017		44,162
Payments to Acquire Businesses and Interest in Affiliates											64,501		220,257		2,486
Depreciation and amortization											55,307		48,977		40,837
Grain
Segment Reporting Information [Line Items]
Sales and merchandising revenues											3,617,943		3,293,632		2,849,358
Inter-segment sales											1		409		2
Interest expense (income)											9,567		12,174		13,277
Equity in earnings of affiliates, net											33,122		29,080		23,748
Other income, net											2,120		2,548		2,462
Income (loss) before income taxes											46,805		63,597		87,288
Identifiable assets	921,914	[1]				1,076,986	[1]				921,914	[1]	1,076,986	[1]	883,395	[1]
Capital expenditures											8,535		30,178		24,284
Payments to Acquire Businesses and Interest in Affiliates											51,544		116,888		0
Depreciation and amortization											15,620	[2]	9,554	[2]	9,625	[2]
Ethanol
Segment Reporting Information [Line Items]
Sales and merchandising revenues											831,965		742,929		641,546
Interest expense (income)											1,038		759		1,048
Equity in earnings of affiliates, net											35,583		(12,598)		17,715
Other income, net											399		53		159
Income (loss) before income taxes											50,600		(3,720)		23,344
Identifiable assets	229,797	[3]				206,975	[3]				229,797	[3]	206,975	[3]	148,975	[3]
Capital expenditures											4,052		1,966		0
Payments to Acquire Businesses and Interest in Affiliates											0		77,400		0
Depreciation and amortization											5,909	[4]	5,003	[4]	382	[4]
Plant Nutrient
Segment Reporting Information [Line Items]
Sales and merchandising revenues											708,654		797,033		690,631
Inter-segment sales											17,537		16,135		16,527
Interest expense (income)											3,312		2,832		3,517
Equity in earnings of affiliates, net											0		5		(13)
Other income, net											1,093		1,917		704
Income (loss) before income taxes											27,275		39,254		38,267
Identifiable assets	268,238	[3]				257,980	[3]				268,238	[3]	257,980	[3]	240,543	[3]
Capital expenditures											17,094		18,038		13,296
Payments to Acquire Businesses and Interest in Affiliates											0		15,286		2,386
Depreciation and amortization											14,143		12,014		9,913
Rail
Segment Reporting Information [Line Items]
Sales and merchandising revenues											164,794		156,426		107,459
Inter-segment sales											427		622		593
Interest expense (income)											5,544		4,807		5,677
Other income, net											7,666		7,136		2,866
Income (loss) before income taxes											42,785		42,841		9,778
Identifiable assets	312,654	[3]				289,467	[3]				312,654	[3]	289,467	[3]	246,188	[3]
Capital expenditures											4,135		3,896		1,478
Payments to Acquire Businesses and Interest in Affiliates											7,804		0		0
Depreciation and amortization											12,031		15,929		14,780
Turf & Specialty
Segment Reporting Information [Line Items]
Sales and merchandising revenues											140,512		131,026		129,716
Inter-segment sales											2,255		2,350		2,062
Interest expense (income)											1,237		1,233		1,381
Other income, net											690		784		880
Income (loss) before income taxes											4,744		2,216		2,000
Identifiable assets	89,939	[3]				82,683	[3]				89,939	[3]	82,683	[3]	69,487	[3]
Capital expenditures											6,563		5,043		2,089
Payments to Acquire Businesses and Interest in Affiliates											4,103		10,683		0
Depreciation and amortization											3,070		2,117		1,801
Retail
Segment Reporting Information [Line Items]
Sales and merchandising revenues											140,706		150,964		157,621
Interest expense (income)											689		776		899
Other income, net											501		554		638
Income (loss) before income taxes											(7,534)		(3,951)		(1,520)
Identifiable assets	44,910	[5]				51,772	[5]				44,910	[5]	51,772	[5]	52,018	[5]
Capital expenditures											2,944		2,794		1,230
Depreciation and amortization											3,119		3,002		2,770
Other Segments
Segment Reporting Information [Line Items]
Interest expense (income)											(527)		(426)		(543)
Other income, net											2,407		1,733		213
Income (loss) before income taxes											(20,925)		(16,189)		(12,998)
Identifiable assets	406,104	[6]				216,441	[6]				406,104	[6]	216,441	[6]	93,517	[6]
Capital expenditures											3,463		7,102		1,785
Payments to Acquire Businesses and Interest in Affiliates											1,050		0		100
Depreciation and amortization											1,415		1,358		1,566
Noncontrolling interests
Segment Reporting Information [Line Items]
Income (loss) before income taxes											$ 5,763		$ (3,915)		$ 1,719

[1] Decrease related to impact of prices on receivables and commodity derivative assets and lower inventory levels

[2] Increase driven by acquisition of GPG in December 2012

[3] See Note 12. Business Acquisitions for identifiable assets acquired during the periods presented

[4] Increase driven by acquisition of TADE in May 2012

[5] Decrease related to closing of the Woodville store in the first quarter of 2013 and asset impairments described in Note 3. Property, Plant, and Equipment

[6] Change driven by increase in cash and cash equivalents and capitalized software