Notes Payable and Long-Term Debt - Footnote Narrative (Details) (USD $)							12 Months Ended						12 Months Ended		12 Months Ended									12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012 Notes payable Line of credit Revolving credit facility		Aug. 31, 2011 Notes payable Line of credit Revolving credit facility		Aug. 31, 2012 Three-year revolving facilities Line of credit Revolving credit facility	Aug. 31, 2012 Five-year revolving facilities Line of credit Revolving credit facility	Aug. 31, 2011 Five-year revolving facilities Line of credit Revolving credit facility	Aug. 31, 2012 Three-year and five-year revolving facilities Line of credit Revolving credit facility Lines_of_credit	Aug. 31, 2011 Two revolving lines of credit Line of credit Revolving credit facility	Oct. 31, 2011 Additional revolving lines of credit Line of credit Revolving credit facility Lines_of_credit	Aug. 31, 2012 Additional revolving lines of credit, 364 day revolving facility Line of credit Revolving credit facility	Oct. 31, 2011 Additional revolving lines of credit, 364 day revolving facility Line of credit Revolving credit facility	Aug. 31, 2012 Additional revolving lines of credit, three year revolving facility Line of credit Revolving credit facility	Oct. 31, 2011 Additional revolving lines of credit, three year revolving facility Line of credit Revolving credit facility	Aug. 31, 2012 Committed revolving credit facility Line of credit Revolving credit facility	Aug. 31, 2012 Uncommitted lines of credit Line of credit Revolving credit facility	Aug. 31, 2011 Uncommitted lines of credit Line of credit Revolving credit facility	Aug. 31, 2011 Other international subsidiaries, lines of credit Line of credit Revolving credit facility	Aug. 31, 2012 Credit facilities, commercial paper programs Line of credit Revolving credit facility	Aug. 31, 2012 Miscellaneous short-term notes payable Line of credit Revolving credit facility	Aug. 31, 2011 Miscellaneous short-term notes payable Line of credit Revolving credit facility	Aug. 31, 2012 Revolving term loans from cooperative and other banks Line of credit Revolving credit facility		Dec. 31, 2007 Revolving term loans from cooperative and other banks Line of credit Revolving credit facility	Aug. 31, 2012 Private placement, payable in equal installments beginning in 2014 through 2018 Unsecured debt		Oct. 31, 2007 Private placement, payable in equal installments beginning in 2014 through 2018 Unsecured debt	Aug. 31, 2012 Private placement, payable in equal installments through 2013 Unsecured debt		Jun. 30, 1998 Private placement, payable in equal installments through 2013 Unsecured debt	Oct. 31, 2002 Private placement, payable in installments through 2018 Unsecured debt	Aug. 31, 2012 Private placement, payable in equal installments beginning in 2011 through 2015 Unsecured debt		Sep. 30, 2004 Private placement, payable in equal installments beginning in 2011 through 2015 Unsecured debt	Apr. 30, 2007 Private placement, note purchase and private shelf agreement with prudential capital group Notes payable, other payables	Apr. 30, 2004 Private placement, note purchase and private shelf agreement with prudential capital group Notes payable, other payables	Aug. 31, 2012 Private placement, note purchase and private shelf agreement with Prudential Capital Group, payable in equal installments beginning in 2014 through 2018 Notes payable, other payables		Feb. 28, 2008 Private placement, note purchase and private shelf agreement with Prudential Capital Group, payable in equal installments beginning in 2014 through 2018 Notes payable, other payables	Aug. 31, 2012 Private placement, note purchase and private shelf agreement with Prudential Capital Group, payable in equal installments beginning in 2017 through 2021 Notes payable, other payables		Nov. 30, 2010 Private placement, note purchase and private shelf agreement with Prudential Capital Group, payable in equal installments beginning in 2017 through 2021 Notes payable, other payables	Jun. 30, 2011 Private placement, accredited investors Unsecured debt	Aug. 31, 2012 Other notes and contracts Secured debt	Aug. 31, 2012 CHS Capital notes payable	Aug. 31, 2011 CHS Capital notes payable	Aug. 31, 2012 CHS Capital notes payable Notes payable, other payables		Aug. 31, 2011 CHS Capital notes payable Notes payable, other payables		Aug. 31, 2012 Short-term notes payable, note purchase agreements Notes payable, other payables Cofina Funding, LLC	Aug. 31, 2011 Short-term notes payable, note purchase agreements Notes payable, other payables Cofina Funding, LLC	Aug. 31, 2012 Master participation agreements Notes payable, other payables	Aug. 31, 2012 Master participation agreements Notes payable, other payables Minimum	Aug. 31, 2012 Master participation agreements Notes payable, other payables Maximum	Aug. 31, 2012 Recourse loan commitments Notes payable, other payables	Aug. 31, 2011 Recourse loan commitments Notes payable, other payables	Aug. 31, 2012 Short-term notes payable surplus funds program Notes payable, other payables	Aug. 31, 2011 Short-term notes payable surplus funds program Notes payable, other payables	Aug. 31, 2012 Short-term notes payable surplus funds program Notes payable, other payables Minimum	Aug. 31, 2012 Short-term notes payable surplus funds program Notes payable, other payables Maximum
Debt Instrument [Line Items]
Number of primary committed lines of credit (in number of lines of credit)										2
Line of credit facility, current borrowing capacity							$ 1,250,000,000			$ 2,500,000,000	$ 2,200,000,000			$ 40,000,000		$ 40,000,000	$ 15,000,000				$ 125,000,000
Number Of Additional Revolving Lines of Credit												2
Line of credit facility, term							3 years	5 years					364 days		3 years									10 years
Line of credit facility, maximum borrowing capacity									1,250,000,000							120,000,000
Line of credit facility, amount outstanding																		190,400,000	128,800,000	77,700,000		1,700,000	1,900,000
Line Of Credit, Collateralized Amount																				43,800,000
Line of credit facility maximum usage allowed to pay principal																					200,000,000
Long-term debt, gross																										150,000,000			400,000,000			225,000,000	175,000,000			125,000,000					50,000,000			100,000,000	500,000,000	33,700,000
Long-term debt, current borrowing capacity																																					150,000,000	70,000,000							1,500,000,000
Short-term bank loans and notes payable current borrowing capacity																																																					300,000,000		261,000,000			238,200,000
Notes payable, weighted average interest rate																																															1.68%	1.86%					1.21%
Short-term debt, maximum borrowing capacity																																																										250,000,000
Notes payable	$ 803,622,000	$ 716,268,000	$ 269,783,000	[1],[2]	$ 130,719,000	[1],[2]																																											$ 533,839,000	[3]	$ 585,549,000	[3]	$ 121,500,000	$ 371,300,000	$ 122,700,000			$ 158,200,000	$ 174,000,000	$ 131,400,000	$ 96,600,000
Interest rate																								5.59%	[2],[4]		6.18%	[2],[5]		6.81%	[2],[6]			5.25%	[2],[7]				5.78%	[2],[8]		4.00%	[2],[8]													2.03%	3.00%	1.82%				0.80%	1.10%

[1] The Company finances its working capital needs through short-term lines of credit with a syndication of domestic and international banks. On August 31, 2012, the Company had two primary committed lines of credit. The Company had a three-year revolving facility and a five-year revolving facility, each with committed amounts of $1.25 billion, for a total of $2.5 billion, which had no amounts outstanding as of August 31, 2012. As of August 31, 2011 the Company had two revolving lines of credit totaling $2.2 billion, with no amounts outstanding at August 31, 2011, both of which were terminated and replaced by the existing facilities in September 2011. In addition to its primary lines of credit, the Company had two additional revolving lines of credit, of which one was a 364-day revolving facility in the amount of $40.0 million committed that was terminated in October 2011, and the other is a three-year revolving facility in the amount of $40.0 million committed, with the right to increase the capacity to $120.0 million, that expires in November 2013. There were no amounts outstanding on either of these two additional revolving lines of credit on August 31, 2012 and 2011. The Company also has a committed revolving credit facility dedicated to NCRA, with a syndication of banks in the amount of $15.0 million that expires in December 2014, with no amounts outstanding on August 31, 2012 and 2011. The Company's wholly-owned subsidiaries, CHS Europe S.A. and CHS do Brasil Ltda., have uncommitted lines of credit to finance their normal trading activities with outstanding amounts of $190.4 million as of August 31, 2012 and $128.8 million as of August 31, 2011, which are collateralized by certain inventories and receivables. In addition, other international subsidiaries have lines of credit totaling $77.7 million outstanding at August 31, 2012, of which, $43.8 million is collateralized. The Company has two commercial paper programs totaling up to $125.0 million with two banks participating in the revolving credit facilities. Terms of the Company’s credit facilities allow a maximum usage of $200.0 million to pay principal under any commercial paper facility. On August 31, 2012 and 2011, there was no commercial paper outstanding. Miscellaneous short-term notes payable totaled $1.7 million and $1.9 million on August 31, 2012 and 2011, respectively.(b)I

[2] The debt is unsecured; however, restrictive covenants under various agreements have requirements for maintenance of minimum working capital levels and other financial ratios.

[3] Cofina Funding, LLC (Cofina Funding), a wholly-owned subsidiary of CHS Capital, has available credit totaling $300.0 million as of August 31, 2012, under note purchase agreements with various purchasers, through the issuance of short-term notes payable. CHS Capital sells eligible commercial loans receivable it has originated to Cofina Funding, which are then pledged as collateral under the note purchase agreements. The notes payable issued by Cofina Funding bear interest at variable rates with a weighted-average interest rate of 1.21% as of August 31, 2012. Borrowings by Cofina Funding utilizing the available credit under the note purchase agreements totaled $121.5 million as of August 31, 2012. CHS Capital has available credit under master participation agreements with numerous counterparties. Borrowings under these agreements are accounted for as secured borrowings and bear interest at variable rates ranging from 2.03% to 3.00% as of August 31, 2012. As of August 31, 2012, the total funding commitment under these agreements was $261.0 million, of which $122.7 million was borrowed. CHS Capital sells loan commitments it has originated to ProPartners Financial (ProPartners) on a recourse basis. The total capacity for commitments under the ProPartners program is $250.0 million. The total outstanding commitments under the program totaled $238.2 million as of August 31, 2012, of which $158.2 million was borrowed under these commitments with an interest rate of 1.82%. CHS Capital borrows funds under short-term notes issued as part of a surplus funds program. Borrowings under this program are unsecured and bear interest at variable rates ranging from 0.80% to 1.10% as of August 31, 2012, and are due upon demand. Borrowings under these notes totaled $131.4 million as of August 31, 2012. As of August 31, 2011, the net borrowings under the Cofina Funding note purchase agreements were $371.3 million. CHS Capital borrowings under the ProPartners program and the surplus funds program were $174.0 million and $96.6 million, respectively, as of August 31, 2011.Weighted-average interest rates at

[4] In December 2007, the Company established a ten-year long-term credit agreement through a syndication of cooperative banks in the amount of $150.0 million.

[5] In October 2007, the Company entered into a private placement with several insurance companies for long-term debt in the amount of $400.0 million.

[6] In June 1998, the Company entered into a private placement with several insurance companies for long-term debt in the amount of $225.0 million.

[7] In September 2004, the Company entered into a private placement with several insurance companies for long-term debt in the amount of $125.0 million.

[8] In March 2004, the Company entered into a note purchase and private shelf agreement with Prudential Capital Group. In April 2007, the agreement was amended with Prudential Investment Management, Inc. and several other participating insurance companies to expand the uncommitted facility from $70.0 million to $150.0 million. In February 2008, the Company borrowed $50.0 million under the shelf arrangement and in November 2010, the Company borrowed $100.0 million under the shelf arrangement.