Segment Reporting - Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013	Aug. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 11,967,398,000	$ 11,936,556,000	$ 32,673,793,000	$ 33,528,872,000
Cost of goods sold	11,460,774,000	11,479,645,000	31,324,819,000	32,055,796,000
Gross profit	506,624,000	456,911,000	1,348,974,000	1,473,076,000
Marketing, general and administrative	158,859,000	138,769,000	447,771,000	397,931,000
Operating earnings	347,765,000	318,142,000	901,203,000	1,075,145,000
Loss (gain) on investments	(108,792,000)	(154,000)	(111,401,000)	(199,000)
Interest, net	42,489,000	66,394,000	102,263,000	186,989,000
Equity (income) loss from investments	(25,522,000)	(27,574,000)	(89,249,000)	(72,406,000)
Income before income taxes	439,590,000	279,476,000	999,590,000	960,761,000
Revenue from Related Parties	0	0	0	0
Goodwill	112,570,000	84,166,000	112,570,000	84,166,000	85,100,000
Capital expenditures			656,288,000	427,070,000
Depreciation and amortization			193,161,000	176,839,000
Total identifiable assets	14,944,947,000	13,114,606,000	14,944,947,000	13,114,606,000	13,504,270,000
Energy [Member]
Segment Reporting Information [Line Items]
Revenues	3,480,673,000	3,205,340,000	10,628,885,000	9,345,304,000
Cost of goods sold	3,211,396,000	2,896,061,000	9,895,167,000	8,392,704,000
Gross profit	269,277,000	309,279,000	733,718,000	952,600,000
Marketing, general and administrative	40,197,000	43,710,000	114,181,000	121,364,000
Operating earnings	229,080,000	265,569,000	619,537,000	831,236,000
Loss (gain) on investments	0	0	0	0
Interest, net	24,044,000	46,058,000	55,212,000	124,229,000
Equity (income) loss from investments	(780,000)	(851,000)	(2,937,000)	(580,000)
Income before income taxes	205,816,000	220,362,000	567,262,000	707,587,000
Revenue from Related Parties	(135,304,000)	(116,061,000)	(419,389,000)	(352,624,000)
Goodwill	1,165,000	1,165,000	1,165,000	1,165,000
Capital expenditures			367,228,000	290,091,000
Depreciation and amortization			99,577,000	86,454,000
Total identifiable assets	4,304,663,000	4,126,022,000	4,304,663,000	4,126,022,000
Ag Business
Segment Reporting Information [Line Items]
Revenues	8,603,834,000	8,831,866,000	22,411,894,000	24,483,835,000
Cost of goods sold	8,384,725,000	8,700,170,000	21,849,095,000	24,017,733,000
Gross profit	219,109,000	131,696,000	562,799,000	466,102,000
Marketing, general and administrative	99,942,000	77,653,000	282,823,000	223,041,000
Operating earnings	119,167,000	54,043,000	279,976,000	243,061,000
Loss (gain) on investments	0	0	116,000	(45,000)
Interest, net	15,357,000	17,434,000	39,498,000	53,472,000
Equity (income) loss from investments	(5,216,000)	(3,365,000)	(19,906,000)	(13,104,000)
Income before income taxes	109,026,000	39,974,000	260,268,000	202,738,000
Revenue from Related Parties	0	0	0	0
Goodwill	104,507,000	76,103,000	104,507,000	76,103,000
Capital expenditures			250,423,000	131,794,000
Depreciation and amortization			85,284,000	77,587,000
Total identifiable assets	7,269,201,000	7,127,300,000	7,269,201,000	7,127,300,000
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	18,195,000	15,411,000	52,403,000	52,357,000
Cost of goods sold	(43,000)	(525,000)	(54,000)	(2,017,000)
Gross profit	18,238,000	15,936,000	52,457,000	54,374,000
Marketing, general and administrative	18,720,000	17,406,000	50,767,000	53,526,000
Operating earnings	(482,000)	(1,470,000)	1,690,000	848,000
Loss (gain) on investments	108,792,000	154,000	111,517,000	(154,000)
Interest, net	3,088,000	2,902,000	7,553,000	9,288,000
Equity (income) loss from investments	(19,526,000)	(23,358,000)	(66,406,000)	(58,722,000)
Income before income taxes	124,748,000	19,140,000	172,060,000	50,436,000
Revenue from Related Parties	0	0	0	0
Goodwill	6,898,000	6,898,000	6,898,000	6,898,000
Capital expenditures			38,637,000	5,185,000
Depreciation and amortization			8,300,000	12,798,000
Total identifiable assets	3,371,083,000	1,861,284,000	3,371,083,000	1,861,284,000
Reconciling Amounts
Segment Reporting Information [Line Items]
Revenues	(135,304,000)	(116,061,000)	(419,389,000)	(352,624,000)
Cost of goods sold	(135,304,000)	(116,061,000)	(419,389,000)	(352,624,000)
Gross profit	0	0	0	0
Marketing, general and administrative	0	0	0	0
Operating earnings	0	0	0	0
Loss (gain) on investments	0	0	0	0
Interest, net	0	0	0	0
Equity (income) loss from investments	0	0	0	0
Income before income taxes	0	0	0	0
Revenue from Related Parties	135,304,000	116,061,000	419,389,000	352,624,000
Goodwill	0	0	0	0
Capital expenditures			0	0
Depreciation and amortization			0	0
Total identifiable assets	$ 0	$ 0	$ 0	$ 0