Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2015	Aug. 31, 2014	Feb. 28, 2014	Aug. 31, 2013
Assets
Cash and cash equivalents	$ 145,512	$ 184,916	$ 143,929	$ 97,435
Restricted cash	8,722	20,140
Accounts receivable, net	207,488	199,679
Inventories	418,590	305,656
Leased railcars for syndication	198,010	125,850
Equipment on operating leases, net	261,234	258,848
Property, plant and equipment, net	271,977	243,698
Investment in unconsolidated affiliates	71,225	69,359
Goodwill	43,265	43,265
Intangibles and other assets, net	64,386	65,757
Total assets	1,690,409	1,517,168
Liabilities and Equity
Revolving notes	90,563	13,081
Accounts payable and accrued liabilities	417,844	383,289
Deferred income taxes	77,632	81,383
Deferred revenue	28,287	20,603
Notes payable	441,326	445,091
Total equity - Greenbrier	541,491	511,390
Noncontrolling interest	93,266	62,331
Total equity	634,757	573,721	497,579	456,827
Liabilities and Equity	1,690,409	1,517,168
Parent
Assets
Cash and cash equivalents	84,528	149,747	111,679	63,173
Accounts receivable, net	644	626
Property, plant and equipment, net	9,840	6,220
Investment in unconsolidated affiliates	1,059,361	910,732
Intangibles and other assets, net	18,237	17,031
Total assets	1,172,610	1,084,356
Liabilities and Equity
Revolving notes	53,000
Accounts payable and accrued liabilities	318,217	315,879
Deferred income taxes	14,954	12,109
Deferred revenue	122	122
Notes payable	244,826	244,856
Total equity - Greenbrier	541,491	511,390
Total equity	541,491	511,390
Liabilities and Equity	1,172,610	1,084,356
Combined Guarantor Subsidiaries
Assets
Cash and cash equivalents	2,329	112	33	25
Restricted cash	1,819	13,238
Accounts receivable, net	433,730	474,409
Inventories	129,303	113,117
Leased railcars for syndication	222,389	128,965
Equipment on operating leases, net	260,850	257,415
Property, plant and equipment, net	103,772	102,972
Investment in unconsolidated affiliates	161,439	143,768
Goodwill	43,265	43,265
Intangibles and other assets, net	42,085	45,013
Total assets	1,400,981	1,322,274
Liabilities and Equity
Accounts payable and accrued liabilities	205,158	221,863
Deferred income taxes	72,073	80,489
Deferred revenue	28,121	19,950
Notes payable	195,188	198,705
Total equity - Greenbrier	900,441	801,267
Total equity	900,441	801,267
Liabilities and Equity	1,400,981	1,322,274
Combined Non-Guarantor Subsidiaries
Assets
Cash and cash equivalents	58,655	35,057	32,217	34,237
Restricted cash	6,903	6,902
Accounts receivable, net	54,491	62,421
Inventories	289,305	192,634
Equipment on operating leases, net	3,075	3,613
Property, plant and equipment, net	158,365	134,506
Investment in unconsolidated affiliates	3,916	3,961
Intangibles and other assets, net	12,752	14,221
Total assets	587,462	453,315
Liabilities and Equity
Revolving notes	37,563	13,081
Accounts payable and accrued liabilities	223,350	185,335
Deferred revenue		487
Notes payable	1,312	1,530
Total equity - Greenbrier	232,418	190,861
Noncontrolling interest	92,819	62,021
Total equity	325,237	252,882
Liabilities and Equity	587,462	453,315
Eliminations
Assets
Accounts receivable, net	(281,377)	(337,777)
Inventories	(18)	(95)
Leased railcars for syndication	(24,379)	(3,115)
Equipment on operating leases, net	(2,691)	(2,180)
Investment in unconsolidated affiliates	(1,153,491)	(989,102)
Intangibles and other assets, net	(8,688)	(10,508)
Total assets	(1,470,644)	(1,342,777)
Liabilities and Equity
Accounts payable and accrued liabilities	(328,881)	(339,788)
Deferred income taxes	(9,395)	(11,215)
Deferred revenue	44	44
Total equity - Greenbrier	(1,132,859)	(992,128)
Noncontrolling interest	447	310
Total equity	(1,132,412)	(991,818)
Liabilities and Equity	$ (1,470,644)	$ (1,342,777)