Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Contingently Redeemable Noncontrolling Interest	Common Stock Shares	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total Attributable to Greenbrier	Attributable to Noncontrolling Interest	Equity Excluding Contingently Redeemable Noncontrolling Interest [Member]
Beginning balance at Aug. 31, 2017		$ 36,148
Net earnings		(3,102)
Ending Balance at Feb. 28, 2018		33,046
Beginning balance (in shares) at Aug. 31, 2017			28,503
Beginning balance at Aug. 31, 2017				$ 315,306	$ 709,103	$ (6,279)	$ 1,018,130	$ 160,763	$ 1,178,893
Net earnings	$ 98,666				87,895		87,895	13,873	101,768
Other comprehensive income (loss), net	2,162					2,158	2,158	4	2,162
Noncontrolling interest adjustments								(2,561)	(2,561)
Joint venture partner distribution declared								(30,993)	(30,993)
Investment by joint venture partner								6,500	6,500
Restricted stock awards (net of cancellations) (in shares)			229
Restricted stock awards (net of cancellations)				(4,250)			(4,250)		(4,250)
Unamortized restricted stock				(950)			(950)		(950)
Restricted stock amortization				5,967			5,967		5,967
Cash dividends					(13,503)		(13,503)		(13,503)
Ending Balance (in shares) at Feb. 28, 2018			28,732
Ending Balance at Feb. 28, 2018				316,073	783,495	(4,121)	1,095,447	147,586	1,243,033
Beginning balance at Nov. 30, 2017		35,209
Net earnings		(2,163)
Ending Balance at Feb. 28, 2018		33,046
Beginning balance (in shares) at Nov. 30, 2017			28,701
Beginning balance at Nov. 30, 2017				312,789	728,755	(8,987)	1,032,557	147,651	1,180,208
Net earnings	65,289				61,642		61,642	5,810	67,452
Other comprehensive income (loss), net	$ 4,874					4,866	4,866	8	4,874
Noncontrolling interest adjustments								(1,679)	(1,679)
Joint venture partner distribution declared								(4,204)	(4,204)
Restricted stock awards (net of cancellations) (in shares)			31
Restricted stock awards (net of cancellations)				811			811		811
Unamortized restricted stock				(950)			(950)		(950)
Restricted stock amortization				3,423			3,423		3,423
Cash dividends					(6,902)		(6,902)		(6,902)
Ending Balance (in shares) at Feb. 28, 2018			28,732
Ending Balance at Feb. 28, 2018				316,073	783,495	(4,121)	1,095,447	147,586	1,243,033
Beginning balance at Aug. 31, 2018		29,768
Net earnings		(4,131)
Ending Balance at Feb. 28, 2019		25,637
Beginning balance (in shares) at Aug. 31, 2018	32,191		32,191
Beginning balance at Aug. 31, 2018	$ 1,384,215			442,569	830,898	(23,366)	1,250,101	134,114	1,384,215
Net earnings	29,165				20,721		20,721	12,575	33,296
Other comprehensive income (loss), net	$ (4,277)					(4,256)	(4,256)	(21)	(4,277)
Noncontrolling interest adjustments								5,306	5,306
Joint venture partner distribution declared								(8,430)	(8,430)
Attributable to noncontrolling interest acquired								1,915	1,915
Cumulative effect adjustment due to adoption of ASU 2014-09 (See Note 1) at Aug. 31, 2018					5,461		5,461		5,461
Restricted stock awards (net of cancellations) (in shares)			188
Restricted stock awards (net of cancellations)				12,683			12,683		12,683
Unamortized restricted stock				(17,445)			(17,445)		(17,445)
Restricted stock amortization				7,155			7,155		7,155
Cash dividends					(16,602)		(16,602)		(16,602)
Ending Balance (in shares) at Feb. 28, 2019	32,379		32,379
Ending Balance at Feb. 28, 2019	$ 1,403,277			444,962	840,478	(27,622)	1,257,818	145,459	1,403,277
Beginning balance at Nov. 30, 2018		28,449
Net earnings		(2,812)
Ending Balance at Feb. 28, 2019		$ 25,637
Beginning balance (in shares) at Nov. 30, 2018			32,350
Beginning balance at Nov. 30, 2018				440,958	846,018	(29,345)	1,257,631	141,590	1,399,221
Net earnings	5,783				2,765		2,765	5,830	8,595
Other comprehensive income (loss), net	$ 1,717					1,723	1,723	(6)	1,717
Noncontrolling interest adjustments								1,387	1,387
Joint venture partner distribution declared								(5,257)	(5,257)
Cumulative effect adjustment due to adoption of ASU 2014-09 (See Note 1) at Nov. 30, 2018								1,915	1,915
Restricted stock awards (net of cancellations) (in shares)			29
Restricted stock awards (net of cancellations)				1,267			1,267		1,267
Unamortized restricted stock				(1,282)			(1,282)		(1,282)
Restricted stock amortization				4,019			4,019		4,019
Cash dividends					(8,305)		(8,305)		(8,305)
Ending Balance (in shares) at Feb. 28, 2019	32,379		32,379
Ending Balance at Feb. 28, 2019	$ 1,403,277			$ 444,962	$ 840,478	$ (27,622)	$ 1,257,818	$ 145,459	$ 1,403,277