Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	2024 Convertible Senior Notes	2024 Convertible Senior Notes Issuance Costs	Contingently Redeemable Noncontrolling Interest	Common Stock Shares	Additional Paid-in Capital	Additional Paid-in Capital 2024 Convertible Senior Notes	Additional Paid-in Capital 2024 Convertible Senior Notes Issuance Costs	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total Attributable to Greenbrier	Total Attributable to Greenbrier 2024 Convertible Senior Notes	Total Attributable to Greenbrier 2024 Convertible Senior Notes Issuance Costs	Attributable to Noncontrolling Interest
Beginning balance (in shares) at Aug. 31, 2016					28,205
Beginning balance at Aug. 31, 2016	$ 1,016,827					$ 282,886			$ 618,178	$ (26,753)	$ 874,311			$ 142,516
Net earnings	96,967								59,498		59,498			37,469
Other comprehensive income, net	(2,597)									(2,597)	(2,597)
Noncontrolling interest adjustments	(3,255)													(3,255)
Joint venture partner distribution declared	(18,783)													(18,783)
Restricted stock awards (net of cancellations) (in shares)					195
Restricted stock awards (net of cancellations)	(1,876)					(1,876)					(1,876)
Unamortized restricted stock	(1,105)					(1,105)					(1,105)
Restricted stock amortization	8,437					8,437					8,437
Tax deficiency from restricted stock awards	(2,453)					(2,453)					(2,453)
Cash dividends	(12,234)								(12,234)		(12,234)
2024 Convertible Senior Notes - equity component, net of tax		$ 20,818	$ (715)				$ 20,818	$ (715)				$ 20,818	$ (715)
Ending Balance (in shares) at Feb. 28, 2017					28,400
Ending Balance at Feb. 28, 2017	$ 1,100,031					305,992			665,442	(29,350)	942,084			157,947
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				28,503
Beginning balance at Aug. 31, 2017	$ 1,178,893					315,306			709,103	(6,279)	1,018,130			160,763
Net earnings	98,666								87,895		87,895			13,873
Other comprehensive income, net	2,162									2,158	2,158			4
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				28,732
Ending Balance at Feb. 28, 2018	$ 1,243,033					$ 316,073			$ 783,495	$ (4,121)	$ 1,095,447			$ 147,586