Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net earnings		$ 35,134	$ 87,586	$ 105,811
Other comprehensive income (loss)
Translation adjustment		3,982	(5,602)	(12,725)
Reclassification of derivative financial instruments recognized in net earnings	[1]	4,979	4,175	1,854
Unrealized gain (loss) on derivative financial instruments	[2]	(394)	(7,304)	(10,264)
Other (net of tax effect)		524	749	(351)
Other comprehensive income		9,091	(7,982)	(21,486)
Comprehensive income		44,225	79,604	84,325
Comprehensive income attributable to noncontrolling interest		(2,644)	(38,639)	(34,698)
Comprehensive income attributable to Greenbrier		$ 41,581	$ 40,965	$ 49,627

[1] Net of tax effect of ($1.7 million), ($1.5 million) and ($0.5 million) for the years ended August 31, 2021, 2020 and 2019, respectively

[2] Net of tax effect of $1.0 million, $2.9 million and $2.9 million for the years ended August 31, 2021, 2020 and 2019, respectively