CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Common Stock	Capital Surplus	Retained Earnings Cumulative effect adjustment	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total AAR Stockholders' Equity Cumulative effect adjustment	Total AAR Stockholders' Equity	Total
Balance (ASC 606) at May. 31, 2019			$ 2.5				$ 2.5
Balance at May. 31, 2019	$ 45.3	$ 479.4		$ 709.8	$ (287.7)	$ (40.9)		$ 905.9
Increase (Decrease) in Stockholders' Equity
Net income				4.4				4.4	$ 4.4
Cash dividends				(10.7)				(10.7)
Stock option activity		3.1			8.3			11.4
Restricted stock activity		(3.9)			0.8			(3.1)
Repurchase of shares					(4.1)			(4.1)
Other comprehensive income (loss), net of tax						(3.7)		(3.7)	(3.7)
Balance at May. 31, 2020	45.3	478.6		706.0	(282.7)	(44.6)		902.6
Increase (Decrease) in Stockholders' Equity
Net income				35.8				35.8	35.8
Cash dividends				(0.1)				(0.1)
Stock option activity		3.6			3.0			6.6
Restricted stock activity		(2.4)			5.6			3.2
Other comprehensive income (loss), net of tax						26.3		26.3	26.3
Balance at May. 31, 2021	45.3	479.8		741.7	(274.1)	(18.3)		974.4	974.4
Increase (Decrease) in Stockholders' Equity
Net income				78.7				78.7	78.7
Stock option activity		2.0			19.3			21.3
Restricted stock activity		(4.3)			8.1			3.8
Repurchase of shares					(42.4)			(42.4)
Other comprehensive income (loss), net of tax						(1.3)		(1.3)	(1.3)
Balance at May. 31, 2022	$ 45.3	$ 477.5		$ 820.4	$ (289.1)	$ (19.6)		$ 1,034.5	$ 1,034.5