Consolidated Statement of Changes in Stockholders’ Equity - USD ($) shares in Millions, $ in Millions	Total	Adoption of ASC606 [Member]	Common Stock [Member]	Common Stock [Member] Common Class A [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Retained Earnings [Member] Adoption of ASC606 [Member]	Treasury Stock At Cost [Member]	Treasury Stock At Cost [Member] Adoption of ASC606 [Member]	Parent [Member]	Parent [Member] Adoption of ASC606 [Member]	Noncontrolling Interest [Member]
Balance (in Shares) at May. 31, 2017			33.4	1.7
Beginning balance at May. 31, 2017	$ 1,307.9		$ 0.4	$ 0.0	$ 606.8	$ (94.2)	$ 1,091.2		$ (296.3)		$ 1,307.9		$ 0.0
Net Income (loss)	(5.0)						(5.0)				(5.0)
Foreign currency translation adjustment	3.4					3.4					3.4
Pension and postretirement adjustments, net of tax	35.1					35.1					35.1
Stock-based compensation	10.7				10.7						10.7
Proceeds pursuant to stock-based compensation plans	15.8				15.8						15.8
Proceeds from issuance of common stock pursuant to stock-based compensation (in Shares)			0.0
Purchases of treasury stock at cost	(27.2)								(27.2)		(27.2)
Purchases of treasury stock at cost (in Shares)			(0.7)
Treasury stock issued pursuant to equity-based plans	1.1				(18.9)				20.0		1.1
Treasury stock issued pursuant to stock purchase plans (in Shares)			0.6
Dividends	(21.0)						(21.0)				(21.0)
Beginning balance at May. 31, 2018	1,320.8		$ 0.4	$ 0.0	614.4	(55.7)	1,065.2		(303.5)		1,320.8		0.0
Beginning balance (Accounting Standards Update 2014-09 [Member]) at May. 31, 2018		$ (47.0)						$ (47.0)		$ 0.0		$ (47.0)
Balance (in Shares) at May. 31, 2018			33.3	1.7
Net Income (loss)	15.6						15.6				15.6
Foreign currency translation adjustment	(5.2)					(5.2)					(5.2)
Pension and postretirement adjustments, net of tax	1.2					1.2					1.2
Stock-based compensation	8.3				8.3						8.3
Proceeds pursuant to stock-based compensation plans	6.0				6.0						6.0
Proceeds from issuance of common stock pursuant to stock-based compensation (in Shares)			0.0
Purchases of treasury stock at cost	(8.5)								(8.5)		(8.5)
Purchases of treasury stock at cost (in Shares)			(0.2)
Treasury stock issued pursuant to equity-based plans	1.5				(7.9)				9.4		1.5
Treasury stock issued pursuant to stock purchase plans (in Shares)			0.3
Dividends	(21.2)						(21.2)				(21.2)
Change in fair value of noncontrolling interest in Make Believe Ideas Limited	1.3												1.3
Beginning balance at May. 31, 2019	1,272.8		$ 0.4	$ 0.0	620.8	(59.7)	1,012.6		(302.6)		1,271.5		1.3
Balance (in Shares) at May. 31, 2019			33.4	1.7
Net Income (loss)	(43.7)						(43.8)				(43.8)		0.1
Foreign currency translation adjustment	(2.9)					(2.9)					(2.9)
Pension and postretirement adjustments, net of tax	4.3					4.3					4.3
Stock-based compensation	3.8				3.8						3.8
Proceeds pursuant to stock-based compensation plans	0.7				0.7						0.7
Purchases of treasury stock at cost	$ (35.5)								(35.5)		(35.5)
Purchases of treasury stock at cost (in Shares)	(1.0)		(1.0)
Treasury stock issued pursuant to equity-based plans	$ 1.9				(2.9)				4.8		1.9
Treasury stock issued pursuant to stock purchase plans (in Shares)			0.1
Dividends	(20.8)						(20.8)				(20.8)
Beginning balance at May. 31, 2020	$ 1,180.6		$ 0.4	$ 0.0	$ 622.4	$ (58.3)	$ 948.0		$ (333.3)		$ 1,179.2		$ 1.4
Balance (in Shares) at May. 31, 2020			32.5	1.7