CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY Statement - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Common Stock Common Class A	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Parent [Member]	Noncontrolling Interest [Member]
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
Ending Balance at Aug. 31, 2018	1,209.4	$ 0.4	$ 0.0	615.5	(58.6)	952.1	(300.0)	1,209.4	0.0
Net Income (loss)	(61.3)					(61.3)		(61.3)
Foreign currency translation adjustment	(3.1)				(3.1)			(3.1)
Pension and post-retirement adjustments (net of tax of $0.0)	0.2				0.2			0.2
Stock-based compensation	1.5			1.5				1.5
Proceeds pursuant to stock-based compensation plans	2.8			2.8				2.8
Treasury stock issued pursuant to equity-based plans (in shares)		0.1
Treasury stock issued pursuant to equity-based plans	0.3			(3.2)			3.5	0.3
Dividends ($0.15 per share)	(5.3)					(5.3)		(5.3)
Balance (in shares) at Aug. 31, 2018		33.4	1.7
Balance (in shares) at May. 31, 2018		33.3	1.7
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
Ending Balance at Nov. 30, 2018	1,284.6	$ 0.4	$ 0.0	617.9	(56.5)	1,018.4	(295.6)	1,284.6	0.0
Net Income (loss)	10.3
Foreign currency translation adjustment	(3.7)
Balance (in shares) at Nov. 30, 2018		33.6	1.7
Balance (in shares) at May. 31, 2018		33.3	1.7
Beginning balance at Aug. 31, 2018	1,209.4	$ 0.4	$ 0.0	615.5	(58.6)	952.1	(300.0)	1,209.4	0.0
Ending Balance at Nov. 30, 2018	1,284.6	$ 0.4	$ 0.0	617.9	(56.5)	1,018.4	(295.6)	1,284.6	0.0
Net Income (loss)	71.6					71.6		71.6
Foreign currency translation adjustment	(0.6)				(0.6)			(0.6)
Pension and post-retirement adjustments (net of tax of $0.0)	2.7				2.7			2.7
Stock-based compensation	3.7			3.7				3.7
Proceeds pursuant to stock-based compensation plans	2.5			2.5				2.5
Purchases of treasury stock at cost (in shares)		0.0
Purchases of treasury stock at cost	0.0						0.0	0.0
Treasury stock issued pursuant to equity-based plans (in shares)		0.2
Treasury stock issued pursuant to equity-based plans	0.6			(3.8)			4.4	0.6
Dividends ($0.15 per share)	(5.3)					(5.3)		(5.3)
Balance (in shares) at Nov. 30, 2018		33.6	1.7
Balance (in shares) at Aug. 31, 2018		33.4	1.7
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
Ending Balance at Aug. 31, 2019	1,196.7	$ 0.4	0.0	622.2	(61.5)	948.9	(314.6)	1,195.4	1.3
Net Income (loss)	(58.5)					(58.5)		(58.5)
Foreign currency translation adjustment	(2.0)				(2.0)			(2.0)
Pension and post-retirement adjustments (net of tax of $0.0)	0.2				0.2			0.2
Stock-based compensation	1.5			1.5				1.5
Purchases of treasury stock at cost (in shares)		(0.3)
Purchases of treasury stock at cost	(12.6)						(12.6)	(12.6)
Treasury stock issued pursuant to equity-based plans (in shares)		0.0
Treasury stock issued pursuant to equity-based plans	0.5			(0.1)			0.6	0.5
Noncontrolling interest in Make Believe Ideas			$ 0.0
Dividends ($0.15 per share)	(5.2)					(5.2)		(5.2)
Balance (in shares) at Aug. 31, 2019		33.1	1.7
Balance (in shares) at May. 31, 2019		33.4	1.7
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
Ending Balance at Nov. 30, 2019	1,261.3	$ 0.4	$ 0.0	621.3	(57.4)	1,014.7	(319.0)	1,260.0	1.3
Net Income (loss)	12.5
Foreign currency translation adjustment	1.9
Purchases of treasury stock at cost	(19.6)
Balance (in shares) at Nov. 30, 2019		33.0	1.7
Balance (in shares) at May. 31, 2019		33.4	1.7
Beginning balance at Aug. 31, 2019	1,196.7	$ 0.4	$ 0.0	622.2	(61.5)	948.9	(314.6)	1,195.4	1.3
Ending Balance at Nov. 30, 2019	1,261.3	$ 0.4	0.0	621.3	(57.4)	1,014.7	(319.0)	1,260.0	$ 1.3
Net Income (loss)	71.0					71.0		71.0
Foreign currency translation adjustment	3.9				3.9			3.9
Pension and post-retirement adjustments (net of tax of $0.0)	0.2				$ 0.2			0.2
Stock-based compensation	0.9			0.9				0.9
Proceeds pursuant to stock-based compensation plans	0.3			0.3				0.3
Purchases of treasury stock at cost (in shares)		(0.1)
Purchases of treasury stock at cost	(7.1)						(7.1)	(7.1)
Treasury stock issued pursuant to equity-based plans (in shares)		0.0
Treasury stock issued pursuant to equity-based plans	0.6			$ (2.1)			$ 2.7	0.6
Noncontrolling interest in Make Believe Ideas			$ 0.0
Dividends ($0.15 per share)	$ (5.2)					$ (5.2)		$ (5.2)
Balance (in shares) at Nov. 30, 2019		33.0	1.7
Balance (in shares) at Aug. 31, 2019		33.1	1.7