Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Feb. 29, 2020	Aug. 31, 2019	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019	Jun. 01, 2019	May 31, 2019
Discontinued Operations
Interest expense	$ 2.4		$ 2.6	$ 6.5	$ 7.2
Operating results for discontinued operations
Sales	6.3		26.6	40.2	68.8
Cost of sales	(6.5)		(31.3)	(44.9)	(79.0)
Asset impairment			(74.1)	(11.8)	(74.1)
Selling, general and administrative expenses	(0.1)		(2.7)	(7.3)	(7.5)
Operating loss from discontinued operations	(0.3)		(81.5)	(23.8)	(91.8)
Provision for income taxes (benefit)			(16.7)	(4.9)	(19.0)
Loss from discontinued operations	(0.3)		(64.8)	(18.9)	(72.8)
Carrying amounts of the major classes of assets and liabilities for our discontinued operations
Accounts receivable, net	2.3			2.3			$ 16.2
Inventory, rotable assets, and equipment							7.5
Operating lease ROU assets	22.7			22.7
Other assets	1.3			1.3			5.5
Assets of discontinued operations	26.3			26.3			29.2
Accounts payable and accrued liabilities	17.7			17.7			29.2
Operating lease liabilities	22.7			22.7
Liabilities of discontinued operations	40.4			40.4		$ 54.5	$ 29.2
COCO | Held for sale or Disposed
Discontinued Operations
Goodwill impairment charge		$ 11.8	74.1
General corporate overhead	0.0		0.0	0.0	0.0
Interest expense	$ 0.0		$ 0.0	$ 0.0	$ 0.0