Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
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Name:	us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Treasury Stock - Schedule of repurchase of common stock (Details) - USD ($) $ in Millions	3 Months Ended		29 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	May 31, 2020	Mar. 31, 2020	Mar. 31, 2018
Stockholders' Equity Attributable to Parent [Abstract]
Authorized amount of stock to be repurchased				$ 100.0	$ 50.0	$ 50.0
Total current Board authorizations	$ 0.0	$ (12.6)	$ (32.7)
Less repurchases made under these authorizations	$ 67.3		$ 67.3
Number of common stock repurchased (in shares)	0