The cumulative amount of the reporting entity's undistributed earnings or deficit.

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Name:	us-gaap_RetainedEarningsAccumulatedDeficit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Significant Accounting Policies, New Accounting Guidance (Details) - USD ($) $ in Millions	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2018
New Accounting Guidance [Abstract]
Retained earnings	$ 259.2	$ 469.9
ASU 2014-09 [Member] \| Maximum [Member]
New Accounting Guidance [Abstract]
Retained earnings			$ 0.7
ASU 2016-16 [Member]
New Accounting Guidance [Abstract]
Retained earnings			$ (8.3)