Summary Of Significant Accounting Policies New Accounting Pronouncements (Details) - USD ($) $ in Millions	6 Months Ended
Oct. 31, 2017	Oct. 31, 2016
Accounting Changes [Abstract]
Prior Period Reclassification Adjustment		$ 5.4
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 5.2

Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements.

No definition available.

Name:	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration