Business, Basis of Presentation and Summary of Significant Accounting Policies - Business (Details)	6 Months Ended
Oct. 31, 2017 location state item
Business
Number of independent operations \| item	0
Number of branches through which products are distributed \| location	210
Number of states in which products are distributed \| state	42

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant