Basis of Presentation, Business and Summary of Significant Accounting Policies - Business (Details)	3 Months Ended
Jul. 31, 2017 state location item
Business
Number of states in which products are distributed \| state	42
Number of independent operations \| item	0
Minimum
Business
Number of branches through which products are distributed \| location	200

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