Cash Flow (Supplemental Disclosures Of Cash Flow Information) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Jan. 31, 2015	Jan. 31, 2014
Supplemental Cash Flow Information [Abstract]
Interest	$ 414us-gaap_InterestPaid	$ 502us-gaap_InterestPaid
Income taxes	$ 10,608us-gaap_IncomeTaxesPaid	$ 3,978us-gaap_IncomeTaxesPaid

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

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