Accrued Expenses and Other Current Liabilities - Additional Information (Details) - USD ($) $ in Millions	Apr. 30, 2017	Apr. 30, 2016
Other Long Term Liabilities [Member]
Accrued Expenses and Other Current Liabilities [Line Items]
Lease Incentive, Payable	$ 5.7	$ 6.3
Accrued Liabilities [Member]
Accrued Expenses and Other Current Liabilities [Line Items]
Lease Incentive, Payable	$ 0.7	$ 0.7

This item represents an incentive or inducement contractually stipulated between parties to a lease whereby the lessor has committed to provide the entity (lessee) with a cash payment as inducement to enter the lease.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.15(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.15(5))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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