Significant Accounting Policies - Summary of the Inventory Values (Details) - USD ($) $ in Thousands	Apr. 30, 2015	Apr. 30, 2014
Inventory
Inventory	$ 197,331	$ 204,833
Fuel
Inventory
Inventory	69,056	95,004
Merchandise
Inventory
Inventory	$ 128,275	$ 109,829

Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.6(a))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InventoryGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant