Other Assets (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Oct. 31, 2012
Kansas Expanded Lottery Act Contract Privilege [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 5,500
JET autopilot intellectual property [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 2,055
Useful life	15 years

The net carrying amount as of the balance sheet date of other indefinite-lived and finite-lived intangible assets that are not separately presented on the statement of financial position.

No definition available.

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