XML 78 R53.htm IDEA: XBRL DOCUMENT v2.4.0.8

Summary of Significant Accounting Policies - Estimated Useful Lives of Assets (Detail)	12 Months Ended
	Apr. 30, 2014
Minimum [Member] | Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	10 years
Minimum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	5 years
Minimum [Member] | Rolling Stock [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	5 years
Minimum [Member] | Containers [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	5 years
Minimum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	3 years
Maximum [Member] | Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	30 years
Maximum [Member] | Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	10 years
Maximum [Member] | Rolling Stock [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	10 years
Maximum [Member] | Containers [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	12 years
Maximum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful life	8 years

X

- Details

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration