Contingencies (Details Textual) (USD $) In Millions, unless otherwise specified	May 31, 2014
Commitment And Contingencies [Line Items]
Loss Contingencies Additional Refund Payable	$ 11.3
Loss Contingencies Additional Interest Payable Amount	$ 3.4

Loss contingencies additional interest payable amount.

No definition available.

Name:	dyii_LossContingenciesAdditionalInterestPayableAmount
Namespace Prefix:	dyii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant