ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES - General Overview (Details) - subsidiary	9 Months Ended	12 Months Ended
Mar. 31, 2017	Jun. 30, 2016
ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES
Number of wholly-owned subsidiaries	2	2

Represents the wholly-owned subsidiaries of the entity.

No definition available.

Name:	hdy_NumberOfWhollyOwnedSubsidiaries
Namespace Prefix:	hdy_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration