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PRIVATE PLACEMENT (Details Textual) (USD $)
 3 Months Ended
Mar. 31, 2015
Oct. 29, 2014
Share Price   $ 10.00us-gaap_SharePrice
Private Placement Warrants [Member]    
Stock Issued During Period, Shares, New Issues 7,500,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_StatementEquityComponentsAxis
= hdrau_PrivatePlacementWarrantsMember		  
Share Price $ 0.50us-gaap_SharePrice
/ us-gaap_StatementEquityComponentsAxis
= hdrau_PrivatePlacementWarrantsMember		  
Stock Issued During Period, Value, New Issues $ 3,750,000us-gaap_StockIssuedDuringPeriodValueNewIssues
/ us-gaap_StatementEquityComponentsAxis
= hdrau_PrivatePlacementWarrantsMember		  
Class Of Warrant Or Right Exercise Price Of Warrants Or Rights Description Each Private Placement Warrant is exercisable to purchase one-half share of Common Stock at $5.75 per half share.