Annual report pursuant to Section 13 and 15(d)

Guaranteed Preferred Beneficial Interest in the Company's Junior Subordinated Debentures - Additional Information (Detail)

v2.4.1.9
Guaranteed Preferred Beneficial Interest in the Company's Junior Subordinated Debentures - Additional Information (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
0 Months Ended 1 Months Ended 12 Months Ended
Jun. 30, 2014
Sep. 30, 1997
Dec. 31, 2014
Jun. 30, 2014
Schedule of Investments [Abstract]        
Trust Preferred Securities issued   $ 105,446hlm_TrustPreferredSecuritiesIssued    
Number of Trust Preferred Securities issued   4,217,724hlm_TrustPreferredSecuritiesIssuedNumber    
Interest rate Junior Subordinated Debentures   11.60%hlm_InterestRateJuniorSubordinatedDebentures    
Maturity date of preferred securities     Sep. 30, 2027  
Liquidation amount of preferred security     $ 25.00hlm_TrustPreferredSecuritiesLiquidationAmountPerPreferredSecurity  
Trust issued common securities to the Company     3,261us-gaap_ProceedsFromRepurchaseOfTrustPreferredSecurities  
Debentures interest payment defer period maximum     60 months  
Trust Preferred Securities, redemption description     The Trust will redeem the preferred securities when the debentures are repaid, or at maturity on September 30, 2027.  
11.6% Junior subordinated debentures, due date     Sep. 30, 2027  
Percentage of redemption price of debentures over principal amount     100.00%hlm_PercentageOfRepurchasePriceToPrincipalDebtAmount  
Junior Subordinated Debentures recorded at fair value based on price       131,141hlm_JuniorSubordinatedDebenturesAtFairValue
Trust Preferred Securities underlying price       $ 30.32hlm_TrustPreferredSecuritiesUnderlyingPrice
Amortizing the premium on Junior Subordinated Debentures $ 22,437hlm_JuniorSubordinatedDebenturesAmortizedPremium