Annual report pursuant to Section 13 and 15(d)

Guaranteed Preferred Beneficial Interest in the Company's Junior Subordinated Debentures - Summary of Financial Information of Trust (Detail)

v2.4.1.9
Guaranteed Preferred Beneficial Interest in the Company's Junior Subordinated Debentures - Summary of Financial Information of Trust (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Preferred Junior Subordinated Debentures [Member]  
Schedule of Investments [Line Items]  
Non-current assets - junior subordinated debentures $ 127,424us-gaap_AssetsNoncurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= hlm_PreferredJuniorSubordinatedDebenturesMember
Common Junior Subordinated Debentures [Member]  
Schedule of Investments [Line Items]  
Non-current assets - junior subordinated debentures 3,261us-gaap_AssetsNoncurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= hlm_CommonJuniorSubordinatedDebenturesMember
Trust Preferred Securities [Member]  
Schedule of Investments [Line Items]  
Non-current liabilities - trust preferred securities 127,424us-gaap_LiabilitiesNoncurrent
/ us-gaap_ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTermsAxis
= hlm_TrustPreferredSecuritiesMember
Common Trust Securities [Member]  
Schedule of Investments [Line Items]  
Stockholder's equity - trust common securities 3,261us-gaap_StockholdersEquity
/ us-gaap_ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTermsAxis
= hlm_CommonTrustSecuritiesMember
Trust Securities [Member]  
Schedule of Investments [Line Items]  
Total liabilities and stockholders' equity 130,685us-gaap_LiabilitiesAndStockholdersEquity
/ us-gaap_ScheduleOfSharesSubjectToMandatoryRedemptionBySettlementTermsAxis
= hlm_TrustSecuritiesMember
Junior Subordinated Debentures [Member]  
Schedule of Investments [Line Items]  
Total Assets $ 130,685us-gaap_Assets
/ us-gaap_InvestmentTypeAxis
= hlm_JuniorSubordinatedDebenturesMember