Annual report pursuant to Section 13 and 15(d)

Long-Term Debt - Additional Information (Detail)

v2.4.1.9
Long-Term Debt - Additional Information (Detail) (USD $)
12 Months Ended 0 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Jun. 30, 2014
Debt Instrument [Line Items]      
Interest underlying the Trust Preferred Securities 11.60%hlm_TrustPreferredSecuritiesInterestRate    
Face amount Subordinated Debentures underlying Trust Preferred Securities $ 105,443,000hlm_TrustPreferredSecurityAtFaceValue    
Aggregate amount of Subordinated Debentures underlying Trust Preferred Securities 12,231,000hlm_InterestOnTrustPreferredSecuritiesAmount    
Deferral Period of distribution payments to holders of the Trust Preferred Securities 60 months    
Deferrals of distribution payments to holders of Trust Preferred Securities 0us-gaap_InterestExpenseTrustPreferredSecurities 0us-gaap_InterestExpenseTrustPreferredSecurities  
Trust Preferred Securities, redemption description The Trust will redeem the preferred securities when the debentures are repaid, or at maturity on September 30, 2027.    
Maturity date of trust preferred securities Sep. 30, 2027    
Letter of credit commitments outstanding 3,723,000us-gaap_LettersOfCreditOutstandingAmount    
Prior Credit Agreement [Member]      
Debt Instrument [Line Items]      
Senior Notes, maturity date May 28, 2017    
6.375% Senior Notes [Member]      
Debt Instrument [Line Items]      
Principal amount of Senior Notes 330,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LongtermDebtTypeAxis
= hlm_SixPointThreeSevenFivePercentSeniorNotesMember
   
Interest rate on Senior Notes 6.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= hlm_SixPointThreeSevenFivePercentSeniorNotesMember
6.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= hlm_SixPointThreeSevenFivePercentSeniorNotesMember
 
Senior Notes, maturity date Jul. 15, 2022    
10.875% Senior Notes [Member]      
Debt Instrument [Line Items]      
Interest rate on Senior Notes 10.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= hlm_TenPointEightSevenFivePercentageSeniorNotesMember
10.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LongtermDebtTypeAxis
= hlm_TenPointEightSevenFivePercentageSeniorNotesMember
 
Senior Notes, maturity date Jun. 01, 2018    
10.875% Senior Notes [Member] | Prior Credit Agreement [Member]      
Debt Instrument [Line Items]      
Principal amount of Senior Notes 265,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_InvestmentTypeAxis
= hlm_OldCreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= hlm_TenPointEightSevenFivePercentageSeniorNotesMember
   
Interest rate on Senior Notes 10.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_InvestmentTypeAxis
= hlm_OldCreditAgreementMember
/ us-gaap_LongtermDebtTypeAxis
= hlm_TenPointEightSevenFivePercentageSeniorNotesMember
   
Term Loan B [Member]      
Debt Instrument [Line Items]      
LIBOR interest rate in Term B Loans 4.50%hlm_LiborInterestRate
/ us-gaap_LongtermDebtTypeAxis
= hlm_TermBLoanMember
   
Senior Secured Credit Facility [Member]      
Debt Instrument [Line Items]      
Senior secured credit facility consisting of revolver and term loan     620,000,000us-gaap_LongTermDebt
/ us-gaap_CreditFacilityAxis
= hlm_SeniorSecuredCreditFacilityMember
Term Loan [Member]      
Debt Instrument [Line Items]      
Credit facility     550,000,000us-gaap_LoansPayable
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
Maturity term of loan     7 years
Debt instrument variable rate description The Senior Facilities provide term loan borrowings at interest rates based on LIBOR plus a LIBOR Spread of 3.50%, or an Alternate Base Rate ("ABR") plus an ABR Spread of 2.50%.    
Adjusted interest rate 4.50%us-gaap_LongTermDebtPercentageBearingVariableInterestRate
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
   
Term Loan [Member] | Prior Credit Agreement [Member]      
Debt Instrument [Line Items]      
Credit facility 384,400,000us-gaap_LoansPayable
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
/ us-gaap_InvestmentTypeAxis
= hlm_OldCreditAgreementMember
   
Revolving Credit Facility [Member]      
Debt Instrument [Line Items]      
Credit facility     70,000,000us-gaap_LineOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
Maturity term of loan     5 years
Debt instrument variable rate description The Senior Facilities provide Revolver borrowings at interest rates based on LIBOR plus a LIBOR Spread of 3.25%, or an ABR plus an ABR Spread of 2.25%. There is no minimum floor rate for Revolver loans.    
Debt instrument maximum borrowing capacity 35.00%us-gaap_DebtInstrumentInterestRateEffectivePercentageRateRangeMaximum
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
   
Letter of credit commitments outstanding 66,277,000us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
   
Revolving Credit Facility [Member] | Prior Credit Agreement [Member]      
Debt Instrument [Line Items]      
Credit facility 30,000,000us-gaap_LineOfCredit
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_InvestmentTypeAxis
= hlm_OldCreditAgreementMember
   
Letter of Credit [Member]      
Debt Instrument [Line Items]      
Debt instrument maximum borrowing capacity 5.00%us-gaap_DebtInstrumentInterestRateEffectivePercentageRateRangeMaximum
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
   
Letter of credit commitments outstanding 3,700,000us-gaap_LettersOfCreditOutstandingAmount
/ us-gaap_CreditFacilityAxis
= us-gaap_LetterOfCreditMember
   
Secured Credit Facility [Member]      
Debt Instrument [Line Items]      
Credit facility 547,857,000us-gaap_DebtAndCapitalLeaseObligations
/ us-gaap_CreditFacilityAxis
= hlm_SecuredCreditFacilityMember
   
Credit facility 607,000us-gaap_CapitalLeaseObligations
/ us-gaap_CreditFacilityAxis
= hlm_SecuredCreditFacilityMember
   
Secured Credit Facility [Member] | Term Loan B [Member]      
Debt Instrument [Line Items]      
Credit facility $ 547,250,000us-gaap_LoansPayable
/ us-gaap_CreditFacilityAxis
= hlm_SecuredCreditFacilityMember
/ us-gaap_LongtermDebtTypeAxis
= hlm_TermBLoanMember
   
London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member]      
Debt Instrument [Line Items]      
Debt instrument spread variable rate 3.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member] | Minimum [Member]      
Debt Instrument [Line Items]      
Debt instrument floor rate 1.00%hlm_DebtInstrumentFloorRate
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]      
Debt Instrument [Line Items]      
Debt instrument spread variable rate 3.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
Adjusted interest rate 3.25%us-gaap_LongTermDebtPercentageBearingVariableInterestRate
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember
   
Alternate Base Rate [Member] | Term Loan [Member]      
Debt Instrument [Line Items]      
Debt instrument spread variable rate 2.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
/ us-gaap_VariableRateAxis
= hlm_AlternateBaseRateMember
   
Alternate Base Rate [Member] | Term Loan [Member] | Minimum [Member]      
Debt Instrument [Line Items]      
Debt instrument floor rate 2.00%hlm_DebtInstrumentFloorRate
/ us-gaap_CreditFacilityAxis
= hlm_TermLoanMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember
/ us-gaap_VariableRateAxis
= hlm_AlternateBaseRateMember
   
Alternate Base Rate [Member] | Revolving Credit Facility [Member]      
Debt Instrument [Line Items]      
Adjusted interest rate 2.25%us-gaap_LongTermDebtPercentageBearingVariableInterestRate
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= hlm_AlternateBaseRateMember
   
Base Rate [Member] | Revolving Credit Facility [Member]      
Debt Instrument [Line Items]      
Debt instrument spread variable rate 2.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= us-gaap_RevolvingCreditFacilityMember
/ us-gaap_VariableRateAxis
= us-gaap_BaseRateMember