Business acquisition cost of acquired entity junior subordinated debentures.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

+ Details

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Details

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- Details

Name:	dei_LegalEntityAxis=hlm_CapitalAdvisorsLlcMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	us-gaap_BusinessAcquisitionAxis=hlm_OakHillCapitalPartnersMember
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- Details

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- Details

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- Details

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Basis of Presentation - Additional Information (Detail) $ in Thousands		6 Months Ended
	May 16, 2014 USD ($)	Jun. 30, 2016 USD ($) Segment	Dec. 31, 2015 USD ($)	May 15, 2014
Business Acquisition [Line Items]
Aggregate purchase price	$ 1,504,498
Goodwill		$ 617,050	$ 615,515
Number of business segments \| Segment		5
Junior Subordinated Debentures [Member]
Business Acquisition [Line Items]
Outstanding debt	$ 105,443
Capital Advisors LLC [Member]
Business Acquisition [Line Items]
Ownership percentage	80.40%
Oak Hill Capital Partners [Member] \| Predecessor [Member]
Business Acquisition [Line Items]
Ownership percentage				95.60%
Oak Hill Capital Partners [Member] \| Successor [Member]
Business Acquisition [Line Items]
Ownership percentage	16.90%
Member Of Management [Member] \| Predecessor [Member]
Business Acquisition [Line Items]
Ownership percentage				4.40%
Member Of Management [Member] \| Successor [Member]
Business Acquisition [Line Items]
Ownership percentage	2.70%