Building And Land Mortgage.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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- Definition

Earnings before interest taxes depreciation and amortization.

+ References

No definition available.

+ Details

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Namespace Prefix:	hdsn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fixed charge coverage ratio

+ References

No definition available.

+ Details

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Namespace Prefix:	hdsn_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6455314&loc=d3e45014-112735

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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- Definition

For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions).

+ References

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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- Details

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Balance Type:
Period Type:

- Details

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Short-term and long-term debt - Additional Information (Detail) (USD $)	12 Months Ended	1 Months Ended
	Dec. 31, 2014	Oct. 25, 2013	Dec. 31, 2013	Feb. 15, 2013	Jun. 01, 2012
Debt Disclosure [Line Items]
Maximum borrowing under PNC facility				$ 40,000,000
Fees and expenses relating to creation of PNC facility	112,000us-gaap_DeferredFinanceCostsNet
Available borrowing under PNC facility	15,000,000
PNC Facility effective rate of interest	4.25%
Interest rate description under PNC facility	Interest charges with respect to loans are computed on the actual principal amount of loans outstanding during the month at a rate per annum equal to (A) with respect to Domestic Rate Loans (as defined in the PNC Facility), the sum of (i) a rate per annum equal to the higher of (1) the base commercial lending rate of PNC, (2) the federal funds open rate plus .5% and (3) the daily LIBOR plus 1%, plus (ii) .5% and (B) with respect to Eurodollar Rate Loans, the sum of the Eurodollar Rate plus 2.75%.
Earnings Before Interest Taxes Depreciation And Amortization	1,116,000
Borrowings outstanding under PNC facility	10,056,000us-gaap_LineOfCredit
Principal balance of this mortgage note	437,000hdsn_BuildingAndLandMortgage		603,000hdsn_BuildingAndLandMortgage
Capital leased assets gross	57,000us-gaap_CapitalLeasedAssetsGross
Minimum
Debt Disclosure [Line Items]
Fixed charge coverage ratio	1.00	1.00
Maximum
Debt Disclosure [Line Items]
Fixed charge coverage ratio	1.10	1.10
Term Loan
Debt Disclosure [Line Items]
Maximum borrowing under PNC facility				4,000,000
Term Loan \| Base Rate
Debt Disclosure [Line Items]
Debt instrument, description of variable rate basis	Base Rate plus one percent
Term Loan \| Eurodollar
Debt Disclosure [Line Items]
Debt instrument, description of variable rate basis	Eurodollar Rate plus two and three quarters of one percent
Revolving Credit Facility
Debt Disclosure [Line Items]
Maximum borrowing under PNC facility				36,000,000
Revolving Credit Facility \| Base Rate
Debt Disclosure [Line Items]
Debt instrument, description of variable rate basis	Base Rate (as defined in the PNC Facility) plus one percent
Revolving Credit Facility \| Eurodollar
Debt Disclosure [Line Items]
Debt instrument, description of variable rate basis	Eurodollar Rate plus two and three quarters of one percent
Mortgage Note
Debt Disclosure [Line Items]
Maximum borrowing under PNC facility					$ 855,000
PNC Facility effective rate of interest					4.00%
PNC credit Facility expiration date	Jun. 01, 2017
Vehicle And Equipment Loans \| Minimum
Debt Disclosure [Line Items]
PNC Facility effective rate of interest	2.90%
Vehicle And Equipment Loans \| Maximum
Debt Disclosure [Line Items]
PNC Facility effective rate of interest	8.90%