DEBT (Details)	3 Months Ended
Mar. 31, 2019 USD ($) instrument item	Dec. 31, 2018 USD ($)
Debt Instruments
Aggregate principal amount outstanding	$ 6,845,000
Number of letters of credit issued \| item	2
Letter Of Credit
Debt Instruments
Funds borrowed under Line of Credit	$ 0
Credit Agreement
Debt Instruments
Borrowing, repaying and re-borrowing capacity	$ 20,000,000
Percentage of maximum borrowing capacity on eligible accounts receivable	80.00%
Percentage of maximum borrowing capacity on eligible core equipment	50.00%
Maximum borrowing capacity on core equipment	$ 12,500,000
Interest rate (as a percent)	4.50%
Minimum tangible net worth	$ 100,000,000
Credit Agreement \| Prime rate
Debt Instruments
Variable interest rate basis	prime rate
Credit Agreement \| Minimum
Debt Instruments
Ratio of current assets to current liabilities	1.50
Credit Agreement \| Minimum \| Prime rate
Debt Instruments
Interest rate (as a percent)	2.50%
Credit Agreement \| Maximum
Debt Instruments
Debt to tangible net worth ratio	1.00
Insurance Obligations
Debt Instruments
Letters of credit issued	$ 1,767,000
Workers' Compensation Insurance
Debt Instruments
Letters of credit issued	$ 583,000
Notes payable to commercial banks
Debt Instruments
Number of outstanding notes payable \| instrument	1
Aggregate principal amount outstanding	$ 5,432,000	$ 5,975,000
Interest rate (as a percent)	5.00%	5.00%

Represents the ratio of current assets to current liabilities

No definition available.

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

- Definition

Represents the ratio of debt to tangible net worth ratio to be maintained during the period.

+ References

No definition available.

+ Details

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

- Definition

Represents the maximum borrowing capacity of the second feature on the Line Of Credit.

+ References

No definition available.

+ Details

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Namespace Prefix:	dwsn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the number of letters of credit issued and outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	dwsn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of outstanding notes payable.

+ References

No definition available.

+ Details

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Namespace Prefix:	dwsn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of maximum borrowing capacity on eligible accounts receivable.

+ References

No definition available.

+ Details

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Namespace Prefix:	dwsn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum percentage allowed to be borrowed against core equipment.

+ References

No definition available.

+ Details

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Namespace Prefix:	dwsn_
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Balance Type:	na
Period Type:	duration

- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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 3: http://fasb.org/us-gaap/role/ref/legacyRef
-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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

- Definition

The lowest amount of net worth (total assets minus total liabilities) required by secondary market investors or state-imposed regulatory mandates.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)(a)
-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
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- Details

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