Represents the number of letters of credit issued and outstanding.

No definition available.

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

Represents the percentage of maximum borrowing capacity on deposits with the lender in the Company's collateral account.

+ 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 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

Face (par) amount of debt instrument at time of issuance.

+ References

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-Name Accounting Standards Codification
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+ Details

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

- Definition

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

+ References

+ Details

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

- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
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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.

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+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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

- Definition

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

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Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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+ Details

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

- Definition

Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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

- Details

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Debt (Details)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) instrument item	Dec. 31, 2018 USD ($)
Debt Instruments
Finance lease obligations		$ 2,412,000	$ 5,125,000
Restricted money market		$ 5,000,000
Dominion Revolving Credit Facility
Debt Instruments
Maximum borrowing capacity	$ 15,000,000
Percentage of maximum borrowing capacity on eligible accounts receivable	80.00%
Percentage of maximum borrowing capacity on deposit with lender	100.00%
Commitment fee (as a percent)	0.10%
Minimum tangible net worth	$ 75,000,000
Restricted money market	$ 5,000,000
Dominion Revolving Credit Facility \| Minimum
Debt Instruments
Interest rate (as a percent)	3.50%
Dominion Revolving Credit Facility \| Maximum
Debt Instruments
Interest rate (as a percent)	6.00%
Veritex Line of Credit
Debt Instruments
Amounts borrowed under Line of Credit	$ 0
Repayment of term loan	$ 4,355,665
Veritex Letters of Credit
Debt Instruments
Number of letters of credit \| item		2
First Veritex Letters of Credit
Debt Instruments
Amount of letter of credit		$ 1,767,000
Second Veritex Letters of Credit
Debt Instruments
Amount of letter of credit		$ 583,000
Notes payable to finance companies for insurance
Debt Instruments
Interest rate (as a percent)			3.80%
Number of notes payable \| instrument		2
Notes payable to finance companies for insurance \| Minimum
Debt Instruments
Interest rate (as a percent)		4.05%
Notes payable to finance companies for insurance \| Maximum
Debt Instruments
Interest rate (as a percent)		4.99%