XML 50 R36.htm IDEA: XBRL DOCUMENT v3.20.4

Short-Term Investments (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Minimum
Maturity period of certificates of deposit	3 months	3 months
Maximum
Maturity period of certificates of deposit	1 year	1 year

X

- Definition

Remaining maturity of certificates of deposit, in 'PnYnMnDTnHnMnS' format.

+ References

No definition available.

+ Details

Name:	dwsn_CertificatesOfDepositMaturityPeriod
Namespace Prefix:	dwsn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: