Represents the assumed number of participants for determining the health care cost trend rate.

No definition available.

Name:	plow_DefinedBenefitPlanHealthCareCostTrendRateAssumedNumberOfParticipants
Namespace Prefix:	plow_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The ultimate trend rate for health care costs in the eight fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	plow_DefinedBenefitPlanUltimateHealthCareCostTrendRateInEightFiscalYear
Namespace Prefix:	plow_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The ultimate trend rate for health care costs in the ninth fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	plow_DefinedBenefitPlanUltimateHealthCareCostTrendRateInNinthFiscalYear
Namespace Prefix:	plow_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The ultimate trend rate for health care costs in the seventh fiscal year following the latest fiscal year.

+ References

No definition available.

+ Details

Name:	plow_DefinedBenefitPlanUltimateHealthCareCostTrendRateInSeventhFiscalYear
Namespace Prefix:	plow_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- Definition

Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan.

+ References

+ Details

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

- Definition

Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(3)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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

- Definition

Ultimate trend rate for health care cost for defined benefit postretirement plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanUltimateHealthCareCostTrendRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=plow_SalariedPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=plow_HourlyPensionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	plow_AgeCriteriaForMedicalBenefitsAxis=plow_UnderAge65Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Retirement Plans - Assumptions (Details)	12 Months Ended
Employee Retirement Plans - Assumptions (Details)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assumptions used in determining net periodic pension cost for the plans
Discount rates (as a percent)		3.60%
Minimum
Assumptions used in determining net periodic pension cost for the plans
Discount rates (as a percent)					4.20%
Pension plan
Assumptions used in determining net periodic pension cost for the plans
Rates of increase in compensation levels: Salaried (as a percent)		3.50%	3.50%	3.50%
Expected long-term rate of return on assets (as a percent)		5.80%	6.50%	7.25%
Assumptions used to determine the benefit obligation
Discount rate (as a percent)			4.20%	4.50%
Salaried Pension Plan
Assumptions used to determine the benefit obligation
Discount rate (as a percent)			3.60%
Salaried Pension Plan \| Forecast
Assumptions used in determining net periodic pension cost for the plans
Expected long-term rate of return on assets (as a percent)	3.60%
Hourly Pension Plan
Assumptions used in determining net periodic pension cost for the plans
Expected long-term rate of return on assets (as a percent)		6.50%	6.50%	7.25%
Assumptions used to determine the benefit obligation
Discount rate (as a percent)		4.20%	4.50%
Hourly Pension Plan \| Forecast
Assumptions used in determining net periodic pension cost for the plans
Expected long-term rate of return on assets (as a percent)	3.20%
Other postretirement benefit cost
Assumptions used in determining net periodic pension cost for the plans
Discount rates (as a percent)		3.40%	3.80%	4.10%
Summary of healthcare cost trend rates
Ultimate healthcare cost trend rate (as a percent)		4.50%	4.50%	4.50%
Participation (as a percent)		60.00%	60.00%	60.00%
Assumed health care cost trend rate for the next fiscal year (as a percent)		6.80%	7.00%
Ultimate rate in 2025 (as a percent)		4.50%
Ultimate rate in 2024 (as a percent)			4.50%
Ultimate rate in 2023 (as a percent)				4.50%
Assumptions used to determine the benefit obligation
Discount rate (as a percent)		3.80%	4.10%
Other postretirement benefit cost \| Under 65
Summary of healthcare cost trend rates
Assumed health care cost trend rate for the next fiscal year (as a percent)				7.00%