Subsequent Events (Details) - USD ($) $ in Thousands		9 Months Ended
	Oct. 31, 2019	Sep. 30, 2019	Sep. 30, 2018
Pension plan
Subsequent Events
Employer contributions during the period		$ 0	$ 7,047
Pension plan | Subsequent
Subsequent Events
Defined Benefit Plan Unrecognized Loss	$ 6,541
Douglas Dynamics LLC Pension Plan For Hourly Employees [Member] | Subsequent
Subsequent Events
Employer contributions during the period	3,245
Douglas Dynamics LLC Salaried Pension Plan [Member] | Subsequent
Subsequent Events
Employer contributions during the period	$ 12,476