Douglas Dynamics, Inc. Annual report pursuant to Section 13 and 15(d)

Changes in Accumulated Other Comprehensive Loss by Component - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amounts reclassified from accumulated other comprehensive loss:
Interest expense, net									$ 18,336	$ 15,195	$ 10,895
Tax expense (benefit)									(2,409)	24,687	22,087
Reclassification net of tax	$ (34,528)	$ (9,327)	$ (14,746)	$ 3,277	$ (10,101)	$ (7,302)	$ (16,328)	$ (5,278)	(54,609)	(38,469)	$ (43,572)
Other Postretirement Benefit Liability \| Amount reclassified from accumulated other comprehensive income
Amounts reclassified from accumulated other comprehensive loss:
Actuarial (gains) losses									(107)	(127)
Tax expense (benefit)									41	48
Reclassification net of tax									(66)	(79)
Pension Liability \| Amount reclassified from accumulated other comprehensive income
Amounts reclassified from accumulated other comprehensive loss:
Actuarial (gains) losses									723	724
Tax expense (benefit)									(275)	(275)
Reclassification net of tax									448	449
Unrealized Net Loss on Interest Rate Swap \| Interest rate swap \| Amount reclassified from accumulated other comprehensive income
Amounts reclassified from accumulated other comprehensive loss:
Interest expense, net									330	390
Tax expense (benefit)									(125)	(148)
Reclassification net of tax									$ 205	$ 242