Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Thousands	3 Months Ended
	Mar. 28, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 315,339
Accumulated impairment losses, beginning balance	(44,519)
Goodwill, net, beginning balance	270,820
Goodwill acquired	8,935
Impairment losses	(21,607)
Foreign currency translation adjustments	26
Goodwill, gross, ending balance	324,300
Accumulated impairment losses, ending balance	(66,126)
Goodwill, net, ending balance	258,174
Office Furniture
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	128,677
Accumulated impairment losses, beginning balance	(44,376)
Goodwill, net, beginning balance	84,301
Goodwill acquired	0
Impairment losses	(21,607)
Foreign currency translation adjustments	26
Goodwill, gross, ending balance	128,703
Accumulated impairment losses, ending balance	(65,983)
Goodwill, net, ending balance	62,720
Hearth Products
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	186,662
Accumulated impairment losses, beginning balance	(143)
Goodwill, net, beginning balance	186,519
Goodwill acquired	8,935
Impairment losses	0
Foreign currency translation adjustments	0
Goodwill, gross, ending balance	195,597
Accumulated impairment losses, ending balance	(143)
Goodwill, net, ending balance	$ 195,454