Goodwill and Other Intangible Assets (Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 28, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	$ 315,307
Accumulated impairment losses, beginning balance	(44,519)
Goodwill, net, beginning balance	270,788
Foreign currency translation adjustments	(7)
Goodwill, gross, ending balance	315,300
Accumulated impairment losses, ending balance	(44,519)
Goodwill, net, ending balance	270,781
Office Furniture
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	128,645
Accumulated impairment losses, beginning balance	(44,376)
Goodwill, net, beginning balance	84,269
Foreign currency translation adjustments	(7)
Goodwill, gross, ending balance	128,638
Accumulated impairment losses, ending balance	(44,376)
Goodwill, net, ending balance	84,262
Hearth Products
Goodwill [Roll Forward]
Goodwill, gross, beginning balance	186,662
Accumulated impairment losses, beginning balance	(143)
Goodwill, net, beginning balance	186,519
Foreign currency translation adjustments	0
Goodwill, gross, ending balance	186,662
Accumulated impairment losses, ending balance	(143)
Goodwill, net, ending balance	$ 186,519