Reportable Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019 USD ($)	Sep. 29, 2018 USD ($)	Sep. 28, 2019 USD ($) segment	Sep. 29, 2018 USD ($)	Dec. 29, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Net sales	$ 625,386	$ 611,120	$ 1,630,868	$ 1,659,803
Operating income	60,656	53,626	87,581	84,372
Interest expense, net	2,205	2,522	6,795	7,375
Income before income taxes	58,451	51,104	80,786	76,997
Depreciation and amortization	19,386	18,607	57,838	55,887
Capital Expenditures (including capitalized software):	12,584	14,655	50,191	46,979
Identifiable Assets:	1,470,476		1,470,476		$ 1,401,844
Operating segments | Office Furniture
Segment Reporting Information [Line Items]
Net sales	484,755	471,687	1,247,778	1,276,480
Operating income	51,162	45,721	68,180	64,898
Depreciation and amortization	11,232	11,012	33,540	33,202
Capital Expenditures (including capitalized software):	6,524	10,324	29,190	35,321
Identifiable Assets:	872,501		872,501		797,574
Operating segments | Hearth Products
Segment Reporting Information [Line Items]
Net sales	140,631	139,433	383,090	383,323
Operating income	23,772	21,824	54,743	55,250
Depreciation and amortization	2,291	2,026	6,521	6,080
Capital Expenditures (including capitalized software):	3,204	2,150	10,779	6,317
Identifiable Assets:	379,534		379,534		352,060
General corporate
Segment Reporting Information [Line Items]
Operating income	(14,278)	(13,919)	(35,342)	(35,776)
Depreciation and amortization	5,863	5,569	17,777	16,605
Capital Expenditures (including capitalized software):	2,856	$ 2,181	10,222	$ 5,341
Identifiable Assets:	$ 218,441		$ 218,441		$ 252,210