Reportable Segment Information (Business Segment Information) (Details) $ in Thousands	12 Months Ended
	Dec. 29, 2018 USD ($) segment	Dec. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | segment	2
Net sales	$ 2,257,895	$ 2,175,882	$ 2,203,489
Operating Income (Loss)	128,173	76,690	133,692
Interest Expense	9,448	6,078	4,781
Total	118,725	70,612	128,911
Depreciation and amortization expense	74,788	72,872	68,947
Capital expenditures (including capitalized software)	63,696	127,391	119,584
Identifiable assets	1,401,844	1,391,550	1,330,234
Restructuring and impairment charges	15,725	37,416	11,005
Office Furniture
Segment Reporting Information [Line Items]
Restructuring and impairment charges	16,400	32,500	10,900
Hearth Products
Segment Reporting Information [Line Items]
Restructuring and impairment charges	1,200	4,900	5,500
Operating | Office Furniture
Segment Reporting Information [Line Items]
Net sales	1,706,092	1,660,723	1,703,885
Operating profit	79,323	50,176	117,397
Depreciation and amortization expense	44,303	48,435	45,088
Capital expenditures (including capitalized software)	47,860	79,458	65,944
Identifiable assets	797,574	821,767	749,145
Operating | Hearth Products
Segment Reporting Information [Line Items]
Net sales	551,803	515,159	499,604
Operating profit	91,367	83,649	69,960
Depreciation and amortization expense	8,171	10,109	12,486
Capital expenditures (including capitalized software)	8,854	17,356	11,217
Identifiable assets	352,060	347,189	340,494
General corporate
Segment Reporting Information [Line Items]
General corporate	(42,517)	(57,135)	(53,665)
Depreciation and amortization expense	22,314	14,328	11,373
Capital expenditures (including capitalized software)	6,982	30,577	42,423
Identifiable assets	$ 252,210	$ 222,594	$ 240,595