Business Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2015 USD ($)	Sep. 27, 2014 USD ($)	Oct. 03, 2015 USD ($) Segment	Sep. 27, 2014 USD ($)	Jan. 03, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			2
Net sales	$ 615,850	$ 614,690	$ 1,707,553	$ 1,576,034
Income before income taxes	59,465	50,868	110,542	81,994
Depreciation and amortization expense	14,504	14,812	42,299	41,764
Capital expenditures (including capitalized software)	31,691	30,627	81,573	81,748
Identifiable assets	1,322,433		1,322,433		$ 1,239,334
Operating Segments [Member]
Segment Reporting Information [Line Items]
Income before income taxes	71,887	66,538	155,493	121,462
Operating Segments [Member] | Office Furniture [Member]
Segment Reporting Information [Line Items]
Net sales	475,960	488,612	1,334,013	1,270,404
Income before income taxes	48,389	42,753	108,332	77,488
Depreciation and amortization expense	10,644	12,427	31,284	34,398
Capital expenditures (including capitalized software)	19,590	13,542	45,989	43,378
Identifiable assets	769,641		769,641		724,293
Operating Segments [Member] | Hearth Products [Member]
Segment Reporting Information [Line Items]
Net sales	139,890	126,078	373,540	305,630
Income before income taxes	23,498	23,785	47,161	43,974
Depreciation and amortization expense	2,166	1,121	6,171	3,455
Capital expenditures (including capitalized software)	2,798	1,691	7,195	4,389
Identifiable assets	374,716		374,716		341,315
Corporate [Member]
Segment Reporting Information [Line Items]
Income before income taxes	(12,422)	(15,670)	(44,951)	(39,468)
Depreciation and amortization expense	1,694	1,264	4,844	3,911
Capital expenditures (including capitalized software)	9,303	$ 15,394	28,389	$ 33,981
Identifiable assets	$ 178,076		$ 178,076		$ 173,726