Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2012	Oct. 01, 2011	Sep. 29, 2012 Segment	Oct. 01, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments			2
Net sales	$ 550,855	$ 504,220	$ 1,476,467	$ 1,333,181
Income before income taxes	39,240	38,102	49,734	42,914
Depreciation and amortization expense	10,747	11,373	32,104	35,135
Capital expenditures	19,593	5,622	44,659	20,194
Identifiable assets	1,122,782	1,055,184	1,122,782	1,055,184	1,054,258
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total operating profit	47,510	48,374	79,412	72,780
Office Furniture [Member]
Segment Reporting Information [Line Items]
Net sales	467,787	421,873	1,264,953	1,125,643
Operations before restructuring charges	38,605	41,776	69,707	69,161
Restructuring and impairment charges	(172)	(277)	(1,361)	(1,711)
Total operating profit	38,433	41,499	68,346	67,450
Depreciation and amortization expense	8,542	8,855	25,423	27,308
Capital expenditures	10,206	4,578	25,206	15,812
Identifiable assets	725,763	618,588	725,763	618,588
Hearth Products [Member]
Segment Reporting Information [Line Items]
Net sales	83,068	82,347	211,514	207,538
Operations before restructuring charges	9,077	6,875	11,066	5,749
Restructuring and impairment charges	0	0	0	(419)
Total operating profit	9,077	6,875	11,066	5,330
Depreciation and amortization expense	1,454	1,818	4,519	5,925
Capital expenditures	519	975	1,472	1,980
Identifiable assets	272,951	282,168	272,951	282,168
Unallocated Amount to Segment [Member]
Segment Reporting Information [Line Items]
Unallocated corporate expense	(8,270)	(10,272)	(29,678)	(29,866)
Depreciation and amortization expense	751	700	2,162	1,902
Capital expenditures	8,868	69	17,981	2,402
Identifiable assets	$ 124,068	$ 154,428	$ 124,068	$ 154,428