Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 29, 2018	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Goodwill [Line Items]
Gain on sale and license of intangible assets	$ 6,000,000
Goodwill impairment			$ 12,168,000	$ 4,838,000
Intangible assets, net (including goodwill)			463,290,000	490,892,000
Goodwill			270,788,000	279,505,000	$ 290,699,000
Trade names, net value			28,788,000	29,201,000
Impairment of long-lived assets		$ 0	0
Office furniture reporting unit one
Goodwill [Line Items]
Goodwill impairment			12,200,000
Goodwill			$ 7,500,000
Office furniture reporting unit two
Goodwill [Line Items]
Discount rate utilized for each reporting unit with rates range (percent)			14.00%
Terminal growth (percent)			3.00%
Decrease in reporting unit due to 100 basis point increase in discount rate			$ 2,300,000
Decrease in reporting unit due to 100 basis point decrease in long-term growth rate			$ 500,000
Office furniture reporting unit two | Minimum
Goodwill [Line Items]
Near term growth (percent)			1.00%
Office furniture reporting unit two | Maximum
Goodwill [Line Items]
Near term growth (percent)			6.00%
Office Furniture
Goodwill [Line Items]
Goodwill impairment		$ 0	$ 12,168,000	4,838,000
Goodwill			$ 84,269,000	$ 96,449,000	$ 107,643,000