CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2018	Dec. 30, 2017
Accounts receivable, reserve for doubtful accounts	$ 13,414	$ 13,182
Property, plant and equipment, accumulated depreciation	150,869	142,278
Finite-Lived Intangible Assets, Accumulated Amortization	$ 218,451	$ 207,334
Preferred stock, par value (in usd per share)	$ 10	$ 10
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Common stock, shares authorized	95,000,000	95,000,000
Common stock, shares issued	62,599,365	62,619,865
Treasury stock, shares	6,889,241	6,889,241