Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2019	Mar. 29, 2019	Jun. 29, 2018	Mar. 30, 2018	Jun. 28, 2019	Jun. 29, 2018
Equity, Class of Treasury Stock [Line Items]
Total cost	$ 1,440,000	$ 1,616,000		$ 964,000
Amount available under repurchase plan	3,900,000				$ 3,900,000
Stock repurchase authorized	$ 142,200,000				$ 142,200,000
Shares repurchased for employee net vesting obligations, shares	825		11		124	184
Shares repurchased for employee net vesting obligations, value	$ 14,000		$ 200,000		$ 2,400,000	$ 3,100,000
Dividend declared	$ 0.18
Dividend payment	$ 5,789,000		$ 5,396,000
Dividend declared, date of payment	Jul. 10, 2019
Minimum [Member]
Equity, Class of Treasury Stock [Line Items]
Dividend declared					$ 0.34
Maximum [Member]
Equity, Class of Treasury Stock [Line Items]
Dividend declared					$ 0.36
Share Repurchase Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchase of common stock	92				193	53
Purchase price per share	$ 15.59				$ 15.80	$ 18.33
Total cost	$ 1,400,000				$ 3,100,000	$ 1,000,000
Stock Appreciation Rights (SARs) [Member]
Equity, Class of Treasury Stock [Line Items]
SARs outstanding	2,900				2,900
Exercise price	$ 4.00				$ 4.00
Expiration date					Feb. 28, 2022