Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Common Shares Held In Treasury	Common Stock	Retained Earnings	Common Stock In Treasury	Accumulated Other Comprehensive Income (Loss)	Other Equity
Beginning balance (in shares) at Dec. 31, 2018		20,242
Beginning balances (in Treasury shares) at Dec. 31, 2018			(6,906)
Beginning balances at Dec. 31, 2018	$ 553,906			$ 234,704	$ 548,374	$ (175,426)	$ (58,234)	$ 4,488
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	16,906			0	16,906	0	0	0
Other comprehensive income (loss)	964			0	0	0	964	0
Cumulative effect of accounting change	(179)			0	(179)	0	0	0
Cash dividends declared	(2,125)			0	(2,125)	0	0	0
Stock-based compensation activity (in shares)		192	192
Stock-based compensation activity	1,547			6,759	(35)	(5,177)	0	0
Payments of withholding taxes for stock-based compensation awards (in shares)		(75)	(75)
Payments of withholding taxes for stock-based compensation awards	(3,978)			0	0	(3,978)	0	0
Repurchase of shares (in shares)		5	5
Repurchase of shares	(199)			0	0	(199)	0	0
Directors' deferred compensation	35	$ 0	$ 0	17	0	(32)	0	50
Ending balance (in shares) at Mar. 29, 2019		20,354
Ending balances (in Treasury shares) at Mar. 29, 2019			(6,794)
Ending balances at Mar. 29, 2019	566,877			241,480	562,941	(184,812)	(57,270)	4,538
Beginning balance (in shares) at Dec. 31, 2019		20,404
Beginning balances (in Treasury shares) at Dec. 31, 2019			(6,744)
Beginning balances at Dec. 31, 2019	610,677			249,674	589,888	(186,845)	(45,462)	3,422
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(3,103)			0	(3,103)	0	0	0
Other comprehensive income (loss)	(1,711)			0	0	0	(1,711)	0
Cash dividends declared	(2,245)			0	(2,245)	0	0	0
Stock-based compensation activity (in shares)		99	99
Stock-based compensation activity	1,584			4,262	(35)	(2,643)	0	0
Payments of withholding taxes for stock-based compensation awards (in shares)		(36)	(36)
Payments of withholding taxes for stock-based compensation awards	(2,015)			0	0	(2,015)	0	0
Repurchase of shares (in shares)		158	158
Repurchase of shares	(6,766)			0	0	(6,766)	0	0
Directors' deferred compensation	57	$ 1	$ 1	31	0	(42)	0	68
Ending balance (in shares) at Mar. 27, 2020		20,310
Ending balances (in Treasury shares) at Mar. 27, 2020			(6,838)
Ending balances at Mar. 27, 2020	$ 596,478			$ 253,967	$ 584,505	$ (198,311)	$ (47,173)	$ 3,490