Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock Including Additional Paid in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2018		$ 83,826	$ 180,356	$ (264)	$ (7,357)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan		1,118
Stock Options Exercised		1,409
Stock Awards Vested		(2)
Stock Repurchased Related to the Exercise of Stock Options and Stock Awards Vested		(4,729)
Stock-Based Compensation		5,322
Net Income	$ 23,590
Other Comprehensive Income, Net of Tax	510				510
Ending Balance at Sep. 28, 2019	283,779	86,944	203,682		(6,847)
Beginning Balance at Jun. 29, 2019		83,959	195,379		(7,108)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan		1,118
Stock Options Exercised		570
Stock Awards Vested		(1)
Stock Repurchased Related to the Exercise of Stock Options and Stock Awards Vested		(753)
Stock-Based Compensation		2,051
Net Income	8,303
Other Comprehensive Income, Net of Tax	261				261
Ending Balance at Sep. 28, 2019	283,779	86,944	203,682		(6,847)
Beginning Balance at Dec. 31, 2019	292,800	88,515	212,553		(8,268)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan		2,197
Stock Options Exercised		349
Stock Awards Vested		(1)
Stock Repurchased Related to the Exercise of Stock Options and Stock Awards Vested		(2,765)
Stock-Based Compensation		6,605
Net Income	19,521
Other Comprehensive Income, Net of Tax	729				729
Ending Balance at Sep. 26, 2020	319,435	94,900	232,074		(7,539)
Beginning Balance at Jun. 27, 2020		91,762	225,573		(7,728)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan		1,085
Stock Options Exercised		79
Stock Repurchased Related to the Exercise of Stock Options and Stock Awards Vested		(102)
Stock-Based Compensation		2,076
Net Income	6,501
Other Comprehensive Income, Net of Tax	189				189
Ending Balance at Sep. 26, 2020	$ 319,435	$ 94,900	$ 232,074		$ (7,539)