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Stockholders' Equity and Stock Plans - Narrative (Details) $ / shares in Units, $ in Thousands					3 Months Ended	12 Months Ended				20 Months Ended
		Jan. 24, 2020 USD ($) $ / shares	Nov. 27, 2018	Jul. 01, 2017 shares	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares		Dec. 31, 2018 USD ($) $ / shares shares		Dec. 31, 2019 USD ($) $ / shares shares	Apr. 23, 2018 USD ($)	Jul. 06, 2017 $ / shares shares	May 11, 2010 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock split ratio			2
Shares withheld for tax withholding and exercise of options (in shares) | shares						7,795		46,794
Adjustments related to tax withholding and exercise of options for share-based compensation						$ 326		$ 1,700
Shares withheld for tax withholding and exercise of options, weighted average price (usd per share) | $ / shares						$ 41.84		$ 36.28
Total compensation cost for share-based payment arrangements						$ 1,500		$ 1,700
Share-based compensation income tax benefit recognized						389		404
Unrecognized compensation expense						$ 783				$ 783
Period for recognizing unrecognized compensation expense						1 year 8 months 12 days
Excess tax benefits recorded as a reduction to income tax expense						$ 145		$ 484
Percentage of share ownership defining an acquiring person												10.00%
Preferred stock, authorized (in shares) | shares						5,000,000		5,000,000		5,000,000
Preferred stock, no par value (in dollars per share) | $ / shares						$ 0		$ 0		$ 0
Amount reclassified from AOCI to retained earnings representing stranded tax income effects					$ 638
Stock repurchase program, authorized amount											$ 25,000
Stock repurchased, net of commissions						$ 15,022		$ 7,012		$ 22,000
Subsequent event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividends declared per common share (usd per share) | $ / shares		$ 0.22
Stock repurchase program, authorized amount		$ 25,000
Restricted stock award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total grant-date fair value of option shares vested						$ 1,200		967
Restricted stock award | During 2006 through 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						5 years
Expiration period of grants						10 years
Restricted stock award | During 2006 through 2014 | Vesting Rate, Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Restricted stock award | During 2006 through 2014 | Vesting Rate, Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Restricted stock award | During 2006 through 2014 | Vesting Rate Year Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Restricted stock award | During 2006 through 2014 | Vesting Rate Year Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Restricted stock award | During 2006 through 2014 | Vesting Rate Year Five
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of grants						10 years
Total grant-date fair value of option shares vested						$ 473		$ 543
Stock options | During 2006 through 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						5 years
Expiration period of grants						10 years
Stock options | During 2006 through 2014 | Vesting Rate, Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | During 2006 through 2014 | Vesting Rate, Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | During 2006 through 2014 | Vesting Rate Year Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | During 2006 through 2014 | Vesting Rate Year Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | During 2006 through 2014 | Vesting Rate Year Five
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Prior to 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						4 years
Expiration period of grants						7 years
Stock options | Prior to 2016 | Vesting Rate, Year One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Prior to 2016 | Immediately Upon Grant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Prior to 2016 | Vesting Rate, Year Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Prior to 2016 | Vesting Rate Year Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Prior to 2016 | Vesting Rate Year Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						20.00%
Stock options | Subsequent To January 1, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						33.00%
Award vesting period						3 years
Expiration period of grants						10 years
Stock options | During 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						33.00%
Award vesting period						3 years
Expiration period of grants						10 years
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period						3 years
Minimum | Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						0.00%
Maximum | Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						200.00%
Director Stock Plan, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved to be issued in common stock (in shares) | shares													300,000
Number of shares available for future grants under plan (in shares) | shares						208,263				208,263
Employee Stock Purchase Plan, 2007
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved to be issued in common stock (in shares) | shares				385,370
Number of shares available for future grants under plan (in shares) | shares						382,515				382,515
Discount from closing market price at end of each quarter				5.00%
Employee Stock Purchase Plan, 2007 | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Approved payroll deduction to purchase shares, percentage				1.00%
Employee Stock Purchase Plan, 2007 | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Approved payroll deduction to purchase shares, percentage				15.00%
The 2017 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future grants under plan (in shares) | shares						989,630				989,630
Common Stock | Director Stock Plan, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares awarded in period from plan (in shares) | shares						5,544		5,470
Series A Junior Participating Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, authorized (in shares) | shares						1,000,000				1,000,000
Preferred stock, no par value (in dollars per share) | $ / shares						$ 0				$ 0
Retained Earnings
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount reclassified from AOCI to retained earnings representing stranded tax income effects					$ 638			$ 638
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld for tax withholding and exercise of options (in shares) | shares	[1]					5,240		1,316
Stock repurchased, net of commissions (in shares) | shares						356,000	[1]	171,217	[1]	527,217
Stock repurchased, net of commissions						$ 15,022		$ 7,012
Series A Junior Participating Preferred Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of rights (in dollars per share) | $ / shares												$ 0.9
Number of securities called by each right (in shares) | shares												0.005
[1] Share and per share data have been adjusted to reflect the two-for-one stock split effective November 27, 2018.

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