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Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Purchased

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Share based compensation arrangement by share based payment award yearly common stock shares received by non employee directors.

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Share based compensation, common stock allowed to purchase on market value.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of expense for employee benefit and equity-based compensation.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Discount rate from fair value on purchase date that participants pay for shares.

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Number of shares authorized for issuance under share-based payment arrangement.

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Gross number of share options (or share units) granted during the period.

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Per share weighted-average price paid for shares purchased on open market for issuance under share-based payment arrangement.

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The number of shares or units of entity securities issued in the transaction in which equity securities were issued to pay for goods or nonemployee services.

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Percentage of vesting of award under share-based payment arrangement.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of noncash expense for option under share-based payment arrangement.

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Stock-Based Compensation (Details Textual)		12 Months Ended
Stock-Based Compensation (Details Textual)	Jun. 01, 2015 shares	Jan. 02, 2021 USD ($) $ / shares shares	Jan. 02, 2021 GBP (£) shares	Dec. 28, 2019 USD ($) $ / shares shares	Dec. 29, 2018 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance		23,000
Fair value of RSUs/restricted stock granted \| $		$ 6,843,000		$ 5,079,000	$ 5,947,000
Recognized weighted average period (in years)		2 years 3 months 18 days	2 years 3 months 18 days
Contractual term of stock options		10 years	10 years
Unrecognized compensation cost related to the stock options \| $		$ 133,000
2012 Nonemployee Director Fees Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate number of shares authorized for grant		270,000
Shares available for issuance		71,549
Common stock shares for each nonemployee director	250
Fee for the chairs of each Board committee	150.00%
Annual retainer of common stock received by non employee directors		2,000	2,000
Stock option granted, shares		26,675	26,675	25,200
Share-based compensation expenses under Director's plan \| $		$ 1,178,000		$ 1,162,000	1,213,000
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Aggregate number of shares authorized for grant		1,096,875
Rate of common stock at market value		85.00%	85.00%
Employee Stock Purchase Plan and U.K. Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance		411,629
Number of shares purchased by employees		43,574	43,574	49,195
Weighted average price \| $ / shares		$ 30.86		$ 33.55
Share-based compensation expenses \| $		$ 431,000		$ 551,000	324,000
Minimum [Member] \| Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allowable employees purchase rate of common stock based on annual salary		10.00%	10.00%
Minimum [Member] \| Employee Stock Purchase Plan [Member] \| United States [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares allowed to be purchased by employees \| $		$ 25,000
Minimum [Member] \| Employee Stock Purchase Plan [Member] \| United Kingdom [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares allowed to be purchased by employees \| £			£ 1,500
Maximum [Member] \| 2012 Nonemployee Director Fees Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum number of share issuable to non employee directors per year		35,000
2019 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for issuance		968,666
Time Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		3 years	3 years
Performance Based [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period		3 years	3 years
RSUs [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Target amount percentage		0.00%	0.00%
RSUs [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Target amount percentage		200.00%	200.00%
Restricted Stock and Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense \| $		$ 4,182,000		$ 3,465,000	$ 2,728,000
Total unrecognized compensation \| $		$ 5,444,000
Recognized weighted average period (in years)		1 year 8 months 12 days	1 year 8 months 12 days