SUPPLEMENTAL FINANCIAL STATEMENT DATA - Equipment and Leasehold Improvements, Net (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Jan. 01, 2021	Dec. 27, 2019
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	$ 39,891	$ 30,715
Accumulated depreciation and amortization	(23,134)	(18,209)
Total equipment and leasehold improvements, net	16,757	12,506
Depreciation	5,600	5,000	$ 3,400
Amortization of assets	577	589	509
Furniture and Fixtures [Member]
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	4,070	4,088
Computer Hardware and Software [Member]
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	26,425	18,047
Leasehold Improvements [Member]
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	3,011	2,994
Equipment under Finance Lease
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	3,286	2,370
Accumulated depreciation and amortization	(1,947)	(1,826)
Total equipment and leasehold improvements, net	1,339	544
Amortization of assets	600	600	$ 500
Automobiles Trucks and Field Equipment [Member]
EQUIPMENT AND LEASEHOLD IMPROVEMENTS
Equipment and leasehold improvements, net	$ 3,099	$ 3,216

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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