Note 3 - Revenue Recognition - Revenues Disaggregated by Revenue Source (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Revenues	$ 32,652	$ 50,705	$ 77,685	$ 102,300
Engineering Services [Member]
Revenues	14,038	18,583	28,201	37,638
Health Care [Member]
Revenues	10,684	23,370	32,881	47,540
Technology Service [Member]
Revenues	7,930	8,752	16,603	17,122
Time-and-materials Contract [Member] | Engineering Services [Member]
Revenues	10,784	13,528	23,611	27,371
Time-and-materials Contract [Member] | Health Care [Member]
Revenues	10,601	23,140	32,654	47,046
Time-and-materials Contract [Member] | Technology Service [Member]
Revenues	7,779	8,641	16,336	16,950
Fixed-price Contract [Member] | Engineering Services [Member]
Revenues	3,189	5,098	4,503	10,267
Permanent Placement Services [Member] | Engineering Services [Member]
Revenues	65	(43)	87
Permanent Placement Services [Member] | Health Care [Member]
Revenues	83	230	227	494
Permanent Placement Services [Member] | Technology Service [Member]
Revenues	$ 151	$ 111	$ 267	$ 172