Note 3 - Revenue Recognition - Revenues Disaggregated by Revenue Source (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Revenues	$ 31,561	$ 40,250	$ 109,246	$ 142,550
Engineering Services [Member]
Revenues	15,087	15,140	43,288	52,778
Health Care [Member]
Revenues	9,015	16,765	41,896	64,305
Technology Service [Member]
Revenues	7,459	8,345	24,062	25,467
Time-and-materials Contract [Member] | Engineering Services [Member]
Revenues	10,369	13,938	33,980	41,309
Time-and-materials Contract [Member] | Health Care [Member]
Revenues	8,844	16,272	41,498	63,318
Time-and-materials Contract [Member] | Technology Service [Member]
Revenues	7,347	8,134	23,683	25,084
Fixed-price Contract [Member] | Engineering Services [Member]
Revenues	4,660	1,202	9,163	11,469
Permanent Placement Services [Member] | Engineering Services [Member]
Revenues	58		145
Permanent Placement Services [Member] | Health Care [Member]
Revenues	171	493	398	987
Permanent Placement Services [Member] | Technology Service [Member]
Revenues	$ 112	$ 211	$ 379	$ 383