Basis of Presentation and General Information (Gain and Loss Results for Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2019	Mar. 30, 2018
Cost of service:
Gain from discontinued operations	$ 45	$ 66
European REL Working Capital group [Member]
Revenue:
Total revenue	109	1,626
Cost of service:
Total cost of service	56	1,227
Selling, general and administrative costs	(5)	359
Total costs and operating expenses	51	1,586
Income from discontinued operations before income taxes	58	40
Income tax expense (benefit)	13	(26)
Gain from discontinued operations	45	66
European REL Working Capital group [Member] | Revenue Before Reimbursements [Member]
Revenue:
Total revenue	92	1,436
European REL Working Capital group [Member] | Reimbursements [Member]
Revenue:
Total revenue	17	190
Cost of service:
Total cost of service	17	190
European REL Working Capital group [Member] | Cost Before Reimbursements [Member]
Cost of service:
Total cost of service	$ 39	$ 1,037