Basis of Presentation and General Information (Gain and Loss Results for Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018
Cost of service:
Income (loss) from discontinued operations	$ 2	$ (514)	$ (4)	$ (599)
European REL Working Capital group [Member]
Revenue:
Total revenue		122	92	2,870
Cost of service:
Total cost of service	2	565	43	2,876
Selling, general and administrative costs	(4)	183	52	785
Total costs and operating expenses	(2)	748	95	3,661
Income (loss) from discontinued operations before income taxes	2	(626)	(3)	(791)
Income tax expense (benefit)		(112)	1	(192)
Income (loss) from discontinued operations	2	(514)	(4)	(599)
European REL Working Capital group [Member] | Revenue Before Reimbursements [Member]
Revenue:
Total revenue		60	75	2,404
European REL Working Capital group [Member] | Reimbursements [Member]
Revenue:
Total revenue		62	17	466
Cost of service:
Total cost of service		62	17	466
European REL Working Capital group [Member] | Cost Before Reimbursements [Member]
Cost of service:
Total cost of service	$ 2	$ 503	$ 26	$ 2,410