Income Taxes (Reconciliation of the Federal Statutory and Effective Income Tax Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income before income taxes	$ 34,393	$ 34,961	$ 39,048
Amount
Statutory taxes at 21.0% (35.0% in 2017)	7,223	7,342	13,667
State and local income taxes	1,063	561	843
Valuation allowances	2,146	233	369
Other non-deductible expenses	346	429	44
Credits	(1,195)	(348)	(458)
Provisional effect of the Tax Cuts and Jobs Act (the Tax Act)	0	0	4,654
Non-deductible spin-related costs	0	0	540
Other, net	(268)	(401)	(741)
Income tax provision	$ 9,315	$ 7,816	$ 18,918
Percent
Statutory taxes at 21.0% (35.0% in 2017)	21.00%	21.00%	35.00%
State and local income taxes	3.10%	1.60%	2.20%
Valuation allowances	6.20%	0.70%	0.90%
Other non-deductible expenses	1.00%	1.20%	0.10%
Credits	(3.50%)	(1.00%)	(1.20%)
Provisional effect of the Tax Cuts and Jobs Act (the Tax Act)	0.00%	0.00%	11.90%
Non-deductible spin-related costs	0.00%	0.00%	1.40%
Other, net	(0.80%)	(1.10%)	(1.90%)
Income tax provision	27.10%	22.40%	48.40%