Other Comprehensive (Loss) Income (Reclassifications Out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax	$ 74	$ 37
Post-retirement obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Compensation and employee benefits, amortization of actuarial losses (gains)	100	61
Income tax expense	(26)	(24)
Net of tax	$ 74	$ 37