Defined Benefit Retirement Plan (Components of Net Periodic Pension Cost) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Net loss (gain)	[1],[2]	$ 55		$ 55
JVB Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		130	$ 161	394	$ 483
Expected return on plan assets		(172)	(202)	(556)	(605)
Recognized net actuarial loss		242	57	323	170
Net periodic benefit cost		200	16	161	48
Amortization of net actuarial loss recognized in other comprehensive income		(242)	(57)	(323)	(170)
Total recognized in net periodic benefit cost and other comprehensive loss (income)		$ (42)	$ (41)	$ (162)	$ (122)

[1] Amounts are included in the computation of net periodic benefit cost and are included in employee benefits expense on the consolidated statements of income as a separate element within total non-interest expense.

[2] Income tax amounts are included in the provision for income taxes on the consolidated statements of income.