Retirement Plans (Details) - Defined Benefit Plan [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 358	$ 366	$ 1,076	$ 1,100
Interest cost	315	282	954	857
Expected return on plan assets	(224)	(236)	(684)	(722)
Recognized actuarial gain	(40)	(27)	(118)	(81)
Total defined benefit expense	$ 409	$ 385	$ 1,228	$ 1,154