Schedule of Net Periodic Pension Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan [Abstract]
Service cost	$ 868	$ 1,008	$ 2,839	$ 3,025
Interest cost	564	567	1,719	1,767
Expected return on plan assets	(151)	(160)	(460)	(510)
Defined Benefit Plan, Settlement and Other Benefit Costs	250	0	250	0
Amortization of actuarial net loss	332	383	1,019	1,178
Amortization of unrecognized prior service costs	16	16	49	50
Net periodic benefit cost	$ 1,879	$ 1,814	$ 5,416	$ 5,510