Benefit Plans - Defined Benefit Plans - Components of Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Supplemental Retirement Plan
Components of net periodic benefit cost:
Service cost	$ 123	$ 55
Interest cost	231	264
Amortization of net actuarial loss	85	46
Net periodic benefit cost	439	365
Plan assets associated with the plan	0
Split-Dollar Life Insurance Benefit Plan
Components of net periodic benefit cost:
Interest cost	62	70	$ 278
Amortization of prior transition obligation	(15)	(25)
Net periodic benefit cost	$ 47	$ 45