Benefit Plans - Defined Benefit Plans - Change in Projected Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Split-Dollar Life Insurance Benefit Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 6,903	$ 6,711
Actuarial loss (gain)	1,017	(35)
Interest cost	278	227
Net actuarial loss	3,776	2,573
Projected benefit obligation at end of period	8,198	6,903
Supplemental Retirement Plan
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	26,781	28,510
Projected benefit obligation of SERP agreements acquired from Presidio	2,541
Service cost	263	249
Actuarial loss (gain)	(4,182)	1,885
Interest cost	1,059	947
Benefits paid	(1,137)	(1,040)
Net actuarial loss	9,670	5,672
Projected benefit obligation at end of period	$ 33,689	$ 26,781