Pension Plans - Qualified Plan - Change in Plan Assets (Details) - Pension Plan [Member] - Qualified Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 66,000	$ 59,653
Actual return on plan assets	9,801	11,346
Employer contributions	1,727	1,479
Benefits paid	(6,307)	(6,478)
Fair value of plan assets at end of year	71,221	66,000
Funded status and accrued pension cost	$ (15,527)	$ (16,518)