Nonqualified Benefit Plans Components of NPBC (Details 11) - Unfunded Plan - Nonqualified Plan - Supplemental Employee Retirement Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 58	$ 109
Interest cost	1,912	2,606	3,473
Recognized net actuarial loss	1,164	1,192	764
Net periodic benefit cost	$ 3,076	$ 3,856	$ 4,346