Pension Plans - Qualified Plan - Change in Plan Assets (Details) - Pension Plan [Member] - Qualified Plan [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	$ 69,245	$ 65,446
Actual return on plan assets	(4,937)	10,107
Employer contributions	1,563
Benefits paid	(6,218)	(6,308)
Fair value of plan assets at end of year	59,653	69,245
Funded status and accrued pension cost	$ (18,194)	$ (16,450)