Employee Benefit Plans - Obligation and Funded Status of Defined Benefit Pension Plan and Retirement Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in benefit obligation
Benefit obligation at beginning of year	$ 33,951	$ 36,002
Service cost	503	601	$ 531
Interest cost	1,388	1,268	1,329
Actuarial (gain) loss	4,769	(2,415)
Benefits paid	(1,526)	(1,505)
Ending benefit obligation	39,085	33,951	36,002
Change in plan assets
Fair value of plan assets at beginning of year	23,749	25,646
Return on assets	4,347	(1,951)
Employer contribution	1,873	1,559
Benefits paid	(1,526)	(1,505)
Fair value of plan assets at end of year	28,443	23,749	25,646
Funded status (underfunded)	(10,642)	(10,202)
Amounts recognized in the consolidated balance sheet
Current liabilities	0	580
Non-current liabilities	10,642	9,622
Unrecognized loss included in accumulated other comprehensive loss
Unrecognized loss before tax, beginning balance	9,485	8,908
Amortization	(885)	(743)
Liability (gain) loss	4,769	(2,415)
Asset loss (gain)	(2,709)	3,735
Unrecognized loss before tax, ending balance	10,660	9,485	$ 8,908
Tax impact	(2,544)	(2,263)
Unrecognized loss included in accumulated other comprehensive loss, net of tax	$ 8,116	$ 7,222