Retirement Plans (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Contribution Plan Disclosure [Line Items]
Discount rate		3.55%	4.53%	3.93%	4.40%
Amount of defined benefit plan from discounted rate change		$ 5,399,000	$ (3,093,000)	$ 2,377,000
Amount of defined benefit plan from change in mortality assumption		$ (199,000)	$ 133,000	277,000
Percentage of portfolio that may be invested in securities with ratings below investment grade		5.00%
Percentage investment in single security, Maximum		5.00%
Maximum percentage of single investment pool or investment company of total plan assets		10.00%
Percentage of plan assets		100.00%	100.00%
401(k) Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Requisite service period		5 years
Annual vesting percentage		20.00%
Cost for contribution plan		$ 459,000	$ 486,000	441,000
401(k) Plan [Member] | Minimum [Member]
Defined Contribution Plan Disclosure [Line Items]
Age of employees eligible to participate in retirement plan		18 years
Pension Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Age of employees eligible to participate in retirement plan		21 years
Requisite service period and vested period		4 years
Requisite service for plan eligibility		12 months
Employee matching contribution, percent		2.00%
Pension benefit vested, Prior to meeting the vesting requirements		0
Estimated minimum pension contribution		$ 0
Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Contribution Plan Disclosure [Line Items]
Percentage of plan assets		0.20%	0.20%
Supplemental Executive Retirement Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Pension and other postretirement benefits expense			$ 285,000	$ 31,000
Subsequent Event [Member] | Pension Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Maximum annual contributions	$ 1,362,000