Other Liabilities (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Aug. 29, 2014
Other Liabilities [Line Items]
Accrued pension costs		$ 4,921,000		$ 4,921,000		$ 5,228,000	$ 7,500,000
Service cost		0	$ 0	0	$ 0
Interest cost		45,000	45,000	90,000	90,000
Actuarial loss (gain)		52,000	$ 51,000	104,000	$ 103,000
Benefit obligation		$ 10,200,000		$ 10,200,000
Discount rate		4.25%		4.25%
Discount term				15 years
Monthly estate payment amount		$ 57,000		$ 57,000
Discounted value		2,700,000		2,700,000
Accumulated prior service cost		3,100,000		$ 3,100,000
Accumulated prior service cost amortization period				15 years
Accrued pension costs included in other liabilities		$ 5,600,000		$ 5,600,000
Payment related to annuity	$ 2,400,000
Payment period				42 months
Supplemental Executive Retirement Plans [Member]
Other Liabilities [Line Items]
Accrued pension costs							$ 7,600,000