Employee Benefit Plans (Detail Textuals 1) - Other Postretirement Benefit Plans - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Future obligation of benefits	$ 736,000	$ 614,000
Amortization rate per year	113,000
Estimated future annual expenses included in accumulated other comprehensive loss, net of deferred taxes	$ 29,000	$ 20,000