Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	$ 255,247	$ 245,822
Commitments outstanding for capital expenditures	2,635,000
Commercial loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	49,409	23,978
Other loans [Member] | Fixed rate [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	6,119	2,961
Other loans [Member] | Adjustable rate [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	2,503	1,077
Unused lines of credit [Member] | Fixed rate [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	20,415	31,446
Unused lines of credit [Member] | Adjustable rate [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	159,580	169,031
Unused overdraft protection amounts on demand and NOW accounts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	16,338	16,249
Standby letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet risks, liability	$ 883	$ 1,080