Employee Benefit Plans (Narrative) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Employee Stock Ownership Plan (ESOP), cash contributions to ESOP				$ 124,000	$ 242,000	$ 99,000
Employee Stock Ownership Plan (ESOP), number of allocated shares	161,173			161,173	223,344
Employee Stock Ownership Plan (ESOP), number of unallocated shares	21,091			21,091	22,908
Employee Stock Ownership Plan (ESOP), allocated shares market value	$ 5,300,000			$ 5,300,000	$ 9,400,000
Employee Stock Ownership Plan (ESOP), allocated excess of fair market value of leveraged ESOP shares released	33,000			$ 33,000	110,000
Employee Stock Ownership Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee Stock Ownership Plan (ESOP) promissory note amortization period				7 years
Employee Stock Ownership Plan (ESOP), debt structure offset by purchase of common shares, amount	137,000	$ 137,000	$ 823,000
Promissory notes	$ 718,000			$ 718,000	755,000
Employee Stock Ownership Plan (ESOP), Debt Structure, Direct Loan, Employer Cash Payments Used for Debt Service				$ 174,000	$ 237,000
Employee Stock Ownership Plan (ESOP), debt structure direct loan employer shares used for debt service, Shares				6,061	10,157
Employee Stock Ownership Plan (ESOP), debt structure offset by purchase of common shares		4,244	23,503
Share Price	$ 29.24			$ 29.24	$ 38.30
Prime Rate [Member] | Employee Stock Ownership Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee Stock Ownership Plan (ESOP) basis spread on variable rate				1.00%
401 (K) Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution				50.00%	50.00%	50.00%
Maximum employee contribution employer will match					8.00%	8.00%	8.00%
Minimim period of service				6 months
Period of service eligible for service				3 years
Retirement plan expense				$ 405,000	$ 298,000	$ 346,000
Individual Supplemental Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Retirement plan expense				$ 1,109,000	637,000	525,000
Number of years following retirement benefit is paid				15 years
Nonqualified Retirement Plan For Non Employee Directors [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee benefit plan requisite service period				15 years
Employee benefit plan vesting period				2 years
Retirement plan expense				$ 35,000	29,000	$ 20,000
Liability	$ 2,100,000			2,100,000	$ 2,000,000
Maximum annual benefit following retirement				$ 3,500
Number of years following retirement benefit is paid				10 years
Maximum [Member] | Nonqualified Retirement Plan For Non Employee Directors [Member]
Defined Benefit Plan Disclosure [Line Items]
Period for distribution of deferred amount				10 years
Minimum [Member] | Nonqualified Retirement Plan For Non Employee Directors [Member]
Defined Benefit Plan Disclosure [Line Items]
Period for distribution of deferred amount				1 year