Loans Receivable, Part II (Details) - USD ($)
Mar. 31, 2018
Dec. 31, 2017
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due $ 6,927,000 $ 5,852,000
Current [1] 1,307,745,000 1,285,962,000
Total Loans 1,314,672,000 1,291,814,000
Loan Receivable, Nonaccrual Status 1,900,000 1,800,000
90 or more days past due 0 0
1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 2,361,000 1,562,000
Loan Receivable, Nonaccrual Status 109,000 241,000
60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 30,000 316,000
Loan Receivable, Nonaccrual Status 0 15,000,000,000
Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 4,536,000 3,974,000
Residential Real Estate [Member] | One-to-Four Family [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 5,820,000 5,156,000
Current [1] 451,434,000 434,441,000
Total Loans 457,254,000 439,597,000
Residential Real Estate [Member] | One-to-Four Family [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 1,950,000 1,494,000
Residential Real Estate [Member] | One-to-Four Family [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 146,000
Residential Real Estate [Member] | One-to-Four Family [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 3,870,000 3,516,000
Residential Real Estate [Member] | Multi Family [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 401,000 320,000
Current [1] 571,289,000 578,120,000
Total Loans 571,690,000 578,440,000
Residential Real Estate [Member] | Multi Family [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 15,000 0
Residential Real Estate [Member] | Multi Family [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 128,000
Residential Real Estate [Member] | Multi Family [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 386,000 192,000
Residential Real Estate [Member] | Home Equity [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 454,000 124,000
Current [1] 20,558,000 21,000,000
Total Loans 21,012,000 21,124,000
Residential Real Estate [Member] | Home Equity [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 350,000 68,000
Residential Real Estate [Member] | Home Equity [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 30,000 0
Residential Real Estate [Member] | Home Equity [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 74,000 56,000
Construction and Land [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 0 0
Current [1] 19,151,000 19,859,000
Total Loans 19,151,000 19,859,000
Construction and Land [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 0 0
Construction and Land [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 0
Construction and Land [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 0 0
Commercial Real Estate [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 180,000 184,000
Current [1] 211,296,000 195,658,000
Total Loans 211,476,000 195,842,000
Commercial Real Estate [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 0 0
Commercial Real Estate [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 0
Commercial Real Estate [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 180,000 184,000
Consumer [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 46,000 0
Current [1] 194,000 255,000
Total Loans 240,000 255,000
Consumer [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 46,000 0
Consumer [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 0
Consumer [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 0 0
Commercial Loans [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due 26,000 68,000
Current [1] 33,823,000 36,629,000
Total Loans 33,849,000 36,697,000
Commercial Loans [Member] | 1 to 59 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [2] 0 0
Commercial Loans [Member] | 60 to 89 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due [3] 0 42,000
Commercial Loans [Member] | Greater than 90 Days Past Due [Member]    
Financing receivable, recorded investment, aging [Abstract]    
Total Past Due $ 26,000 $ 26,000
[1] Includes $1.9 million and $4.4 million at June 30, 2017 and December 31, 2016, respectively, which are on non-accrual status.
[2] Includes $59,000 and $148,000 at June 30, 2017 and December 31, 2016, respectively, which are on non-accrual status.
[3] Includes $1.3 million and $- at June 30, 2017 and December 31, 2016, respectively, which are on non-accrual status.