Loans Receivable: Schedule of Allowance for Loan and Lease Losses, Roll Forward (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       $ 9,463                 $ 9,463          
(Recapture) provision $ (100) $ 900 $ 600 (100) $ (900) $ (700) $ (500) $ (100) $ (1,200) $ (300) $ (100) $ (500) 1,300 $ (2,200) $ (2,100)      
Loans and Leases Receivable, Allowance, Ending Balance 10,951       9,463               10,951 9,463        
Loans receivable allowance for loan losses 10,951     9,463 9,463               9,463 9,463   $ 10,951 $ 9,463  
One-to-four family residential                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       3,028       3,691       5,141 3,028 3,691 5,141      
Charge-offs                         0 (27) (78)      
Recoveries                         165 936 50      
(Recapture) provision                         (642) (1,572) (1,422)      
Loans and Leases Receivable, Allowance, Ending Balance 2,551       3,028       3,691       2,551 3,028 3,691      
Loans receivable allowance for loan losses 2,551     3,028 3,028     3,691 3,691     5,141 3,028 3,691 5,141 2,551 3,028 $ 3,691
Total Loans [1]                               249,435 253,772 273,193
One-to-four family residential | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       2,516       2,891         2,516 2,891        
Loans and Leases Receivable, Allowance, Ending Balance 2,349       2,516       2,891       2,349 2,516 2,891      
Loans receivable allowance for loan losses 2,349     2,516 2,516     2,891 2,891       2,516 2,891 2,891 2,349 2,516 2,891
Total Loans [1],[2]                               224,363 217,677 229,455
One-to-four family residential | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       512       800         512 800        
Loans and Leases Receivable, Allowance, Ending Balance 202       512       800       202 512 800      
Loans receivable allowance for loan losses 202     512 512     800 800       512 800 800 202 512 800
Total Loans [1],[3]                               25,072 36,095 43,738
Multifamily                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       1,193       1,606       1,269 1,193 1,606 1,269      
Charge-offs                         0 (281) 0      
Recoveries                         1 78 0      
(Recapture) provision                         5 (210) 337      
Loans and Leases Receivable, Allowance, Ending Balance 1,199       1,193       1,606       1,199 1,193 1,606      
Loans receivable allowance for loan losses 1,199     1,193 1,193     1,606 1,606     1,269 1,193 1,606 1,269 1,199 1,193 1,606
Total Loans [1]                               123,250 122,747 116,014
Multifamily | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       1,190       1,579         1,190 1,579        
Loans and Leases Receivable, Allowance, Ending Balance 1,199       1,190       1,579       1,199 1,190 1,579      
Loans receivable allowance for loan losses 1,199     1,190 1,190     1,579 1,579       1,190 1,579 1,579 1,199 1,190 1,579
Total Loans [1],[2]                               121,686 121,152 113,842
Multifamily | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       3       27         3 27        
Loans and Leases Receivable, Allowance, Ending Balance 0       3       27       0 3 27      
Loans receivable allowance for loan losses 0     3 3     27 27       3 27 27 0 3 27
Total Loans [1],[3]                               1,564 1,595 2,172
Commercial Real Estate                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       3,395       4,476       5,101 3,395 4,476 5,101      
Charge-offs                         0 0 (311)      
Recoveries                         104 181 174      
(Recapture) provision                         394 (1,262) (488)      
Loans and Leases Receivable, Allowance, Ending Balance 3,893       3,395       4,476       3,893 3,395 4,476      
Loans receivable allowance for loan losses 3,893     3,395 3,395     4,476 4,476     5,101 3,395 4,476 5,101 3,893 3,395 4,476
Total Loans [1]                               303,694 244,211 239,211
Commercial Real Estate | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       3,270       4,172         3,270 4,172        
Loans and Leases Receivable, Allowance, Ending Balance 3,867       3,270       4,172       3,867 3,270 4,172      
Loans receivable allowance for loan losses 3,867     3,270 3,270     4,172 4,172       3,270 4,172 4,172 3,867 3,270 4,172
Total Loans [1],[2]                               299,987 239,765 230,155
Commercial Real Estate | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       125       304         125 304        
Loans and Leases Receivable, Allowance, Ending Balance 26       125       304       26 125 304      
Loans receivable allowance for loan losses 26     125 125     304 304       125 304 304 26 125 304
Total Loans [1],[3]                               3,707 4,896 9,056
Construction Land Development                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       1,193       519       1,287 1,193 519 1,287      
Charge-offs                         0 0 (223)      
Recoveries                         0 0 0      
(Recapture) provision                         1,599 674 (545)      
Loans and Leases Receivable, Allowance, Ending Balance 2,792       1,193       519       2,792 1,193 519      
Loans receivable allowance for loan losses 2,792     1,193 1,193     519 519     1,287 1,193 519 1,287 2,792 1,193 519
Total Loans [1]                               136,922 62,103 37,702
Construction Land Development | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       1,140       494         1,140 494        
Loans and Leases Receivable, Allowance, Ending Balance 2,711       1,140       494       2,711 1,140 494      
Loans receivable allowance for loan losses 2,711     1,140 1,140     494 494       1,140 494 494 2,711 1,140 494
Total Loans [1],[2]                               136,427 61,158 37,206
Construction Land Development | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       53       25         53 25        
Loans and Leases Receivable, Allowance, Ending Balance 81       53       25       81 53 25      
Loans receivable allowance for loan losses 81     53 53     25 25       53 25 25 81 53 25
Total Loans [1],[3]                               495 495 496
Business                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       229       47       14 229 47 14      
Charge-offs                         0 0 0      
Recoveries                         0 3 10      
(Recapture) provision                         8 179 23      
Loans and Leases Receivable, Allowance, Ending Balance 237       229       47       237 229 47      
Loans receivable allowance for loan losses 237     229 229     47 47     14 229 47 14 237 229 47
Total Loans [1]                               7,938 7,604 3,783
Business | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       229       47         229 47        
Loans and Leases Receivable, Allowance, Ending Balance 237       229       47       237 229 47      
Loans receivable allowance for loan losses 237     229 229     47 47       229 47 47 237 229 47
Total Loans [1],[2]                               7,938 7,604 3,783
Business | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       0       0         0 0        
Loans and Leases Receivable, Allowance, Ending Balance 0       0       0       0 0 0      
Loans receivable allowance for loan losses 0     0 0     0 0       0 0 0 0 0 0
Total Loans [1],[3]                               0 0 0
Consumer                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       425       152       182 425 152 182      
Charge-offs                         (83) (54) (30)      
Recoveries                         1 336 5      
(Recapture) provision                         (64) (9) (5)      
Loans and Leases Receivable, Allowance, Ending Balance 279       425       152       279 425 152      
Loans receivable allowance for loan losses 279     425 425     152 152     182 425 152 182 279 425 152
Total Loans [1]                               6,922 6,979 7,130
Consumer | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       386       93         386 93        
Loans and Leases Receivable, Allowance, Ending Balance 279       386       93       279 386 93      
Loans receivable allowance for loan losses 279     386 386     93 93       386 93 93 279 386 93
Total Loans [1],[2]                               6,819 6,771 6,933
Consumer | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       39       59         39 59        
Loans and Leases Receivable, Allowance, Ending Balance 0       39       59       0 39 59      
Loans receivable allowance for loan losses 0     39 39     59 59       39 59 59 0 39 59
Total Loans [1],[3]                               103 208 197
Property total                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       9,463       10,491       (12,994) 9,463 10,491 (12,994)      
Charge-offs                         (83) (362) (642)      
Recoveries                         271 1,534 239      
(Recapture) provision                         1,300 (2,200) (2,100)      
Loans and Leases Receivable, Allowance, Ending Balance 10,951       9,463       10,491       10,951 9,463 10,491      
Loans receivable allowance for loan losses 10,951     9,463 9,463     10,491 10,491     $ (12,994) 9,463 10,491 (12,994) 10,951 9,463 10,491
Total Loans [1]                               828,161 697,416 677,033
Property total | General Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       8,731       9,276         8,731 9,276        
Loans and Leases Receivable, Allowance, Ending Balance 10,642       8,731       9,276       10,642 8,731 9,276      
Loans receivable allowance for loan losses 10,642     8,731 8,731     9,276 9,276       8,731 9,276 9,276 10,642 8,731 9,276
Total Loans [1],[2]                               797,220 654,127 621,374
Property total | Specific Reserve                                    
Allowance for Loan and Lease Losses [Roll Forward]                                    
Loans and Leases Receivable, Allowance, Beginning Balance       732       1,215 [1]         732 1,215 [1]        
Loans and Leases Receivable, Allowance, Ending Balance 309       732       1,215 [1]       309 732 1,215 [1]      
Loans receivable allowance for loan losses $ 309     $ 732 $ 732     $ 1,215 [1] $ 1,215 [1]       $ 732 $ 1,215 [1] $ 1,215 [1] 309 732 1,215 [1]
Total Loans [1],[3]                               $ 30,941 $ 43,289 $ 55,659
[1] Net of LIP.
[2] Loans collectively evaluated for impairment.
[3] Loans individually evaluated for impairment