Note 7 - Fair Values of Financial Instruments (Tables)
 3 Months Ended
Mar. 31, 2018
Notes Tables  
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]
   
Fair Value Measurements Using
  
   
Quoted Prices
    
Significant
                  
   
in Active
    
Other
    
Significant
          
   
Markets for
    
Observable
    
Unobservable
          
   
Identical Assets
    
Inputs
    
Inputs
          
   
Level 1
    
Level 2
    
Level 3
    
Fair Value
  
                                 
March 31, 2018
  
 
 
 
  
 
 
 
  
 
 
 
  
 
 
 
Recurring basis
                                
Mortgage-backed securities
  
$
-
   
$
22,655,713
   
$
-
   
$
22,655,713
 
U.S. Government agencies
  
 
-
   
 
1,780,336
   
 
-
   
 
1,780,336
 
Municipal obligations
  
 
-
   
 
1,659,611
   
 
-
   
 
1,659,611
 
Loans held for sale
  
 
-
   
 
15,260,895
   
 
-
   
 
15,260,895
 
Derivative IRLC's
  
 
-
   
 
-
   
 
475,735
   
 
475,735
 
Derivative forward commitments
  
 
-
   
 
(64,609
)
  
 
-
   
 
(64,609
)
  Nonrecurring basis                                
   Impaired loans
  
 
-
   
 
-
   
 
5,479,627
    
 
5,479,627
 
                                 
Totals
  
$
-
   
$
41,291,946
   
$
5,955,362
    
$
47,247,308
  
                                 
December 31, 2017
                                
Recurring basis
                                
Mortgage-backed securities
   $
-
     $
20,768,592
     $
-
     $
20,768,592
  
U.S. Government agencies
    
-
      
1,957,783
      
-
      
1,957,783
  
Municipal obligations
    
-
      
1,673,506
      
-
      
1,673,506
  
Loans held for sale
    
-
      
15,423,670
      
-
      
15,423,670
  
Derivative IRLC's
    
 
      
-
      
183,087
      
183,087
  
Derivative forward commitments
    
 
      
(15,820
 )    
-
      
(15,820
 )
Nonrecurring basis
                                
Impaired loans
    
-
      
-
      
5,436,972
      
5,436,972
  
                                 
Totals
   $
-
     $
39,807,731
     $
5,620,059
     $
45,427,790
  
Fair Value Measurement Inputs and Valuation Techniques [Table Text Block]
   
Fair Value
  
Valuation
Methodologies
  
Valuation Model
  
Unobservable
Input
Valuation
  
At March 31, 2018
  
 
 
 
        
 
  
 
 
Impaired loans
                        
Commercial real estate
   $
3,494,122
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
One- to four-family residential real estate
    
710,795
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
Commercial and industrial
    
1,274,710
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
   
$
5,479,627
  
 
  
 
  
 
 
 
 
                         
At December 31, 2017
                        
Impaired loans
                        
Commercial real estate
   $
3,483,078
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
One- to four-family residential real estate
    
679,184
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
Commercial and industrial
    
1,274,710
  
Appraisal
  
Appraisal discount and estimated selling costs
  
 17
-
18%
  
    $
5,436,972
  
 
  
 
  
 
 
 
  
Fair Value, by Balance Sheet Grouping [Table Text Block]
                   
Quoted Prices
    
Significant
          
                   
in Active
    
Other
    
Significant
  
                   
Markets for
    
Observable
    
Unobservable
  
   
Carrying
      
 
    
Identical Assets
    
Inputs
    
Inputs
  
   
Amount
    
Fair Value
    
Level 1
    
Level 2
    
Level 3
  
   
(Dollars in thousands)
  
At March 31, 2018
  
 
 
 
  
 
 
 
  
 
 
 
  
 
 
 
  
 
 
 
Financial assets:
                                        
Cash and due from banks
  
$
4,762
   
$
4,762
   
$
4,762
   
$
-
   
$
-
 
Interest-bearing deposits with banks
  
 
7,580
   
 
7,580
   
 
7,580
   
 
-
   
 
-
 
Available-for-sale securities
  
 
26,096
   
 
26,096
   
 
-
   
 
26,096
   
 
-
 
Loans held for sale
  
 
15,261
   
 
15,261
   
 
-
   
 
15,261
   
 
-
 
Loans held for investment, net
  
 
258,357
   
 
258,197
   
 
-
   
 
-
   
 
258,197
 
Derivative IRLCs
  
 
475,735
   
 
475,735
   
 
-
 
  
 
475,735
   
 
-
 
Derivative forward commitments
  
 
(64,609
)
  
 
(64,609
)
  
 
-
 
  
 
(64,609
)
  
 
-
 
Stock in financial institutions
  
 
3,843
   
 
3,843
   
 
-
   
 
3,843
   
 
-
 
                                         
Financial liabilities:
                                        
Demand deposits, savings and NOW deposits
  
 
174,580
   
 
165,716
   
 
-
   
 
165,716
   
 
-
 
Time deposits
  
 
67,229
   
 
66,995
   
 
-
   
 
66,995
   
 
-
 
Federal Home Loan Bank advances
  
 
45,000
   
 
45,133
   
 
-
   
 
45,133
   
 
-
 
                                         
At December 31, 2017
                                        
Financial assets:
                                        
Cash and due from banks
   $
4,988
     $
4,988
     $
4,988
     $
-
     $
-
  
Interest-bearing deposits with banks
    
4,885
      
4,885
      
4,885
      
-
      
-
  
Available-for-sale securities
    
24,400
      
24,400
      
-
      
24,400
      
-
  
Loans held for sale
    
15,424
      
15,424
      
-
      
15,424
      
-
  
Loans held for investment, net
    
257,896
      
257,937
      
-
      
-
      
257,937
  
Stock in financial institutions
    
3,826
      
3,826
      
-
      
3,826
      
-
  
                                         
Financial liabilities:
                                        
Demand deposits, savings and NOW deposits
    
172,512
      
168,080
      
168,080
      
-
      
-
  
Time deposits
    
63,049
      
63,076
      
-
      
63,076
      
-
  
Federal Home Loan Bank advances
    
45,000
      
45,176
      
-
      
45,176
      
-