Investment securities available for sale (Details) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 26,364
|
$ 36,885
|
| Amortized Cost |
26,698
|
38,584
|
| Gross Unrealized Gains |
107
|
1
|
| Gross Unrealized Losses |
(33)
|
(666)
|
| Estimated Fair Value |
$ 26,772
|
$ 37,919
|
| Average yield (in percent) |
0.92%
|
1.57%
|
| U.S. Government Agencies [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 24,024
|
$ 32,812
|
| Amortized Cost |
24,284
|
34,286
|
| Gross Unrealized Gains |
89
|
0
|
| Gross Unrealized Losses |
(33)
|
(573)
|
| Estimated Fair Value |
$ 24,340
|
$ 33,713
|
| Average yield (in percent) |
0.89%
|
1.51%
|
| U.S. Government Agencies [Member] | One To five Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 21,000
|
$ 11,000
|
| Amortized Cost |
21,254
|
11,270
|
| Gross Unrealized Gains |
89
|
0
|
| Gross Unrealized Losses |
(14)
|
(157)
|
| Estimated Fair Value |
$ 21,329
|
$ 11,113
|
| Average yield (in percent) |
0.86%
|
0.91%
|
| U.S. Government Agencies [Member] | Five To Ten Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
|
$ 18,500
|
| Amortized Cost |
|
19,697
|
| Gross Unrealized Gains |
|
0
|
| Gross Unrealized Losses |
|
(403)
|
| Estimated Fair Value |
|
$ 19,294
|
| Average yield (in percent) |
|
2.32%
|
| U.S. Government Agencies [Member] | More Than Ten Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 3,024
|
$ 3,312
|
| Amortized Cost |
3,030
|
3,319
|
| Gross Unrealized Gains |
0
|
0
|
| Gross Unrealized Losses |
(19)
|
(13)
|
| Estimated Fair Value |
$ 3,011
|
$ 3,306
|
| Average yield (in percent) |
1.08%
|
0.85%
|
| Mortgage Backed Securities [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 2,340
|
$ 2,943
|
| Amortized Cost |
2,414
|
3,043
|
| Gross Unrealized Gains |
18
|
1
|
| Gross Unrealized Losses |
0
|
(43)
|
| Estimated Fair Value |
$ 2,432
|
$ 3,001
|
| Average yield (in percent) |
1.22%
|
1.35%
|
| Mortgage Backed Securities [Member] | One To five Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 1,480
|
$ 1,794
|
| Amortized Cost |
1,514
|
1,841
|
| Gross Unrealized Gains |
14
|
0
|
| Gross Unrealized Losses |
0
|
(28)
|
| Estimated Fair Value |
$ 1,528
|
$ 1,813
|
| Average yield (in percent) |
1.21%
|
1.30%
|
| Mortgage Backed Securities [Member] | More Than Ten Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
$ 860
|
$ 1,149
|
| Amortized Cost |
900
|
1,202
|
| Gross Unrealized Gains |
4
|
1
|
| Gross Unrealized Losses |
0
|
(15)
|
| Estimated Fair Value |
$ 904
|
$ 1,188
|
| Average yield (in percent) |
1.25%
|
1.34%
|
| Municipals [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
|
$ 1,130
|
| Amortized Cost |
|
1,255
|
| Gross Unrealized Gains |
|
0
|
| Gross Unrealized Losses |
|
(50)
|
| Estimated Fair Value |
|
$ 1,205
|
| Average yield (in percent) |
|
3.72%
|
| Municipals [Member] | More Than Ten Years [Member] |
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
| Par value |
|
$ 1,130
|
| Amortized Cost |
|
1,255
|
| Gross Unrealized Gains |
|
0
|
| Gross Unrealized Losses |
|
(50)
|
| Estimated Fair Value |
|
$ 1,205
|
| Average yield (in percent) |
|
3.72%
|