Note 4 - Investment Securities - Amortized Cost and Fair Value of Available for Sale Investment Securities (Details) - USD ($)
$ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Amortized Cost |
$ 568,890
|
$ 347,776
|
| Gross Unrealized Gains |
1,669
|
2,279
|
| Gross Unrealized Losses |
(3,563)
|
(1,089)
|
| Fair Value |
566,996
|
348,966
|
| US Treasury Securities [Member] |
|
|
| Amortized Cost |
200,094
|
101
|
| Gross Unrealized Gains |
3
|
|
| Gross Unrealized Losses |
|
(1)
|
| Fair Value |
200,097
|
100
|
| US Government Agencies Debt Securities [Member] |
|
|
| Amortized Cost |
83,111
|
101,342
|
| Gross Unrealized Gains |
167
|
470
|
| Gross Unrealized Losses |
(1,080)
|
(317)
|
| Fair Value |
82,198
|
101,495
|
| US States and Political Subdivisions Debt Securities [Member] |
|
|
| Amortized Cost |
33,625
|
41,892
|
| Gross Unrealized Gains |
26
|
123
|
| Gross Unrealized Losses |
(121)
|
(49)
|
| Fair Value |
33,530
|
41,966
|
| Collateralized Mortgage Backed Securities [Member] |
|
|
| Amortized Cost |
185,997
|
157,422
|
| Gross Unrealized Gains |
1,260
|
1,482
|
| Gross Unrealized Losses |
(1,306)
|
(215)
|
| Fair Value |
185,951
|
158,689
|
| Collateralized Mortgage Obligations [Member] |
|
|
| Amortized Cost |
49,488
|
29,756
|
| Gross Unrealized Gains |
108
|
166
|
| Gross Unrealized Losses |
(902)
|
(123)
|
| Fair Value |
48,694
|
29,799
|
| Other Debt Obligations [Member] |
|
|
| Amortized Cost |
16,575
|
17,263
|
| Gross Unrealized Gains |
105
|
38
|
| Gross Unrealized Losses |
(154)
|
(384)
|
| Fair Value |
$ 16,526
|
$ 16,917
|