Carrying Amount and Fair Value of Financial Instruments (Detail) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Jun. 30, 2016 |
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Dec. 31, 2014 |
| Assets |
|
|
|
|
|
|
| Securities available for sale |
$ 220,856
|
|
$ 366,173
|
|
|
|
| Securities held to maturity |
72,607
|
|
72,490
|
|
|
|
| FDIC indemnification asset |
14,332
|
$ 16,431
|
20,844
|
$ 22,049
|
$ 23,653
|
$ 27,900
|
| Interest receivable |
5,498
|
|
6,007
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Derivative financial liabilities |
450
|
|
251
|
|
|
|
| Carrying (Reported) Amount, Fair Value Disclosure |
|
|
|
|
|
|
| Assets |
|
|
|
|
|
|
| Cash and cash equivalents |
65,929
|
|
51,787
|
|
|
|
| Securities available for sale |
220,856
|
|
366,173
|
|
|
|
| Securities held to maturity |
72,182
|
|
72,541
|
|
|
|
| Loans held for investment, net of allowance |
1,816,751
|
|
1,686,308
|
|
|
|
| FDIC indemnification asset |
14,332
|
|
20,844
|
|
|
|
| Interest receivable |
5,498
|
|
6,007
|
|
|
|
| Deferred compensation assets |
3,842
|
|
3,464
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Securities sold under agreements to repurchase |
118,532
|
|
138,614
|
|
|
|
| Interest payable |
1,252
|
|
1,260
|
|
|
|
| FHLB and other borrowings |
105,707
|
|
80,756
|
|
|
|
| Derivative financial liabilities |
450
|
|
251
|
|
|
|
| Deferred compensation liabilities |
3,842
|
|
3,464
|
|
|
|
| Carrying (Reported) Amount, Fair Value Disclosure | Demand Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
473,509
|
|
451,511
|
|
|
|
| Carrying (Reported) Amount, Fair Value Disclosure | Interest-bearing Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
339,563
|
|
347,705
|
|
|
|
| Carrying (Reported) Amount, Fair Value Disclosure | Savings Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
441,724
|
|
530,585
|
|
|
|
| Carrying (Reported) Amount, Fair Value Disclosure | Bank Time Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
527,103
|
|
543,458
|
|
|
|
| Estimate of Fair Value, Fair Value Disclosure |
|
|
|
|
|
|
| Assets |
|
|
|
|
|
|
| Cash and cash equivalents |
65,929
|
|
51,787
|
|
|
|
| Securities available for sale |
220,856
|
|
366,173
|
|
|
|
| Securities held to maturity |
72,607
|
|
72,490
|
|
|
|
| Loans held for investment, net of allowance |
1,833,791
|
|
1,685,061
|
|
|
|
| FDIC indemnification asset |
7,226
|
|
10,753
|
|
|
|
| Interest receivable |
5,498
|
|
6,007
|
|
|
|
| Deferred compensation assets |
3,842
|
|
3,464
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Securities sold under agreements to repurchase |
120,070
|
|
140,880
|
|
|
|
| Interest payable |
1,252
|
|
1,260
|
|
|
|
| FHLB and other borrowings |
110,172
|
|
85,774
|
|
|
|
| Derivative financial liabilities |
450
|
|
251
|
|
|
|
| Deferred compensation liabilities |
3,842
|
|
3,464
|
|
|
|
| Estimate of Fair Value, Fair Value Disclosure | Demand Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
473,509
|
|
451,511
|
|
|
|
| Estimate of Fair Value, Fair Value Disclosure | Interest-bearing Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
339,563
|
|
347,705
|
|
|
|
| Estimate of Fair Value, Fair Value Disclosure | Savings Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
441,724
|
|
530,585
|
|
|
|
| Estimate of Fair Value, Fair Value Disclosure | Bank Time Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
528,183
|
|
541,059
|
|
|
|
| Level 1 |
|
|
|
|
|
|
| Assets |
|
|
|
|
|
|
| Cash and cash equivalents |
65,929
|
|
51,787
|
|
|
|
| Securities available for sale |
55
|
|
54
|
|
|
|
| Deferred compensation assets |
3,842
|
|
3,464
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deferred compensation liabilities |
3,842
|
|
3,464
|
|
|
|
| Level 2 |
|
|
|
|
|
|
| Assets |
|
|
|
|
|
|
| Securities available for sale |
220,801
|
|
366,119
|
|
|
|
| Securities held to maturity |
72,607
|
|
72,490
|
|
|
|
| Loans held for investment, net of allowance |
4,464
|
|
4,886
|
|
|
|
| Interest receivable |
5,498
|
|
6,007
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Securities sold under agreements to repurchase |
120,070
|
|
140,880
|
|
|
|
| Interest payable |
1,252
|
|
1,260
|
|
|
|
| FHLB and other borrowings |
110,172
|
|
85,774
|
|
|
|
| Derivative financial liabilities |
450
|
|
251
|
|
|
|
| Level 2 | Demand Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
473,509
|
|
451,511
|
|
|
|
| Level 2 | Interest-bearing Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
339,563
|
|
347,705
|
|
|
|
| Level 2 | Savings Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
441,724
|
|
530,585
|
|
|
|
| Level 2 | Bank Time Deposits |
|
|
|
|
|
|
| Liabilities |
|
|
|
|
|
|
| Deposits Fair Value |
528,183
|
|
541,059
|
|
|
|
| Level 3 |
|
|
|
|
|
|
| Assets |
|
|
|
|
|
|
| Loans held for investment, net of allowance |
1,829,327
|
|
1,680,175
|
|
|
|
| FDIC indemnification asset |
$ 7,226
|
|
$ 10,753
|
|
|
|