Securities - Available for Sale Securities, Continuous Unrealized Loss Position, Fair value (Detail)
$ in Thousands |
12 Months Ended |
|
Dec. 31, 2016
USD ($)
Security
|
Dec. 31, 2015
USD ($)
Security
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 4,496
|
$ 2,628
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 320,260
|
$ 359,531
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
128
|
104
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 757
|
$ 2,191
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 26,991
|
$ 87,120
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
15
|
36
|
| Available-for-sale, Gross Unrealized Loss |
$ 5,253
|
$ 4,819
|
| Available-for-sale, Estimated Fair Value |
$ 347,251
|
$ 446,651
|
| Available-for-sale, Number of Securities | Security |
143
|
140
|
| Mortgage-backed securities [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 1,345
|
$ 1,734
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 102,647
|
$ 193,931
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
38
|
52
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 112
|
$ 727
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 11,350
|
$ 21,659
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
3
|
9
|
| Available-for-sale, Gross Unrealized Loss |
$ 1,457
|
$ 2,461
|
| Available-for-sale, Estimated Fair Value |
$ 113,997
|
$ 215,590
|
| Available-for-sale, Number of Securities | Security |
41
|
61
|
| Collateralized mortgage obligations [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 676
|
$ 335
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 60,786
|
$ 48,970
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
27
|
18
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 326
|
$ 662
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 10,579
|
$ 32,964
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
7
|
13
|
| Available-for-sale, Gross Unrealized Loss |
$ 1,002
|
$ 997
|
| Available-for-sale, Estimated Fair Value |
$ 71,365
|
$ 81,934
|
| Available-for-sale, Number of Securities | Security |
34
|
31
|
| U.S. government agency securities [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 58
|
$ 201
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 7,441
|
$ 23,289
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
3
|
8
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 0
|
$ 455
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 0
|
$ 24,533
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
0
|
8
|
| Available-for-sale, Gross Unrealized Loss |
$ 58
|
$ 656
|
| Available-for-sale, Estimated Fair Value |
$ 7,441
|
$ 47,822
|
| Available-for-sale, Number of Securities | Security |
3
|
16
|
| SBA loan pool securities [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 0
|
$ 161
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 0
|
$ 50,499
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
0
|
12
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 210
|
$ 250
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 4,146
|
$ 7,036
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
2
|
3
|
| Available-for-sale, Gross Unrealized Loss |
$ 210
|
$ 411
|
| Available-for-sale, Estimated Fair Value |
$ 4,146
|
$ 57,535
|
| Available-for-sale, Number of Securities | Security |
2
|
15
|
| Municipal bonds-tax exempt [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 1,995
|
$ 19
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 125,004
|
$ 8,922
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
54
|
6
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 0
|
$ 0
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 0
|
$ 0
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
0
|
0
|
| Available-for-sale, Gross Unrealized Loss |
$ 1,995
|
$ 19
|
| Available-for-sale, Estimated Fair Value |
$ 125,004
|
$ 8,922
|
| Available-for-sale, Number of Securities | Security |
54
|
6
|
| Municipal bonds-taxable [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 9
|
$ 88
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 2,904
|
$ 7,106
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
2
|
4
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 0
|
$ 0
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 0
|
$ 0
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
0
|
0
|
| Available-for-sale, Gross Unrealized Loss |
$ 9
|
$ 88
|
| Available-for-sale, Estimated Fair Value |
$ 2,904
|
$ 7,106
|
| Available-for-sale, Number of Securities | Security |
2
|
4
|
| Corporate bonds [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
|
$ 24
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
|
$ 4,994
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
|
1
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
|
$ 0
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
|
$ 0
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
|
0
|
| Available-for-sale, Gross Unrealized Loss |
|
$ 24
|
| Available-for-sale, Estimated Fair Value |
|
$ 4,994
|
| Available-for-sale, Number of Securities | Security |
|
1
|
| Other securities [Member] |
|
|
| Summary of Investment Holdings [Line Items] |
|
|
| Available-for-sale, Less Than 12 Months, Gross Unrealized Loss |
$ 413
|
$ 66
|
| Available-for-sale, Less Than 12 Months, Estimated Fair Value |
$ 21,478
|
$ 21,820
|
| Available-for-sale, Less Than 12 Months, Number of Securities | Security |
4
|
3
|
| Available-for-sale, 12 Months or More, Gross Unrealized Loss |
$ 109
|
$ 97
|
| Available-for-sale, 12 Months or More, Estimated Fair Value |
$ 916
|
$ 928
|
| Available-for-sale, 12 Months or More, Number of Securities | Security |
3
|
3
|
| Available-for-sale, Gross Unrealized Loss |
$ 522
|
$ 163
|
| Available-for-sale, Estimated Fair Value |
$ 22,394
|
$ 22,748
|
| Available-for-sale, Number of Securities | Security |
7
|
6
|