Amortized Cost and Aggregate Fair Value of Held-to-Maturity Securities, Including Gross Unrealized Gains and Losses (Detail) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Schedule of Held-to-maturity Securities [Line Items] |
|
|
| Held-to-maturity Securities, Amortized Cost |
$ 72,182
|
$ 72,541
|
| Held-to-maturity Securities, Unrealized Gains |
425
|
78
|
| Held-to-maturity Securities, Unrealized Losses |
|
(129)
|
| Held-to-maturity Securities, Fair Value |
72,607
|
72,490
|
| U.S. Agency securities |
|
|
| Schedule of Held-to-maturity Securities [Line Items] |
|
|
| Held-to-maturity Securities, Amortized Cost |
61,766
|
61,863
|
| Held-to-maturity Securities, Unrealized Gains |
317
|
75
|
| Held-to-maturity Securities, Unrealized Losses |
|
(106)
|
| Held-to-maturity Securities, Fair Value |
62,083
|
61,832
|
| Corporate securities |
|
|
| Schedule of Held-to-maturity Securities [Line Items] |
|
|
| Held-to-maturity Securities, Amortized Cost |
10,416
|
10,488
|
| Held-to-maturity Securities, Unrealized Gains |
108
|
|
| Held-to-maturity Securities, Unrealized Losses |
|
(23)
|
| Held-to-maturity Securities, Fair Value |
$ 10,524
|
10,465
|
| Municipal securities |
|
|
| Schedule of Held-to-maturity Securities [Line Items] |
|
|
| Held-to-maturity Securities, Amortized Cost |
|
190
|
| Held-to-maturity Securities, Unrealized Gains |
|
3
|
| Held-to-maturity Securities, Fair Value |
|
$ 193
|