Summary of Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Securities available-for-sale |
$ 22,216
|
$ 21,876
|
| Rabbi Trust |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading securities |
2,595
|
2,460
|
| Fair Value, Measurements, Recurring |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Totals |
24,811
|
24,336
|
| Fair Value, Measurements, Recurring | Corporate debt securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Securities available-for-sale |
22,216
|
21,876
|
| Fair Value, Measurements, Recurring | Rabbi Trust |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading securities |
2,595
|
2,460
|
| Fair Value, Measurements, Recurring | Level 1 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Totals |
2,595
|
2,460
|
| Fair Value, Measurements, Recurring | Level 1 | Rabbi Trust |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Trading securities |
2,595
|
2,460
|
| Fair Value, Measurements, Recurring | Level 2 |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Totals |
22,216
|
21,876
|
| Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Securities available-for-sale |
$ 22,216
|
$ 21,876
|