Investment Securities - Additional Information (Detail)
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3 Months Ended |
9 Months Ended |
|
|
Sep. 30, 2016
USD ($)
Securities
|
Sep. 30, 2015
USD ($)
|
Sep. 30, 2016
USD ($)
Securities
|
Sep. 30, 2015
USD ($)
|
Dec. 31, 2015
USD ($)
Securities
|
| Schedule of Available-for-sale Securities [Line Items] |
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|
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| Held-to-maturity securities in continuous unrealized loss position, less than 12 Months |
$ 0
|
|
$ 0
|
|
$ 129,000
|
| Held-to-maturity securities in continuous unrealized loss position, 12 Months or Longer |
$ 0
|
|
$ 0
|
|
$ 0
|
| Number of securities in an unrealized loss position | Securities |
20
|
|
20
|
|
107
|
| Percentage of combined depreciation of the combined reported value of the aggregate securities portfolio |
0.98%
|
|
0.98%
|
|
2.44%
|
| Carrying amount of available-for-sale securities pledged |
$ 151,820,000
|
|
$ 151,820,000
|
|
$ 236,730,000
|
| OTTI charges incurred |
4,635,000
|
|
4,646,000
|
|
|
| Debt Securities |
|
|
|
|
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| Schedule of Available-for-sale Securities [Line Items] |
|
|
|
|
|
| OTTI charges incurred |
4,640,000
|
$ 0
|
4,640,000
|
$ 0
|
|
| Equity Securities |
|
|
|
|
|
| Schedule of Available-for-sale Securities [Line Items] |
|
|
|
|
|
| OTTI charges incurred |
$ 0
|
$ 0
|
$ 11,000
|
$ 0
|
|