|
Reconciliation of Activity for Assets Measured at Fair Value based on Significant Unobservable (Non-market) Information (Detail) (Bank-Issued Trust Preferred Securities, USD $)
In Thousands, unless otherwise specified |
9 Months Ended | 12 Months Ended |
|---|---|---|
|
Sep. 30, 2012
|
Dec. 31, 2011
|
|
|
Bank-Issued Trust Preferred Securities
|
||
| Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] | ||
| Balance, January 1 | $ 2,252 | $ 2,619 |
| Transfers into Level 3 | ||
| Transfers out of Level 3 | ||
| Other-than-temporary impairment loss included in earnings | (4) | |
| Unrealized gain (loss) included in comprehensive income | 679 | (363) |
| Balance at September 30, 2012 and December 31, 2011 | $ 2,931 | $ 2,252 |