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Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015 | Dec. 31, 2015
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | $ 44,574 |  | $ 44,574 |  | $ 45,032
Without a related allowance, Unpaid Principal Balance | 60,120 |  | 60,120 |  | 50,286
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 5,593 |  | 5,593 |  | 618
With a related allowance recorded, Unpaid Principal Balance | 6,649 |  | 6,649 |  | 1,468
Impaired Financing Receivable, Recorded Investment | 50,167 |  | 50,167 |  | 45,650
Impaired Financing Receivable, Unpaid Principal Balance, Total | 66,769 |  | 66,769 |  | 51,754
Impaired Financing Receivable, Related Allowance | 2,162 |  | 2,162 |  | 37
Without a related allowance recorded, Average Recorded Investment | 47,269 | $ 45,651 | 47,849 | $ 45,274 |
Without a related allowance recorded, Interest Income Recognized | 317 | 418 | 673 | 792 |
With a related allowance recorded, Average Recorded Investment | 5,879 | 545 | 6,275 | 337 |
With a related allowance recorded, Interest Income Recognized | 38 | 2 | 76 | 3 |
Impaired Financing Receivable, Average Recorded Investment, Total | 53,148 | 46,196 | 54,124 | 45,611 |
Impaired Financing Receivable, Interest Income Recognized, Total | 355 | 420 | 749 | 795 |
Commercial and Industrial |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | 11,313 |  | 11,313 |  | 14,417
Without a related allowance, Unpaid Principal Balance | 12,174 |  | 12,174 |  | 15,220
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 4,499 |  | 4,499 |  | 0
With a related allowance recorded, Unpaid Principal Balance | 4,984 |  | 4,984 |  | 0
Impaired Financing Receivable, Recorded Investment | 15,812 |  | 15,812 |  | 14,417
Impaired Financing Receivable, Unpaid Principal Balance, Total | 17,158 |  | 17,158 |  | 15,220
Impaired Financing Receivable, Related Allowance | 1,991 |  | 1,991 |  | 0
Without a related allowance recorded, Average Recorded Investment | 10,959 | 10,782 | 11,253 | 11,162 |
Without a related allowance recorded, Interest Income Recognized | 98 | 84 | 189 | 146 |
With a related allowance recorded, Average Recorded Investment | 4,617 | 0 | 4,999 | 0 |
With a related allowance recorded, Interest Income Recognized | 31 | 0 | 63 | 0 |
Impaired Financing Receivable, Average Recorded Investment, Total | 15,576 | 10,782 | 16,252 | 11,162 |
Impaired Financing Receivable, Interest Income Recognized, Total | 129 | 84 | 252 | 146 |
Commercial Real Estate |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | 12,326 |  | 12,326 |  | 12,661
Without a related allowance, Unpaid Principal Balance | 22,765 |  | 22,765 |  | 13,157
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 0 |  | 0 |  | 0
With a related allowance recorded, Unpaid Principal Balance | 0 |  | 0 |  | 0
Impaired Financing Receivable, Recorded Investment | 12,326 |  | 12,326 |  | 12,661
Impaired Financing Receivable, Unpaid Principal Balance, Total | 22,765 |  | 22,765 |  | 13,157
Impaired Financing Receivable, Related Allowance | 0 |  | 0 |  | 0
Without a related allowance recorded, Average Recorded Investment | 14,619 | 19,733 | 14,798 | 20,455 |
Without a related allowance recorded, Interest Income Recognized | 64 | 158 | 132 | 322 |
With a related allowance recorded, Average Recorded Investment | 0 | 420 | 0 | 211 |
With a related allowance recorded, Interest Income Recognized | 0 | 0 | 0 | 0 |
Impaired Financing Receivable, Average Recorded Investment, Total | 14,619 | 20,153 | 14,798 | 20,666 |
Impaired Financing Receivable, Interest Income Recognized, Total | 64 | 158 | 132 | 322 |
Commercial Construction |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | 9,918 |  | 9,918 |  | 10,998
Without a related allowance, Unpaid Principal Balance | 13,494 |  | 13,494 |  | 14,200
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 1,064 |  | 1,064 |  | 500
With a related allowance recorded, Unpaid Principal Balance | 1,635 |  | 1,635 |  | 1,350
Impaired Financing Receivable, Recorded Investment | 10,982 |  | 10,982 |  | 11,498
Impaired Financing Receivable, Unpaid Principal Balance, Total | 15,129 |  | 15,129 |  | 15,550
Impaired Financing Receivable, Related Allowance | 141 |  | 141 |  | 3
Without a related allowance recorded, Average Recorded Investment | 10,625 | 8,119 | 10,669 | 6,628 |
Without a related allowance recorded, Interest Income Recognized | 48 | 81 | 108 | 134 |
With a related allowance recorded, Average Recorded Investment | 1,232 | 0 | 1,244 | 0 |
With a related allowance recorded, Interest Income Recognized | 6 | 0 | 12 | 0 |
Impaired Financing Receivable, Average Recorded Investment, Total | 11,857 | 8,119 | 11,913 | 6,628 |
Impaired Financing Receivable, Interest Income Recognized, Total | 54 | 81 | 120 | 134 |
Consumer Real Estate |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | 10,983 |  | 10,983 |  | 6,845
Without a related allowance, Unpaid Principal Balance | 11,646 |  | 11,646 |  | 7,521
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 29 |  | 29 |  | 116
With a related allowance recorded, Unpaid Principal Balance | 29 |  | 29 |  | 116
Impaired Financing Receivable, Recorded Investment | 11,012 |  | 11,012 |  | 6,961
Impaired Financing Receivable, Unpaid Principal Balance, Total | 11,675 |  | 11,675 |  | 7,637
Impaired Financing Receivable, Related Allowance | 29 |  | 29 |  | 32
Without a related allowance recorded, Average Recorded Investment | 11,028 | 6,891 | 11,089 | 6,943 |
Without a related allowance recorded, Interest Income Recognized | 107 | 91 | 243 | 186 |
With a related allowance recorded, Average Recorded Investment | 29 | 121 | 30 | 122 |
With a related allowance recorded, Interest Income Recognized | 1 | 2 | 1 | 3 |
Impaired Financing Receivable, Average Recorded Investment, Total | 11,057 | 7,012 | 11,119 | 7,065 |
Impaired Financing Receivable, Interest Income Recognized, Total | 108 | 93 | 244 | 189 |
Other Consumer |  |  |  |  |
Financing Receivable, Impaired [Line Items] |  |  |  |  |
Without a related allowance recorded, Recorded Investment | 34 |  | 34 |  | 111
Without a related allowance, Unpaid Principal Balance | 41 |  | 41 |  | 188
Without a related allowance recorded, Related Allowance | 0 |  | 0 |  | 0
With a related allowance recorded, Recorded Investment | 1 |  | 1 |  | 2
With a related allowance recorded, Unpaid Principal Balance | 1 |  | 1 |  | 2
Impaired Financing Receivable, Recorded Investment | 35 |  | 35 |  | 113
Impaired Financing Receivable, Unpaid Principal Balance, Total | 42 |  | 42 |  | 190
Impaired Financing Receivable, Related Allowance | 1 |  | 1 |  | $ 2
Without a related allowance recorded, Average Recorded Investment | 38 | 126 | 40 | 86 |
Without a related allowance recorded, Interest Income Recognized | 0 | 4 | 1 | 4 |
With a related allowance recorded, Average Recorded Investment | 1 | 4 | 2 | 4 |
With a related allowance recorded, Interest Income Recognized | 0 | 0 | 0 | 0 |
Impaired Financing Receivable, Average Recorded Investment, Total | 39 | 130 | 42 | 90 |
Impaired Financing Receivable, Interest Income Recognized, Total | $ 0 | $ 4 | $ 1 | $ 4 |

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- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5258-111524 + Details
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