Loans - Average Recorded Investment and Interest Income Recognized on Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	$ 118,697	$ 155,019	$ 128,485	$ 147,922
Interest Income Recognized	1,093	1,160	3,220	3,840
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	31,499	28,892	28,008	27,570
Interest Income Recognized	293	232	727	689
Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	64,752	96,516	75,685	92,966
Interest Income Recognized	550	677	1,765	2,333
Commercial real estate loans \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	58,117	76,509	66,871	76,900
Interest Income Recognized	513	538	1,627	1,918
Commercial real estate loans \| Construction
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	6,635	20,007	8,814	16,066
Interest Income Recognized	37	139	138	415
Residential mortgage
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	20,193	25,336	22,232	23,261
Interest Income Recognized	225	208	660	707
Consumer
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	2,253	4,275	2,560	4,125
Interest Income Recognized	25	43	68	111
Consumer \| Home equity
Accounts, Notes, Loans and Financing Receivable
Average Recorded Investment	2,253	4,275	2,560	4,125
Interest Income Recognized	$ 25	$ 43	$ 68	$ 111

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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

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- Definition

Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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