Loans - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2015 USD ($) SecurityLoan	Dec. 31, 2014 USD ($) SecurityLoan
Accounts, Notes, Loans and Financing Receivable
Threshold period for loans in default (in days)	30 days
TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	113
Pre-modification outstanding recorded investment	$ 62,631
Post-modification outstanding recorded investment	$ 57,041
Number of loans \| SecurityLoan	62	40
Recorded investment	$ 35,793	$ 1,600
Commercial Loans \| Real Estate \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	11
Pre-modification outstanding recorded investment	$ 26,764
Post-modification outstanding recorded investment	$ 25,250
Number of loans \| SecurityLoan	6	30
Recorded investment	$ 22,075	$ 0
Commercial Loans \| Commercial and Industrial \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	26
Pre-modification outstanding recorded investment	$ 21,233
Post-modification outstanding recorded investment	$ 18,114
Number of loans \| SecurityLoan	20	9
Recorded investment	$ 8,970	$ 1,600
Commercial Loans \| Energy-Related \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	2
Pre-modification outstanding recorded investment	$ 9,797
Post-modification outstanding recorded investment	$ 9,484
Number of loans \| SecurityLoan	1	0
Recorded investment	$ 3,120	$ 0
Residential Mortgage \| Residential Mortgage \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	1
Pre-modification outstanding recorded investment	$ 70
Post-modification outstanding recorded investment	$ 68
Number of loans \| SecurityLoan	0	0
Recorded investment	$ 0	$ 0
Consumer and Other Loans \| Consumer - Home Equity \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	50
Pre-modification outstanding recorded investment	$ 4,440
Post-modification outstanding recorded investment	$ 3,865
Number of loans \| SecurityLoan	20	0
Recorded investment	$ 1,547	$ 0
Consumer and Other Loans \| Consumer - Indirect Automobile \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	6
Pre-modification outstanding recorded investment	$ 79
Post-modification outstanding recorded investment	$ 79
Number of loans \| SecurityLoan	6	0
Recorded investment	$ 79	$ 0
Consumer and Other Loans \| Consumer - Other \| TDRs Occurring during the Period \| Non-Covered TDRs
Accounts, Notes, Loans and Financing Receivable
Number of loans \| SecurityLoan	17
Pre-modification outstanding recorded investment	$ 248
Post-modification outstanding recorded investment	$ 181
Number of loans \| SecurityLoan	9	1
Recorded investment	$ 2	$ 0

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953676-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953682-111524

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