Commitments and Contingencies - Summary of Financial Instruments with Off-Balance Sheet Risk (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commitments to sell loans	$ 25,796	$ 100,400
Standby letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	224,002	228,694
Commercial letters of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Commercial letters of credit	8,016	6,043
Commercial loans [Member] | Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	1,958,955	1,944,815
Commercial loans [Member] | Loan Origination Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	382,939	253,235
Home equity [Member] | Unused lines of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	669,447	620,397
Residential [Member] | Loan Origination Commitments [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	43,618	247,275
Credit Card [Member] | Unused lines of credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Financial instruments with off-balance sheet risk	$ 57,017	$ 59,969