Commitments and Contingent Liabilities - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Loan commitments outstanding	$ 2,474,381	$ 1,895,682
Loan commitments expiry period	1 year
Commercial Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	0	0
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 163,831	$ 114,664