Derivative Instruments and Hedging Activities - (Losses) Gains Related to Derivative Instruments Not Designated as Hedging Instruments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Non-designated hedge interest rate derivatives
Other non-interest expense	$ (43)	$ 1,461	$ (216)	$ 1,090