Mortgage Servicing Rights - Changes in Mortgage Servicing Rights (Detail) (Mortgage Servicing Rights [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Mortgage Servicing Rights [Member]
Servicing Asset at Amortized Cost [Line Items]
Beginning of period	$ 5,406	$ 4,723	$ 5,519	$ 4,152
Servicing rights capitalized	236	871	359	1,639
Amortization of servicing rights	(264)	(381)	(507)	(812)
Changes in valuation allowance		14	7	248
End of period	5,378	5,227	5,378	5,227
Mortgage loans serviced for others	$ 761,413	$ 705,999	$ 761,413	$ 705,999