Acquired and Covered Loans (Detail) - Changes in Accretable Yield - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at the beginning of the year		$ 28,244	$ 36,792	$ 51,498
Additions		1,168	3,517	0
Accretion		(11,311)	(12,535)	(15,016)
Other	[1]	6,811	470	310
Balance at the end of the year		$ 24,912	$ 28,244	$ 36,792

[1] Represents a rise in the expected future cash flows to be collected over the remaining estimated life of the underlying portfolio.