COVERED LOANS AND FDIC SHARED-LOSS ASSET (Details 2) (Covered Loans, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Balance, beginning of period	$ 64,717	$ 5,457
Additions resulting from acquisition		31,885
Accretion to interest income	(18,905)	(13,925)
Reclassifications (to)/from nonaccretable difference	(5,493)	41,300
Balance, end of period	40,319	64,717
Western Commercial
Balance, beginning of period	9,399	5,457
Additions resulting from acquisition
Accretion to interest income	(4,174)	(3,836)
Reclassifications (to)/from nonaccretable difference	2,516	7,778
Balance, end of period	7,741	9,399
San Luis Trust Bank (SLTB)
Balance, beginning of period	55,318
Additions resulting from acquisition		31,885
Accretion to interest income	(14,731)	(10,089)
Reclassifications (to)/from nonaccretable difference	(8,009)	33,522
Balance, end of period	$ 32,578	$ 55,318