INVESTMENT SECURITIES (Details) (USD $)	9 Months Ended			3 Months Ended	9 Months Ended									3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013 First California Financial Group	Sep. 30, 2013 First California Financial Group	Sep. 30, 2013 Government agency and government-sponsored enterprise pass through securities	Dec. 31, 2012 Government agency and government-sponsored enterprise pass through securities	Sep. 30, 2013 Government agency and government-sponsored enterprise collateralized mortgage obligations	Dec. 31, 2012 Government agency and government-sponsored enterprise collateralized mortgage obligations	Sep. 30, 2013 Covered private label collateralized mortgage obligations	Dec. 31, 2012 Covered private label collateralized mortgage obligations	Sep. 30, 2013 Municipal securities	Dec. 31, 2012 Municipal securities	Mar. 31, 2013 Corporate debt securities	Sep. 30, 2013 Corporate debt securities	Dec. 31, 2012 Corporate debt securities	Sep. 30, 2013 Other securities	Dec. 31, 2012 Other securities	Sep. 30, 2013 Residential mortgage-backed securities issued by the Federal National Mortgage Association and federal Home Loan Mortgage Corporation
Amortized cost, gross unrealized gains and losses and estimated fair values of securities available-for-sale
Amortized Cost	$ 1,511,583,000		$ 1,298,661,000			$ 695,768,000	$ 774,677,000	$ 201,531,000	$ 99,956,000	$ 31,503,000	$ 36,078,000	$ 460,754,000	$ 339,547,000		$ 84,028,000	$ 42,014,000	$ 37,999,000	$ 6,389,000
Gross Unrealized Gains	30,778,000		59,464,000			19,853,000	33,618,000	730,000	1,870,000	7,983,000	8,729,000	2,150,000	10,445,000		61,000	432,000	1,000	4,370,000
Gross Unrealized Losses	(30,214,000)		(2,740,000)			(1,659,000)	(453,000)	(2,901,000)	(132,000)	(108,000)	(123,000)	(23,269,000)	(1,951,000)		(1,983,000)	(81,000)	(294,000)
Carrying Value	1,512,147,000		1,355,385,000			713,962,000	807,842,000	199,360,000	101,694,000	39,378,000	44,684,000	439,635,000	348,041,000		82,106,000	42,365,000	37,706,000	10,759,000	774,800,000
Non-taxable gain on previously-held equity interest				5,200,000	5,200,000
Proceeds from investment securities previously held in portfolio and/or obtained in acquisition	12,810,000	45,639,000												12,400,000
Gross realized gain														$ 409,000