BUSINESS SEGMENTS (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 item	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business segments
Number of reportable segments									3
Loans and leases, net of unearned income	$ 4,312,352,000				$ 3,590,297,000				$ 4,312,352,000	$ 3,590,297,000
Total allowance for loans and lease losses	(82,034,000)				(91,968,000)				(82,034,000)	(91,968,000)	(116,588,000)
Total loans and leases, net	4,230,318,000				3,498,329,000				4,230,318,000	3,498,329,000
Goodwill	208,743,000				79,866,000				208,743,000	79,866,000	39,141,000	47,301,000
Core deposit and customer relationship intangibles, net	17,248,000				14,723,000				17,248,000	14,723,000
Total assets	6,533,363,000				5,463,658,000				6,533,363,000	5,463,658,000
Total deposits	5,280,987,000				4,709,121,000				5,280,987,000	4,709,121,000
Interest income	83,856,000	85,158,000	71,631,000	69,269,000	73,702,000	75,123,000	72,890,000	74,400,000	309,914,000	296,115,000	295,284,000
Other interest expense	(2,598,000)	(2,869,000)	(3,158,000)	(3,576,000)	(4,099,000)	(4,352,000)	(4,477,000)	(6,720,000)	(12,201,000)	(19,648,000)	(32,643,000)
Net interest income	81,258,000	82,289,000	68,473,000	65,693,000	69,603,000	70,771,000	68,413,000	67,680,000	297,713,000	276,467,000	262,641,000
Negative provision (provision) for credit losses	1,338,000	4,167,000	1,842,000	(3,137,000)	4,333,000	2,141,000	271,000	6,074,000	4,210,000	12,819,000	(26,570,000)
FDIC loss sharing income (expense), net	(10,593,000)	(7,032,000)	(5,410,000)	(3,137,000)	(6,022,000)	(367,000)	(102,000)	(3,579,000)	(26,172,000)	(10,070,000)	7,776,000
Acquisition-related securities gain		5,222,000							5,222,000
Other noninterest income									25,194,000	25,942,000	23,650,000
Total noninterest income	(3,926,000)	5,127,000	203,000	2,840,000	2,057,000	5,682,000	4,871,000	3,262,000	4,244,000	15,872,000	31,426,000
Accelerated vesting of restricted stock	(12,420,000)								(12,420,000)
OREO income (expense)									1,503,000	(10,931,000)	(10,676,000)
Intangible asset amortization									(5,402,000)	(6,326,000)	(8,428,000)
Acquisition and integration	(4,253,000)	(5,450,000)	(17,997,000)	(692,000)	(1,092,000)	(2,101,000)	(871,000)	(25,000)	(28,392,000)	(4,089,000)	(600,000)
Debt termination expense										(22,598,000)
Other noninterest expense									(185,976,000)	(167,718,000)	(160,289,000)
Total noninterest expense	(66,088,000)	(56,200,000)	(64,216,000)	(44,183,000)	(43,525,000)	(51,657,000)	(47,585,000)	(68,895,000)	(230,687,000)	(211,662,000)	(179,993,000)
Earnings from continuing operations before income taxes	12,582,000	35,383,000	6,302,000	21,213,000	32,468,000	26,937,000	25,970,000	8,121,000	75,480,000	93,496,000	87,504,000
Income tax (expense) benefit	(9,135,000)	(11,243,000)	(1,906,000)	(7,719,000)	(12,576,000)	(10,849,000)	(10,413,000)	(2,857,000)	(30,003,000)	(36,695,000)	(36,800,000)
NET EARNINGS FROM CONTINUING OPERATIONS	3,447,000	24,140,000	4,396,000	13,494,000					45,477,000	56,801,000	50,704,000
Earnings (loss) from discontinued operations before income taxes	(578,000)	39,000	(81,000)						(620,000)
Income tax (expense) benefit	240,000	(16,000)	34,000						258,000
NET EARNINGS FROM DISCONTINUED OPERATIONS	(338,000)	23,000	(47,000)						(362,000)
NET EARNINGS	3,109,000	24,163,000	4,349,000	13,494,000	19,892,000	16,088,000	15,557,000	5,264,000	45,115,000	56,801,000	50,704,000
FCAL
Business segments
Non-tax deductible addition from the FCAL acquisition									129,070,000
Banking
Business segments
Loans and leases, net of unearned income	3,837,475,000				3,175,165,000				3,837,475,000	3,175,165,000
Total allowance for loans and lease losses	(75,498,000)				(87,538,000)				(75,498,000)	(87,538,000)
Total loans and leases, net	3,761,977,000				3,087,627,000				3,761,977,000	3,087,627,000
Goodwill	183,065,000				54,188,000				183,065,000	54,188,000
Core deposit and customer relationship intangibles, net	15,331,000				12,151,000				15,331,000	12,151,000
Total assets	6,004,067,000				4,991,927,000				6,004,067,000	4,991,927,000
Total deposits	5,302,822,000				4,737,593,000				5,302,822,000	4,737,593,000
Other interest expense									(7,873,000)	(15,043,000)	(27,720,000)
Net interest income									255,144,000	238,732,000	250,240,000
Negative provision (provision) for credit losses									8,079,000	14,585,000	(26,520,000)
FDIC loss sharing income (expense), net									(26,172,000)	(10,070,000)	7,776,000
Other noninterest income									21,532,000	21,811,000	22,833,000
Total noninterest income									(4,640,000)	11,741,000	30,609,000
Accelerated vesting of restricted stock									(12,420,000)
OREO income (expense)									1,503,000	(10,931,000)	(10,676,000)
Intangible asset amortization									(4,748,000)	(5,898,000)	(8,264,000)
Acquisition and integration									28,132,000	4,089,000	600,000
Debt termination expense										(24,195,000)
Other noninterest expense									(156,600,000)	(138,640,000)	(141,188,000)
Total noninterest expense									(200,397,000)	(183,753,000)	(160,728,000)
Earnings from continuing operations before income taxes									58,186,000	81,305,000	93,601,000
Income tax (expense) benefit									(24,940,000)	(31,542,000)	(39,554,000)
NET EARNINGS FROM CONTINUING OPERATIONS									33,246,000
Earnings (loss) from discontinued operations before income taxes									(620,000)
Income tax (expense) benefit									258,000
NET EARNINGS FROM DISCONTINUED OPERATIONS									(362,000)
NET EARNINGS									32,884,000	49,763,000	54,047,000
Asset Financing
Business segments
Loans and leases, net of unearned income	474,877,000				415,132,000				474,877,000	415,132,000
Total allowance for loans and lease losses	(6,536,000)				(4,430,000)				(6,536,000)	(4,430,000)
Total loans and leases, net	468,341,000				410,702,000				468,341,000	410,702,000
Goodwill	25,678,000				25,678,000				25,678,000	25,678,000
Core deposit and customer relationship intangibles, net	1,917,000				2,572,000				1,917,000	2,572,000
Total assets	519,675,000				451,557,000				519,675,000	451,557,000
Other interest expense									(532,000)	(884,000)
Net interest income									46,365,000	41,456,000	17,324,000
Negative provision (provision) for credit losses									(3,869,000)	(1,766,000)	(50,000)
Other noninterest income									3,558,000	4,017,000	660,000
Total noninterest income									3,558,000	4,017,000	660,000
Intangible asset amortization									(654,000)	(428,000)	(164,000)
Other noninterest expense									(23,575,000)	(23,502,000)	(10,846,000)
Total noninterest expense									(24,229,000)	(23,930,000)	(11,010,000)
Earnings from continuing operations before income taxes									21,825,000	19,777,000	6,924,000
Income tax (expense) benefit									(9,101,000)	(8,327,000)	(2,917,000)
NET EARNINGS FROM CONTINUING OPERATIONS									12,724,000
NET EARNINGS									12,724,000	11,450,000	4,007,000
Other
Business segments
Total assets	9,621,000				20,174,000				9,621,000	20,174,000
Total deposits	(21,835,000)				(28,472,000)				(21,835,000)	(28,472,000)
Other interest expense									(3,796,000)	(3,721,000)	(4,923,000)
Net interest income									(3,796,000)	(3,721,000)	(4,923,000)
Acquisition-related securities gain									5,222,000
Other noninterest income									104,000	114,000	157,000
Total noninterest income									5,326,000	114,000	157,000
Acquisition and integration									260,000
Debt termination expense										1,597,000
Other noninterest expense									(5,801,000)	(5,576,000)	(8,255,000)
Total noninterest expense									(6,061,000)	(3,979,000)	(8,255,000)
Earnings from continuing operations before income taxes									(4,531,000)	(7,586,000)	(13,021,000)
Income tax (expense) benefit									4,038,000	3,174,000	5,671,000
NET EARNINGS FROM CONTINUING OPERATIONS									(493,000)
NET EARNINGS									(493,000)	(4,412,000)	(7,350,000)
Operating segment
Business segments
Interest income									309,914,000	296,115,000	295,284,000
Operating segment | Banking
Business segments
Interest income									261,492,000	251,720,000	276,734,000
Operating segment | Asset Financing
Business segments
Interest income									48,422,000	44,395,000	18,550,000
Intersegment | Banking
Business segments
Net interest income									1,525,000	2,055,000	1,226,000
Intersegment | Asset Financing
Business segments
Net interest income									$ (1,525,000)	$ (2,055,000)	$ (1,226,000)