Business Segment (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Interest Income	$ 202,356	$ 204,363	$ 85,158	$ 495,079	$ 226,058
Interest expense	(13,510)	(11,830)	(2,869)	(27,685)	(9,603)
Intersegment interest income (expense), net	0	0	0	0	0
Net interest income	188,846	192,533	82,289	467,394	216,455
Provision for Loan, Lease, and Other Losses	(5,050)	(5,030)	4,167	(9,436)	2,872
Gain on securities	0	89	5,222	4,841	5,631
FDIC loss sharing expense	(7,415)	(8,525)	(7,032)	(27,370)	(15,579)
Other noninterest income	23,729	16,915	12,159	52,013	18,118
Total non-interest income	16,314	8,479	5,127	29,484	8,170
Foreclosed assets (expense) income, net	(4,827)	(497)	420	(3,463)	934
Intangible asset amortization	(1,608)	(1,677)	(1,512)	(4,649)	(3,972)
Acquisition, integration and reorganization costs	(5,193)	(86,242)	(5,450)	(93,635)	(24,139)
Other noninterest expense	84,001	81,490	49,658	214,657	137,422
Total noninterest expense	(95,629)	(169,906)	(56,200)	(316,404)	(164,599)
Intersegment noninterest income (expense_	0	0		0
Total noninterest expense - adjusted	(95,629)	(169,906)		(316,404)
Earnings (loss) from continuing operations before taxes	104,481	26,076	35,383	171,038	62,898
Income Tax Expense (Benefit)	(42,205)	(14,846)	(11,243)	(71,627)	(20,868)
Net earnings (loss) from continuing operations	62,276	11,230	24,140	99,411	42,030
Loss from discontinued operations before taxes	(8)	(1,151)	39	(2,572)	(42)
Discontinued Operation, Tax Effect of Discontinued Operation	3	476	(16)	1,067	18
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	(5)	(675)	23	(1,505)	(24)
Net earnings	62,271	10,555	24,163	97,906	42,006
Pacific Western Bank [Member]
Segment Reporting Information [Line Items]
Interest Income	67,132	69,977	72,873	214,704	189,101
Interest expense	(8,851)	(7,450)	(1,692)	(17,528)	(6,422)
Intersegment interest income (expense), net	5,250	4,071	353	9,543	1,284
Net interest income	63,531	66,598	71,534	206,719	183,963
Provision for Loan, Lease, and Other Losses	6,314	4,418	5,782	11,558	6,053
Gain on securities	0	89		4,841	5,631
FDIC loss sharing expense	(7,415)	(8,525)	(7,032)	(27,370)	(15,579)
Other noninterest income	7,566	3,681	5,466	18,144	10,240
Total non-interest income	151	(4,755)	(1,566)	(4,385)	292
Foreclosed assets (expense) income, net	(4,627)	(633)	420	(3,399)	934
Intangible asset amortization	(1,517)	(1,530)	(1,354)	(4,238)	(3,474)
Acquisition, integration and reorganization costs	(3,953)	(77,713)	(5,190)	(83,866)	(23,879)
Other noninterest expense	53,784	51,507	42,435	146,281	115,352
Total noninterest expense	(63,881)	(131,383)	(48,559)	(237,784)	(141,771)
Intersegment noninterest income (expense_	26,411	23,533		49,944
Total noninterest expense - adjusted	(37,470)	(107,850)		(187,840)
Earnings (loss) from continuing operations before taxes	32,526	(41,589)	27,191	26,052	48,537
Income Tax Expense (Benefit)	(13,870)	12,081	(9,996)	(14,123)	(17,038)
Net earnings (loss) from continuing operations	18,656	(29,508)	17,195	11,929	31,499
Loss from discontinued operations before taxes	(8)	(1,151)	39	(2,572)	(42)
Discontinued Operation, Tax Effect of Discontinued Operation	3	476	(16)	1,067	18
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	(5)	(675)	23	(1,505)	(24)
Net earnings	18,651	(30,183)	17,218	10,424	31,475
National Lending Segment [Member]
Segment Reporting Information [Line Items]
Interest Income	134,624	132,742	12,285	278,131	36,957
Interest expense	(45)	(62)	(108)	(184)	(447)
Intersegment interest income (expense), net	(5,250)	(4,071)	(353)	(9,543)	(1,284)
Net interest income	129,329	128,609	11,824	268,404	35,226
Provision for Loan, Lease, and Other Losses	(11,364)	(9,448)	(1,615)	(20,994)	(3,181)
Gain on securities	0	0		0	0
FDIC loss sharing expense	0	0	0	0	0
Other noninterest income	9,953	12,487	1,443	26,885	2,579
Total non-interest income	9,953	12,487	1,443	26,885	2,579
Foreclosed assets (expense) income, net	(322)	38	0	(284)	0
Intangible asset amortization	(91)	(147)	(158)	(411)	(498)
Acquisition, integration and reorganization costs	(1,240)	(7,474)	0	(8,714)	0
Other noninterest expense	24,835	24,484	5,822	55,892	17,855
Total noninterest expense	(26,488)	(32,067)	(5,980)	(65,301)	(18,353)
Intersegment noninterest income (expense_	(26,411)	(23,533)		(49,944)
Total noninterest expense - adjusted	(52,899)	(55,600)		(115,245)
Earnings (loss) from continuing operations before taxes	75,019	76,048	5,672	159,050	16,271
Income Tax Expense (Benefit)	(30,113)	(30,259)	(2,378)	(63,703)	(6,814)
Net earnings (loss) from continuing operations	44,906	45,789	3,294	95,347	9,457
Loss from discontinued operations before taxes	0	0	0	0	0
Discontinued Operation, Tax Effect of Discontinued Operation	0	0	0	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	0	0	0	0	0
Net earnings	44,906	45,789	3,294	95,347	9,457
Other Segments [Member]
Segment Reporting Information [Line Items]
Interest Income	600	1,644	0	2,244	0
Interest expense	(4,614)	(4,318)	(1,069)	(9,973)	(2,734)
Intersegment interest income (expense), net	0	0	0	0	0
Net interest income	(4,014)	(2,674)	(1,069)	(7,729)	(2,734)
Provision for Loan, Lease, and Other Losses	0	0	0	0	0
Gain on securities	0	0		0	0
FDIC loss sharing expense	0	0	0	0	0
Other noninterest income	6,210	747	5,250	6,984	5,299
Total non-interest income	6,210	747	5,250	6,984	5,299
Foreclosed assets (expense) income, net	122	98	0	220	0
Intangible asset amortization	0	0	0	0	0
Acquisition, integration and reorganization costs	0	(1,055)	(260)	(1,055)	(260)
Other noninterest expense	5,382	5,499	1,401	12,484	4,215
Total noninterest expense	(5,260)	(6,456)	(1,661)	(13,319)	(4,475)
Intersegment noninterest income (expense_	0	0		0
Total noninterest expense - adjusted	(5,260)	(6,456)		(13,319)
Earnings (loss) from continuing operations before taxes	(3,064)	(8,383)	2,520	(14,064)	(1,910)
Income Tax Expense (Benefit)	1,778	3,332	1,131	6,199	2,984
Net earnings (loss) from continuing operations	(1,286)	(5,051)	3,651	(7,865)	1,074
Loss from discontinued operations before taxes	0	0	0	0	0
Discontinued Operation, Tax Effect of Discontinued Operation	0	0	0	0	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	0	0	0	0	0
Net earnings	$ (1,286)	$ (5,051)	$ 3,651	$ (7,865)	$ 1,074