Business Segment Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Loans held for investment, net	$ 11,882,432		$ 4,312,352
Loans and Leases Receivable, Allowance	(84,455)		(82,034)
Total loans and leases, net	11,797,977		4,230,318
Goodwill	1,720,479	[1]	208,743	[1]	79,866	39,141
Core deposit and customer relationship intangibles, net	17,204		17,248
Total assets	16,234,800		6,533,363
Total deposits	11,755,128	[2]	5,280,987	[2]
Operating Segments [Member] | Pacific Western Bank [Member]
Loans held for investment, net	3,401,129		3,837,475
Loans and Leases Receivable, Allowance	(48,253)		(75,498)
Total loans and leases, net	3,352,876		3,761,977
Goodwill	326,078	[1]	183,065	[1]
Core deposit and customer relationship intangibles, net	16,306		15,331
Total assets	6,512,313		6,004,067
Total deposits	12,030,436	[2]	5,302,822	[2]
Operating Segments [Member] | National Lending Segment [Member]
Loans held for investment, net	8,455,849		474,877
Loans and Leases Receivable, Allowance	(36,202)		(6,536)
Total loans and leases, net	8,419,647		468,341
Goodwill	1,394,401	[1]	25,678	[1]
Core deposit and customer relationship intangibles, net	898		1,917
Total assets	9,483,601		519,675
Total deposits	33,179	[2]	0	[2]
Operating Segments [Member] | Other Segments [Member]
Loans held for investment, net	25,454		0
Loans and Leases Receivable, Allowance	0		0
Total loans and leases, net	25,454		0
Goodwill	0	[1]	0	[1]
Core deposit and customer relationship intangibles, net	0		0
Total assets	238,886		9,621
Total deposits	$ (308,487)	[2]	$ (21,835)	[2]

[1] (1)The increase in the goodwill for the Community Banking segment and National Lending segment during 2014 was due primarily to $1.5 billion from the CapitalSource merger.

[2] (2)The negative balance for total deposits in the “Other” segment represents the elimination of holding company cash held in deposit accounts at the Bank.