Business Segment Segment Reporting (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Apr. 07, 2014	Dec. 31, 2013	Sep. 30, 2013		May 31, 2013
Loans and Leases Receivable, Net of Deferred Income	$ 11,574,885			$ 4,312,352	$ 4,383,393
Loans and Leases Receivable, Allowance	(81,899)				83,786
Total loans and leases, net	11,492,986			4,230,318	4,299,607
Goodwill	1,722,129		1,520,031	208,743	215,862		129,070
Core deposit and customer relationship intangibles, net	18,823			17,248	18,678
Total assets	15,938,345			6,533,363	6,616,855
Total deposits	11,523,437	[1]		5,280,987	5,433,144	[2]
National Lending Segment [Member]
Loans and Leases Receivable, Net of Deferred Income	8,064,868				470,508
Loans and Leases Receivable, Allowance	(25,187)				(7,290)
Total loans and leases, net	8,039,681				463,218
Goodwill	1,394,401				25,678
Core deposit and customer relationship intangibles, net	1,009				2,074
Total assets	9,182,617				507,339
Total deposits	0	[1]			0	[2]
Other Segments [Member]
Loans and Leases Receivable, Net of Deferred Income	27,892				0
Loans and Leases Receivable, Allowance	0				0
Total loans and leases, net	27,892				0
Goodwill	0				0
Core deposit and customer relationship intangibles, net	0				0
Total assets	262,859				8,929
Total deposits	(303,244)	[1]			(34,424)	[2]
Pacific Western Bank [Member]
Loans and Leases Receivable, Net of Deferred Income	3,482,125				3,912,885
Loans and Leases Receivable, Allowance	(56,712)				(76,496)
Total loans and leases, net	3,425,413				3,836,389
Goodwill	327,728				190,184
Core deposit and customer relationship intangibles, net	17,814				16,604
Total assets	6,492,869				6,100,587
Total deposits	$ 11,826,681	[1]			$ 5,467,568	[2]

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

[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.