Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Cash Equivalents, at Carrying Value [Abstract]
Cash and due from banks	$ 243,583	$ 96,424
Interest-bearing deposits in other banks	119,782	50,998
Cash and Cash Equivalents, at Carrying Value	363,365	147,422
Investments Schedule [Abstract]
Securities Available For Sale Including Covered Securities	1,552,115	1,494,745
Federal Home Loan Bank Stock	49,983	27,939
Total Investments	1,602,098	1,522,684
Loans and Leases Receivable Gross Carrying Amount Covered And Noncovered	11,200,524	4,313,335
Less deferred loan fees and discounts	(10,419)	(983)
Loans and Leases Receivable Allowance Covered And Noncovered	(82,149)	(82,034)
Loans and Leases Receivable, Net Reported Amount, Covered and Not Covered	11,107,956	4,230,318
Equipment Leased To Others Under Operating Leases	127,289	0
Property, Plant and Equipment, Net	40,440	32,435
Other Real Estate Owned Net Covered and Noncovered including Foreclosed Assets	53,821	55,891
Goodwill	1,725,153	208,743
Finite Lived Core Deposits Customer Relations Net	20,431	17,248
FDIC Indemnification Asset	28,834	45,524
Deferred tax assets, net	342,105	79,636
Other assets	273,374	193,462
Total assets	15,684,866	6,533,363
Liabilities:
Deposits	2,701,434	2,318,446
Term debt - obligations of consolidated VIEs for which there is no recourse to the general credit of CapitalSource Inc.	8,966,363	2,962,541
Total Deposits	11,667,797	5,280,987
Other liabilities	4,596	113,726
Subordinated Debt	434,878	132,645
Accrued Liabilities and Other Liabilities	139,663	196,912
Total liabilities	12,246,934	5,724,270
Commitments and contingencies (Note 12)	0	0
Shareholders' equity:
Preferred Stock, Value, Issued	0	0
Common stock ($0.01 par value, 1,200,000,000 shares authorized; 196,944,961 and 209,551,674 shares issued/outstanding, respectively	1,042	465
Additional Paid in Capital	3,878,203	1,286,737
Retained Earnings (Accumulated Deficit)	(418,787)	(454,422)
Treasury Stock, Value	(42,647)	(20,340)
Accumulated other comprehensive income, net	20,121	(3,347)
Total shareholders' equity	3,437,932	809,093
Total liabilities and shareholders' equity	$ 15,684,866	$ 6,533,363