Consolidated Statement of Shareholders' Equity (USD $)	Total USD ($)	Common Stock [Member] USD ($)	Shares Of Common Stock [Member] USD ($)	Additional Paid-in Capital [Member] USD ($)	Accumulated Deficit [Member] USD ($)	Treasury Stock [Member] USD ($)	Accumulated Other Comprehensive Income [Member] USD ($)	CapitalSource Inc. [Member] [Member] USD ($)	CapitalSource Inc. [Member] [Member] Common Stock [Member] USD ($)	CapitalSource Inc. [Member] [Member] Shares Of Common Stock [Member]	CapitalSource Inc. [Member] [Member] Additional Paid-in Capital [Member] USD ($)	CapitalSource Inc. [Member] [Member] Accumulated Deficit [Member] USD ($)	CapitalSource Inc. [Member] [Member] Treasury Stock [Member] USD ($)	CapitalSource Inc. [Member] [Member] Accumulated Other Comprehensive Income [Member] USD ($)
Shareholders' Equity - Beginning Balance at Dec. 31, 2013	$ 809,093,000	$ 465,000		$ 1,286,737,000	$ (454,422,000)	$ (20,340,000)	$ (3,347,000)
Shares, Outstanding	103,027,830,000
Net income	97,906,000				97,906,000
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	24,168,000	0	0	0	0	0	24,168,000
Common Stock, Shares, Issued	104,225,010									56,601,997,000
Common stock ($0.01 par value, 200,000,000 and 75,000,000 shares authorized at September 30, 2014 and December 31, 2013, respectively; 104,225,010 and 46,526,124 shares issued, respectively, includes 1,115,550 and 1,216,524 shares of unvested restricted stock, respectively)	1,042,000							2,594,070,000	566,000		2,593,504,000	0	0	0
Stock Issued During Period, Shares, Restricted Stock Award, Forfeited			1,095,538,000
Restricted Stock Award, Forfeitures	33,641,000	11,000		33,630,000	0	0	0
Treasury Stock, Retired, Cost Method, Amount	(22,307,000)	0	(493,890,000)		0	(22,307,000)	0
Stock Issued During Period, Shares, Dividend Reinvestment Plan		1,351,000
Stock Issued During Period, Value, Dividend Reinvestment Plan	57,000	0		57,000	0	0	0
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	4,402,000	0	0	4,402,000		0	0
Dividends paid	(62,784,000)	0	0	(62,784,000)	0	0	0
Shareholders' Equity - Ending balance at Sep. 30, 2014	$ 3,478,246,000	$ 1,042,000		$ 3,855,546,000	$ (356,516,000)	$ (42,647,000)	$ 20,821,000