Business Segment Business Segments (Details 1) - USD ($) $ in Thousands		Jun. 30, 2015		Dec. 31, 2014	Jun. 30, 2014	Apr. 07, 2014
Loans and Leases Receivable, Net of Deferred Income		$ 12,034,189		$ 11,882,432
Loans and Leases Receivable, Allowance		(99,375)		(84,455)
Total loans and leases, net		11,934,814		11,797,977
Goodwill		1,728,380		1,720,479
Core deposit and customer relationship intangibles, net		14,201		17,204
Total assets		16,697,020		16,234,605
Total deposits		12,581,816		$ 11,755,128
Consolidated Entities [Member]
Loans and Leases Receivable, Net of Deferred Income		12,034,189			$ 11,190,105
Loans and Leases Receivable, Allowance		(99,375)			(82,149)
Total loans and leases, net		11,934,814			11,107,956
Goodwill	[1]	1,728,380			1,725,153
Core deposit and customer relationship intangibles, net		14,201			20,431
Total assets		16,697,020			15,684,671
Total deposits		12,581,816			11,667,797
Operating Segments [Member] | Community Banking Segment [Member]
Loans and Leases Receivable, Net of Deferred Income		3,101,834			3,537,994
Loans and Leases Receivable, Allowance		(41,108)			(66,039)
Total loans and leases, net		3,060,726			3,471,955
Goodwill		333,979	[1]		279,296
Core deposit and customer relationship intangibles, net		13,528			19,330
Total assets		6,685,456			6,100,744
Total deposits		12,962,905			11,909,853
Operating Segments [Member] | National Lending Segment [Member]
Loans and Leases Receivable, Net of Deferred Income		8,923,079			7,599,030
Loans and Leases Receivable, Allowance		(58,260)			(16,110)
Total loans and leases, net		8,864,819			7,582,920
Goodwill		1,394,401	[1]		1,445,857
Core deposit and customer relationship intangibles, net		673			1,101
Total assets		9,870,154			9,275,500
Total deposits		35,420			28,302
Operating Segments [Member] | Other Segments [Member]
Loans and Leases Receivable, Net of Deferred Income		9,276			53,081
Loans and Leases Receivable, Allowance		(7)			0
Total loans and leases, net		9,269			53,081
Goodwill		0	[1]		0
Core deposit and customer relationship intangibles, net		0			0
Total assets		141,410			308,427
Total deposits		$ (416,509)			$ (270,358)
Capitalsource, Inc. [Member]
Goodwill						$ 1,526,282

[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.