Loans and Allowance for Loan Losses (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	$ 7,635,776		$ 6,936,587
Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	113,168		265,501
Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,291,476	[1]	1,688,149	[2]
Commercial and Industrial Financing Receivable [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	2,748,702		1,985,829
Commercial and Industrial Financing Receivable [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	26,774		96,148
Commercial and Industrial Financing Receivable [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	197,539	[1]	259,194	[2]
Commercial and Industrial Financing Receivable [Member] | Grade 1 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	37,607		66,802
Commercial and Industrial Financing Receivable [Member] | Grade 1 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial and Industrial Financing Receivable [Member] | Grade 1 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	948		641
Commercial and Industrial Financing Receivable [Member] | Grade 2 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	122,124		64,740
Commercial and Industrial Financing Receivable [Member] | Grade 2 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial and Industrial Financing Receivable [Member] | Grade 2 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,376		0
Commercial and Industrial Financing Receivable [Member] | Grade 3 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	479,119		260,351
Commercial and Industrial Financing Receivable [Member] | Grade 3 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		451
Commercial and Industrial Financing Receivable [Member] | Grade 3 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		3,045
Commercial and Industrial Financing Receivable [Member] | Grade 4 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,973,671		1,476,930
Commercial and Industrial Financing Receivable [Member] | Grade 4 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	26,036		95,392
Commercial and Industrial Financing Receivable [Member] | Grade 4 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	109,360		111,792
Commercial and Industrial Financing Receivable [Member] | Grade 5 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	50,789		61,284
Commercial and Industrial Financing Receivable [Member] | Grade 5 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		5
Commercial and Industrial Financing Receivable [Member] | Grade 5 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	9,661		63,624
Commercial and Industrial Financing Receivable [Member] | Grade 6 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	85,392		55,720
Commercial and Industrial Financing Receivable [Member] | Grade 6 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	738		300
Commercial and Industrial Financing Receivable [Member] | Grade 6 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	69,330		67,253
Commercial and Industrial Financing Receivable [Member] | Grade 7 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		2
Commercial and Industrial Financing Receivable [Member] | Grade 7 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial and Industrial Financing Receivable [Member] | Grade 7 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	6,864		12,839
Commercial and Industrial Financing Receivable [Member] | Grade 8 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial and Industrial Financing Receivable [Member] | Grade 8 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial and Industrial Financing Receivable [Member] | Grade 8 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,992,193		2,027,320
Commercial Real Estate Other Receivable [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	62,743		141,041
Commercial Real Estate Other Receivable [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	777,848	[1]	1,018,215	[2]
Commercial Real Estate Other Receivable [Member] | Grade 1 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		13,387
Commercial Real Estate Other Receivable [Member] | Grade 1 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 1 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 2 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	4,218		4,462
Commercial Real Estate Other Receivable [Member] | Grade 2 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 2 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 3 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	249,382		278,274
Commercial Real Estate Other Receivable [Member] | Grade 3 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,871		5,934
Commercial Real Estate Other Receivable [Member] | Grade 3 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	516		1,337
Commercial Real Estate Other Receivable [Member] | Grade 4 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,548,420		1,486,620
Commercial Real Estate Other Receivable [Member] | Grade 4 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	55,129		133,613
Commercial Real Estate Other Receivable [Member] | Grade 4 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	303,231		430,553
Commercial Real Estate Other Receivable [Member] | Grade 5 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	58,942		87,155
Commercial Real Estate Other Receivable [Member] | Grade 5 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 5 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	103,919		221,020
Commercial Real Estate Other Receivable [Member] | Grade 6 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	130,968		157,422
Commercial Real Estate Other Receivable [Member] | Grade 6 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	5,743		1,494
Commercial Real Estate Other Receivable [Member] | Grade 6 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	344,445		317,134
Commercial Real Estate Other Receivable [Member] | Grade 7 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	263		0
Commercial Real Estate Other Receivable [Member] | Grade 7 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 7 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	25,737		48,171
Commercial Real Estate Other Receivable [Member] | Grade 8 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 8 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Other Receivable [Member] | Grade 8 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	277,335		277,159
Commercial Real Estate Construction Financing Receivable [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	89,909		117,170
Commercial Real Estate Construction Financing Receivable [Member] | Grade 1 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		3,301
Commercial Real Estate Construction Financing Receivable [Member] | Grade 1 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 1 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 2 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	615		6,700
Commercial Real Estate Construction Financing Receivable [Member] | Grade 2 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 2 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 3 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	16,752		39,986
Commercial Real Estate Construction Financing Receivable [Member] | Grade 3 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 3 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 4 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	241,302		188,949
Commercial Real Estate Construction Financing Receivable [Member] | Grade 4 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 4 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	487		4,262
Commercial Real Estate Construction Financing Receivable [Member] | Grade 5 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	4,583		8,055
Commercial Real Estate Construction Financing Receivable [Member] | Grade 5 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 5 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	1,567		3,260
Commercial Real Estate Construction Financing Receivable [Member] | Grade 6 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	14,083		30,168
Commercial Real Estate Construction Financing Receivable [Member] | Grade 6 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 6 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	80,009		69,998
Commercial Real Estate Construction Financing Receivable [Member] | Grade 7 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 7 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 7 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	7,846		39,650
Commercial Real Estate Construction Financing Receivable [Member] | Grade 8 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 8 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Real Estate Construction Financing Receivable [Member] | Grade 8 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	73,530		63,004
Commercial Leases Financing Receivable [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0
Commercial Leases Financing Receivable [Member] | Grade 1 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	10,636		8,069
Commercial Leases Financing Receivable [Member] | Grade 1 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 1 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 2 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 2 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 2 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 3 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	5,868		11,414
Commercial Leases Financing Receivable [Member] | Grade 3 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 3 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 4 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	57,026		43,210
Commercial Leases Financing Receivable [Member] | Grade 4 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 4 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 5 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		311
Commercial Leases Financing Receivable [Member] | Grade 5 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 5 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 6 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 6 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 6 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 7 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 7 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 7 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 8 [Member] | Legacy Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 8 [Member] | Acquired Loans (Noncovered) [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	0		0
Commercial Leases Financing Receivable [Member] | Grade 8 [Member] | Covered Loans [Member]
Summary of loans by portfolio type and the Corporation's internal credit quality rating
Total Loans	$ 0		$ 0

[1] Excludes loss share receivable of $205.7 million as of December 31, 2011.

[2] Excludes loss share receivable of $288.6 million as of December 31, 2010.