Loans and Leases (Loans And Leases Outstanding) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011
Total covered loans acquired	$ 2,183,869	[1]	$ 2,362,152	[2]	$ 2,658,134	[1]
Noncovered loans	11,489,529	[1]	11,581,637	[2]	11,392,351	[1]
Total loans and leases	13,673,398		13,943,789		14,050,485
Commercial Mortgage [Member]
Total covered loans acquired	1,745,709		1,872,685		2,171,294
Noncovered loans	7,830,041		7,866,572		7,546,718
Non-Commercial Loans [Member]
Total covered loans acquired	438,160		489,467		486,840
Noncovered loans	3,659,488		3,715,065		3,845,633
Construction and Land Development [Member] | Commercial Mortgage [Member]
Total covered loans acquired	310,601		338,873		402,316
Noncovered loans	346,557		381,163		373,769
Construction and Land Development [Member] | Non-Commercial Loans [Member]
Total covered loans acquired	85,555		105,536		111,425
Noncovered loans	132,677		137,271		145,864
Commercial Mortgage [Member] | Commercial Mortgage [Member]
Total covered loans acquired	1,195,541		1,260,589		1,432,632
Noncovered loans	5,127,948		5,104,993		4,763,393
Other Commercial Real Estate [Member] | Commercial Mortgage [Member]
Total covered loans acquired	144,978		158,394		163,305
Noncovered loans	150,316		144,771		147,150
Residential Mortgage [Member] | Non-Commercial Loans [Member]
Total covered loans acquired	298,538		327,568		347,393
Noncovered loans	793,612		784,118		808,650
Revolving Mortgage [Member] | Non-Commercial Loans [Member]
Total covered loans acquired	50,016		51,552		23,409
Noncovered loans	2,282,138		2,296,306		2,299,668
Consumer [Member] | Non-Commercial Loans [Member]
Total covered loans acquired	4,051		4,811		4,613
Noncovered loans	451,061		497,370		591,451
Lease Financing [Member] | Commercial Mortgage [Member]
Total covered loans acquired	45		57		271
Noncovered loans	315,704		312,869		295,994
Other Loans [Member] | Commercial Mortgage [Member]
Total covered loans acquired	1,283		1,330		1,729
Noncovered loans	$ 149,792		$ 158,369		$ 174,370

[1] Unaudited

[2] Derived from 2011 Annual Report on Form 10-K.