Loans and Leases (Loans and Leases Outstanding) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 485,300,000	$ 1,029,400,000
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	1,186,498,000	1,029,426,000	1,809,235,000
Non-PCI	17,582,967,000	12,104,298,000
Total loans and leases	18,769,465,000	13,133,724,000
Commercial
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	726,123,000	781,307,000
Non-PCI	11,263,074,000	8,499,348,000
Commercial | Construction and land development
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	78,079,000	78,915,000
Non-PCI	550,568,000	319,847,000
Commercial | Mortgage
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	577,518,000	642,891,000
Non-PCI	7,552,948,000	6,362,490,000
Commercial | Commercial and industrial
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	27,254,000	17,254,000
Non-PCI	1,988,934,000	1,081,158,000
Commercial | Lease financing
Non-PCI	571,916,000	381,763,000
Commercial | Other commercial real estate
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	40,193,000	41,381,000
Non-PCI	244,875,000	178,754,000
Commercial | Other
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	3,079,000	866,000
Non-PCI	353,833,000	175,336,000
Noncommercial
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	460,375,000	248,119,000
Non-PCI	6,319,893,000	3,604,950,000
Noncommercial | Mortgage
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	382,340,000	213,851,000
Non-PCI	2,520,542,000	982,421,000
Noncommercial | Construction and land development
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	912,000	2,583,000
Non-PCI	120,097,000	122,792,000
Noncommercial | Revolving mortgage
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	74,109,000	30,834,000
Non-PCI	2,561,800,000	2,113,285,000
Noncommercial | Consumer
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net	3,014,000	851,000
Non-PCI	1,117,454,000	386,452,000
Temecula Valley Bank [Member]
Loans, not covered by FDIC loss share agreements	177,300,000
Venture Bank [Member]
Loans, not covered by FDIC loss share agreements	61,400,000
Georgian Bank [Domain]
Loans, not covered by FDIC loss share agreements	40,900,000
Sun American Bank
Loans and Leases Receivable, Gross, Carrying Amount, Covered	41,100,000
First Regional Bank
Loans and Leases Receivable, Gross, Carrying Amount, Covered	73,200,000
Williamsburg First National Bank
Loans and Leases Receivable, Gross, Carrying Amount, Covered	$ 9,100,000