Loans and Leases (Details 3) - Non Purchased Credit Impaired Loans and Leases [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	$ 14,289,209	$ 11,591,641
Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	13,897,455	11,349,030
Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	391,754	242,611
Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	5,688,063	5,336,930
Mortgages [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	5,577,000	5,239,944
Mortgages [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	111,063	96,986
Mortgages [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	4,551,958	4,429,886
Mortgages [Member] | Commercial Real Estate [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	4,453,522	4,343,313
Mortgages [Member] | Commercial Real Estate [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	98,436	86,573
Mortgages [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,136,105	907,044
Mortgages [Member] | Residential Real Estate [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,123,478	896,631
Mortgages [Member] | Residential Real Estate [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	12,627	10,413
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	527,720	310,765
Real Estate Construction [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	525,754	307,017
Real Estate Construction [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,966	3,748
Real Estate Construction [Member] | Commercial Real Estate Construction Loan Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	343,360	214,037
Real Estate Construction [Member] | Commercial Real Estate Construction Loan Receivable [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	342,789	210,691
Real Estate Construction [Member] | Commercial Real Estate Construction Loan Receivable [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	571	3,346
Real Estate Construction [Member] | Residential Real Estate Construction Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	184,360	96,728
Real Estate Construction [Member] | Residential Real Estate Construction Financing Receivable [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	182,965	96,326
Real Estate Construction [Member] | Residential Real Estate Construction Financing Receivable [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,395	402
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	7,952,577	5,842,463
Commercial Portfolio Segment [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	7,676,352	5,704,659
Commercial Portfolio Segment [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	276,225	137,804
Commercial Portfolio Segment [Member] | Cash Flow [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	3,062,268	2,638,936
Commercial Portfolio Segment [Member] | Cash Flow [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	2,878,542	2,551,085
Commercial Portfolio Segment [Member] | Cash Flow [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	183,726	87,851
Commercial Portfolio Segment [Member] | Asset Based [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	2,547,533	2,234,038
Commercial Portfolio Segment [Member] | Asset Based [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	2,528,193	2,200,058
Commercial Portfolio Segment [Member] | Asset Based [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	19,340	33,980
Commercial Portfolio Segment [Member] | Equipment Finance Commercial Financing Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	890,349	969,489
Commercial Portfolio Segment [Member] | Equipment Finance Commercial Financing Receivable [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	836,295	953,516
Commercial Portfolio Segment [Member] | Equipment Finance Commercial Financing Receivable [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	54,054	15,973
Commercial Portfolio Segment [Member] | Venture Capital Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,452,427	0
Commercial Portfolio Segment [Member] | Venture Capital Loans [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	1,433,322	0
Commercial Portfolio Segment [Member] | Venture Capital Loans [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	19,105	0
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	120,849	101,483
Consumer Portfolio Segment [Member] | Nonclassified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	118,349	97,410
Consumer Portfolio Segment [Member] | Classified [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, net	$ 2,500	$ 4,073