Loans and Leases (Details 3) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016	Jun. 30, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	$ 15,543,457		$ 15,455,954
Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	15,471,031	[1],[2]	15,347,530	$ 14,504,580
Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	339,977	[1]	409,645
Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	15,131,054	[1]	14,937,885
Real Estate Mortgage | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	6,071,798	[1],[2]	5,617,956	5,563,380
Real Estate Mortgage | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	129,782	[1]	117,181
Real Estate Mortgage | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	5,942,016	[1]	5,500,775
Real Estate Mortgage | Commercial real estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	4,387,696	[1]	4,353,633
Real Estate Mortgage | Commercial real estate | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	120,336	[1]	99,641
Real Estate Mortgage | Commercial real estate | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	4,267,360	[1]	4,253,992
Real Estate Mortgage | Residential Real Estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,684,102	[1]	1,264,323
Real Estate Mortgage | Residential Real Estate | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	9,446	[1]	17,540
Real Estate Mortgage | Residential Real Estate | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,674,656	[1]	1,246,783
Real Estate Construction and Land | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,163,340	[1],[2]	962,839	696,233
Real Estate Construction and Land | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	0	[1]	773
Real Estate Construction and Land | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,163,340	[1]	962,066
Real Estate Construction and Land | Commercial Real Estate Construction Loan Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	690,058	[1]	578,838
Real Estate Construction and Land | Commercial Real Estate Construction Loan Receivable | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	0	[1]	409
Real Estate Construction and Land | Commercial Real Estate Construction Loan Receivable | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	690,058	[1]	578,429
Real Estate Construction and Land | Residential Real Estate Construction Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	473,282	[1]	384,001
Real Estate Construction and Land | Residential Real Estate Construction Financing Receivable | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	0	[1]	364
Real Estate Construction and Land | Residential Real Estate Construction Financing Receivable | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	473,282	[1]	383,637
Commercial | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	7,837,667	[1],[2]	8,391,560	8,032,333
Commercial | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	209,555	[1]	291,267
Commercial | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	7,628,112	[1]	8,100,293
Commercial | Cash Flow | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,830,612	[1]	3,107,392
Commercial | Cash Flow | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	100,652	[1]	177,661
Commercial | Cash Flow | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,729,960	[1]	2,929,731
Commercial | Asset Based | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,392,124	[1]	2,609,045
Commercial | Asset Based | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	18,313	[1]	28,112
Commercial | Asset Based | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,373,811	[1]	2,580,933
Commercial | Venture Capital Loans | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	2,001,381	[1]	1,983,156
Commercial | Venture Capital Loans | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	59,479	[1]	52,646
Commercial | Venture Capital Loans | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	1,941,902	[1]	1,930,510
Commercial | Equipment Finance Commercial Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	613,550	[1]	691,967
Commercial | Equipment Finance Commercial Financing Receivable | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	31,111	[1]	32,848
Commercial | Equipment Finance Commercial Financing Receivable | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	582,439	[1]	659,119
Consumer | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	398,226	[1]	375,175	$ 212,634
Consumer | Non Purchased Credit Impaired Loans and Leases | Classified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	640	[1]	424
Consumer | Non Purchased Credit Impaired Loans and Leases | Nonclassified
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment	$ 397,586	[1]	$ 374,751

[1] Excludes loans held for sale carried at lower of cost or fair value.

[2] Excludes loans held for sale carried at lower of cost or fair value.