Loans and Leases (Details 1) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Delinquent loans in loan portfolio
30-89 Days Past Due		$ 17,085	$ 3,200
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		10,723	14,200
Financing Receivable, Recorded Investment, Past Due		27,808
Current		17,929,905
Loans held for investment, net		17,957,713	16,972,743
Mortgages [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		5,044
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		8,017
Financing Receivable, Recorded Investment, Past Due		13,061
Current		7,905,080
Loans held for investment, net		7,918,141	7,798,991	[1]
Mortgages [Member] | Commercial Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		3,487
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		7,541
Financing Receivable, Recorded Investment, Past Due		11,028
Current		4,813,270
Loans held for investment, net		4,824,298	5,361,487	[1]
Mortgages [Member] | Residential Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		1,557
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		476
Financing Receivable, Recorded Investment, Past Due		2,033
Current		3,091,810
Loans held for investment, net		3,093,843	2,437,504	[1]
Real Estate Construction [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		1,527
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		442
Financing Receivable, Recorded Investment, Past Due		1,969
Current		2,231,687
Loans held for investment, net		2,233,656	1,591,229	[1]
Real Estate Construction [Member] | Commercial Real Estate Construction Loan Receivable [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		0
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		442
Financing Receivable, Recorded Investment, Past Due		442
Current		912,141
Loans held for investment, net		912,583	769,075	[1]
Real Estate Construction [Member] | Residential Real Estate Construction Financing Receivable [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		1,527
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0
Financing Receivable, Recorded Investment, Past Due		1,527
Current		1,319,546
Loans held for investment, net		1,321,073	822,154	[1]
Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		9,933
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		1,931
Financing Receivable, Recorded Investment, Past Due		11,864
Current		7,392,731
Loans held for investment, net		7,404,595	7,114,920	[1]
Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		581
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		333
Financing Receivable, Recorded Investment, Past Due		914
Current		400,407
Loans held for investment, net		401,321	409,567	[1]
Asset Based [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		47
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		646
Financing Receivable, Recorded Investment, Past Due		693
Current		3,304,728
Loans held for investment, net		3,305,421	2,924,871	[1]
Venture Capital Loans [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		4,705
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0
Financing Receivable, Recorded Investment, Past Due		4,705
Current		2,034,043
Loans held for investment, net		2,038,748	2,122,711	[1]
Other Commercial [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due		5,181
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		1,285
Financing Receivable, Recorded Investment, Past Due		6,466
Current		2,053,960
Loans held for investment, net		$ 2,060,426	2,067,338	[1]
Non Purchased Credit Impaired Loans and Leases [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		48,435
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		14,165
Financing Receivable, Recorded Investment, Past Due	[2]		62,600
Current	[2]		16,852,107
Loans held for investment, net	[2],[3]		16,914,707
Non Purchased Credit Impaired Loans and Leases [Member] | Mortgages [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		36,069
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		11,129
Financing Receivable, Recorded Investment, Past Due	[2]		47,198
Current	[2]		7,751,793
Loans held for investment, net	[2],[3]		7,798,991
Non Purchased Credit Impaired Loans and Leases [Member] | Mortgages [Member] | Commercial Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		29,070
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		9,107
Financing Receivable, Recorded Investment, Past Due	[2]		38,177
Current	[2]		5,323,310
Loans held for investment, net	[2],[3]		5,361,487
Non Purchased Credit Impaired Loans and Leases [Member] | Mortgages [Member] | Residential Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		6,999
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		2,022
Financing Receivable, Recorded Investment, Past Due	[2]		9,021
Current	[2]		2,428,483
Loans held for investment, net	[2],[3]		2,437,504
Non Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		2,081
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		0
Financing Receivable, Recorded Investment, Past Due	[2]		2,081
Current	[2]		1,589,148
Loans held for investment, net	[2],[3]		1,591,229
Non Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member] | Commercial Real Estate Construction Loan Receivable [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		0
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		0
Financing Receivable, Recorded Investment, Past Due	[2]		0
Current	[2]		769,075
Loans held for investment, net	[2],[3]		769,075
Non Purchased Credit Impaired Loans and Leases [Member] | Real Estate Construction [Member] | Residential Real Estate Construction Financing Receivable [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		2,081
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		0
Financing Receivable, Recorded Investment, Past Due	[2]		2,081
Current	[2]		820,073
Loans held for investment, net	[2],[3]		822,154
Non Purchased Credit Impaired Loans and Leases [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		9,723
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		3,036
Financing Receivable, Recorded Investment, Past Due	[2]		12,759
Current	[2]		7,102,161
Loans held for investment, net	[2],[3]		7,114,920
Non Purchased Credit Impaired Loans and Leases [Member] | Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		562
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		0
Financing Receivable, Recorded Investment, Past Due	[2]		562
Current	[2]		409,005
Loans held for investment, net	[2],[3]		409,567
Non Purchased Credit Impaired Loans and Leases [Member] | Asset Based [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		344
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		690
Financing Receivable, Recorded Investment, Past Due	[2]		1,034
Current	[2]		2,923,837
Loans held for investment, net	[2],[3]		2,924,871
Non Purchased Credit Impaired Loans and Leases [Member] | Venture Capital Loans [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		6,533
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		760
Financing Receivable, Recorded Investment, Past Due	[2]		7,293
Current	[2]		2,115,418
Loans held for investment, net	[2],[3]		2,122,711
Non Purchased Credit Impaired Loans and Leases [Member] | Other Commercial [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	[2]		2,846
Loan Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[2]		1,586
Financing Receivable, Recorded Investment, Past Due	[2]		4,432
Current	[2]		2,062,906
Loans held for investment, net	[2],[3]		$ 2,067,338

[1] Excludes PCI loans.

[2] {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOjUwNzc4YjE4OWFlZTQ1MWU5MzcxMGY5M2EwOWY4MDVifFRleHRTZWxlY3Rpb246MkY4OUNBOTc0OUY1M0QwNEMyMUYwN0U5Q0Y0MTQ1MzMM}

[3] Excludes PCI loans.