Loans and Leases (Details 1) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016	Jun. 30, 2016
Delinquent loans in loan portfolio
30-89 Days Past Due	$ 3,200		$ 3,000
90 or More Days Past Due	22,900		15,900
Loans held for investment, net	15,543,457		15,455,954
Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	30,384	[1]	31,569
90 or More Days Past Due	22,893	[1]	15,945
Total Past Due	53,277	[1]	47,514
Current	15,417,754	[1]	15,300,016
Loans held for investment, net	15,471,031	[2],[3]	15,347,530	$ 14,504,580
Real Estate Mortgage | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	4,865		14,284
90 or More Days Past Due	5,906		5,302
Total Past Due	10,771		19,586
Current	6,061,027		5,598,370
Loans held for investment, net	6,071,798	[2],[3]	5,617,956	5,563,380
Real Estate Mortgage | Commercial real estate | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	4,421		8,590
90 or More Days Past Due	4,008		3,303
Total Past Due	8,429		11,893
Current	4,379,267		4,341,740
Loans held for investment, net	4,387,696	[2]	4,353,633
Real Estate Mortgage | Residential Real Estate | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	444		5,694
90 or More Days Past Due	1,898		1,999
Total Past Due	2,342		7,693
Current	1,681,760		1,256,630
Loans held for investment, net	1,684,102	[2]	1,264,323
Real Estate Construction and Land | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	0		364
90 or More Days Past Due	0		0
Total Past Due	0		364
Current	1,163,340		962,475
Loans held for investment, net	1,163,340	[2],[3]	962,839	696,233
Real Estate Construction and Land | Commercial Real Estate Construction Loan Receivable | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	0		0
90 or More Days Past Due	0		0
Total Past Due	0		0
Current	690,058		578,838
Loans held for investment, net	690,058	[2]	578,838
Real Estate Construction and Land | Residential Real Estate Construction Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	0		364
90 or More Days Past Due	0		0
Total Past Due	0		364
Current	473,282		383,637
Loans held for investment, net	473,282	[2]	384,001
Commercial | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	25,221		16,697
90 or More Days Past Due	16,943		10,643
Total Past Due	42,164		27,340
Current	7,795,503		8,364,220
Loans held for investment, net	7,837,667	[2],[3]	8,391,560	8,032,333
Commercial | Cash Flow | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	1,360		191
90 or More Days Past Due	10,040		1,821
Total Past Due	11,400		2,012
Current	2,819,212		3,105,380
Loans held for investment, net	2,830,612	[2]	3,107,392
Commercial | Asset Based | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	0		1,500
90 or More Days Past Due	203		2
Total Past Due	203		1,502
Current	2,391,921		2,607,543
Loans held for investment, net	2,392,124	[2]	2,609,045
Commercial | Venture Capital Loans | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	23,171		13,589
90 or More Days Past Due	6,531		5,769
Total Past Due	29,702		19,358
Current	1,971,679		1,963,798
Loans held for investment, net	2,001,381	[2]	1,983,156
Commercial | Equipment Finance Commercial Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	690		1,417
90 or More Days Past Due	169		3,051
Total Past Due	859		4,468
Current	612,691		687,499
Loans held for investment, net	613,550	[2]	691,967
Consumer | Non Purchased Credit Impaired Loans and Leases
Delinquent loans in loan portfolio
30-89 Days Past Due	298		224
90 or More Days Past Due	44		0
Total Past Due	342		224
Current	397,884		374,951
Loans held for investment, net	$ 398,226	[2]	$ 375,175	$ 212,634

[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.

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