Loans and Credit Quality (Details 3) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Delinquent loans in loan portfolio
30-89 Days Past Due	$ 4,500	$ 8,700
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	33,700	18,800
Loans held for investment, net	12,034,189	11,882,432
NonCovered [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	10,326	19,406
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	33,657	18,818
Financing Receivable, Recorded Investment, Past Due	43,983	38,224
Current	11,767,568	11,553,417
Loans held for investment, net	11,811,551	11,591,641	$ 10,791,669
NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	6,691	11,628
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	12,434	11,987
Financing Receivable, Recorded Investment, Past Due	19,125	23,615
Current	5,396,545	5,316,945
Loans held for investment, net	5,415,670	5,340,560	5,236,452
NonCovered [Member] | Real Estate Construction [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	715
Financing Receivable, Recorded Investment, Past Due	0	715
Current	343,500	306,420
Loans held for investment, net	343,500	307,135	298,477
NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	3,610	7,677
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	18,077	2,970
Financing Receivable, Recorded Investment, Past Due	21,687	10,647
Current	5,944,415	5,831,816
Loans held for investment, net	5,966,102	5,842,463	5,193,735
NonCovered [Member] | Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
Loans held for investment, net	86,279	101,483	$ 63,005
Consumer Financing Receivable [Member] | NonCovered [Member] | Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	25	101
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	3,146	3,146
Financing Receivable, Recorded Investment, Past Due	3,171	3,247
Current	83,108	98,236
Loans held for investment, net		101,483
Collateralized Loan Obligations [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	733	878
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	427	965
Financing Receivable, Recorded Investment, Past Due	1,160	1,843
Current	370,631	437,344
Loans held for investment, net	371,791	439,187
Unsecured Commercial Member [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	33	69
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	15	45
Financing Receivable, Recorded Investment, Past Due	48	114
Current	120,087	131,710
Loans held for investment, net	120,135	131,824
Asset Based [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Current	1,840,453	1,794,851
Loans held for investment, net	1,840,453	1,794,851
Cash Flow [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	232
Financing Receivable, Recorded Investment, Past Due	0	232
Current	2,683,466	2,459,619
Loans held for investment, net	2,683,466	2,459,851
Equipment Finance Commercial Financing Receivable [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	2,551	6,525
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	16,443	366
Financing Receivable, Recorded Investment, Past Due	18,994	6,891
Current	885,494	962,598
Loans held for investment, net	904,488	969,489
SBA Financing Receivable [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	293	205
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	1,192	1,362
Financing Receivable, Recorded Investment, Past Due	1,485	1,567
Current	44,284	45,694
Loans held for investment, net	45,769	47,261
Residential Real Estate Construction Financing Receivable [Member] | NonCovered [Member] | Real Estate Construction [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Current	119,805	96,728
Loans held for investment, net	119,805	96,728
Commercial Real Estate Construction Loan Receivable [Member] | NonCovered [Member] | Real Estate Construction [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	715
Financing Receivable, Recorded Investment, Past Due	0	715
Current	223,695	209,692
Loans held for investment, net	223,695	210,407
Hospitality [Member] | NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due	0	0
Current	596,659	560,219
Loans held for investment, net	596,659	560,219
SBA Loans [Member] | NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	2,526	5,530
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	6,919	4,357
Financing Receivable, Recorded Investment, Past Due	9,445	9,887
Current	388,617	366,040
Loans held for investment, net	398,062	375,927
Real Estate Other Class [Member] | NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	4,165	6,098
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	5,515	7,630
Financing Receivable, Recorded Investment, Past Due	9,680	13,728
Current	4,411,269	4,390,686
Loans held for investment, net	$ 4,420,949	$ 4,404,414