Loans and Credit Quality (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Delinquent loans in loan portfolio
30-89 Days Past Due	$ 21,700	$ 8,700
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	15,800	18,800
Loans held for investment, net	12,272,166	11,882,432	4,161,067
NonCovered [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	37,804	19,406
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	15,804	18,818
Financing Receivable, Recorded Investment, Past Due	53,608	38,224
Current	11,964,273	11,553,417
Loans held for investment, net	12,017,881	11,591,641	3,828,551
NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	11,816	11,628
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	10,806	11,987
Financing Receivable, Recorded Investment, Past Due	22,622	23,615
Current	5,565,808	5,316,945
Loans held for investment, net	5,588,430	5,340,560	2,320,554
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	328,709	306,420
Loans held for investment, net	328,709	307,135	240,073
NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	25,979	7,677
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	1,802	2,970
Financing Receivable, Recorded Investment, Past Due	27,781	10,647
Current	5,979,286	5,831,816
Loans held for investment, net	6,007,067	5,842,463	1,201,142
NonCovered [Member] | Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
Loans held for investment, net	93,675	101,483	66,782
Consumer Financing Receivable [Member] | NonCovered [Member] | Consumer Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	9	101
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	3,196	3,146
Financing Receivable, Recorded Investment, Past Due	3,205	3,247
Current	90,470	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	1,782	878
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	424	965
Financing Receivable, Recorded Investment, Past Due	2,206	1,843
Current	392,182	437,344
Loans held for investment, net	394,388	439,187
Unsecured Commercial Member [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	0	69
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	16	45
Financing Receivable, Recorded Investment, Past Due	16	114
Current	143,298	131,710
Loans held for investment, net	143,314	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	1,719,777	1,794,851
Loans held for investment, net	1,719,777	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	2,793,184	2,459,619
Loans held for investment, net	2,793,184	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	23,409	6,525
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	366
Financing Receivable, Recorded Investment, Past Due	23,409	6,891
Current	890,607	962,598
Loans held for investment, net	914,016	969,489
SBA Financing Receivable [Member] | NonCovered [Member] | Commercial Portfolio Segment [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	788	205
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	1,362	1,362
Financing Receivable, Recorded Investment, Past Due	2,150	1,567
Current	40,238	45,694
Loans held for investment, net	42,388	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	122,316	96,728
Loans held for investment, net	122,316	96,728
Commercial 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	715
Financing Receivable, Recorded Investment, Past Due	0	715
Current	206,393	209,692
Loans held for investment, net	206,393	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	612,089	560,219
Loans held for investment, net	612,089	560,219
SBA Loans [Member] | NonCovered [Member] | Mortgage Loans on Real Estate [Member]
Delinquent loans in loan portfolio
30-89 Days Past Due	5,582	5,530
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	5,487	4,357
Financing Receivable, Recorded Investment, Past Due	11,069	9,887
Current	377,707	366,040
Loans held for investment, net	388,776	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	6,234	6,098
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	5,319	7,630
Financing Receivable, Recorded Investment, Past Due	11,553	13,728
Current	4,576,012	4,390,686
Loans held for investment, net	$ 4,587,565	$ 4,404,414