Loans and Leases (Details 2) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 130,418	$ 129,019
Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	130,418	129,019
Loans and Leases Receivable, Net of Deferred Income	14,306,961	14,289,209	$ 12,017,881
Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	14,176,543	14,160,190
Consumer Portfolio Segment | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	926	1,531
Loans and Leases Receivable, Net of Deferred Income	110,622	120,849	93,675
Consumer Portfolio Segment | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	109,696	119,318
Commercial Portfolio Segment | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	92,958	69,839
Loans and Leases Receivable, Net of Deferred Income	7,990,569	7,952,577	6,007,067
Commercial Portfolio Segment | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	7,897,611	7,882,738
Commercial Portfolio Segment | Venture Capital Loans | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	124
Loans and Leases Receivable, Net of Deferred Income	1,502,611	1,452,427
Commercial Portfolio Segment | Venture Capital Loans | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	1,502,611	1,452,303
Commercial Portfolio Segment | Asset Based | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	2,046	2,505
Loans and Leases Receivable, Net of Deferred Income	2,588,916	2,547,533
Commercial Portfolio Segment | Asset Based | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	2,586,870	2,545,028
Commercial Portfolio Segment | Cash Flow | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	39,665	15,800
Loans and Leases Receivable, Net of Deferred Income	3,165,814	3,062,268
Commercial Portfolio Segment | Cash Flow | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	3,126,149	3,046,468
Commercial Portfolio Segment | Equipment Finance Commercial Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	51,247	51,410
Loans and Leases Receivable, Net of Deferred Income	733,228	890,349
Commercial Portfolio Segment | Equipment Finance Commercial Financing Receivable | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	681,981	838,939
Real Estate Construction | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	370	372
Loans and Leases Receivable, Net of Deferred Income	575,473	527,720	328,709
Real Estate Construction | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	575,103	527,348
Real Estate Construction | Commercial Real Estate Construction Loan Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	0	0
Loans and Leases Receivable, Net of Deferred Income	305,529	343,360
Real Estate Construction | Commercial Real Estate Construction Loan Receivable | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	305,529	343,360
Real Estate Construction | Residential Real Estate Construction Financing Receivable | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	370	372
Loans and Leases Receivable, Net of Deferred Income	269,944	184,360
Real Estate Construction | Residential Real Estate Construction Financing Receivable | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	269,574	183,988
Mortgage Loans on Real Estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	36,164	57,277
Loans and Leases Receivable, Net of Deferred Income	5,630,297	5,688,063	$ 5,588,430
Mortgage Loans on Real Estate | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	5,594,133	5,630,786
Mortgage Loans on Real Estate | Commercial Real Estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	30,357	52,363
Loans and Leases Receivable, Net of Deferred Income	4,552,961	4,551,958
Mortgage Loans on Real Estate | Commercial Real Estate | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	4,522,604	4,499,595
Mortgage Loans on Real Estate | Residential Real Estate | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	5,807	4,914
Loans and Leases Receivable, Net of Deferred Income	1,077,336	1,136,105
Mortgage Loans on Real Estate | Residential Real Estate | Performing Financing Receivable [Member] | Non Purchased Credit Impaired Loans and Leases
Financing Receivable, Impaired [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 1,071,529	$ 1,131,191