Allowance for Loan Losses Allowance for Losses on Lending-Related Commitments and Impaired Loans (Schedule of Aging of the Company's Loan Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	$ 77,602	$ 77,578
90+ days and still accruing	22,659	33,738
Current	21,408,938	19,508,748
Total loans	21,640,797	19,761,317
Loans, net of unearned income excluding covered loans, Nonaccrual		75,457
Loans, net of unearned income excluding covered loans, 90+ days past due and still accruing		31,246
Loans, net of unearned income excluding covered loans, current		19,456,994
Loans, net of unearned income, excluding covered loans	21,640,797	19,703,172
Covered loans, Nonaccrual		2,121
Covered loans, 90+ days past due and still accruing		2,492
Covered loans, Current		51,754
Covered loans	0	58,145
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	15,696	15,875
90+ days and still accruing	877	1,863
Current	6,737,479	5,967,468
Loans, net of unearned income, excluding covered loans	6,787,677	6,005,422
Commercial | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	11,260	13,441
90+ days and still accruing	0	174
Current	4,314,107	3,716,977
Loans, net of unearned income, excluding covered loans	4,342,505	3,744,712
Commercial | Franchise
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	2,447	0
90+ days and still accruing	0	0
Current	845,150	869,228
Loans, net of unearned income, excluding covered loans	847,597	869,721
Commercial | Mortgage warehouse lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
90+ days and still accruing	0	0
Current	190,523	204,225
Loans, net of unearned income, excluding covered loans	194,523	204,225
Commercial | Asset-based lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	1,550	1,924
90+ days and still accruing	0	0
Current	968,576	871,402
Loans, net of unearned income, excluding covered loans	980,466	875,070
Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	439	510
90+ days and still accruing	0	0
Current	410,772	293,073
Loans, net of unearned income, excluding covered loans	413,172	294,914
Commercial | PCI - commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
90+ days and still accruing	877	1,689
Current	8,351	12,563
Loans, net of unearned income, excluding covered loans	9,414	16,780
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	22,048	21,924
90+ days and still accruing	7,135	16,188
Current	6,517,763	6,110,999
Loans, net of unearned income, excluding covered loans	6,580,618	6,196,087
Commercial real estate | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,143	2,408
90+ days and still accruing	0	0
Current	742,171	606,007
Loans, net of unearned income, excluding covered loans	745,514	610,239
Commercial real estate | Land
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	188	394
90+ days and still accruing	0	0
Current	121,140	104,219
Loans, net of unearned income, excluding covered loans	126,484	104,801
Commercial real estate | Office
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	2,438	4,337
90+ days and still accruing	0	0
Current	887,937	857,599
Loans, net of unearned income, excluding covered loans	894,833	867,674
Commercial real estate | Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	811	7,047
90+ days and still accruing	0	0
Current	879,796	756,602
Loans, net of unearned income, excluding covered loans	883,019	770,601
Commercial real estate | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	12,328	597
90+ days and still accruing	0	0
Current	938,383	907,872
Loans, net of unearned income, excluding covered loans	951,527	912,593
Commercial real estate | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	643
90+ days and still accruing	0	0
Current	914,610	805,312
Loans, net of unearned income, excluding covered loans	915,644	807,624
Commercial real estate | Mixed use and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,140	6,498
90+ days and still accruing	0	0
Current	1,921,501	1,931,859
Loans, net of unearned income, excluding covered loans	1,935,705	1,952,175
Commercial real estate | PCI - commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
90+ days and still accruing	7,135	16,188
Current	112,225	141,529
Loans, net of unearned income, excluding covered loans	127,892	170,380
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	8,978	9,761
90+ days and still accruing	0	0
Current	648,915	707,887
Loans, net of unearned income, excluding covered loans	663,045	725,793
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	17,977	12,749
90+ days and still accruing	5,304	1,309
Current	799,158	681,956
Loans, net of unearned income, excluding covered loans	832,120	705,221
Premium finance receivables | Commercial insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	12,163	14,709
90+ days and still accruing	9,242	7,962
Current	2,579,515	2,435,684
Loans, net of unearned income, excluding covered loans	2,634,565	2,478,581
Premium finance receivables | Life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
90+ days and still accruing	0	3,717
Current	3,820,936	3,182,935
Loans, net of unearned income, excluding covered loans	3,835,790	3,220,370
Premium finance receivables | PCI - life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
90+ days and still accruing	0	0
Current	199,269	249,657
Loans, net of unearned income, excluding covered loans	199,269	249,657
Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	740	439
90+ days and still accruing	101	207
Current	105,903	120,408
Loans, net of unearned income, excluding covered loans	107,713	122,041
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	33,260	43,880
Loans, net of unearned income excluding covered loans, 60-89 days past due and still accruing		43,655
Covered loans, 60-89 days past due and still accruing		225
60 to 89 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,218	2,576
60 to 89 Days Past Due | Commercial | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	3,746	2,341
60 to 89 Days Past Due | Commercial | Franchise
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	0
60 to 89 Days Past Due | Commercial | Mortgage warehouse lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	0
60 to 89 Days Past Due | Commercial | Asset-based lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	283	135
60 to 89 Days Past Due | Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	3	0
60 to 89 Days Past Due | Commercial | PCI - commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	186	100
60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,346	15,253
60 to 89 Days Past Due | Commercial real estate | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	0
60 to 89 Days Past Due | Commercial real estate | Land
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	188
60 to 89 Days Past Due | Commercial real estate | Office
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	4,506
60 to 89 Days Past Due | Commercial real estate | Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	4,516
60 to 89 Days Past Due | Commercial real estate | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	668	760
60 to 89 Days Past Due | Commercial real estate | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	322
60 to 89 Days Past Due | Commercial real estate | Mixed use and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	1,423	1,186
60 to 89 Days Past Due | Commercial real estate | PCI - commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	2,255	3,775
60 to 89 Days Past Due | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	518	1,630
60 to 89 Days Past Due | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	1,303	936
60 to 89 Days Past Due | Premium finance receivables | Commercial insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	17,796	5,646
60 to 89 Days Past Due | Premium finance receivables | Life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,837	17,514
60 to 89 Days Past Due | Premium finance receivables | PCI - life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	0
60 to 89 Days Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	242	100
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	98,338	97,373
Loans, net of unearned income excluding covered loans, 30-59 days past due and still accruing		95,820
Covered loans, 30-59 days past due and still accruing		1,553
30 to 59 Days Past Due | Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	29,407	17,640
30 to 59 Days Past Due | Commercial | Commercial, industrial and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	13,392	11,779
30 to 59 Days Past Due | Commercial | Franchise
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	493
30 to 59 Days Past Due | Commercial | Mortgage warehouse lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,000	0
30 to 59 Days Past Due | Commercial | Asset-based lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	10,057	1,609
30 to 59 Days Past Due | Commercial | Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	1,958	1,331
30 to 59 Days Past Due | Commercial | PCI - commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	2,428
30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	29,326	31,723
30 to 59 Days Past Due | Commercial real estate | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	200	1,824
30 to 59 Days Past Due | Commercial real estate | Land
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	5,156	0
30 to 59 Days Past Due | Commercial real estate | Office
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,458	1,232
30 to 59 Days Past Due | Commercial real estate | Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	2,412	2,436
30 to 59 Days Past Due | Commercial real estate | Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	148	3,364
30 to 59 Days Past Due | Commercial real estate | Multi-family
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	1,034	1,347
30 to 59 Days Past Due | Commercial real estate | Mixed use and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	9,641	12,632
30 to 59 Days Past Due | Commercial real estate | PCI - commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	6,277	8,888
30 to 59 Days Past Due | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	4,634	6,515
30 to 59 Days Past Due | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	8,378	8,271
30 to 59 Days Past Due | Premium finance receivables | Commercial insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	15,849	14,580
30 to 59 Days Past Due | Premium finance receivables | Life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	10,017	16,204
30 to 59 Days Past Due | Premium finance receivables | PCI - life insurance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	0	0
30 to 59 Days Past Due | Consumer and other
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 to 89 days past due	$ 727	$ 887