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, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Nonaccrual	$ 105,908	$ 105,326
90 days and still accruing	34,376	18,872
Current	26,361,332	23,526,168
Total Loans	26,800,290	23,820,691
Commercial
Financing Receivable, Past Due [Line Items]
Nonaccrual	37,224	50,984
90 days and still accruing	1,855	3,313
Current	8,166,242	7,737,729
Total Loans	8,285,920	7,828,538
Commercial | Commercial, industrial and other
Financing Receivable, Past Due [Line Items]
Nonaccrual	33,983	34,298
90 days and still accruing	0	0
Current	5,075,335	5,062,729
Total Loans	5,159,805	5,120,096
Commercial | Franchise
Financing Receivable, Past Due [Line Items]
Nonaccrual	2,391	16,051
90 days and still accruing	0	0
Current	934,875	924,190
Total Loans	937,482	948,979
Commercial | Mortgage warehouse lines of credit
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
90 days and still accruing	0	0
Current	288,592	144,199
Total Loans	292,781	144,199
Commercial | Asset-based lending
Financing Receivable, Past Due [Line Items]
Nonaccrual	128	635
90 days and still accruing	0	0
Current	982,165	1,022,065
Total Loans	989,018	1,026,056
Commercial | Leases
Financing Receivable, Past Due [Line Items]
Nonaccrual	722	0
90 days and still accruing	0	0
Current	866,561	564,430
Total Loans	878,528	565,680
Commercial | PCI - commercial
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
90 days and still accruing	1,855	3,313
Current	18,714	20,116
Total Loans	28,306	23,528
Commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	26,113	19,129
90 days and still accruing	14,946	6,241
Current	7,850,104	6,845,490
Total Loans	8,020,276	6,933,252
Commercial real estate | Construction
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,030	1,554
90 days and still accruing	0	0
Current	1,004,115	749,846
Total Loans	1,023,300	760,824
Commercial real estate | Land
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,082	107
90 days and still accruing	0	0
Current	165,008	141,097
Total Loans	177,483	141,481
Commercial real estate | Office
Financing Receivable, Past Due [Line Items]
Nonaccrual	8,034	3,629
90 days and still accruing	0	0
Current	1,026,916	929,739
Total Loans	1,044,769	939,322
Commercial real estate | Industrial
Financing Receivable, Past Due [Line Items]
Nonaccrual	99	285
90 days and still accruing	0	0
Current	1,020,904	885,367
Total Loans	1,032,866	902,248
Commercial real estate | Retail
Financing Receivable, Past Due [Line Items]
Nonaccrual	6,789	10,753
90 days and still accruing	0	0
Current	1,081,427	878,106
Total Loans	1,097,930	892,478
Commercial real estate | Multi-family
Financing Receivable, Past Due [Line Items]
Nonaccrual	913	311
90 days and still accruing	0	0
Current	1,306,810	970,597
Total Loans	1,311,542	976,560
Commercial real estate | Mixed use and other
Financing Receivable, Past Due [Line Items]
Nonaccrual	8,166	2,490
90 days and still accruing	0	0
Current	2,061,528	2,192,105
Total Loans	2,094,946	2,205,195
Commercial real estate | PCI - commercial real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
90 days and still accruing	14,946	6,241
Current	183,396	98,633
Total Loans	237,440	115,144
Home equity
Financing Receivable, Past Due [Line Items]
Nonaccrual	7,363	7,147
90 days and still accruing	0	0
Current	501,716	541,960
Total Loans	513,066	552,343
Residential real estate, including PCI
Financing Receivable, Past Due [Line Items]
Nonaccrual	13,797	16,383
90 days and still accruing	5,771	1,292
Current	1,313,523	976,926
Total Loans	1,354,221	1,002,464
Premium finance receivables | Commercial insurance loans
Financing Receivable, Past Due [Line Items]
Nonaccrual	20,590	11,335
90 days and still accruing	11,517	7,799
Current	3,379,018	2,796,058
Total Loans	3,442,027	2,841,659
Premium finance receivables | Life insurance loans
Financing Receivable, Past Due [Line Items]
Nonaccrual	590	0
90 days and still accruing	0	0
Current	4,902,171	4,340,856
Total Loans	4,935,320	4,373,891
Premium finance receivables | PCI - life insurance loans
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
90 days and still accruing	0	0
Current	139,282	167,903
Total Loans	139,282	167,903
Consumer and other, including PCI
Financing Receivable, Past Due [Line Items]
Nonaccrual	231	348
90 days and still accruing	287	227
Current	109,276	119,246
Total Loans	110,178	120,641
60-89 days past due
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	50,523	34,176
60-89 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,275	1,651
60-89 days past due | Commercial | Commercial, industrial and other
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	1,647	1,451
60-89 days past due | Commercial | Franchise
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	0
60-89 days past due | Commercial | Mortgage warehouse lines of credit
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	0
60-89 days past due | Commercial | Asset-based lending
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	956	200
60-89 days past due | Commercial | Leases
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	249	0
60-89 days past due | Commercial | PCI - commercial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	423	0
60-89 days past due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	31,546	10,826
60-89 days past due | Commercial real estate | Construction
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	1,499	0
60-89 days past due | Commercial real estate | Land
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	170
60-89 days past due | Commercial real estate | Office
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,692	877
60-89 days past due | Commercial real estate | Industrial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	1,660	0
60-89 days past due | Commercial real estate | Retail
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	6,168	1,890
60-89 days past due | Commercial real estate | Multi-family
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	731	77
60-89 days past due | Commercial real estate | Mixed use and other
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	9,823	1,617
60-89 days past due | Commercial real estate | PCI - commercial real estate
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	7,973	6,195
60-89 days past due | Home equity
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	454	131
60-89 days past due | Residential real estate, including PCI
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,089	1,692
60-89 days past due | Premium finance receivables | Commercial insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	12,119	11,382
60-89 days past due | Premium finance receivables | Life insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	8,407
60-89 days past due | Premium finance receivables | PCI - life insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	0
60-89 days past due | Consumer and other, including PCI
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	40	87
30-59 days past due
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	248,151	136,149
30-59 days past due | Commercial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	77,324	34,861
30-59 days past due | Commercial | Commercial, industrial and other
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	48,840	21,618
30-59 days past due | Commercial | Franchise
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	216	8,738
30-59 days past due | Commercial | Mortgage warehouse lines of credit
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	4,189	0
30-59 days past due | Commercial | Asset-based lending
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	5,769	3,156
30-59 days past due | Commercial | Leases
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	10,996	1,250
30-59 days past due | Commercial | PCI - commercial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	7,314	99
30-59 days past due | Commercial real estate
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	97,567	51,566
30-59 days past due | Commercial real estate | Construction
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	16,656	9,424
30-59 days past due | Commercial real estate | Land
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	11,393	107
30-59 days past due | Commercial real estate | Office
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	6,127	5,077
30-59 days past due | Commercial real estate | Industrial
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	10,203	16,596
30-59 days past due | Commercial real estate | Retail
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,546	1,729
30-59 days past due | Commercial real estate | Multi-family
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,088	5,575
30-59 days past due | Commercial real estate | Mixed use and other
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	15,429	8,983
30-59 days past due | Commercial real estate | PCI - commercial real estate
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	31,125	4,075
30-59 days past due | Home equity
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	3,533	3,105
30-59 days past due | Residential real estate, including PCI
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	18,041	6,171
30-59 days past due | Premium finance receivables | Commercial insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	18,783	15,085
30-59 days past due | Premium finance receivables | Life insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	32,559	24,628
30-59 days past due | Premium finance receivables | PCI - life insurance loans
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	0	0
30-59 days past due | Consumer and other, including PCI
Financing Receivable, Past Due [Line Items]
Less than 90 days past due	$ 344	$ 733