Loans - Loans by FICO Score, Consumer (Details) - USD ($) $ in Thousands	Mar. 31, 2020		Dec. 31, 2019		Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, net of unearned income	$ 33,378,303	[1]	$ 31,061,111	[1]	$ 27,990,048
Consumer | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	198,340
2019	819,799
2018	591,922
2017	572,833
2016	730,077
Prior to 2016	1,952,360
Revolving Loans	915,536
Revolving Loans converted to term loans (c)	338,516
Total loans, net of unearned income	6,119,383		6,177,139		6,360,763
Consumer | Consumer real estate | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	134,032
2019	586,720
2018	451,497
2017	438,007
2016	541,683
Prior to 2016	1,346,587
Revolving Loans	646,462
Revolving Loans converted to term loans (c)	142,848
Total loans, net of unearned income	4,287,836
Consumer | Consumer real estate | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	25,129
2019	80,851
2018	50,344
2017	42,134
2016	78,632
Prior to 2016	135,173
Revolving Loans	75,392
Revolving Loans converted to term loans (c)	31,629
Total loans, net of unearned income	519,284
Consumer | Consumer real estate | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	10,325
2019	63,306
2018	32,469
2017	36,606
2016	35,111
Prior to 2016	130,881
Revolving Loans	58,913
Revolving Loans converted to term loans (c)	29,201
Total loans, net of unearned income	396,812
Consumer | Consumer real estate | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	27,489
2019	54,870
2018	38,198
2017	33,127
2016	45,329
Prior to 2016	175,873
Revolving Loans	80,018
Revolving Loans converted to term loans (c)	54,440
Total loans, net of unearned income	509,344
Consumer | Consumer real estate | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,026
2019	21,260
2018	9,708
2017	11,482
2016	16,651
Prior to 2016	72,843
Revolving Loans	28,433
Revolving Loans converted to term loans (c)	31,527
Total loans, net of unearned income	192,930
Consumer | Consumer real estate | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	339
2019	12,792
2018	9,706
2017	11,477
2016	12,671
Prior to 2016	91,003
Revolving Loans	26,318
Revolving Loans converted to term loans (c)	48,871
Total loans, net of unearned income	213,177
Consumer | Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	17,102
2019	66,578
2018	38,263
2017	20,934
2016	13,070
Prior to 2016	37,727
Revolving Loans	292,358
Revolving Loans converted to term loans (c)	8,766
Total loans, net of unearned income	494,798		495,864		$ 506,230
Consumer | Other Consumer | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	9,410
2019	41,336
2018	24,423
2017	12,035
2016	5,338
Prior to 2016	21,272
Revolving Loans	176,917
Revolving Loans converted to term loans (c)	3,293
Total loans, net of unearned income	294,024
Consumer | Other Consumer | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,509
2019	6,235
2018	3,799
2017	1,911
2016	1,054
Prior to 2016	2,954
Revolving Loans	36,173
Revolving Loans converted to term loans (c)	709
Total loans, net of unearned income	54,344
Consumer | Other Consumer | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,236
2019	5,986
2018	2,551
2017	2,103
2016	924
Prior to 2016	2,674
Revolving Loans	23,185
Revolving Loans converted to term loans (c)	934
Total loans, net of unearned income	40,593
Consumer | Other Consumer | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,219
2019	8,803
2018	4,355
2017	3,221
2016	1,524
Prior to 2016	4,041
Revolving Loans	32,282
Revolving Loans converted to term loans (c)	1,700
Total loans, net of unearned income	59,145
Consumer | Other Consumer | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	449
2019	2,760
2018	1,945
2017	912
2016	1,196
Prior to 2016	2,213
Revolving Loans	13,020
Revolving Loans converted to term loans (c)	632
Total loans, net of unearned income	23,127
Consumer | Other Consumer | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	279
2019	1,458
2018	1,190
2017	752
2016	3,034
Prior to 2016	4,573
Revolving Loans	10,781
Revolving Loans converted to term loans (c)	1,498
Total loans, net of unearned income	23,565
Unsecured Debt | Consumer | Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving Loans converted to term loans (c)	1,500
HELOC | Consumer | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving Loans converted to term loans (c)	9,000
Total loans, net of unearned income	$ 1,254,052		$ 1,286,875

[1] March 31, 2020 and December 31, 2019 include $20.8 million and $18.8 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.