Loans - Loans by FICO Score, Consumer (Details) - USD ($) $ in Thousands	Jun. 30, 2020		Dec. 31, 2019		Jun. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans, net of unearned income	$ 32,708,937	[1]	$ 31,061,111	[1]	$ 29,712,810
Consumer | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	525,422
2019	789,595
2018	514,908
2017	539,006
2016	684,993
Prior to 2016	1,801,009
Revolving loans	884,134
Revolving loans converted to term loans (c)	313,326
Total loans, net of unearned income	6,052,393		6,177,139		6,303,134
Consumer | Consumer real estate | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	394,137
2019	576,132
2018	410,188
2017	420,822
2016	527,019
Prior to 2016	1,255,357
Revolving loans	626,844
Revolving loans converted to term loans (c)	135,436
Total loans, net of unearned income	4,345,935
Consumer | Consumer real estate | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	43,808
2019	67,904
2018	26,383
2017	37,259
2016	48,677
Prior to 2016	132,407
Revolving loans	76,045
Revolving loans converted to term loans (c)	28,913
Total loans, net of unearned income	461,396
Consumer | Consumer real estate | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	31,459
2019	66,155
2018	28,201
2017	26,164
2016	45,038
Prior to 2016	110,244
Revolving loans	54,941
Revolving loans converted to term loans (c)	29,613
Total loans, net of unearned income	391,815
Consumer | Consumer real estate | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	41,314
2019	51,096
2018	33,382
2017	32,745
2016	36,625
Prior to 2016	153,335
Revolving loans	76,593
Revolving loans converted to term loans (c)	44,067
Total loans, net of unearned income	469,157
Consumer | Consumer real estate | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	12,524
2019	17,140
2018	10,922
2017	12,789
2016	13,178
Prior to 2016	70,067
Revolving loans	24,185
Revolving loans converted to term loans (c)	29,940
Total loans, net of unearned income	190,745
Consumer | Consumer real estate | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,180
2019	11,168
2018	5,832
2017	9,227
2016	14,456
Prior to 2016	79,599
Revolving loans	25,526
Revolving loans converted to term loans (c)	45,357
Total loans, net of unearned income	193,345
Consumer | Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	26,822
2019	55,913
2018	32,571
2017	17,220
2016	10,011
Prior to 2016	26,315
Revolving loans	269,748
Revolving loans converted to term loans (c)	10,710
Total loans, net of unearned income	449,310		495,864		$ 494,376
Consumer | Other Consumer | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	16,160
2019	36,450
2018	21,476
2017	10,499
2016	3,988
Prior to 2016	14,774
Revolving loans	173,832
Revolving loans converted to term loans (c)	4,401
Total loans, net of unearned income	281,580
Consumer | Other Consumer | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,238
2019	5,226
2018	2,784
2017	1,615
2016	747
Prior to 2016	1,844
Revolving loans	27,603
Revolving loans converted to term loans (c)	1,319
Total loans, net of unearned income	44,376
Consumer | Other Consumer | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,168
2019	4,246
2018	2,542
2017	1,521
2016	706
Prior to 2016	1,980
Revolving loans	19,983
Revolving loans converted to term loans (c)	1,052
Total loans, net of unearned income	34,198
Consumer | Other Consumer | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,654
2019	6,546
2018	3,149
2017	2,172
2016	1,423
Prior to 2016	2,737
Revolving loans	27,534
Revolving loans converted to term loans (c)	1,581
Total loans, net of unearned income	48,796
Consumer | Other Consumer | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,269
2019	2,386
2018	1,576
2017	891
2016	836
Prior to 2016	1,813
Revolving loans	10,759
Revolving loans converted to term loans (c)	963
Total loans, net of unearned income	20,493
Consumer | Other Consumer | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	333
2019	1,059
2018	1,044
2017	522
2016	2,311
Prior to 2016	3,167
Revolving loans	10,037
Revolving loans converted to term loans (c)	1,394
Total loans, net of unearned income	19,867
Unsecured Debt | Consumer | Other Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving loans converted to term loans (c)	3,900
HELOC | Consumer | Consumer real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Revolving loans converted to term loans (c)	10,800
Total loans, net of unearned income	$ 1,197,460		$ 1,286,875

[1] June 30, 2020 and December 31, 2019 include $16.9 million and $18.8 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.