Loans - Loans by FICO Score, Consumer (Details) - Consumer	Dec. 31, 2019	Dec. 31, 2018
HELOC | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	62.00%	61.40%
HELOC | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	8.60%	8.50%
HELOC | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	7.60%	7.60%
HELOC | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	10.80%	10.90%
HELOC | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	4.70%	5.10%
HELOC | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	6.30%	6.50%
HELOC | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	100.00%	100.00%
R/E installment loans | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	72.90%	71.30%
R/E installment loans | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	8.30%	8.80%
R/E installment loans | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	6.10%	7.00%
R/E installment loans | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	7.70%	7.60%
R/E installment loans | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	2.60%	2.80%
R/E installment loans | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	2.40%	2.50%
R/E installment loans | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	100.00%	100.00%
Permanent mortgage | FICO score 740 or greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	44.80%	51.80%
Permanent mortgage | FICO score 720-739
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	9.70%	7.60%
Permanent mortgage | FICO score 700-719
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	12.30%	10.60%
Permanent mortgage | FICO score 660-699
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	16.30%	14.70%
Permanent mortgage | FICO score 620-659
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	9.70%	6.50%
Permanent mortgage | FICO score less than 620
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	7.20%	8.80%
Permanent mortgage | Total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average refreshed FICO score (percent)	100.00%	100.00%