Commitments and Contingencies (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Allowance for loan losses	$ 477,532,000	$ 421,359,000	$ 477,532,000	$ 421,359,000	$ 471,238,000	$ 443,424,000	$ 407,837,000	$ 427,597,000
Covered chargebacks	10,800,000		10,800,000
Minimum
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	0		0
Maximum
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	5,000,000		5,000,000
Guarantee obligations
Loss Contingencies [Line Items]
Maximum potential exposure for sponsored transactions	27,780,000,000	$ 30,330,000,000	87,280,000,000	$ 89,940,000,000
Total letters of credit and unfunded lending commitments	16,660,498,000		16,660,498,000			17,181,946,000
Unfunded Loan Commitment
Loss Contingencies [Line Items]
Allowance for loan losses	$ 55,200,000		$ 55,200,000			$ 57,500,000