Commitments and Contingencies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Allowance for loan losses	$ 421,359,000	$ 492,243,000	$ 421,359,000	$ 492,243,000	$ 407,837,000	$ 427,597,000	$ 516,708,000	$ 605,736,000
Carrying amount included in other assets	465,361,000		465,361,000			426,137,000
Amount of future funding commitments	265,209,000		265,209,000			250,733,000
Permanent and short-term construction loans and letter of credit commitments	164,863,000		164,863,000			204,391,000
Funded portion of permanent and short-term loans and letters of credit	202,392,000		202,392,000			104,315,000
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]
Total letters of credit and unfunded lending commitments	17,137,648,000		17,137,648,000			16,256,231,000
Maximum potential exposure for sponsored transactions	30,330,000,000	$ 28,390,000,000	89,940,000,000	$ 83,540,000,000
Letters of credit
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	215,645,000		215,645,000			183,463,000
Contractual amount net of risk participations	26,100,000		26,100,000			26,100,000
Commitments to fund commercial and industrial loans
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	9,869,096,000		9,869,096,000			9,595,793,000
Commitments to fund commercial real estate, construction, and land development loans
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	3,741,186,000		3,741,186,000			3,593,171,000
Commitments under home equity lines of credit
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	2,092,533,000		2,092,533,000			1,805,869,000
Unused credit card lines
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	463,253,000		463,253,000			473,582,000
Other loan commitments
Loss Contingencies [Line Items]
Total letters of credit and unfunded lending commitments	755,935,000		755,935,000			604,353,000
Permanent and short-term construction loans and letter of credit commitments
Loss Contingencies [Line Items]
Contractual amount net of risk participations	1,700,000		1,700,000			6,000,000
Funded portion of permanent and short-term loans and letters of credit
Loss Contingencies [Line Items]
Contractual amount net of risk participations	5,700,000		5,700,000			3,000,000
Unfunded Loan Commitment
Loss Contingencies [Line Items]
Allowance for loan losses	$ 57,900,000		$ 57,900,000			$ 41,900,000