Loans - Summary of loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Summary of Loans
Total loans	$ 32,016,672		$ 30,177,862
Less allowance for credit losses	(447,956)	$ (427,392)	(356,444)	$ (324,398)	$ (319,708)	$ (301,807)
Loans, net	31,568,716		29,821,418
Deferred costs	64,700		49,700
Unamortized Discounts	55,200		72,100
Accrued interest receivable (AIR)	$ 123,100		$ 105,400
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets.		Other Assets.
Construction and land development
Summary of Loans
Total loans	$ 2,776,241		$ 2,860,360
Consumer Owner Occupied Loans
Summary of Loans
Total loans	6,259,048		5,162,042
Home equity loans
Summary of Loans
Total loans	1,349,097		1,313,168
Commercial and industrial
Summary of Loans
Total loans	5,458,229		5,313,483
Other income producing property
Summary of Loans
Total loans	670,331		696,242
Consumer loans
Summary of Loans
Total loans	1,258,078		1,278,426
Other loans
Summary of Loans
Total loans	4,199		20,989
Commercial loans
Summary of Loans
Total loans	22,222,778		21,430,337
Commercial loans | Construction and land development
Summary of Loans
Total loans	1,913,161		1,956,300
Commercial loans | Commercial non-owner occupied
Summary of Loans
Total loans	8,702,352		8,072,959
Commercial loans | Commercial non-owner occupied real estate.
Summary of Loans
Total loans	5,539,097		5,460,193
Commercial loans | Consumer Owner Occupied Loans
Summary of Loans
Total loans	50,186		30,741
Commercial loans | Commercial owner occupied real estate loan
Summary of Loans
Total loans	5,539,097		5,460,193
Commercial loans | Commercial and industrial
Summary of Loans
Total loans	5,458,229		5,313,483
Commercial loans | Other income producing property
Summary of Loans
Total loans	555,554		575,672
Commercial loans | Other loans
Summary of Loans
Total loans	4,199		20,989
Consumer portfolio loans
Summary of Loans
Total loans	9,793,894		8,747,525
Consumer portfolio loans | Construction and land development
Summary of Loans
Total loans	863,080		904,060
Consumer portfolio loans | Consumer Owner Occupied Loans
Summary of Loans
Total loans	6,208,862		5,131,301
Consumer portfolio loans | Home equity loans
Summary of Loans
Total loans	1,349,097		1,313,168
Consumer portfolio loans | Other income producing property
Summary of Loans
Total loans	114,777		120,570
Consumer portfolio loans | Consumer loans
Summary of Loans
Total loans	$ 1,258,078		$ 1,278,426