Loans and Leases - Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 200,732	$ 200,564
Charge-offs	(10,397)	(3,234)
Recoveries	1,220	2,068
Net (charge-offs) recoveries	(9,177)	(1,166)
Provision for credit losses	18,500	2,000
Balance, end of period	210,055	197,398
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	1,179
Collectively evaluated	210,055	196,219
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	85,451	75,608
Collectively evaluated	25,586,930	24,276,464
Loans held for investment, net	25,672,381	24,352,072	$ 28,609,129
Real Estate Mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	87,309	98,624
Charge-offs	(9,835)	(168)
Recoveries	200	163
Net (charge-offs) recoveries	(9,635)	(5)
Provision for credit losses	(31,809)	11,391
Balance, end of period	109,483	87,228
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	156
Collectively evaluated	109,483	87,072
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	82,835	51,280
Collectively evaluated	15,324,776	12,457,784
Loans held for investment, net	15,407,611	12,509,064	15,730,324
Real Estate Construction and Land
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	52,320	44,508
Charge-offs	0	0
Recoveries	0	149
Net (charge-offs) recoveries	0	149
Provision for credit losses	(2,714)	1,009
Balance, end of period	55,034	43,648
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	0
Collectively evaluated	55,034	43,648
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	0	6,515
Collectively evaluated	4,608,440	3,217,201
Loans held for investment, net	4,608,440	3,223,716	4,152,172
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	52,849	48,718
Charge-offs	(137)	(2,833)
Recoveries	975	1,735
Net (charge-offs) recoveries	838	(1,098)
Provision for credit losses	(16,492)	(9,436)
Balance, end of period	37,195	57,056
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	1,023
Collectively evaluated	37,195	56,033
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	2,616	17,813
Collectively evaluated	5,226,491	8,096,882
Loans held for investment, net	5,229,107	8,114,695	8,281,962
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	8,254	8,714
Charge-offs	(425)	(233)
Recoveries	45	21
Net (charge-offs) recoveries	(380)	(212)
Provision for credit losses	(469)	964
Balance, end of period	8,343	9,466
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	0
Collectively evaluated	8,343	9,466
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	0	0
Collectively evaluated	427,223	504,597
Loans held for investment, net	$ 427,223	$ 504,597	$ 444,671