Loans and Leases - Allowance for Loan and Lease Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 200,564	$ 348,181
Charge-offs	(3,234)	(3,988)
Recoveries	2,068	1,252
Net (charge-offs) recoveries	(1,166)	(2,736)
Provision	(2,000)	(53,000)
Balance, end of period	197,398	292,445
Amount of the allowance applicable to loans and leases:
Individually evaluated	1,179	1,801
Collectively evaluated	196,219	290,644
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	75,608	90,155
Collectively evaluated	24,276,464	18,889,073
Loans held for investment, net	24,352,072	18,979,228	$ 22,941,548
Real Estate Mortgage
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	98,053	138,342
Charge-offs	(168)	(368)
Recoveries	163	545
Net (charge-offs) recoveries	(5)	177
Provision	(11,333)	2,603
Balance, end of period	86,715	141,122
Amount of the allowance applicable to loans and leases:
Individually evaluated	156	220
Collectively evaluated	86,559	140,902
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	44,392	52,823
Collectively evaluated	11,994,899	7,934,390
Loans held for investment, net	12,039,291	7,987,213	11,178,720
Real Estate Construction and Land
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	45,079	78,356
Charge-offs	0	(700)
Recoveries	149	0
Net (charge-offs) recoveries	149	(700)
Provision	(1,067)	(10,881)
Balance, end of period	44,161	66,775
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	0
Collectively evaluated	44,161	66,775
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	13,403	2,047
Collectively evaluated	3,680,086	3,563,776
Loans held for investment, net	3,693,489	3,565,823	3,437,127
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	48,718	126,403
Charge-offs	(2,833)	(2,574)
Recoveries	1,735	697
Net (charge-offs) recoveries	(1,098)	(1,877)
Provision	9,436	(45,810)
Balance, end of period	57,056	78,716
Amount of the allowance applicable to loans and leases:
Individually evaluated	1,023	1,581
Collectively evaluated	56,033	77,135
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	17,813	35,285
Collectively evaluated	8,096,882	7,050,555
Loans held for investment, net	8,114,695	7,085,840	7,868,051
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	8,714	5,080
Charge-offs	(233)	(346)
Recoveries	21	10
Net (charge-offs) recoveries	(212)	(336)
Provision	964	1,088
Balance, end of period	9,466	5,832
Amount of the allowance applicable to loans and leases:
Individually evaluated	0	0
Collectively evaluated	9,466	5,832
The ending balance of the loan and lease portfolio is composed of loans and leases:
Individually evaluated	0	0
Collectively evaluated	504,597	340,352
Loans held for investment, net	$ 504,597	$ 340,352	$ 457,650

Financing Receivable, Allowance for Credit Loss, Additional Information, Portfolio Composition [Abstract]

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Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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