Allowance for Credit Losses - Schedule of Allowance for Loan Losses and Carrying Amount of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	$ 214,594	$ 216,016	$ 235,830
Initial allowance for PCD loans (acquired during the period)			12,629
Charge-offs	(2,119)	(3,595)	(19,297)
Recoveries	3,060	6,516	10,578
Provision	(1,806)	(5,208)	(23,724)
Allowance for Loan and Lease Losses Ending balance	213,729	213,729	216,016
Construction & Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	41,579	39,395	39,077
Initial allowance for PCD loans (acquired during the period)			823
Charge-offs	0	(2)	(560)
Recoveries	1,077	1,261	604
Provision	1,183	3,185	(549)
Allowance for Loan and Lease Losses Ending balance	43,839	43,839	39,395
Bank Card [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	321	317	322
Initial allowance for PCD loans (acquired during the period)			0
Charge-offs	(102)	(245)	(190)
Recoveries	2	3	42
Provision	127	273	143
Allowance for Loan and Lease Losses Ending balance	348	348	317
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	13,359	14,443	23,354
Initial allowance for PCD loans (acquired during the period)			1,241
Charge-offs	0	(31)	(414)
Recoveries	459	465	869
Provision	(880)	(1,939)	(10,607)
Allowance for Loan and Lease Losses Ending balance	12,938	12,938	14,443
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	36,665	42,156	49,150
Initial allowance for PCD loans (acquired during the period)			4,363
Charge-offs	0	0	(3,531)
Recoveries	40	115	1,907
Provision	(3,872)	(9,438)	(9,733)
Allowance for Loan and Lease Losses Ending balance	32,833	32,833	42,156
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	80,487	78,432	78,138
Initial allowance for PCD loans (acquired during the period)			5,009
Charge-offs	(521)	(794)	(6,182)
Recoveries	1,189	3,338	4,307
Provision	(2,112)	(1,933)	(2,840)
Allowance for Loan and Lease Losses Ending balance	79,043	79,043	78,432
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	27,109	26,404	29,125
Initial allowance for PCD loans (acquired during the period)			1,192
Charge-offs	(778)	(1,272)	(6,016)
Recoveries	179	1,059	2,400
Provision	1,613	1,932	(297)
Allowance for Loan and Lease Losses Ending balance	28,123	28,123	26,404
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses Beginning balance	15,074	14,869	16,664
Initial allowance for PCD loans (acquired during the period)			1
Charge-offs	(718)	(1,251)	(2,404)
Recoveries	114	275	449
Provision	2,135	2,712	159
Allowance for Loan and Lease Losses Ending balance	$ 16,605	$ 16,605	$ 14,869