Condensed Parent Company Financial Statements - Schedule of Condensed Income Statement (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Income Statements, Captions [Line Items]
Other income	$ 13,701	$ 12,403	$ 13,774
Interest expense	230,178	39,343	27,034
Other expense	67,814	64,317	70,061
Total non-interest expense	390,002	356,966	353,143
Income tax benefit	35,017	44,288	59,589
Net income	159,032	192,113	242,260
Preferred stock dividends	10,125	10,125	10,125
Net income available to common shareholders	148,907	181,988	232,135
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Dividends from subsidiaries—Bank	77,000	172,500	250,500
Dividends from subsidiaries—Nonbank	7,384	1,750	1,800
Other income	718	4
Total income	85,102	174,254	252,300
Interest expense	16,492	10,860	5,673
Other expense	6,286	5,851	5,698
Total non-interest expense	22,778	16,711	11,371
Income before income tax benefit and undistributed net income of subsidiaries	62,324	157,543	240,929
Income tax benefit	(5,126)	(3,652)	(4,163)
Income before undistributed net income of subsidiaries	67,450	161,195	245,092
Equity in undistributed net income (excess dividends) of subsidiaries	91,582	30,918	(2,832)
Net income	159,032	192,113	242,260
Preferred stock dividends	10,125	10,125	10,125
Net income available to common shareholders	$ 148,907	$ 181,988	$ 232,135