Segment Information - Results of Operations and Selected Financial Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Net interest income	$ 86,867	$ 82,363	$ 162,374	$ 159,569
Noninterest income	42,598	44,618	86,248	84,553
Income before taxes	55,247	62,907	98,956	115,085
Total assets	12,530,073		12,530,073		$ 9,405,612
Operating Segments [Member] | Metropolitan Banks [Member]
Segment Reporting Information [Line Items]
Net interest income	21,962	19,848	41,570	39,181
Noninterest income	5,504	3,669	15,277	8,813
Income before taxes	15,142	17,602	33,313	31,526
Total assets	3,430,347		3,430,347		2,627,874
Operating Segments [Member] | Community Banks [Member]
Segment Reporting Information [Line Items]
Net interest income	49,615	45,024	94,183	87,794
Noninterest income	18,152	16,197	34,997	31,173
Income before taxes	36,462	36,514	67,801	66,283
Total assets	6,899,994		6,899,994		5,821,220
Operating Segments [Member] | Pegasus [Member]
Segment Reporting Information [Line Items]
Net interest income	9,964	5,808	17,584	11,167
Noninterest income	293	355	484	739
Income before taxes	4,672	1,947	7,499	3,592
Total assets	1,424,086		1,424,086		1,045,699
Operating Segments [Member] | Worthington [Member]
Segment Reporting Information [Line Items]
Net interest income	3,743		5,437
Noninterest income	286		419
Income before taxes	1,436		1,821
Total assets	540,608		540,608
Operating Segments [Member] | Other Financial Services [Member]
Segment Reporting Information [Line Items]
Net interest income	2,079	11,457	4,992	21,339
Noninterest income	10,753	10,913	23,736	22,488
Income before taxes	4,643	5,220	10,688	11,171
Total assets	108,723		108,723		71,694
Operating Segments [Member] | Executive, Operations & Support [Member]
Segment Reporting Information [Line Items]
Net interest income	(505)	9	(1,412)	(398)
Noninterest income	52,756	62,025	95,330	111,756
Income before taxes	37,901	49,790	61,549	92,130
Total assets	1,574,991		1,574,991		1,201,974
Eliminations [Member]
Segment Reporting Information [Line Items]
Net interest income	9	217	20	486
Noninterest income	(45,146)	(48,541)	(83,995)	(90,416)
Income before taxes	(45,009)	$ (48,166)	(83,715)	$ (89,617)
Total assets	$ (1,448,676)		$ (1,448,676)		$ (1,362,849)