Goodwill and Other Amortizing Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill And Other Intangibles [Line Items]
Goodwill	$ 303,328,000	$ 303,328,000
Impairment charges on goodwill	0	0	$ 0
Servicing Asset	2,500,000	1,900,000
Total amortization	16,169,000	13,223,000
Intangible amortization	3,497,000	3,689,000	3,344,000
Servicing Asset at Amortized Cost, Amortization	$ 600,000	300,000
Customer deposit intangibles
Goodwill And Other Intangibles [Line Items]
Core deposits remaining amortization period	7 years 8 months 12 days
Core deposits weighted average amortization period	6 years 2 months 12 days
Total amortization	$ 14,407,000	11,653,000
Customer list intangible
Goodwill And Other Intangibles [Line Items]
Core deposits remaining amortization period	7 years 8 months 12 days
Core deposits weighted average amortization period	5 years 10 months 24 days
Total amortization	$ 1,762,000	1,570,000
Customer-Related Intangible Assets [Member]
Goodwill And Other Intangibles [Line Items]
Intangible amortization	$ 2,900,000	$ 3,400,000	$ 3,200,000