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Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($)		3 Months Ended
	Aug. 31, 2023	Mar. 31, 2025	Mar. 31, 2024	Apr. 01, 2024
Goodwill [Line Items]
Goodwill impairment	$ 0
Impairment charges		$ 0	$ 0
Amortization of other intangible assets		$ 6,830,000	$ 5,455,000
Core deposit \| CapStar Financial Holdings, Inc.
Goodwill [Line Items]
Estimated useful lives				10 years
Minimum \| Core Deposits and Other Intangible Assets
Goodwill [Line Items]
Estimated useful lives		5 years
Maximum \| Core Deposits and Other Intangible Assets
Goodwill [Line Items]
Estimated useful lives		15 years