GOODWILL AND OTHER INTANGIBLE ASSETS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($) segment	Dec. 31, 2024 USD ($)
Goodwill and other intangibles assets
Number of operating segments | segment	3
CrossFirst
Goodwill and other intangibles assets
Goodwill acquired during the period	$ 49.5
Other intangible assets acquired during the period	81.8
M&M
Goodwill and other intangibles assets
Goodwill acquired during the period	$ 0.1	$ 15.8
Other intangible assets acquired during the period		$ 6.3