MERGERS AND ACQUISITIONS - Narrative (Details) $ / shares in Units, $ in Thousands			9 Months Ended	12 Months Ended
	Aug. 26, 2024 USD ($) state location shares	Apr. 01, 2024 USD ($) $ / shares shares	Dec. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Business Acquisition, Contingent Consideration [Line Items]
Assets			$ 12,046,722	$ 12,046,722	$ 12,283,415
Deposits			9,982,490	9,982,490	10,291,156
Total portfolio loans			7,697,087	7,697,087	7,651,034
Fair value adjustments			400
Goodwill			333,695	333,695	317,873
CrossFirst Bankshares, Inc.
Business Acquisition, Contingent Consideration [Line Items]
Number of full-service locations | location	77
Number of states in which entity operates | state	10
Assets	$ 20,000,000
Deposits	17,000,000
Total portfolio loans	$ 14,000,000
Pre-tax acquisition expenses				3,900
Pre-tax acquisition expenses, legal, professional and consulting fees				3,100
CrossFirst Bankshares, Inc. | Common Stock | CrossFirst Bankshares, Inc.
Business Acquisition, Contingent Consideration [Line Items]
Shares received for each share owned (in shares) | shares	0.6675
Merchants and Manufacturers Bank Corporation
Business Acquisition, Contingent Consideration [Line Items]
Pre-tax acquisition expenses				3,000
Pre-tax acquisition expenses, legal, professional and consulting fees				100
Per share cash consideration entitled (in dollars per share) | $ / shares		$ 117.74
Share consideration conversion ratio		5.7294
Mixed consideration (in dollars per share) | $ / shares		$ 34.55
Mixed consideration ratio		4.0481
Business combination consideration, number of shares (in shares) | shares		1,429,304
Cash		$ 12,200
Consideration transferred per share in cash, Share Election (in dollars per share) | $ / shares		$ 5.3966
Consideration transferred per share in shares, Share Election (in shares) | shares		5.4668
Cash consideration received (in dollars per share) | $ / shares		$ 117.74
Fractional shares, payment rate (in dollars per share) | $ / shares		$ 23.32
Additional consideration transferred		$ 3,000
Number of shares redeemed ( in shares) | shares		300
Goodwill		$ 15,822
Wealth Management
Business Acquisition, Contingent Consideration [Line Items]
Goodwill			$ 14,108	$ 14,108	$ 14,108
Wealth Management | CrossFirst Bankshares, Inc.
Business Acquisition, Contingent Consideration [Line Items]
Assets	$ 14,000,000