BUSINESS COMBINATIONS - Pro Forma (Details) - Veritex Holdings, Inc. - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Business Combination [Line Items]
Net income attributable to Huntington	$ 2,281	$ 2,032
Net interest income
Business Combination [Line Items]
Pro forma revenue	6,316	5,721
Noninterest income
Business Combination [Line Items]
Pro forma revenue	$ 2,222	$ 2,085