REVENUES - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Disaggregation of Revenue [Line Items]
Contract liabilities	$ 57	$ 11
Contract liabilities, current	12,317	$ 7,448
TradePMR
Disaggregation of Revenue [Line Items]
Contract liabilities	19
Contract liabilities, current	8
Contract liabilities, noncurrent	11
Unearned Robinhood Gold Subscription Revenue
Disaggregation of Revenue [Line Items]
Contract liabilities	$ 37