Derivative Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Bank And PrimeLending [Member]
Derivative financial instruments
Cash collateral advanced to offset net derivative assets	$ 51,800	$ 65,000
Not Designated as Hedging Instrument | Prime Lending
Derivative financial instruments
Increase (decrease) in the fair value of the derivatives	(7,097)	(21,282)	$ (22,170)
Not Designated as Hedging Instrument | Hilltop Broker-Dealers
Derivative financial instruments
Increase (decrease) in the fair value of the derivatives	(7,814)	16,405	(19,884)
Not Designated as Hedging Instrument | Plains Capital Bank
Derivative financial instruments
Increase (decrease) in the fair value of the derivatives	65	46	$ 43
Not Designated as Hedging Instrument | PrimeLending and Hilltop Broker-Dealers
Derivative financial instruments
Cash collateral advanced to offset net derivative liability	7,600	10,600
Interest Rate Lock Commitments | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	383,767	506,278
Estimated Fair Value	7,734	1,767
Commitments to Purchase MBSs | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	1,470,142	819,681
Estimated Fair Value	15,666	2,435
Commitments to Sell MBSs | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	2,222,225	2,188,964
Estimated Fair Value	(17,870)	10,711
Commitments to Sell MBSs | Not Designated as Hedging Instrument | Prime Lending
Derivative financial instruments
Cash collateral advanced to offset net derivative liability	14,700	8,400
Interest rate swaps | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	33,500	35,784
Estimated Fair Value	(5,349)	(1,421)
Interest rate swaps | Cash Flow Hedging | Designated as hedges
Derivative financial instruments
Notional Amount	410,000	430,000
Estimated Fair Value	14,277	21,703
Carrying value of available for sale securities and loans held for investment	290,200	322,500
Interest rate swaps | Fair Value Hedging | Designated as hedges
Derivative financial instruments
Notional Amount	325,193	365,323
Estimated Fair Value	34,799	42,828
Designated hedge amount from closed portfolio of available for sale securities and loans held for investment	325,300	365,300
Cumulative adjustment in available for sale securities and loans held for investment	35,000	42,800
Interest rate swaps back-to-back (asset) | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	1,421
Estimated Fair Value	176
Interest rate swaps back-to-back (liability) | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	1,421
Estimated Fair Value	(191)
U.S. Treasury bond futures and options | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	306,200	395,500
Estimated Fair Value	430	(449)
Interest rate and other futures | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	224,800	2,612,000
Credit default swaps | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount		3,000
Estimated Fair Value		$ (2)
Warrant | Not Designated as Hedging Instrument
Derivative financial instruments
Notional Amount	866
Estimated Fair Value	$ 820