Short-term Borrowings (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Short-term borrowings
Short-term borrowings	$ 999,476		$ 762,696
Hilltop Broker-Dealers
Short-term borrowings
Weighted average interest rate (as a percent)	1.11%		1.07%
Federal funds purchased.
Short-term borrowings
Short-term borrowings	140,600		128,100
Securities sold under agreement to repurchase.
Short-term borrowings
Short-term borrowings	374,176		136,396
Federal Home Loan Bank notes
Short-term borrowings
Short-term borrowings	225,000		375,000
Average balance during the period	235,111	8
Average interest rate during the period (as a percent)	0.22%	0.13%
Average interest rate at end of period (as a percent)	0.22%		0.16%
Federal Home Loan Bank notes | Maximum
Short-term borrowings
Maturity term of debt	365 days
Short-term bank loans.
Short-term borrowings
Short-term borrowings	259,700		123,200
Schedule of federal funds purchased and securities sold under agreements to repurchase
Short-term borrowings
Average balance during the period	361,600	343,233
Average interest rate during the period (as a percent)	0.25%	0.18%
Average interest rate at end of period (as a percent)	0.26%		0.15%
Carrying value.	379,985		166,734
Estimated fair value	$ 379,802		$ 163,852