Long-Term Debt (Narrative) (Details) - USD ($) $ in Thousands					12 Months Ended
	Sep. 15, 2023	Nov. 15, 2018	May 15, 2014	Dec. 15, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2016
Debt Instrument [Line Items]
Unamortized Debt Issuance Expense						$ 5,000
Junior Subordinated Notes					$ 0	164,950
Long-term Debt, Interest Rate 6.95%					6.95%
Long-Term Debt, Interest Rate 5.65%					5.65%
Stock Redeemed or Called During Period, Value					$ 126,144	(176,049)
Subordinated debt converted to preferred stock						104	$ 34
Senior medium-term notes					287,560	400,334
Gains (Losses) on Extinguishment of Debt					(353)	(2,530)	$ (44,422)
Long-term debt, Parent only maturities					381,699
Parent Company [Member]
Debt Instrument [Line Items]
Long-term debt, Parent only maturities					381,699
4.50%
Debt Instrument [Line Items]
Senior medium-term notes					152,411
Subordinated Notes Interest Rate 5.65 Percent [Member]
Debt Instrument [Line Items]
New interest rate		3mL+4.19%
Interest payments begin			May 15, 2014
Subordinated Notes Interest Rate 6.95 Percent [Member]
Debt Instrument [Line Items]
New interest rate	3mL+3.89%
Interest payments begin				Dec. 15, 2013
redeemed [Member]
Debt Instrument [Line Items]
Junior Subordinated Notes					36,000			$ 129,000
AMEGY STATUTORY TRUSTS 2 [Member]
Debt Instrument [Line Items]
Junior Subordinated Notes					$ 0	$ 36,083