Stock-Based Payment Arrangements (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years
Schedule of option activity under stock option plans
Number of Shares, Outstanding at Beginning Balance	1,129,520
Number of Shares, Whitney options converted at acquisition date	775,261
Number of Shares, Granted	200,601
Number of Shares, Exercised	(21,919)
Number of Shares, Forfeited or expired	(396,556)
Number of Shares, Outstanding at Ending Balance	1,686,907
Number of Shares, Exercisable at Ending Balance	1,183,667
Weighted- Average Exercise Price, Outstanding at Beginning Balance	$ 35.08
Weighted- Average Exercise Price, Whitney Bank options at acquisition date	$ 62.64
Weighted- Average Exercise Price, Granted	$ 29.97
Weighted- Average Exercise Price, Exercised	$ 18.14
Weighted- Average Exercise Price, Forfeited or expired	$ 61.83
Weighted- Average Exercise Price, Outstanding at Ending Balance	$ 41.05
Weighted- Average Exercise Price, Exercisable at Ending Balance	$ 44.25
Weighted-Average Remaining Contractual Term, Outstanding at Ending Balance	5.2
Weighted-Average Remaining Contractual Term, Exercisable at Ending Balance (in years)	3.6
Aggregate Intrinsic Value, Outstanding at Ending Balance	$ 1,642
Aggregate Intrinsic Value, Exercisable at Ending Balance	$ 1,241