Long-Term Debt (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 years	Nov. 30, 2007	Dec. 31, 2011 Junior Subordinated Deferrable Interest Debentures [Member]	Dec. 31, 2011 Blanket Floating Lien [Member]	Dec. 31, 2011 Pledge Of Investment Securities [Member]	Dec. 31, 2011 Statutory Trust I, 3 Month LIBOR Plus 3.25% [Member]		Dec. 31, 2010 Statutory Trust I, 3 Month LIBOR Plus 3.25% [Member]		Dec. 31, 2011 Statutory Trust II, 3 Month LIBOR Plus 3.15% [Member]		Dec. 31, 2010 Statutory Trust II, 3 Month LIBOR Plus 3.15% [Member]		Dec. 31, 2011 Statutory Trust III, 3 Month LIBOR Plus 2.00% [Member]		Dec. 31, 2010 Statutory Trust III, 3 Month LIBOR Plus 2.00% [Member]		Dec. 31, 2011 Statutory Trust IV, 3 Month LIBOR Plus 1.60% [Member]		Dec. 31, 2010 Statutory Trust IV, 3 Month LIBOR Plus 1.60% [Member]		Dec. 31, 2011 American Horizons Statutory Trust I, 3 Month LIBOR Plus 3.15% [Member]		Dec. 31, 2010 American Horizons Statutory Trust I, 3 Month LIBOR Plus 3.15% [Member]		Dec. 31, 2011 Statutory Trust V, 3 Month LIBOR Plus 1.435% [Member]		Dec. 31, 2010 Statutory Trust V, 3 Month LIBOR Plus 1.435% [Member]		Dec. 31, 2011 Statutory Trust VI, 3 Month LIBOR Plus 2.75% [Member]		Dec. 31, 2010 Statutory Trust VI, 3 Month LIBOR Plus 2.75% [Member]		Dec. 31, 2011 Statutory Trust VII, 3 Month LIBOR Plus 2.54% [Member]		Dec. 31, 2010 Statutory Trust VII, 3 Month LIBOR Plus 2.54% [Member]		Dec. 31, 2010 Pocahontas Capital Trust I, Fixed Rate Of 10.18% [Member]	Dec. 31, 2010 Pulaski Capital Trust I, Fixed Rate Of 10.875% [Member]	Dec. 31, 2011 Statutory Trust VIII, 3 Month LIBOR Plus 3.50% [Member]		Dec. 31, 2010 Statutory Trust VIII, 3 Month LIBOR Plus 3.50% [Member]		Dec. 31, 2011 OMNI Trust I, 3 Month LIBOR Plus 3.30% [Member]		Dec. 31, 2011 OMNI Trust II, 3 Month LIBOR Plus 2.79% [Member]
Debt Instrument [Line Items]
FHLB advance repayments amortization period, in years, minimum	2
FHLB advance repayments amortization period, in years, maximum	30
Additional advances available from FHLB				$ 715,614,000	$ 123,644,000
Weighted average advance rate on FHLB advances	4.07%
Line of credit facility, maximum borrowing capacity	115,000,000
Junior subordinated debt		$ 25,775,000	$ 111,862,000			$ 10,310,000	[1]	$ 10,310,000	[1]	$ 10,310,000	[1]	$ 10,310,000	[1]	$ 10,310,000	[1]	$ 10,310,000	[1]	$ 15,464,000	[1]	$ 15,464,000	[1]	$ 6,186,000	[1]	$ 6,186,000	[1]	$ 10,310,000	[1]	$ 10,310,000	[1]	$ 12,372,000	[1]	$ 12,372,000	[1]	$ 13,403,000	[1]	$ 13,403,000	[1]	$ 7,824,000	$ 7,544,000	$ 7,217,000	[1]	$ 7,217,000	[1]	$ 8,248,000	[1]	$ 7,732,000	[1]
Securities maturity term, years	30
Securities earliest call date, years	5
Securities earliest call date, quarterly	20

[1] The interest rate on the Company's long-term debt indexed to LIBOR is based on the 3-month LIBOR rate. At December 31, 2011, the 3-month LIBOR rate was 0.58%.