Acquisition Activity (Schedule Of Acquisition Consideration) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	May 31, 2011
Omni Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Common Stock issued, Number of Shares	698,768
Common Stock issued, Amount	$ 41,053,000
Options issued, Number of Shares	41,979
Options issued, Amount	513,000
Total Equity Consideration	41,566,000
Change in Control Payments	4,832,000
Cash	9,000
Total Non-Equity Consideration	4,841,000
Total Consideration Paid	46,407,000	46,407,000
Fair Value of Net Liabilities Assumed including Identifiable Intangible Assets	(17,567,000)
Goodwill	63,974,000	63,974,000
Cameron Bancshares, Inc. [Member]
Business Acquisition [Line Items]
Common Stock issued, Number of Shares	2,384,461
Common Stock issued, Amount	140,087,000
Total Equity Consideration	140,087,000
Change in Control Payments	3,144,000
Cash	10,000
Total Non-Equity Consideration	3,154,000
Total Consideration Paid	143,241,000	143,241,000
Fair Value of Net Liabilities Assumed including Identifiable Intangible Assets	71,684,000
Goodwill	$ 71,557,000