Acquired Loans Part 4 (Details) (USD $)	3 Months Ended					3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Feb. 15, 2013 BancTrust Financial Group, Inc. [Member]	Mar. 16, 2012 Bay Bank and Trust Company [Member]	Mar. 31, 2013 Covered Loans [Member]	Mar. 31, 2012 Covered Loans [Member]	Mar. 31, 2013 Noncovered Loans [Member]	Mar. 31, 2012 Noncovered Loans [Member]
Allowance for loan loss [Abstract]
Balance, beginning	$ 6,075,000	$ 502,000				$ 4,190,000	$ 502,000	$ 1,885,000	$ 0
Provision for loan losses, acquired loans	130,000	(194,000)				(564,000)	(248,000)	694,000	54,000
Loans charged-off	220,000	63,000				862,000	89,000	(642,000)	(26,000)
Recoveries	33,000	402,000				9,000	393,000	24,000	9,000
Net charge-offs	253,000	465,000				871,000	482,000	(618,000)	(17,000)
Balance, ending	6,458,000	773,000				4,497,000	736,000	1,961,000	37,000
Revolving credit agreements acquired				154,800,000	5,900,000
Nonaccrual loans not accounted for under FASB ASC Topic 310 30		$ 2,911,000	$ 1,103,000