Acquired Loans Part 2 (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Carrying value of acquired loans [Abstract]
Accretion to interest income	$ 7,816	[1]
Acquired Impaired [Member] | Covered Loans [Member]
Carrying value of acquired loans [Abstract]
Net carrying value, beginning	45,391		72,131
Loans acquired	0	[2]	0	[3]
Accretion to interest income	1,516	[1]	8,031
Payments received, net	(5,801)		(27,496)
Other	76		(3,085)
Less allowance for loan losses, acquired loans	(307)		(4,190)
Net carrying value, ending	40,875		45,391
Acquired Impaired [Member] | Noncovered Loans [Member]
Carrying value of acquired loans [Abstract]
Net carrying value, beginning	72,942		4,350
Loans acquired	796,172	[2]	91,987	[3]
Accretion to interest income	6,301	[1]	4,138
Payments received, net	(33,477)		(24,330)
Other	(1,024)		(1,318)
Less allowance for loan losses, acquired loans	(76)		(1,885)
Net carrying value, ending	840,838		72,942
Acquired Not ASC 310-30 [Member] | Covered Loans [Member]
Carrying value of acquired loans [Abstract]
Net carrying value, beginning	2,460	[4]	4,171	[4]
Loans acquired	0	[2],[4]	0	[3],[4]
Accretion to interest income	156	[1],[4]	367	[4]
Payments received, net	(370)	[4]	(2,107)	[4]
Other	(29)	[4]	29	[4]
Less allowance for loan losses, acquired loans	0	[4]	0	[4]
Net carrying value, ending	2,217	[4]	2,460	[4]
Acquired Not ASC 310-30 [Member] | Noncovered Loans [Member]
Carrying value of acquired loans [Abstract]
Net carrying value, beginning	6,696	[4]	13	[4]
Loans acquired	154,839	[2],[4]	5,927	[3],[4]
Accretion to interest income	453	[1],[4]	161	[4]
Payments received, net	(1,700)	[4]	868	[4]
Other	40	[4]	(273)	[4]
Less allowance for loan losses, acquired loans	0	[4]	0	[4]
Net carrying value, ending	$ 160,328	[4]	$ 6,696	[4]

[1] Accretion to interest income for BancTrust since acquisition at February 15, 2013 is considered immaterial.

[2] Fair value of loans acquired from BancTrust on February 15, 2013.

[3] Fair value of loans acquired from Bay Bank on March 16, 2012.

[4] Acquired nonimpaired loans consist of revolving credit agreements and commercial leases that are not in scope for FASB ASC Topic 310-30.