Covered Assets and Indemnification Asset (Details 3) (USD $)	1 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Covered Assets and Indemnification Asset
Total loans	$ 3,310,224,000	$ 3,152,396,000
Covered OREO	119,660,000
Carrying value of covered OREO properties sold	1,300,000
FDIC indemnification asset	190,041,000
Accretion in FDIC indemnification asset since acquisition	300,000
Covered loans | PCI loans
Covered Assets and Indemnification Asset
Specific reserves in the allowance for loan losses	0
Bank | Covered loans
Covered Assets and Indemnification Asset
Loans past Due 30-59 Days	91,000
Total Past Due Loans	91,000
Current Loans	313,939,000
Total loans	1,096,590,000
Bank | Covered loans | PCI loans
Covered Assets and Indemnification Asset
Total loans	782,560,000
Bank | Covered loans | Secured
Covered Assets and Indemnification Asset
Loans past Due 30-59 Days	54,000
Total Past Due Loans	54,000
Current Loans	28,529,000
Total loans	63,577,000
Bank | Covered loans | Secured | PCI loans
Covered Assets and Indemnification Asset
Total loans	34,994,000
Bank | Covered loans | Unsecured
Covered Assets and Indemnification Asset
Current Loans	2,854,000
Total loans	11,004,000
Bank | Covered loans | Unsecured | PCI loans
Covered Assets and Indemnification Asset
Total loans	8,150,000
Bank | Covered loans | Secured by commercial properties
Covered Assets and Indemnification Asset
Loans past Due 30-59 Days	37,000
Total Past Due Loans	37,000
Current Loans	80,627,000
Total loans	454,513,000
Bank | Covered loans | Secured by commercial properties | PCI loans
Covered Assets and Indemnification Asset
Total loans	373,849,000
Bank | Covered loans | Secured by residential properties
Covered Assets and Indemnification Asset
Current Loans	163,514,000
Total loans	378,980,000
Bank | Covered loans | Secured by residential properties | PCI loans
Covered Assets and Indemnification Asset
Total loans	215,466,000
Bank | Covered loans | Residential construction loans
Covered Assets and Indemnification Asset
Current Loans	6,490,000
Total loans	11,141,000
Bank | Covered loans | Residential construction loans | PCI loans
Covered Assets and Indemnification Asset
Total loans	4,651,000
Bank | Covered loans | Commercial construction loans and land development
Covered Assets and Indemnification Asset
Current Loans	31,914,000
Total loans	177,364,000
Bank | Covered loans | Commercial construction loans and land development | PCI loans
Covered Assets and Indemnification Asset
Total loans	145,450,000
Bank | Covered loans | Consumer
Covered Assets and Indemnification Asset
Current Loans	11,000
Total loans	$ 11,000