Loans and Allowance for Loan Losses (Details 6) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Allowance for loan losses:
Charge-offs	$ (4,607)	$ (5,698)
Recoveries	1,045	1,640
Provision	1,060	2,723
Non-acquired loans
Allowance for loan losses:
Balance at the beginning of the period	44,378	49,367
Charge-offs	(4,607)	(5,698)
Recoveries	1,045	1,640
Provision	853	2,298
Balance at the end of the period	41,669	47,607
Loans individually evaluated for impairment	4,802	3,840
Loans collectively evaluated for impairment	36,867	43,767
Loans:
Loans individually evaluated for impairment	41,698	57,127
Loans collectively evaluated for impairment	2,562,600	2,380,187
Total loans	2,604,298	2,437,314	2,571,003
Non-acquired loans | Construction & Land Development
Allowance for loan losses:
Balance at the beginning of the period	10,836	12,373
Charge-offs	(2,197)	(1,010)
Recoveries	258	780
Provision	339	455
Balance at the end of the period	9,236	12,598
Loans individually evaluated for impairment	1,027	2,052
Loans collectively evaluated for impairment	8,209	10,546
Loans:
Loans individually evaluated for impairment	12,057	22,641
Loans collectively evaluated for impairment	261,431	272,224
Total loans	273,488	294,865	273,420
Non-acquired loans | Commercial Non-owner Occupied
Allowance for loan losses:
Balance at the beginning of the period	4,921	6,109
Charge-offs		(1,002)
Recoveries	254	16
Provision	96	539
Balance at the end of the period	5,271	5,662
Loans individually evaluated for impairment	2,059	528
Loans collectively evaluated for impairment	3,212	5,134
Loans:
Loans individually evaluated for impairment	4,861	8,017
Loans collectively evaluated for impairment	293,846	276,027
Total loans	298,707	284,044	290,071
Non-acquired loans | Commercial Owner Occupied
Allowance for loan losses:
Balance at the beginning of the period	8,743	10,356
Charge-offs	(695)	(1,495)
Recoveries	10	1
Provision	150	409
Balance at the end of the period	8,208	9,271
Loans individually evaluated for impairment	623	294
Loans collectively evaluated for impairment	7,585	8,977
Loans:
Loans individually evaluated for impairment	17,629	16,895
Loans collectively evaluated for impairment	778,510	727,546
Total loans	796,139	744,441	784,152
Non-acquired loans | Consumer Owner Occupied
Allowance for loan losses:
Balance at the beginning of the period	6,568	7,453
Charge-offs	(150)	(446)
Recoveries	89	12
Provision	16	548
Balance at the end of the period	6,523	7,567
Loans individually evaluated for impairment	200	644
Loans collectively evaluated for impairment	6,323	6,923
Loans:
Loans individually evaluated for impairment	1,177	4,004
Loans collectively evaluated for impairment	441,957	403,693
Total loans	443,134	407,697	434,503
Non-acquired loans | Home Equity
Allowance for loan losses:
Balance at the beginning of the period	3,626	4,269
Charge-offs	(197)	(500)
Recoveries	72	181
Provision	35	83
Balance at the end of the period	3,536	4,033
Loans collectively evaluated for impairment	3,536	4,033
Loans:
Loans collectively evaluated for impairment	249,356	258,054
Total loans	249,356	258,054	255,284
Non-acquired loans | Commercial & Industrial
Allowance for loan losses:
Balance at the beginning of the period	4,939	3,901
Charge-offs	(324)	(330)
Recoveries	99	110
Provision	71	69
Balance at the end of the period	4,785	3,750
Loans individually evaluated for impairment	84
Loans collectively evaluated for impairment	4,701	3,750
Loans:
Loans individually evaluated for impairment	1,934	884
Loans collectively evaluated for impairment	289,374	215,199
Total loans	291,308	216,083	279,763
Non-acquired loans | Other Income Producing Property
Allowance for loan losses:
Balance at the beginning of the period	3,747	3,636
Charge-offs	(339)	(455)
Recoveries	9	273
Provision	42	63
Balance at the end of the period	3,459	3,517
Loans individually evaluated for impairment	809	322
Loans collectively evaluated for impairment	2,650	3,195
Loans:
Loans individually evaluated for impairment	4,040	4,686
Loans collectively evaluated for impairment	127,736	125,491
Total loans	131,776	130,177	133,713
Non-acquired loans | Consumer
Allowance for loan losses:
Balance at the beginning of the period	781	1,145
Charge-offs	(705)	(409)
Recoveries	254	256
Provision	104	83
Balance at the end of the period	434	1,075
Loans collectively evaluated for impairment	434	1,075
Loans:
Loans collectively evaluated for impairment	93,997	85,350
Total loans	93,997	85,350	86,934
Non-acquired loans | Other Loans
Allowance for loan losses:
Balance at the beginning of the period		125	217
Charge-offs		(51)
Recoveries		11
Provision		49
Balance at the end of the period	217	134	217
Loans collectively evaluated for impairment	217	134
Loans:
Loans collectively evaluated for impairment	26,393	16,603
Total loans	$ 26,393	$ 16,603	$ 33,163