Loans (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Mortgage loans on real estate:
Total mortgage loan on real estate	$ 1,007,432		$ 965,922
Consumer:
Total consumer loans	388,844		406,330
Commercial	145,469		139,131
Construction:
Total construction	33,902		39,649
Total loans, net of deferred loan fees	1,575,647		1,551,032
Total principal balance of loans owed-net of charge-offs	1,620,654		1,607,039
Unamortized net deferred loan fees	(2,324)		(2,308)
Discounts to principal balance of loans owed, net of charge-offs	(42,683)		(53,699)
Total loans, net of unamortized deferred loan fees	1,575,647		1,551,032
Noncovered loans	1,533,027		1,501,961
Covered loans	42,620		49,071
Total loans, net of unamortized deferred loan fees	1,575,647		1,551,032
Allowance for loan losses	(44,146)	(45,849)	(45,914)	(45,300)	(43,962)	(42,571)
Auto Indirect [Member]
Consumer:
Total consumer loans	5,067		10,821
Other [Member]
Consumer:
Total consumer loans	26,609		23,360
Home Equity Lines of Credit [Member]
Consumer:
Total consumer loans	342,898		357,305
Home Equity Loans [Member]
Consumer:
Total consumer loans	14,270		14,844
Residential [Member]
Construction:
Total construction	18,332		22,122
Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	873,391		826,336
Construction:
Total construction	15,570		17,527
Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	134,041		139,586
Originated [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	886,050		818,002
Consumer:
Total consumer loans	354,483		367,245
Commercial	132,162		123,486
Construction:
Total construction	22,618		26,652
Total loans, net of deferred loan fees	1,395,313		1,335,385
Total principal balance of loans owed-net of charge-offs	1,397,637		1,337,693
Unamortized net deferred loan fees	(2,324)		(2,308)
Discounts to principal balance of loans owed, net of charge-offs
Total loans, net of unamortized deferred loan fees	1,395,313		1,335,385
Noncovered loans	1,395,313		1,335,385
Covered loans
Total loans, net of unamortized deferred loan fees	1,395,313		1,335,385
Allowance for loan losses	(38,207)		(41,458)
Originated [Member] | Auto Indirect [Member]
Consumer:
Total consumer loans	5,067		10,821
Originated [Member] | Other [Member]
Consumer:
Total consumer loans	23,933		20,270
Originated [Member] | Home Equity Lines of Credit [Member]
Consumer:
Total consumer loans	311,749		321,834
Originated [Member] | Home Equity Loans [Member]
Consumer:
Total consumer loans	13,734		14,320
Originated [Member] | Residential [Member]
Construction:
Total construction	10,574		13,908
Originated [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	765,367		699,682
Construction:
Total construction	12,044		12,744
Originated [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	120,683		118,320
PNCI [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	82,794		108,178
Consumer:
Total consumer loans	20,169		24,310
Commercial	1,021		1,805
Construction:
Total construction
Total loans, net of deferred loan fees	103,984		134,293
Total principal balance of loans owed-net of charge-offs	119,264		152,549
Unamortized net deferred loan fees
Discounts to principal balance of loans owed, net of charge-offs	(15,280)		(18,256)
Total loans, net of unamortized deferred loan fees	103,984		134,293
Noncovered loans	103,984		134,293
Covered loans
Total loans, net of unamortized deferred loan fees	103,984		134,293
Allowance for loan losses	(1,059)		(245)
PNCI [Member] | Auto Indirect [Member]
Consumer:
Total consumer loans
PNCI [Member] | Other [Member]
Consumer:
Total consumer loans	2,653		3,041
PNCI [Member] | Home Equity Lines of Credit [Member]
Consumer:
Total consumer loans	17,184		20,902
PNCI [Member] | Home Equity Loans [Member]
Consumer:
Total consumer loans	332		367
PNCI [Member] | Residential [Member]
Construction:
Total construction
PNCI [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	75,490		93,428
Construction:
Total construction
PNCI [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	7,304		14,750
PCI- Cash basis [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	1,345
Consumer:
Total consumer loans	8,130		8,615
Commercial	1,905		811
Construction:
Total construction
Total loans, net of deferred loan fees	11,380		9,426
Total principal balance of loans owed-net of charge-offs	23,552		22,137
Unamortized net deferred loan fees
Discounts to principal balance of loans owed, net of charge-offs	(12,172)		(12,711)
Total loans, net of unamortized deferred loan fees	11,380		9,426
Noncovered loans	11,380		9,426
Covered loans
Total loans, net of unamortized deferred loan fees	11,380		9,426
Allowance for loan losses	(1,349)		(1,034)
PCI- Cash basis [Member] | Auto Indirect [Member]
Consumer:
Total consumer loans
PCI- Cash basis [Member] | Other [Member]
Consumer:
Total consumer loans
PCI- Cash basis [Member] | Home Equity Lines of Credit [Member]
Consumer:
Total consumer loans	8,082
PCI- Cash basis [Member] | Home Equity Loans [Member]
Consumer:
Total consumer loans	48
PCI- Cash basis [Member] | Residential [Member]
Construction:
Total construction
PCI- Cash basis [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	1,345
Construction:
Total construction
PCI- Cash basis [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate
PCI- Other [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	37,243		39,742
Consumer:
Total consumer loans	6,062		6,160
Commercial	10,381		13,029
Construction:
Total construction	11,284		12,997
Total loans, net of deferred loan fees	64,970		71,928
Total principal balance of loans owed-net of charge-offs	80,201		94,660
Unamortized net deferred loan fees
Discounts to principal balance of loans owed, net of charge-offs	(15,231)		(22,732)
Total loans, net of unamortized deferred loan fees	64,970		71,928
Noncovered loans	22,350		22,857
Covered loans	42,620		49,071
Total loans, net of unamortized deferred loan fees	64,970		71,928
Allowance for loan losses	(3,531)		(3,177)
PCI- Other [Member] | Auto Indirect [Member]
Consumer:
Total consumer loans
PCI- Other [Member] | Other [Member]
Consumer:
Total consumer loans	23		49
PCI- Other [Member] | Home Equity Lines of Credit [Member]
Consumer:
Total consumer loans	5,883		5,954
PCI- Other [Member] | Home Equity Loans [Member]
Consumer:
Total consumer loans	156		157
PCI- Other [Member] | Residential [Member]
Construction:
Total construction	7,758		8,214
PCI- Other [Member] | Commercial [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	31,189		33,226
Construction:
Total construction	3,526		4,783
PCI- Other [Member] | Residential 1-4 family [Member]
Mortgage loans on real estate:
Total mortgage loan on real estate	$ 6,054		$ 6,516