Loans and Allowance for Loan Losses (Allowance for Loan Losses, by Segment Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 26,039	$ 29,641	$ 26,785	$ 29,314
Charge-offs	(2,033)	(6,102)	(4,010)	(9,113)
Recoveries	1,654	2,603	3,569	5,831
Provision (recovery of provision)	(1,685)	(1,057)	(2,369)	(947)
Balance, end of period	23,975	25,085	23,975	25,085
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	3,441	3,373	2,931	3,238
Charge-offs	(621)	(875)	(1,010)	(1,194)
Recoveries	262	633	654	911
Provision (recovery of provision)	426	(939)	933	(763)
Balance, end of period	3,508	2,192	3,508	2,192
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	5,308	5,594	5,233	4,987
Charge-offs	(91)	(584)	(624)	(928)
Recoveries	363	271	1,327	1,067
Provision (recovery of provision)	(802)	371	(1,158)	526
Balance, end of period	4,778	5,652	4,778	5,652
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	7,923	8,803	8,869	8,701
Charge-offs	(151)	(2,537)	(635)	(3,169)
Recoveries	263	492	498	677
Provision (recovery of provision)	(625)	642	(1,322)	1,191
Balance, end of period	7,410	7,400	7,410	7,400
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	6,966	9,291	7,195	9,627
Charge-offs	(730)	(1,371)	(796)	(2,262)
Recoveries	527	1,075	593	2,007
Provision (recovery of provision)	(1,097)	(1,608)	(1,326)	(1,985)
Balance, end of period	5,666	7,387	5,666	7,387
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	2,401	2,580	2,557	2,761
Charge-offs	(440)	(735)	(945)	(1,560)
Recoveries	239	132	497	1,169
Provision (recovery of provision)	413	477	504	84
Balance, end of period	$ 2,613	$ 2,454	$ 2,613	$ 2,454