Loans and Allowance for Loan Losses (Allowance for Loan Losses, by Segment Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013	Mar. 31, 2012
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			$ 29,314	$ 39,360	$ 25,085	$ 38,551
Charge-offs	(1,724)	(9,276)	(10,836)	(23,580)
Recoveries	2,376	1,552	8,206	4,202
Provision for losses charged to continuing operations	(350)	32	(1,297)	10,877
Balance, end of period	25,387	30,859	25,387	30,859	25,085	38,551
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			3,238	5,776	2,192	7,151
Charge-offs	(2)	(1,156)	(1,196)	(2,774)
Recoveries	465	286	1,376	777
Provision for losses charged to continuing operations	(45)	(1,128)	(808)	1,374
Balance, end of period	2,610	5,153	2,610	5,153	2,192	7,151
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			4,987	11,995	5,652	11,320
Charge-offs	(36)	(2,465)	(964)	(8,761)
Recoveries	1,039	323	2,106	1,169
Provision for losses charged to continuing operations	(1,560)	(3,195)	(1,034)	1,580
Balance, end of period	5,095	5,983	5,095	5,983	5,652	11,320
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			8,701	8,885	7,400	8,784
Charge-offs	(394)	(1,646)	(3,563)	(4,805)
Recoveries	285	69	962	447
Provision for losses charged to continuing operations	1,493	2,787	2,684	5,467
Balance, end of period	8,784	9,994	8,784	9,994	7,400	8,784
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			9,627	11,063	7,387	9,218
Charge-offs	(592)	(2,602)	(2,853)	(3,594)
Recoveries	357	388	2,363	725
Provision for losses charged to continuing operations	(677)	54	(2,662)	(1,136)
Balance, end of period	6,475	7,058	6,475	7,058	7,387	9,218
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period			2,761	1,641	2,454	2,078
Charge-offs	(700)	(1,407)	(2,260)	(3,646)
Recoveries	230	486	1,399	1,084
Provision for losses charged to continuing operations	439	1,514	523	3,592
Balance, end of period	$ 2,423	$ 2,671	$ 2,423	$ 2,671	$ 2,454	$ 2,078