COMMON STOCK ACTIVITY (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares outstanding at beginning of year (in shares)	27,658,059
Common stock offerings (in shares)	2,179,153	586,977	0
Dividend reinvestment plan (in shares)	3,915	5,989	6,705
Shares outstanding at end of year (in shares)	29,928,490	27,658,059
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares outstanding at beginning of year (in shares)	27,658,059	26,973,531	26,826,100
Common stock offerings (in shares)	2,179,153	586,977	0
Stock options exercised (in shares)	4,500	9,250	18,000
Dividend reinvestment plan (in shares)	3,915	5,989	6,705
Incentive restricted stock granted (in shares)	111,732	79,491	135,704
Incentive restricted stock forfeited (in shares)	0	(233)	0
Director common stock awarded (in shares)	7,326	6,618	6,690
Restricted stock withheld for tax obligations (in shares)	(36,195)	(3,564)	(19,668)
Shares outstanding at end of year (in shares)	29,928,490	27,658,059	26,973,531
Common Stock Repurchase Plan [Abstract]
Proceeds from issuance of common stock common equity program	109,600,000	25,200,000
Common stocks outstanding authorized to be repurchased (in shares)	1,500,000
Treasury stock shares acquired	827,700
Total cost of shares repurchased	14,170,000
Average cost per share of shares of common stock purchased (in dollar per share)	17.12