Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized	1,000,000	1,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	150,000,000	150,000,000
Common stock, issued	87,737,329	87,543,781
Purchase of treasury shares	87,183	36,448
Redeemable Series C Preferred Stock [Member]
Preferred stock, shares issued	550	550
Preferred stock, shares outstanding	550	550
Preferred stock, liquidation preference, Value	$ 550,000	$ 550,000
Convertible Series B Preferred Stock [Member]
Preferred stock, shares issued	130	130
Preferred stock, shares outstanding	130	130
Preferred stock, liquidation preference, Value	13,000	13,000
Convertible Series E Preferred Stock [Member]
Preferred stock, shares issued	22,740	22,740
Preferred stock, shares outstanding	22,740	22,740
Preferred stock, liquidation preference, Value	$ 2,274,000	$ 2,274,000