Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
SHAREHOLDERS' EQUITY
Common stock, par value	$ 0.01	$ 0.01
Common stock, share authorized	150,000,000	150,000,000
Common stock, share issued	89,901,675	89,655,124