Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
SHAREHOLDERS' EQUITY
Common stock, par value	$ 0.01	$ 0.01
Common stock, share authorized	150,000,000	150,000,000
Common stock, share issued	89,743,142	90,342,338