Common Shares (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Common Shares (Textuals) [Abstract]
Vested options exercised by employees , shares	1,000,000	400,000
Proceeds from issuance of common shares	$ 11,622,000	$ 4,733,000
Common shares withheld by company	100,000	100,000
Common shares fair value	2,500,000	1,900,000
Issuance of common shares for stock options exercised		103,925
Value of surrendered unexercised vested stock options		$ 5,900,000