Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	48,321,305	37,949,229
Common stock, shares outstanding	48,321,305	37,949,229
Excess stock, par value	$ 0.01	$ 0.01
Excess stock, shares authorized	10,000,000	10,000,000
Excess stock, shares issued	0	0
Excess stock, shares outstanding	0	0