Condensed Consolidated Balance Sheets (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	57,050,684	53,832,782
Common stock, shares outstanding	57,050,684	53,832,782