CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized (in share)	5,000,000	5,000,000
Convertible stock, shares issued (in shares)	0	0
Convertible preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	80,482,000	74,287,000
Common stock, shares outstanding (in shares)	80,482,000	74,287,000