Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2015	Dec. 31, 2014
Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	30,000	30,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	116,101	112,849
Common stock, shares outstanding	115,981	112,729
Treasury stock, shares	120	120