Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock shares authorized (in shares)	300,000,000	300,000,000
Common stock shares issued (in shares)	99,220,559	95,877,947
Common stock shares outstanding (in shares)	91,717,769	95,832,238
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Treasury stock, shares held (in shares)	7,502,790	0