Quarterly report pursuant to Section 13 or 15(d)

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical)

v3.8.0.1
CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Mar. 31, 2018
Dec. 31, 2017
Statement Of Financial Position [Abstract]    
Common stock, par value $ 0.001 $ 0.001
Common stock, shares authorized 300,000,000 300,000,000
Common stock, shares issued 121,385,985 121,000,903
Common stock, shares outstanding 116,778,802 116,475,033
Treasury stock, shares 4,607,183 4,525,870