v3.7.0.1
Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 31, 2016
Dec. 31, 2015
Statement Of Financial Position [Abstract]    
Common stock, par value $ 0.001 $ 0.001
Common stock, shares authorized 400,000,000 400,000,000
Common stock, shares issued 67,600,000 67,900,000
Common stock, shares outstanding 67,600,000 67,900,000
Common stock held in treasury, shares 1,900,000 0