Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v3.6.0.2
CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Common stock, par value $ 0.001 $ 0.001    
Common stock, shares authorized 300,000,000 300,000,000    
Common stock, shares issued 120,657,254 120,107,563    
Common stock, shares outstanding 116,210,252 115,924,059    
Treasury stock, shares 4,447,002 4,183,504 4,057,135 3,694,935