Quarterly report pursuant to Section 13 or 15(d)

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical)

v3.8.0.1
CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares
Mar. 31, 2018
Dec. 31, 2017
Convertible preferred stock issued 0 0
Class A common stock    
Common stock, par value (usd per share) $ 0.01 $ 0.01
Common stock, shares authorized 100,000,000 100,000,000
Common stock, shares issued 64,084,704 63,456,698
Common stock, shares outstanding 30,641,717 31,166,205
Treasury stock, shares 33,442,987 32,290,493
Class B common stock    
Common stock, par value (usd per share) $ 0.01 $ 0.01
Common stock, shares authorized 30,000,000 30,000,000
Common stock, shares issued 12,029,375 12,029,375
Common stock, shares outstanding 12,029,375 12,029,375