Annual report pursuant to Section 13 and 15(d)

Consolidated Balance Sheets (Parenthetical)

v3.8.0.1
Consolidated Balance Sheets (Parenthetical) - $ / shares
Dec. 31, 2017
Dec. 31, 2016
Preferred stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Preferred stock, shares authorized (in shares) 5,000,000 5,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Treasury stock, shares (in shares) 1,873,266 1,298,418
Class A Common Stock    
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 500,000,000 500,000,000
Common stock, shares issued (in shares) 29,406,315 29,005,284
Common stock, shares outstanding (in shares) 27,533,049 27,706,866
Class B Common Stock    
Common stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 144,000,000 144,000,000
Common stock, shares issued (in shares) 18,000,000 18,000,000
Common stock, shares outstanding (in shares) 18,000,000 18,000,000