Annual report pursuant to Section 13 and 15(d)

Non-Controlling Interests and Equity (Details)

v3.8.0.1
Non-Controlling Interests and Equity (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended
Jun. 30, 2017
Sep. 30, 2015
Dec. 31, 2017
USD ($)
vote
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Class of Stock [Line Items]        
Term of extension of Call Option 6 months 6 months    
Term of extension of Put Option 1 year 1 year    
Redeemable non-controlling interests | $     $ 10,338 $ 6,847
Preferred stock, shares authorized (in shares)     5,000,000 5,000,000
Preferred stock, par value (in dollars per share) | $ / shares     $ 0.0001 $ 0.0001
Class A Common Stock        
Class of Stock [Line Items]        
Common stock, shares authorized (in shares)     500,000,000 500,000,000
Common stock, par value (in dollars per share) | $ / shares     $ 0.0001 $ 0.0001
Number of votes per share (in vote/share) | vote     1  
Class B Common Stock        
Class of Stock [Line Items]        
Common stock, shares authorized (in shares)     144,000,000 144,000,000
Common stock, par value (in dollars per share) | $ / shares     $ 0.0001 $ 0.0001
Number of votes per share (in vote/share) | vote     5  
Conversion basis, number of shares (in shares)     1  
Preferred Stock        
Class of Stock [Line Items]        
Preferred stock, shares authorized (in shares)     5,000,000  
Preferred stock, par value (in dollars per share) | $ / shares     $ 0.0001  
Minimum        
Class of Stock [Line Items]        
Variable interest entity, aggregate exercise price of put options | $     $ 659  
Maximum        
Class of Stock [Line Items]        
Variable interest entity, aggregate exercise price of put options | $     $ 917