Stockholders' equity (Tables)
12 Months Ended
Dec. 31, 2016
Stockholders' Equity Note [Abstract]  
Summary of changes in common shares outstanding

The following is a summary of the changes in our common shares outstanding during the years ended December 31, 2016, 2015 and 2014.

 

     Common Stock  
     Class A     Class B     Class C      Class D     Class E      Class F      Class G     Total  

Shares issued at January 1, 2014

     70,117       357,882       209,882        279,999       504,276        1        3       1,422,160  

Stock transfers (1)

     293,023       (13,023     —          (279,999     —          —          (1     —    

Restricted stock issuance

     15,278       —         —          —         —          —          —         15,278  

Restricted stock repurchased

     (2,025     —         —          —         —          —          —         (2,025

Restricted stock forfeited

     (11,497     —         —          —         —          —          —         (11,497
  

 

 

   

 

 

   

 

 

    

 

 

   

 

 

    

 

 

    

 

 

   

 

 

 

Shares issued at December 31, 2014

     364,896       344,859       209,882        —         504,276        1        2       1,423,916  

Restricted stock issuance

     1,209       —         —          —         —          —          —         1,209  

Restricted stock repurchased

     (5,725     —         —          —         —          —          —         (5,725

Restricted stock forfeited

     (15,091     —         —          —         —          —          —         (15,091
  

 

 

   

 

 

   

 

 

    

 

 

   

 

 

    

 

 

    

 

 

   

 

 

 

Shares issued at December 31, 2015

     345,289       344,859       209,882        —         504,276        1        2       1,404,309  

Restricted stock issuance

     —         —         —          —         —          —          —         —    

Restricted stock repurchased

     (2,597     —         —          —         —          —          —         (2,597

Restricted stock forfeited

     (9,006     —         —          —         —          —          —         (9,006
  

 

 

   

 

 

   

 

 

    

 

 

   

 

 

    

 

 

    

 

 

   

 

 

 

Shares issued at December 31, 2016

     333,686       344,859       209,882        —         504,276        1        2       1,392,706  
  

 

 

   

 

 

   

 

 

    

 

 

   

 

 

    

 

 

    

 

 

   

 

 

 

 

(1) In this transaction, Healthcare of Ontario Pension Plan Trust Fund (“HOOPP”) purchased 280,000 shares of Class A common stock converted from Class D and Class G common stock held by CHK Energy Holdings, Inc. (“CHK Energy Holdings”) on January 13, 2014. An additional 15,078 shares of Class A common stock was purchased by HOOPP from various other stockholders of which 13,023 shares were converted from Class B common stock.