Stockholders' equity - Summary of Changes in Common Shares Outstanding (Detail) - shares
 3 Months Ended 12 Months Ended
Mar. 21, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Equity [Line Items]        
Balance at end of period (in shares) 44,982,142      
Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 1,392,706 1,404,309 1,423,916 1,422,160
Restricted stock issuance     1,209 15,278
Restricted stock repurchased   (2,597) (5,725) (2,025)
Restricted stock forfeited   (9,006) (15,091) (11,497)
Balance at end of period (in shares)   1,392,706 1,404,309 1,423,916
Common Class A | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 333,686 345,289 364,896 70,117
Stock transfers [1]       293,023
Restricted stock issuance     1,209 15,278
Restricted stock repurchased   (2,597) (5,725) (2,025)
Restricted stock forfeited   (9,006) (15,091) (11,497)
Balance at end of period (in shares)   333,686 345,289 364,896
Common Class B | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 344,859 344,859 344,859 357,882
Stock transfers [1]       (13,023)
Balance at end of period (in shares)   344,859 344,859 344,859
Common Class C | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 209,882 209,882 209,882 209,882
Balance at end of period (in shares)   209,882 209,882 209,882
Class D Common Stock | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares)       279,999
Stock transfers [1]       (279,999)
Common Class E | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 504,276 504,276 504,276 504,276
Balance at end of period (in shares)   504,276 504,276 504,276
Common Class F | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 1 1 1 1
Balance at end of period (in shares)   1 1 1
Common Class G | Predecessor        
Equity [Line Items]        
Balance at beginning of period (in shares) 2 2 2 3
Stock transfers [1]       (1)
Balance at end of period (in shares)   2 2 2
[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.