Annual report pursuant to Section 13 and 15(d)

Activity of Awarded Restricted Stock Units (Detail)

v3.6.0.2
Activity of Awarded Restricted Stock Units (Detail) - USD ($)
8 Months Ended 12 Months Ended
Sep. 12, 2016
Dec. 31, 2016
Weighted-Average Grant Date Fair Value    
Share-based Compensation Arrangements by Share-based Payment Award, Options, Cancelled $ 3,083,821  
Share-based Compensation Arrangement by Share-by Payment Awards, Options, Weighted Average Price of Shares Canceled $ 16.05  
Restricted Stock Units (RSUs)    
Number of shares    
Balance at beginning of year (in shares) 468,986 468,986
Granted (in shares)   107,563
Vested (in shares)   0
Forfeited (in shares)   0
Balance at end of year (in shares)   107,563
Weighted-Average Grant Date Fair Value    
Balance at beginning of year (in dollars per share) $ 6.97 $ 6.97
Granted (in dollars per share)   23.15
Vested (in dollars per share)   0.00
Forfeited (in dollars per share)   $ 0.00
Share-based Compensation Arrangements by Share-based Payment Award, Options, Cancelled   $ (468,986)
Balance at end of year (in dollars per share)   $ 23.15
Share-based Compensation Arrangement by Share-by Payment Awards, Options, Weighted Average Price of Shares Canceled   $ 6.97
Performance Based Restricted Stock Units (PBRSUs)    
Number of shares    
Balance at beginning of year (in shares) 941,097 941,097
Granted (in shares)   0
Forfeited (in shares)   0
Balance at end of year (in shares)   0
Weighted-Average Grant Date Fair Value    
Balance at beginning of year (in dollars per share) $ 9.19 $ 9.19
Granted (in dollars per share)   0.00
Forfeited (in dollars per share)   $ 0.00
Share-based Compensation Arrangements by Share-based Payment Award, Options, Cancelled   $ (941,097)
Balance at end of year (in dollars per share)   $ 0.00
Share-based Compensation Arrangement by Share-by Payment Awards, Options, Weighted Average Price of Shares Canceled   $ 9.19
Minimum | Performance Based Restricted Stock Units (PBRSUs)    
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Shares, Expected to Vest, Percentage 0.00%  
Maximum | Performance Based Restricted Stock Units (PBRSUs)    
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Shares, Expected to Vest, Percentage 200.00%