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Stockholders' Equity (Deficit) - Summary of Activity for Non-vested Three-year PSU awards (Detail) - $ / shares
12 Months Ended
May 18, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Vested (in shares)   (151,280) (607,231) (179,826)
Forfeited or expired (in shares)   (86,518) (184,235) (89,699)
PSU Awards        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Performance period 3 years 3 years    
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]        
Non-vested at beginng of period (in shares)   118,956    
Shares issued (in shares)   171,585    
Vested (in shares)   (61,091)    
Forfeited or expired (in shares)   (12,243)    
Non-vested at end of period (in shares)   217,207 118,956  
Weighted-Average per Share Fair Value on Grant Date        
Non-vested, Weighted- Average per Share Fair value on Grant Date, beginning of period (in usd per share)   $ 48.40    
Granted (in usd per share)   42.29    
Vested (in usd per share)   47.50    
Forfeited or expired (in usd per share)   45.67    
Non-vested, Weighted- Average per Share Fair Value on Grant Date, end of period (in usd per share)   $ 42.94 $ 48.40