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Stock-based Compensation - Additional Information (Detail)
$ / shares in Units, $ in Thousands
1 Months Ended 12 Months Ended
Jun. 01, 2014
May 31, 2016
$ / shares
shares
Dec. 31, 2016
USD ($)
shares
Dec. 31, 2015
USD ($)
shares
Dec. 31, 2014
USD ($)
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Compensation expense associated with grants | $     $ 1,546 $ 1,522 $ 154
Restricted Stock Awards [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Compensation expense associated with grants | $     1,500 $ 1,500 $ 200
Unamortized stock-based compensation expense related to unvested awards | $     $ 2,400    
Weighted-average remaining vesting period     2 years 3 months 18 days    
Shares vested (in shares)     121,899 32,643  
Unvested stock awards outstanding (in shares)     286,068 394,697 155,040
Stock awards granted (in shares)     20,770 272,300  
Restricted Stock Awards [Member] | Ensign Employees [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock award conversion ratio related to the spin-off 1        
Stock awards unvested during spin-off (in shares)     207,580    
Shares vested (in shares)     46,650    
Unvested stock awards outstanding (in shares)     42,180    
Restricted Stock Awards [Member] | Members of the Board of Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock awards granted (in shares)   20,770      
Stock awards granted, fair market value (in dollars per share) | $ / shares   $ 13.13      
Award vesting period   1 year