Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Additional Information (Detail)

v3.8.0.1
Share-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Total grant date fair value     $ 21,165    
Share-based compensation expense for vested shares employees and directors $ 4,000 $ 19,100 $ 22,000 $ 24,200  
Settlement of Bonuses Accrued at December 31, 2016          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation expense for vested shares employees and directors         $ 2,000
Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Weighted average grant date fair value per share $ 10.68        
Final Investment Decision (FID Awards)          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Total grant date fair value $ 17,400        
2016 Omnibus Compensation Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of common stock authorized for issuance 40,000,000   40,000,000    
Maximum number of common shares granted to an employee     10,000,000    
Awards per share granted 40.00%   40.00%    
2016 Omnibus Compensation Incentive Plan | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of shares granted     7,500,000    
2016 Omnibus Incentive Plan (Legacy Plan) | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of shares granted     14,900,000