XML 79 R66.htm IDEA: XBRL DOCUMENT v3.19.1
Share-based compensation - Schedule of Restricted Share Units and Restricted Stock Activity (Detail) - Restricted Stock Units and Restricted Stock - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Number of units    
Number of units, beginning balance (in shares) 8,150,905 12,407,029
Granted (in shares) 4,598,125 2,732,000
Vested and delivered (in shares) (11,468,333) (3,659,520)
Withheld as treasury stock (in shares) (875,675) (192,288)
Vested not delivered (in shares) 3,766,068 (2,568,318)
Forfeited (in shares) (339,125) (567,998)
Number of units, ending balance (in shares) 3,831,965 8,150,905
Weighted average grant-date fair value    
Weighted average grant-date fair value, beginning balance (in dollars per share) $ 9.27 $ 8.40
Granted (in dollars per share) 2.63 5.61
Vested and delivered (in dollars per share) 7.63 8.29
Withheld as treasury stock (in dollars per share) 6.05 8.48
Vested not delivered (in dollars per share) 9.85 3.43
Forfeited (in dollars per share) 4.68 5.65
Weighted average grant-date fair value, ending balance (in dollars per share) $ 7.95 $ 9.27