XML 39 R30.htm IDEA: XBRL DOCUMENT v3.22.2
Share-based compensation - RSU activity (Details) - 2014 Plan
$ / shares in Units, $ in Millions
 6 Months Ended
Jun. 30, 2022
USD ($)
$ / shares
shares
Other disclosure  
Vesting period (in years) 4 years
Non-executive directors  
Other disclosure  
Vesting period (in years) 1 year
Restricted share units ("RSUs")  
Number of shares  
Non-vested at beginning of period (in shares) | shares 710,617
Granted (in shares) | shares 1,496,443
Vested (in shares) | shares (230,794)
Forfeited (in shares) | shares (94,596)
Non-vested at end of period (in shares) | shares 1,881,670
Weighted average grant-date fair value  
Non-vested at beginning of period (in dollars per share) | $ / shares $ 38.89
Granted (in dollars per share) | $ / shares 15.81
Vested (in dollars per share) | $ / shares 39.64
Forfeited (in dollars per share) | $ / shares 25.20
Non-vested at end of period (in dollars per share) | $ / shares $ 21.13
Other disclosure  
Total weighted average grant date fair value of RSUs granted during the period (in millions) | $ $ 23.7
Restricted share units ("RSUs") | Non-executive directors  
Other disclosure  
Vesting period (in years) 1 year
Minimum | Restricted share units ("RSUs")  
Other disclosure  
Vesting period (in years) 1 year
Maximum | Restricted share units ("RSUs")  
Other disclosure  
Vesting period (in years) 3 years