Stock incentive plan - Non vested restricted stock award (Details) - USD ($)
$ / shares in Units, $ in Thousands |
9 Months Ended |
Sep. 30, 2020 |
Sep. 30, 2019 |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Ending Balance |
6,573
|
|
| Restricted Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
| Beginning Balance |
12,310
|
|
| Shares, Granted |
17,498
|
|
| Shares, Vested |
(4,224)
|
|
| Shares, Forfeited |
(1,094)
|
(8,074)
|
| Shares, Other |
246
|
|
| Ending Balance |
24,736
|
12,110
|
| Weighted-Average Grant-Date Fair-Value, Beginning Balance |
$ 33.83
|
|
| Weighted-Average Grant-Date Fair-Value, Granted |
29.68
|
|
| Weighted-Average Grant-Date Fair-Value, Vested |
33.82
|
|
| Weighted-Average Grant-Date Fair-Value, Forfeited |
33.82
|
|
| Weighted-Average Grant Date Fair Value, Other |
33.82
|
|
| Weighted-Average Grant-Date Fair-Value, Ending Balance |
$ 30.90
|
|
| Aggregate Intrinsic Value, Beginning Balance |
$ 369,300
|
|
| Aggregate Intrinsic Value, Granted |
524,940
|
|
| Aggregate Intrinsic Value, Vested |
(126,720)
|
|
| Aggregate Intrinsic Value, Forfeited |
(32,820)
|
|
| Aggregate Intrinsic Value, Other |
7,380
|
|
| Aggregate Intrinsic Value, Ending Balance |
$ 742,080
|
|