Share based compensation - Options Exercised (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Share based compensation | |||
| Option Exercised (in shares) | 11,401,390 | 3,549,298 | 5,334,936 |
| Intrinsic value of stock options exercised | $ 8,195,000 | $ 1,977,000 | $ 6,727,000 |
| Proceeds from exercise of stock options | 5,663,000 | 366,000 | 3,037,000 |
| Tax benefit from stock option exercises | $ 1,265,000 | $ 1,488,000 | $ 1,325,000 |
| X | ||||||||||
- Definition Amount of tax benefit from exercise of option under share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of cash inflow from exercise of option under share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Number of share options (or share units) exercised during the current period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|