XML 114 R99.htm IDEA: XBRL DOCUMENT v3.20.4
Stock-Based Compensation Plans - Summarizes Transactions of SEUs (Detail) - Stock Equivalent Units [Member]
 12 Months Ended
Dec. 31, 2020
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Outstanding, Number of SEUs, Beginning balance | shares 390,816
Granted at discount, Number of SEUs | shares 113,107
Granted at market value, Number of SEUs | shares 3,634
Exercised, Number of SEUs | shares (93,057)
Forfeited, Number of SEUs | shares (24,336)
Outstanding, Number of SEUs, Ending balance | shares 390,164
Outstanding, Weighted Average Exercise Price, Beginning balance $ 3.69
Granted at discount, Weighted Average Exercise Price 0.00
Granted at market value, Weighted Average Exercise Price 95.70
Exercised, Weighted Average Exercise Price 0.82
Forfeited, Weighted Average Exercise Price 0.60
Outstanding, Weighted Average Exercise Price, Ending balance 4.35
Outstanding, Weighted Average Grant-Date Fair Value 59.91
Granted at discount, Weighted Average Grant-Date Fair Value 76.63
Granted at market value, Weighted Average Grant-Date Fair Value 18.69
Exercised, Weighted Average Grant-Date Fair Value 60.04
Forfeited, Weighted Average Grant-Date Fair Value 65.99
Outstanding, Weighted Average Grant-Date Fair Value $ 63.96