Stock-based Compensation Plans - TSR - PSUs Activities (Parenthetical) (Detail) - Performance Based TSR - PSUs |
9 Months Ended |
---|---|
Sep. 30, 2020 | |
May 2017 Grant | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Return on common stock percentile | 80.00% |
March 2017 Grant | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Return on common stock percentile | 60.00% |
Minimum [Member] | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Potential payout of shares on performance units granted | 0.00% |
Maximum | |
Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |
Potential payout of shares on performance units granted | 200.00% |