XML 113 R96.htm IDEA: XBRL DOCUMENT v3.21.1
Stock-Based Incentive Plans - Movement in Outstanding Shares of Restricted Class A Common Stock and Weighted-Average Grant Date Fair Value Per Share (Detail) - Restricted Class A Common Stock [Member]
3 Months Ended
Mar. 31, 2021
$ / shares
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Restricted Class A Common Stock, Beginning Balance | shares 1,627,890
Restricted Class A Common Stock, Granted | shares 263,809
Restricted Class A Common Stock, Vested | shares (170,942)
Restricted Class A Common Stock, Forfeited | shares (13,273)
Restricted Class A Common Stock, Ending Balance | shares 1,707,484
Weighted-Average Grant Date Fair Value Per Share, Beginning Balance | $ / shares $ 33.14
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares 26.16
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares 35.21
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares 32.61
Weighted-Average Grant Date Fair Value Per Share, Ending Balance | $ / shares $ 31.86