Stock-Based Compensation - Schedule of Employee Awards and Non-employee Director Award Plan Activity (Detail) - shares shares in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted awards	80,370	2,711,066	370,137	3,161,573
Employees Awards | RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted awards	80,370	1,476,059	370,137	1,926,566
Employees Awards | Market RSU's
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted awards		918,775		918,775
Non-employee Directors Awards | RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted awards		316,232		316,232