Summary of Stock Awards Granted (Detail) - $ / shares		1 Months Ended	3 Months Ended
		Jun. 30, 2017	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options		3,300,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options			1,291,537	1,359,637
Weighted Average Grant Date Fair Value, Stock options			$ 46.99	$ 49.35
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants, Stock options			38,500
Grants, Restricted stock units and awards	[1]		712,435	689,367
Weighted Average Grant Date Fair Value, Restricted stock units and awards	[1]		$ 79.98	$ 87.14

[1] Included in 2022 restricted stock units (“RSUs”) are 38,500 shares with performance conditions which are related to regulatory approval of certain of the Company's product candidates. As of March 31, 2022, none of the performance conditions are probable of being achieved. If the performance milestones are achieved within the required time frame, the Company may recognize up to $3.1 million of stock-based compensation related to these grants. Stock options and the remaining RSUs granted during the periods presented in the table have only service-based criteria and vest over four years.