Stock Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2016	Sep. 30, 2014	Jun. 30, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of award		10 years
Share based compensation granted under plan vest period		4 years
Granted		1,186,399
Weighted-average grant date fair value per share of stock-based awards, granted to employees		$ 70.94	$ 48.82	$ 48.16
Stock-based compensation Grants		$ 26,300
Share-Based Compensation Arrangement by Share-Based Payment Award, Terms of Award		550,110 options relating to the Unvested Tranche became vested as they met the conditions for vesting as a result of the average closing price of the Company's common stock exceeding $128.65 and $105.74 during 20 consecutive trading days and the compound annual growth rate of the Company's common stock exceeding that of the Nasdaq Biotech Index by greater than 5%
Average closing price		$ 70.91
Stock-based compensation expense		$ 182,514	$ 233,018	$ 113,943
Weighted average period expected to recognize unrecognized stock based compensation expense		3 years
Unrecognized stock based compensation expense		$ 260,700
Options with Service conditions [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based compensation expense		110,300
Stock Units with Service Conditions [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based compensation expense		143,800
Restricted Stock Units With Certain Peformance Conditions [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based compensation expense		$ 6,600
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compound annual growth rate		5.00%	5.00%
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation granted under plan vest period		4 years
Stock-based compensation expense		$ 79,472	$ 174,868	$ 68,995
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation granted under plan vest period		1 year 2 months 12 days
Granted		38,500
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount		$ 48,500
Stock options granted		502,225
Stock-based compensation Grants		$ 3,300
Weighted Average Grant Date Fair Value			$ 85.39	$ 85.32
Fair Value of RSUs		82,600	$ 33,100	$ 23,100
CEO [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted	3,300,000
Incremental compensation cost		$ 123,300
2013 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares approved under the plan					300,000			500,000		300,000		300,000
Common stock remain available for future grant		300,000
Term of award		24 months
Percentage of closing price of common stock		85.00%
2013 Employee Stock Purchase Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation award, expiration date		Aug. 31, 2025
2013 Employee Stock Purchase Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation award, expiration date		Feb. 29, 2024
2014 Employment Commencement Incentive Plan (2014 Plan) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares approved under the plan											600,000
Common stock remain available for future grant		600,000
Common stock increase in available for future grant shares		7,000,000
2018 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares approved under the plan					2,500,000	2,500,000	3,800,000		2,900,000
Common stock remain available for future grant		5,100,000
Share based compensation award tranche one [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting, Stock options		550,110	550,110
Average closing price		$ 128.65	$ 105.74
Share based compensation award tranche one [Member] | CEO [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense		$ 13,400	$ 109,900