Net Income (Loss) Per Share - Schedule of Weighted-Average Shares Used for Net Income per Share Footnotes (Detail) - $ / shares	May 02, 2020	Sep. 30, 2019	Jun. 30, 2018	Jun. 30, 2015
Earnings Per Share Diluted
Conversion price per share		$ 211.40
Common Stock
Earnings Per Share Diluted
Conversion price per share			$ 193.65
Convertible senior notes due 2020 | Common Stock
Earnings Per Share Diluted
Conversion price per share	$ 118.13			$ 118.13
Convertible senior notes due 2023
Earnings Per Share Diluted
Conversion price per share			$ 309.84
Convertible senior notes due 2023 | Common Stock
Earnings Per Share Diluted
Conversion price per share	193.65
Convertible senior notes due 2024 | Common Stock
Earnings Per Share Diluted
Conversion price per share	$ 211.40