Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	$ 779,827		$ 1,263,784
Derivative Asset, Statement of Financial Position	Prepaid expenses and other current assets		Prepaid expenses and other current assets
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration liability	$ 1,400	$ 18,500
Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	779,827		$ 1,263,782
Foreign exchange contracts	150		634
Net investment hedge	1,278		124,789
Total Assets	1,291,898		1,764,009
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration liability	1,406
Foreign exchange contracts	164		230
Total Liabilities	1,570		230
Fair Value, Recurring | Cash Equivalents
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	510,643		374,804
Fair Value, Recurring | Fair Value, Inputs, Level 1
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	208,527		651,800
Total Assets	707,810		1,025,855
Fair Value, Recurring | Fair Value, Inputs, Level 1 | Cash Equivalents
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	499,283		374,055
Fair Value, Recurring | Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Available-for-sale securities	571,300		611,982
Foreign exchange contracts	150		634
Net investment hedge	1,278		124,789
Total Assets	584,088		738,154
Liabilities, Fair Value Disclosure [Abstract]
Foreign exchange contracts	164		230
Total Liabilities	164		230
Fair Value, Recurring | Fair Value, Inputs, Level 2 | Cash Equivalents
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	11,360		$ 749
Fair Value, Recurring | Fair Value, Inputs, Level 3
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration liability	1,406
Total Liabilities	$ 1,406