Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table presents information about our assets and liabilities that are measured at fair value on a recurring basis and indicates the level of the fair value hierarchy and the valuation techniques we utilized to determine such fair value:

	As of March 31, 2021
	Level 1		Level 2		Level 3		Total
Assets:
Corporate notes and bonds	$	—	$	510,663	$	—	$	510,663
Corporate commercial paper	—		478,442		—		478,442
Obligations of U.S. government agencies	—		4,884		—		4,884
Money market funds	123,607		—		—		123,607
Total assets	$	123,607	$	993,989	$	—	$	1,117,596
Liabilities:
Development derivative liability	$	—	$	—	$	4,597	$	4,597
	As of December 31, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Corporate notes and bonds	$	—	$	687,469	$	—	$	687,469
Corporate commercial paper	—		313,497		—		313,497
Obligations of U.S. government agencies	—		2,382		—		2,382
Money market funds	179,302		—		—		179,302
Total assets	179,302		$	1,003,348	$	—	$	1,182,650
Liabilities:
Development derivative liability	$	—	$	—	$	—	$	—