Short-Term Investments (Tables)

6 Months Ended

Jun. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Schedule of Short-Term Investments

The following tables summarize the Company's short-term investments (dollars in thousands):

		As of June 30, 2020
	Maturity	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Corporate debt securities	2 years or less	$	177,244	$	1,044	$	—		$	178,288
Commercial paper	1 year or less	233,296		594		(1		)	233,889
U.S. Agency bonds	2 years or less	38,308		75		(1		)	38,382
U.S. Treasury bills	1 year or less	63,411		52		(1		)	63,462
		$	512,259	$	1,765	$	(3	)	$	514,021

		As of December 31, 2019
	Maturity	Amortized cost		Gross unrealized gains		Gross unrealized losses			Estimated fair value
Corporate debt securities	2 years or less	$	160,065	$	233	$	(1	)	$	160,297
Commercial paper	1 year or less	120,862		74		—			120,936
U.S. Agency bonds	2 years or less	50,745		41		(4		)	50,782
U.S. Treasury bills	2 years or less	36,474		27		(1		)	36,500
		$	368,146	$	375	$	(6	)	$	368,515