Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2019

Cash And Cash Equivalents [Abstract]

Summary of Available-for-Sale Short-Term and Long-Term Investments

The following tables summarize the amortized cost, gross unrealized gains and losses and fair value of our short-term and long-term investments as of June 30, 2019 and December 31, 2018 (in thousands):

	June 30, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized		Aggregate
	Cost		Gains		Losses		Fair Value
Short-term investments:
Corporate debt securities	$	134,219	$	43	$	—	$	134,262
U.S. government and government agency debt    securities		3,000		3		—		3,003
Total	$	137,219	$	46	$	—	$	137,265
Long-term investments:
Corporate debt securities	$	1,997	$	7			$	2,004
Total	$	1,997	$	7	$	—	$	2,004

	December 31, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized		Aggregate
	Cost		Gains		Losses		Fair Value
Short-term investments:
Corporate debt securities	$	36,230	$	2	$	—	$	36,232
Total	$	36,230	$	2	$	—	$	36,232