Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Summary of Marketable Securities

Below is a summary of our marketable securities as of December 31, 2018 and 2017 (in thousands):

	December 31,
	2018							2017
	Amortized Cost		Unrealized Loss			Estimated Fair Value		Cost or Amortized Cost		Unrealized Gain, Net		Estimated Fair Value
Marketable securities	$	249,944	$	(342	)	$	249,602	$	276,567	$	361	$	276,928