Short-term investments (Tables)

12 Months Ended

Dec. 31, 2019

Cash, Cash Equivalents, and Short-term Investments [Abstract]

Schedule of Available-for-sale Securities Reconciliation

The following tables summarize unrealized gains and losses related to our short-term investments designated as available-for-sale:

(In thousands)	As of December 31, 2019
	Adjusted Cost		Gross Unrealized Gain		Gross  Unrealized Loss			Fair Value
Corporate bonds	$	237,423	$	628	$	(68	)	$	237,983
Short-term investments	$	237,423	$	628	$	(68	)	$	237,983

(In thousands)	As of December 31, 2018
	Adjusted Cost		Gross Unrealized Gain		Gross  Unrealized Loss			Fair Value
Corporate bonds	$	235,045	$	726	$	(1,298	)	$	234,473
U.S. treasuries and agencies	36,932		2		(11		)	36,923
Short-term investments	$	271,977	$	728	$	(1,309	)	$	271,396

Investments Classified by Contractual Maturity Date

The following tables summarize the contractual maturities of our short-term investments designated as available-for-sale:

(In thousands)	As of December 31, 2019
	Adjusted Cost		Fair Value
Due in less than 1 year	$	102,843	$	103,239
Due in 1 to 5 years	134,580		134,744
Total available-for-sale debt securities	$	237,423	$	237,983
Due in less than 1 year	Adjusted Cost		Fair Value
Corporate bonds	$	102,843	$	103,239
Total available-for-sale debt securities	$	102,843	$	103,239
Due in 1 to 5 years	Adjusted Cost		Fair Value
Corporate bonds	134,580		134,744
Total available-for-sale debt securities	$	134,580	$	134,744