Financial Instruments And Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Summary of Available-for-Sale Marketable Securities

The following table summarizes our investments by significant categories and fair value measurement on a recurring basis as of December 31, 2016 and 2015:

(In thousands)	Maturity  (in years)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2016
Level 1:
Investments:
U.S. treasuries	< 3	$	51,376	$	25	$	(77	)	$	51,324
Mutual funds	N/A	500		5		—			505
Total investments		$	51,876	$	30	$	(77	)	$	51,829
Level 2:
Certificates of deposit	< 1	$	2,320	$	—	$	—		2,320
Total									$	54,149
December 31, 2015
Level 1:
Investments
U.S. treasuries	< 4	$	64,226	$	9	$	(144	)	$	64,091
Mutual funds	N/A	500		4		—			504
Total investments		$	64,726	$	13	$	(144	)	$	64,595
Level 2:
Certificates of deposit	< 1	$	2,319	$	—	$	—		$	2,319
Total									$	66,914