Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2016

Cash and Cash Equivalents [Abstract]

Summary of cash and available-for-sale securities

Summary of Cash and Available-For-Sale Securities	Adjusted Cost		Unrealized Gains		Fair Value		Cash and Cash Equivalents		Short-Term Investments
(In thousands)
December 31, 2016
Cash	$	147,150	$	—	$	147,150	$	147,150	$	—
Money market funds	4		—		4		4		—
Commercial paper	19,987		—		19,987		—		19,987
Total	$	167,141	$	—	$	167,141	$	147,154	$	19,987
December 31, 2015
Cash	$	124,082	$	—	$	124,082	$	124,082	$	—
Money market funds	94,801		—		94,801		94,801		—
Corporate securities	799		670		1,469		—		1,469
Total	$	219,682	$	670	$	220,352	$	218,883	$	1,469