Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Summary of Significant Accounting Policies [Abstract]

Schedule of Cash and Equivalents

Cash and cash equivalents consist of highly liquid investments with maturities of three months or less from the date of purchase. Cash and cash equivalents consist of the following at December 31 (in thousands):

	2016		2015
Cash	$	17,481	$	29,569
Money market funds		95,896		14,950
Government-backed securities		19,000		20,000
Asset-backed securities		—		8,185
Corporate debt securities		11,976		20,404
Cash and cash equivalents	$	144,353	$	93,108