Restructuring Activities (Tables)

12 Months Ended

Dec. 31, 2017

Restructuring And Related Activities [Abstract]

Rollforward of accrued restructuring liability

A rollforward of the accrued restructuring liability is presented below (in thousands):

Balance as of January 1, 2017	$	1,328
Accrued restructuring charges		2,206
Payments		(3,014	)
Balances as of December 31, 2017	$	520