Restructuring Charges (Tables)

12 Months Ended

Dec. 31, 2017

Restructuring And Related Activities [Abstract]

Changes to Restructuring Liability by Major Restructuring Activity

Changes to the restructuring liability by major restructuring activity are as follows:

	GES Consolidation						Other Restructurings
(in thousands)	Severance & Employee Benefits			Facilities			Severance & Employee Benefits			Total
Balance at December 31, 2014	$	543		$	1,161		$	240		$	1,944
Restructuring charges		1,767			587			602			2,956
Cash payments		(1,514	)		(457	)		(601	)		(2,572	)
Adjustment to liability		(45	)		—			(7	)		(52	)
Balance at December 31, 2015		751			1,291			234			2,276
Restructuring charges		3,693			759			731			5,183
Cash payments		(2,170	)		(1,150	)		(546	)		(3,866	)
Adjustment to liability		—			192			(3	)		189
Balance at December 31, 2016		2,274			1,092			416			3,782
Restructuring charges		442			265			297			1,004
Cash payments		(1,165	)		(550	)		(538	)		(2,253	)
Adjustment to liability		—			—			16			16
Balance at December 31, 2017	$	1,551		$	807		$	191		$	2,549