Restructuring Charges - Reconciliation of Beginning and Ending Liability Balances by Major Restructuring Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance			$ 5,796
Restructuring charges	238	639	1,814	2,132
Restructuring liabilities			(4,268)	(3,771)
Adjustment to liability			85
Closing Balance	3,427		3,427
Marketing & Events Group
Reconciliation of beginning and ending liability balances by major restructuring activity
Restructuring charges	186	185	392	309
Marketing & Events Group | Severance & Employee Benefits
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance			1,240
Restructuring charges			2,030
Restructuring liabilities			(2,497)
Adjustment to liability			0
Closing Balance	773		773
Marketing & Events Group | Facilities
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance			3,565
Restructuring charges			10
Restructuring liabilities			(926)
Adjustment to liability			0
Closing Balance	2,649		2,649
Other Restructuring | Severance & Employee Benefits
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance			991
Restructuring charges			(226)
Restructuring liabilities			(845)
Adjustment to liability			85
Closing Balance	$ 5		$ 5