Restructuring Charges - Reconciliation of Beginning and Ending Liability Balances by Major Restructuring Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance	$ 5,796
Restructuring charges	211	720
Restructuring liabilities	(1,860)	(1,443)
Adjustment to liability	328
Closing Balance	4,475
Marketing & Events Group
Reconciliation of beginning and ending liability balances by major restructuring activity
Restructuring charges	(38)	(194)
Marketing & Events Group | Severance & Employee Benefits
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance	1,240
Restructuring charges	492
Restructuring liabilities	(893)
Adjustment to liability	64
Closing Balance	903
Marketing & Events Group | Facilities
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance	3,565
Restructuring charges	0
Restructuring liabilities	(136)
Adjustment to liability	0
Closing Balance	3,429
Other Restructuring | Severance & Employee Benefits
Reconciliation of beginning and ending liability balances by major restructuring activity
Beginning Balance	991
Restructuring charges	(281)
Restructuring liabilities	(831)
Adjustment to liability	264
Closing Balance	$ 143