Restructuring Charges - Reconciliation of Beginning and Ending Liability Balances by Major Restructuring Activity (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Balance at January 1, 2013			$ 7,224
Restructuring charges, net	714	608	2,207	3,511
Cash payments			(3,771)	(2,761)
Balance at September 30, 2013	5,660		5,660
Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net			2,200
Marketing & Events Group [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	185	392	309	2,879
Marketing & Events Group [Member] | Severance & Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Balance at January 1, 2013			720
Restructuring charges, net			1,890
Cash payments			(1,434)
Balance at September 30, 2013	1,176		1,176
Marketing & Events Group [Member] | Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Balance at January 1, 2013			5,571
Restructuring charges, net			872
Cash payments			(2,034)
Balance at September 30, 2013	4,409		4,409
Other Restructurings [Member] | Severance & Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Balance at January 1, 2013
Restructuring charges, net			137
Cash payments			(62)
Balance at September 30, 2013	75		75
Other Restructurings [Member] | Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Balance at January 1, 2013			933
Restructuring charges, net			(692)
Cash payments			(241)
Balance at September 30, 2013