Restructuring Charges - Additional Information (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Restructuring Charges (Textual) [Abstract]
Restructuring Reserve	$ 5,796	$ 7,224	$ 6,950	$ 7,996
Marketing & Events Group | Severance & Employee Benefits
Restructuring Charges (Textual) [Abstract]
Restructuring Reserve	1,240	720	831	1,106
Marketing & Events Group | Facilities
Restructuring Charges (Textual) [Abstract]
Restructuring Reserve	3,565	5,571	4,819	5,051
Other Restructuring | Severance & Employee Benefits
Restructuring Charges (Textual) [Abstract]
Restructuring Reserve	991	0	24	197
Other Restructuring | Facilities
Restructuring Charges (Textual) [Abstract]
Restructuring Reserve	$ 0	$ 933	$ 1,276	$ 1,642