Segment Information - Revenues for Each Group of Products and Services (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues
Exhibition And Event Services	$ 685,350	$ 726,429	$ 670,054
Exhibits and Environments	159,554	175,611	170,496
Travel and Recreation Services	127,888	123,191	101,814
Total revenues	$ 972,792	$ 1,025,231	$ 942,364