Goodwill and Other Intangible Assets - Summary of Goodwill Balances by Component and Segment (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($)
Goodwill [Line Items]
Balance at December 31, 2015	$ 185,223
Business acquisitions	38,116
Foreign currency translation adjustments	(443)
Balance at September 30, 2016	222,896
Marketing & Events U.S. Segment
Goodwill [Line Items]
Balance at December 31, 2015	112,300
Business acquisitions	36,764
Balance at September 30, 2016	149,064
Marketing & Events International Segment
Goodwill [Line Items]
Balance at December 31, 2015	38,635
Foreign currency translation adjustments	(2,529)
Balance at September 30, 2016	36,106
Travel & Recreation Group
Goodwill [Line Items]
Balance at December 31, 2015	34,288
Business acquisitions	1,352
Foreign currency translation adjustments	2,086
Balance at September 30, 2016	$ 37,726