Revenue and Related Contract Costs and Contract Liabilities - Disaggregate GES and Pursuit Revenue by Major Product Line Timing of Revenue Recognition and Markets Served (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Total revenue		$ 358,163	$ 339,099	$ 999,268	$ 1,029,680
GES
Disaggregation Of Revenue [Line Items]
Total revenue		246,110		829,138
GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		246,110	232,119	829,138	870,099
GES | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total revenue		(2,479)	(6,682)	(12,173)	(17,126)
Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		112,053		170,130
Pursuit | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		112,053	106,980	170,130	159,581
Pursuit | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total revenue		(554)		(1,260)
U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		191,699	184,761	636,806	684,003
International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		56,890	54,040	204,505	203,222
Services Transferred Over Time | GES
Disaggregation Of Revenue [Line Items]
Total revenue		216,450		732,144
Services Transferred Over Time | GES | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total revenue		(2,479)		(12,173)
Services Transferred Over Time | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		83,638		128,215
Services Transferred Over Time | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		176,823		589,899
Services Transferred Over Time | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		42,106		154,418
Products Transferred Over Time | GES
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	13,507		44,000
Products Transferred Over Time | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	10,281		30,957
Products Transferred Over Time | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue	[1]	3,226		13,043
Products Transferred at a Point in Time | GES
Disaggregation Of Revenue [Line Items]
Total revenue		16,153		52,994
Products Transferred at a Point in Time | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		28,415		41,915
Products Transferred at a Point in Time | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		4,595		15,950
Products Transferred at a Point in Time | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		11,558		37,044
Core Services | GES
Disaggregation Of Revenue [Line Items]
Total revenue		190,577		643,729
Core Services | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		154,640		511,322
Core Services | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		35,937		132,407
Audio Visual | GES
Disaggregation Of Revenue [Line Items]
Total revenue		21,732		69,278
Audio Visual | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		17,309		55,134
Audio Visual | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		4,423		14,144
Event Technology | GES
Disaggregation Of Revenue [Line Items]
Total revenue		6,619		31,309
Event Technology | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		4,874		23,443
Event Technology | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		1,745		7,866
Total Services | GES
Disaggregation Of Revenue [Line Items]
Total revenue		216,449		732,143
Total Services | GES | Intersegment Eliminations
Disaggregation Of Revenue [Line Items]
Total revenue		(2,479)		(12,173)
Total Services | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		83,638		128,215
Total Services | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		176,823		589,899
Total Services | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		42,105		154,417
Core Products | GES
Disaggregation Of Revenue [Line Items]
Total revenue		29,661		96,995
Core Products | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		14,876		46,907
Core Products | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		14,785		50,088
Exhibitions | GES
Disaggregation Of Revenue [Line Items]
Total revenue		150,273		514,639
Exhibitions | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		108,348		364,016
Exhibitions | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		41,925		150,623
Conferences | GES
Disaggregation Of Revenue [Line Items]
Total revenue		46,285		192,587
Conferences | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		41,367		163,782
Conferences | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		4,918		28,805
Corporate Events | GES
Disaggregation Of Revenue [Line Items]
Total revenue		42,283		110,967
Corporate Events | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		34,093		89,347
Corporate Events | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		8,190		21,620
Consumer Events | GES
Disaggregation Of Revenue [Line Items]
Total revenue		9,748		23,118
Consumer Events | U.S. | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		7,891		19,661
Consumer Events | International | GES | Operating Segments
Disaggregation Of Revenue [Line Items]
Total revenue		1,857		3,457
Accommodations | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		24,623		35,358
Admissions | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		51,316		78,375
Transportation | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		7,602		14,292
Travel Planning | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		651		1,450
Food and Beverage | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		16,074		23,998
Retail Operations | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		12,341		17,917
Products
Disaggregation Of Revenue [Line Items]
Total revenue		58,076	$ 52,347	138,910	$ 133,106
Products | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		28,415		41,915
Banff Jasper Collection | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		58,525		94,133
Alaska Collection | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		25,546		36,373
Glacier Park Collection | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		23,418		30,684
FlyOver | Pursuit
Disaggregation Of Revenue [Line Items]
Total revenue		$ 4,564		$ 8,940

[1] GES’ graphics product revenue is recognized over time as it is considered a part of the single performance obligation satisfied over time.