Description of Business and Summary of Significant Accounting Policies Revenue Recognition (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Operating revenue	$ 124,626,000		$ 87,387,000	$ 232,856,000	$ 166,490,000
Cost of Goods and Services Sold	43,559,000		30,932,000	83,150,000	56,119,000
Revenue, Net, Increase (Decrease)	37,239,000			66,366,000
Capitalized Contract Costs, net, Current	848,000			848,000
Capitalized Contract Costs, net, Noncurrent	1,300,000			1,300,000
United States
Disaggregation of Revenue [Line Items]
Operating revenue	48,400,000		52,900,000	98,302,000	105,079,000
Revenue, Net, Increase (Decrease)				(6,800,000)
Canada
Disaggregation of Revenue [Line Items]
Operating revenue	1,456,000		2,034,000	3,056,000	4,142,000
Revenue, Net, Increase (Decrease)				(1,100,000)
Latin America
Disaggregation of Revenue [Line Items]
Operating revenue	5,161,000		4,319,000	10,555,000	8,218,000
Australia
Disaggregation of Revenue [Line Items]
Operating revenue	8,740,000		7,617,000	18,227,000	16,516,000
Revenue, Net, Increase (Decrease)				1,700,000
SINGAPORE
Disaggregation of Revenue [Line Items]
Operating revenue	1,924,000		1,394,000	4,140,000	3,125,000
New Zealand
Disaggregation of Revenue [Line Items]
Operating revenue	526,000		543,000	1,013,000	1,023,000
India
Disaggregation of Revenue [Line Items]
Operating revenue	51,351,000		14,379,000	83,354,000	19,999,000
Revenue, Net, Increase (Decrease)				63,400,000
Europe
Disaggregation of Revenue [Line Items]
Operating revenue	3,841,000		4,201,000	7,872,000	8,388,000
Dubai [Member]
Disaggregation of Revenue [Line Items]
Operating revenue	0		0	4,000	0
INDONESIA
Disaggregation of Revenue [Line Items]
Operating revenue	1,828,000		0	3,369,000	0
PHILIPPINES
Disaggregation of Revenue [Line Items]
Operating revenue	1,245,000		0	2,593,000	0
UNITED ARAB EMIRATES
Disaggregation of Revenue [Line Items]
Operating revenue	154,000		0	371,000	0
Exchanges [Member]
Disaggregation of Revenue [Line Items]
Operating revenue	101,581,000		60,373,000	183,439,000	112,987,000
Broker Systems [Member]
Disaggregation of Revenue [Line Items]
Operating revenue	3,696,000		3,595,000	7,306,000	7,383,000
RCS [Member]
Disaggregation of Revenue [Line Items]
Operating revenue	19,007,000		22,663,000	41,274,000	44,515,000
Carrier Systems [Member]
Disaggregation of Revenue [Line Items]
Operating revenue	342,000		$ 756,000	837,000	$ 1,605,000
Accounting Standards Update 2014-09 Adjustments
Disaggregation of Revenue [Line Items]
Operating revenue	(1,000)			(624,000)
Cost of Goods and Services Sold	19,000			$ (120,000)
M.I.C.E. (meetings, incentives, conference, events) [Member]
Disaggregation of Revenue [Line Items]
Revenue, net of associated costs		$ 256,000
Operating revenue	1,140,000	2,060,000
Cost of Goods and Services Sold	$ 1,030,000	1,800,000
Revenue, Net, Increase (Decrease)		$ 1,800,000