Description of Business and Summary of Significant Accounting Policies (Segment Reporting) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 ProductService_Groups	Mar. 31, 2014
Accounting Policies [Abstract]
Total revenue, international percentage	23.90%	32.30%
Number of product/service groups	4
Segment Reporting Information [Line Items]
Document Period End Date	Mar. 31, 2015
Operating revenue	$ 63,753	$ 51,404
Exchanges [Member]
Segment Reporting Information [Line Items]
Operating revenue	46,678	42,105
Broker Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue	3,736	4,486
RCS [Member]
Segment Reporting Information [Line Items]
Operating revenue	12,175	3,425
Carrier Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue	$ 1,164	$ 1,388