Description of Business and Summary of Significant Accounting Policies (Segment Reporting) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 ProductService_Groups	Mar. 31, 2013
Accounting Policies [Abstract]
Total revenue, international percentage	32.30%	31.10%
Number of product/service groups	4
Segment Reporting Information [Line Items]
Operating revenue	$ 51,404	$ 52,566
Exchanges [Member]
Segment Reporting Information [Line Items]
Operating revenue	42,105	41,686
Broker Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue	4,486	4,722
RCS [Member]
Segment Reporting Information [Line Items]
Operating revenue	3,425	4,164
Carrier Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue	$ 1,388	$ 1,994