Description of Business and Summary of Significant Accounting Policies (Segment Reporting) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012 ProductService_Groups	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Total revenue, international percentage													29.00%	28.00%	25.00%
Number of product/service groups													4
Operating revenue	$ 54,023	$ 53,804	$ 47,716	$ 43,827	$ 44,050	$ 42,602	$ 42,267	$ 40,050	$ 35,097	$ 33,281	$ 32,207	$ 31,603	$ 199,370	$ 168,969	$ 132,188
Exchanges [Member]
Segment Reporting Information [Line Items]
Operating revenue													159,678	130,638	94,212
Broker Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue													18,612	18,006	13,841
BPO [Member]
Segment Reporting Information [Line Items]
Operating revenue													16,140	14,944	15,586
Carrier Systems [Member]
Segment Reporting Information [Line Items]
Operating revenue													$ 4,940	$ 5,381	$ 8,549