Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended									12 Months Ended
	Dec. 31, 2012 Country	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Segment Country	Dec. 31, 2011	Dec. 31, 2010
Summary of Significant Accounting Policies (Additional Textual) [Abstract]
Number of countries in which services are provided to clients	40									40
Estimated change in earnings									$ 200,000		$ 400,000
Estimated change in revenue											1,400,000
Minimum estimated change in basic and diluted earnings per common share											$ 0.02	$ 0.01
Cash and cash equivalents included short-term investments	25,100,000				8,200,000					25,100,000	8,200,000
Long-term debt	6,000,000				9,000,000					6,000,000	9,000,000
Business acquisition obligations	6,700,000				9,100,000					6,700,000	9,100,000
Amortization period of leasehold improvements										shorter of the lease term or ten years
Reduction in depreciation expense												600,000
Depreciation of property and equipment	2,276,000	1,716,000	1,579,000	1,513,000	1,542,000	1,464,000	1,214,000	1,181,000		7,084,000	5,401,000	4,903,000
Asset Impairment Charges	0
Research and development costs										4,000,000	3,400,000	3,200,000
Estimated Useful Lives										three years
Period of revenue recognition										Three months to a year
Deferred costs	900,000				1,100,000					900,000	1,100,000
Number of operating segments										3
Banks in Brazil [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Short-term Investments at Foreign Banks	$ 1,600,000				$ 2,700,000					$ 1,600,000	$ 2,700,000
Maximum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										7 years
Minimum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										3 years
Computer Laptops [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										3 years
Desktops [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										4 years
Server and Tools [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										5 years
Furniture and fixtures [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										5 years
Purchased Software [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Revised estimated useful lives for fixed assets										3 years