Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of Significant Accounting Policies [Abstract]
Percentage of total revenue (international)	48.70%	52.70%	55.30%
Advertising Expense	$ 11,316	$ 10,474	$ 8,782
Cash Equivalents, Maturity Period	3 months
Defined Benefit Plan, Period of Return for Fixed Income Investments From Discount Rate Assumptions	20 years
Defined Benefit Plan, Pensions, Threshold for Amortization of Unrecognized Net Gain (Loss) If Gain (Loss) exceeds Greater of Projected Benefit Obligation Or Market-Value of Plan Assets	5.00%
Financial self-service [Member]
Summary of Significant Accounting Policies [Abstract]
Service Contract Term	12 months
Software Solutions [Member]
Summary of Significant Accounting Policies [Abstract]
Service Contract Term	12 months