Summary of Significant Accounting Policies (Details 5) (USD $)	12 Months Ended
	Dec. 31, 2012 M Y D	Dec. 31, 2011	Dec. 31, 2010
Software license fees
Standard collection period of receivables, maximum (in days)	180
Recurring revenues
Term licenses	$ 159,940,000	$ 135,235,000	$ 108,838,000
Maintenance revenues	67,063,000	70,454,000	72,907,000
Asset under administration revenues	6,895,000	8,232,000	6,947,000
Other recurring revenues	90,729,000	77,565,000	63,362,000
Total recurring revenues	324,627,000	291,486,000	252,054,000
Non-recurring revenues
Professional services and other	31,280,000	31,475,000	26,593,000
Perpetual license fees	2,912,000	3,287,000	4,854,000
Total non-recurring revenues	34,192,000	34,762,000	31,447,000
Revenue recognition disclosures
Term License Contracts: Period of binding commitment for customer under term license contract (in years)	3
Maintenace revenues: Period of maintenance over which revenue typically recognized	1
Other recurring revenues: Period over which revenue typically recognized	1
Allowance for doubtful accounts and sales returns
Provision for bad debt	403,000	230,000	188,000
Right of return period for shrink-wrap license agreements (in days)	7
Past period considered for calculating value of reserves (in months)	12
Sales returns provision (benefit)	1,154,000	(187,000)	(616,000)
Advertising costs
Advertising expense	$ 600,000	$ 500,000	$ 700,000
Stock-based compensation
Period considered for estimating the forfeiture of stock-based awards (in years)	10