Summary of Significant Accounting Policies (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Property, Plant and Equipment [Line Items]
Number of shares authorized to repurchase		705,406	461,938	715,975
Amortization period of computer software		5 years
Share price		$ 30,727,000	$ 21,643,000	$ 30,608,000
Average price		$ 43.56	$ 46.85	$ 42.75
Summary of Significant Accounting Policies (Textual) [Abstract]
Stock split ratio		0.5
Stock dividend percentage	100.00%	100.00%
Stock dividend distribution date	Jun. 26, 2013
Stock dividend recording date		Jun. 12, 2013
Interest-bearing securities with maturities		90 days
Accounts receivable due period		30 days
Unbilled account receivables	5,221,000	5,221,000	5,775,000
Maximum Customer Percentage of Accounts Receivable not accounted	10.00%	10.00%	10.00%
Maximum Customer Percentage of Revenues not accounted		10.00%	10.00%	10.00%
Capitalized software development costs	18,276,000	18,276,000	16,598,000
Accumulated amortization of software development costs	97,551,000	97,551,000	91,097,000
Accumulated amortization of software development costs	47,178,000	47,178,000	41,647,000
Impairment of goodwill, intangible assets		0
Goodwill	36,814,000	36,814,000	36,814,000
Accumulated amortization of goodwill	2,069,000	2,069,000	2,069,000
Stock-based compensation expense		997,000	2,276,000	2,544,000
Software License Arrangement [Member]
Property, Plant and Equipment [Line Items]
Desktop software licenses agreement value	3,500,000	3,500,000
Amortization period of computer software		3 years
Future Shares [Member]
Property, Plant and Equipment [Line Items]
Number of shares authorized to repurchase		92,658
Share price		$ 4,500,000
Average price		$ 48.67