Pro Forma Financial Information (Details) (USD $)	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	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition, Pro Forma Information [Abstract]
Revenue, As Reported	$ 54,023,000	$ 53,804,000	$ 47,716,000	$ 43,827,000	$ 44,050,000	$ 42,602,000	$ 42,267,000	$ 40,050,000	$ 35,097,000	$ 33,281,000	$ 32,207,000	$ 31,603,000	$ 199,370,000	$ 168,969,000	$ 132,188,000
Net Income, As Reported	18,745,000	18,072,000	18,067,000	15,685,000	17,330,000	16,536,000	22,348,000	15,164,000	15,944,000	16,681,000	14,010,000	12,384,000	70,569,000	71,378,000	59,019,000
Basic EPS, As Reported (in dollars per share)	$ 0.50	$ 0.49	$ 0.49	$ 0.43	$ 0.48	$ 0.44	$ 0.57	$ 0.40	$ 0.45	$ 0.48	$ 0.40	$ 0.36	$ 1.91	$ 1.89	$ 1.69
Diluted EPS, As Reported (in dollars per share)	$ 0.48	$ 0.46	$ 0.47	$ 0.40	$ 0.44	$ 0.41	$ 0.53	$ 0.37	$ 0.42	$ 0.43	$ 0.36	$ 0.32	$ 1.80	$ 1.75	$ 1.51
Parent, ADAM, Planetsoft, BSI, Taimma, Fintechnix, TriSystems , Combined [Member] [Domain]
Business Acquisition, Pro Forma Information [Abstract]
Revenue, Pro forma													212,360,000	209,748,000
Net Income, Pro Forma													70,086,000	72,391,000
Basic EPS, Pro Forma (in dollars per share)													$ 1.89	$ 1.88
Diluted EPS, Pro Forma (in dollars per share)													$ 1.79	$ 1.74
Increase in unaudited pro forma revenue													2,600,000
Increase in unaudited pro forma revenue, percentage													1.20%
Increase in reported revenue													$ 30,400,000
Increase in reported revenue, percentage													18.00%