Cost of Revenue (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Cost of revenue [Abstract]
Software service costs	$ 64,200	$ 62,500	$ 127,800	$ 135,500
Software service costs, changes	1,700		(7,700)
Software service costs, changes (in hundredths)	2.70%		(5.70%)
Software product costs	73,100	69,900	121,300	135,400
Software product costs, changes	3,200		(14,100)
Software product costs, changes (in hundredths)	4.60%		(10.40%)
Cost of revenue	137,300	132,400	249,100	270,900
Cost of revenue, changes	$ 4,900		$ (21,800)
Cost of revenue changes, in (hundredths)	3.70%		(8.00%)