Commitments and Contingent Liabilities, Technology Agreements (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
IBM Agreement [Member]
Technology Agreements [Abstract]
Amount paid under technology agreement	$ 93.6	$ 95.6
Amount paid for other project business	1.4	2.0
Technology Agreements, Minimum Payments Due [Abstract]
2012	19.2
2013	17.6
2014	17.2
2015	11.9
2016 and thereafter	0
Accenture Agreement [Member]
Technology Agreements [Abstract]
Amount paid under technology agreement	15.2	22.7
Amount paid for other project business	5.6	8.4
Percent of contract value to be paid if contract is terminated (in hundredths)	50.00%
Technology Agreements, Minimum Payments Due [Abstract]
2012	8.7
2013	8.4
2014	8.2
2015	8.2
2016 and thereafter	$ 8.1