Commitments and Contingencies (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended				1 Months Ended	9 Months Ended			0 Months Ended
	Dec. 16, 2009 Proceedings Related to Special Committee Investigations	Jul. 13, 2012 Israeli Optionholder Class Actions	Mar. 26, 2009 Israeli Optionholder Class Actions litigation_case	Mar. 16, 2009 Israeli Optionholder Class Actions litigation_case	Mar. 31, 2009 Israeli Optionholder Class Actions litigation_case	Oct. 31, 2012 Israeli Optionholder Class Actions	Oct. 31, 2012 Guarantee Obligations	Jan. 31, 2012 Guarantee Obligations	Dec. 16, 2009 CTI Proceedings Related to Special Committee Investigations
Commitments And Contingencies [Line Items]
Bank guarantees to provide customer assurance							$ 37.3	$ 41.2
Aggregate amount to be paid under settlement agreement	160.2
Issuance of shares under settlement agreement value									82.5
Issuance of shares under settlement agreement (in shares)									12,462,236
Number of claims filed			2	2	4
Amounts in motion filed by plaintiffs		$ 150.0				$ 3.5