Commitments and Contingencies (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended				1 Months Ended	6 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	Jul. 31, 2012 Israeli Optionholder Class Actions	Jul. 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							$ 63.0
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