Commitments and Contingencies - Additional Information (Detail) (USD $)					0 Months Ended			0 Months Ended
	Jul. 31, 2014	Oct. 31, 2013	Jul. 31, 2014 Effective date starting after July 31, 2014	Jul. 31, 2014 Contract Dispute, Work Performed By A Third Party Administrative	Jul. 31, 2012 Augustus Claim	Feb. 08, 2012 Augustus	Jul. 31, 2014 Augustus	Jan. 14, 2013 Augustus Motion against others	Jul. 31, 2012 Augustus Motion against others	Apr. 11, 2013 Bojorquez	May 17, 2012 Bojorquez	Jul. 31, 2014 Standby Letters of Credit	Oct. 31, 2013 Standby Letters of Credit
Loss Contingencies
Surety bonds	$ 332,100,000		$ 1,200,000
Guarantor Obligations, Maximum Exposure, Undiscounted	36,600,000	31,400,000
Standby letters of credit												115,100,000	100,600,000
Loss contingency amount accrued for probable losses	5,000,000			3,400,000
Amount of reasonably possible losses, Minimum	0
Amount of reasonably possible losses, Maximum	95,800,000
Loss Contingency, estimate of possible loss							94,200,000
Damages sought amount						103,100,000		4,500,000	12,400,000
Payment awarded to plaintiffs					$ 89,700,000					$ 2,500,000	$ 800,000
Number of claim suit filed					3