Auction Rate Securities (Tables)
 12 Months Ended
Oct. 31, 2016
Investments, Debt and Equity Securities [Abstract]  
Significant Assumptions Used to Determine Fair Value of Auction Rate Securities
Significant Assumptions Used to Determine the Fair Values of Our Auction Rate Securities
Assumption
 
October 31, 2016
 
October 31, 2015
Discount rates
 
L + 0.46% and L + 1.30%
 
L + 0.38% – L + 2.13%
Yields
 
2.15%, L + 2.00%
 
2.15%, L + 2.00%
Average expected lives
 
4 – 10 years
 
4 – 10 years

L – One Month LIBOR