Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Income Tax Disclosure [Abstract]
Effective income tax rate reconciliation, before discrete items, percent	44.20%	41.90%
Re-measurement of certain unrecognized tax benefits	$ 3.4		$ 3.4
Tax deductions for energy efficient government buildings	$ 1.8		$ 1.8
Effective income tax rate reconciliation, percent			9.40%	41.60%
Tax Credit			$ 4.8
State employment-based tax credits			$ 2.5