Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Income Tax Disclosure [Abstract]
Effective tax rates	31.80%	28.60%	30.60%	23.40%
Discrete tax expense related to nondeductible acquisition costs	$ 2,600
Favorable adjustment to unrecognized tax benefits		$ 1,136
Additional tax benefit relating to retroactive reinstatement of research and development credit				$ 2,025
Additional tax benefit related to dividends paid from foreign earnings tax credit				$ 6,184