Quarterly Financial Data (Unaudited) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended			36 Months Ended
	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2017
Interim Period Costs Not Allocable [Line Items]
Severance and restructuring costs				$ 227	$ 6,411	$ 1,714	$ 1,633	$ 1,017	$ 2,438	$ 10,775	$ 11,411	$ 16,660
Discrete tax expense related to nondeductible acquisition costs									$ 1,070
Other expense related to reversal of indemnification asset resulting from effective settlement of tax exam						2,722
Discrete tax benefit related to effective settlement of tax exam						$ 1,651	1,136
Other income on legal settlement.							800
Favorable adjustment to unrecognized tax benefits							$ 1,192			2,682
Additional tax benefit relating to retroactive reinstatement of research and development credit								2,025			$ 2,486
Additional tax benefit related to dividends paid from foreign earnings tax credit								$ 6,184		$ 6,154
Vention [Member]
Interim Period Costs Not Allocable [Line Items]
Severance and restructuring costs	$ 1,017	$ 703	$ 491
Pre-tax acquisition costs	$ 391	$ 865	13,415
Discrete tax expense related to nondeductible acquisition costs			$ 2,600