Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jan. 31, 2016	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Income Taxes [Line Items]
U.S. Federal statutory tax rate		35.00%	35.00%	35.00%
Discrete tax benefit		$ 1.2	$ 2.9
Increase in uncertain tax positions primarily associated with the BK Medical matter	$ 1.5	1.5
Federal tax credits for R&D		0.4	0.8
Reduction in uncertain tax positions associated with expiration of statute of limitations		0.3	3.4
Other items		0.3	1.0
Provision on reduction of domestic production deduction due to NOL carryback claim			0.3
Undistributed earnings of consolidated foreign subsidiaries		85.9
Unrecognized tax benefits		7.6	6.0	$ 8.1
Unrecognized tax benefits that would impact effective tax rate		2.2
Unrecognized tax benefits, interest on income taxes expense		0.7
Reduction in uncertain tax benefits and accrued interest		0.3
Unrecognized tax benefits, accrued interest and penalties		0.4	0.3
Refundable income tax assets current		3.0	10.4
Increases based on tax positions related to current year		1.8	0.7
Previously Reported
Income Taxes [Line Items]
Unrecognized tax benefits			4.7	$ 6.9
Increases based on tax positions related to current year			$ 0.6
BELGIUM
Income Taxes [Line Items]
Net operating loss carryforwards, not subject to expiration		2.9
DENMARK
Income Taxes [Line Items]
Net operating loss carryforwards, not subject to expiration		8.6
CANADA
Income Taxes [Line Items]
Net operating loss carryforwards, subject to expiration		$ 6.0
Net operating loss carryforwards, expiration year		2024
Tax credit carryforwards		$ 3.0
Tax credit carryforwards, expiration year		2025
State and Local Jurisdiction
Income Taxes [Line Items]
Tax credit carryforwards		$ 14.9
Tax credit carryforwards, expiration year		2021
LUXEMBOURG
Income Taxes [Line Items]
Net operating loss carryforwards, subject to expiration		$ 14.9