Nonqualified Deferred Compensation Plan - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Sep. 27, 2014	Sep. 28, 2013	Sep. 29, 2012
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Mutual funds	$ 15.4	$ 6.9
Gen-Probe Incorporated [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Discretionary contribution, net of forfeitures	35.8	38.6
Nonqualified Deferred Compensation Plan [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Maximum employee contributions from base salary, percentage	75.00%
Maximum employee contributions from annual bonus, percentage	100.00%
Employee contributions vested, percentage	100.00%
Contributions, vesting period, years	3 years
Compensation expense for the DCP discretionary contributions	3.7	2.7	2.6
Investment in group life insurance contracts	$ 22.4	$ 33.9

Employee contributions vested, percentage.

No definition available.

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Namespace Prefix:	holx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The vesting period for discretionary employer contributions, which vest ratably on an annual basis.

No definition available.

Name:	holx_EmployerContributionsVestingPeriod
Namespace Prefix:	holx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Cash surrender value of group life insurance contracts at the balance sheet date.

No definition available.

Name:	holx_InvestmentInGroupLifeInsuranceContracts
Namespace Prefix:	holx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Maximum employee contributions from annual bonus percentage to dcp.

No definition available.

Name:	holx_MaximumEmployeeContributionsFromAnnualBonusPercentageToDcp
Namespace Prefix:	holx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Maximum employee contributions from base salary percentage to dcp.

No definition available.

Name:	holx_MaximumEmployeeContributionsFromBaseSalaryPercentageToDcp
Namespace Prefix:	holx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Mutual Funds

No definition available.

Nonqualified deferred compensation plan annual contribution.

No definition available.

Name:	holx_NonqualifiedDeferredCompensationPlanAnnualContribution
Namespace Prefix:	holx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the company's liability as of the balance sheet date for its nonqualified deferred compensation plan.

No definition available.

Name:	holx_NonqualifiedDeferredCompensationPlanLiability
Namespace Prefix:	holx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Name:	us-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration