Significant Accounting Policies - Summary of Expenses in Special Items (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure Significant Accounting Policies Summary Of Expenses In Special Items [Abstract]
Impairment/loss on disposal of assets	$ 32.4us-gaap_OtherAssetImpairmentCharges	$ 10.9us-gaap_OtherAssetImpairmentCharges	$ 14.6us-gaap_OtherAssetImpairmentCharges
Consulting and professional fees	176.7zmh_ConsultingAndProfessionalFees	99.1zmh_ConsultingAndProfessionalFees	90.1zmh_ConsultingAndProfessionalFees
Employee severance and retention, including share-based compensation acceleration	0.9	14.2	8.2
Dedicated project personnel	50.8zmh_DedicatedProjectPersonnel	34.0zmh_DedicatedProjectPersonnel	15.1zmh_DedicatedProjectPersonnel
Certain R&D agreements	4.5	0.8
Relocated facilities	0.7zmh_CostOfRelocation	3.6zmh_CostOfRelocation	1.8zmh_CostOfRelocation
Distributor acquisitions	0.6zmh_DistributorAcquisitions	0.4zmh_DistributorAcquisitions	0.8zmh_DistributorAcquisitions
Certain litigation matters	70.0	26.9	13.7
Contract terminations	6.2zmh_ContractTerminations	3.9zmh_ContractTerminations	6.6zmh_ContractTerminations
Contingent consideration adjustments	0.6	9.0	(2.8)
Accelerated software amortization	6.0zmh_AcceleratedSoftwareAmortization	6.0zmh_AcceleratedSoftwareAmortization	4.5zmh_AcceleratedSoftwareAmortization
Other	7.1	7.9	2.8
Special items	$ 356.5zmh_SpecialItems	$ 216.7zmh_SpecialItems	$ 155.4zmh_SpecialItems

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 30

-Section 50

-Paragraph 4

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e7008-128479

+ Details

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The charge against earnings resulting from the write down of long lived assets other than goodwill due to the difference between the carrying value and lower fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230

+ Details

Name:	us-gaap_OtherAssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Accelerated software amortization expense resulting from decreasing the estimated life of certain software.

+ References

No definition available.

+ Details

Name:	zmh_AcceleratedSoftwareAmortization
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Consulting and professional fees incurred as part of our Special Items expense.

+ References

No definition available.

+ Details

Name:	zmh_ConsultingAndProfessionalFees
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expenses related to certain contract terminations.

+ References

No definition available.

+ Details

Name:	zmh_ContractTerminations
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Moving and lease-related expenses associated with relocating certain facilities.

+ References

No definition available.

+ Details

Name:	zmh_CostOfRelocation
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Salary, benefits, travel costs and other costs associated with employees who are working on quality and operational excellence initiatives or integration of acquired businesses.

+ References

No definition available.

+ Details

Name:	zmh_DedicatedProjectPersonnel
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	zmh_DisclosureSignificantAccountingPoliciesSummaryOfExpensesInSpecialItemsAbstract
Namespace Prefix:	zmh_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Distributor acquisitions.

+ References

No definition available.

+ Details

Name:	zmh_DistributorAcquisitions
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Employee severance and retention including share based compensation acceleration.

+ References

No definition available.

+ Details

Name:	zmh_EmployeeSeveranceAndRetentionIncludingShareBasedCompensationAcceleration
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Upfront payments to acquire intellectual property to be used in R&D projects that have no alternative future use.

+ References

No definition available.

+ Details

Name:	zmh_ExpensesRecognizedFromCertainResearchAndDevelopmentAgreements
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expenses related to certain legal matters for estimated or actual settlements.

+ References

No definition available.

+ Details

Name:	zmh_IncreaseDecreaseInCertainLitigationMatters
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Other expenses related to our quality and operational excellence initiatives, acquisition or integration of business, or other certain items.

+ References

No definition available.

+ Details

Name:	zmh_OtherAcquisitionIntegrationRealignmentAndOther
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Special items expenses related to quality and operational excellence initiatives, acquisition and integration costs of acquired businesses, and other certain items.

+ References

No definition available.

+ Details

Name:	zmh_SpecialItems
Namespace Prefix:	zmh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration