Significant Accounting Policies - Summary of Expenses in Special Items (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Disclosure Significant Accounting Policies Summary Of Expenses In Special Items [Abstract]
Impairment/loss on disposal of assets	$ 2.3us-gaap_AssetImpairmentCharges	$ 1.3us-gaap_AssetImpairmentCharges
Consulting and professional fees	63.9zmh_ConsultingAndProfessionalFees	15.0zmh_ConsultingAndProfessionalFees
Employee severance and retention	0.5	0.9
Dedicated project personnel	13.4zmh_DedicatedProjectPersonnel	10.9zmh_DedicatedProjectPersonnel
Certain R&D agreements		4.5
Relocated facilities	0.5zmh_CostOfRelocation	0.7zmh_CostOfRelocation
Contingent consideration adjustments	2.3	0.5
Accelerated software amortization	1.5zmh_AcceleratedSoftwareAmortization	1.5zmh_AcceleratedSoftwareAmortization
Other	2.6	1.3
Special items	$ 87.0zmh_SpecialItems	$ 36.6zmh_SpecialItems

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-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 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

+ Details

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

- Definition

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

+ References

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

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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

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

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Namespace Prefix:	zmh_
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Balance Type:	na
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- Definition

Employee severance and retention including share based compensation acceleration.

+ References

No definition available.

+ Details

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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

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