Name:	omcl_PercentileRankingOf2011ShareholderReturn
Namespace Prefix:	omcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

PSU percentage eligible for time-based vesting = the percentage of the original PSU award which will continue with service-based vesting based on the percentile ranking against total stock performance in the reference year for the health care index.

No definition available.

Name:	omcl_PsuPercentageEligibleForTimeBasedVesting
Namespace Prefix:	omcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

PSU percentage eligible for vesting based on actual return = percentage of original PSU awards that continue under service-based vesting, based on percentile performance in the grant year for Total Shareholder Return

No definition available.

Name:	omcl_PsuPercentageEligibleForVestingBasedOnActualReturn
Namespace Prefix:	omcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

PSU shares eligible for vesting based on actual shareholder return = No. of PSU shares that continue with service-based vesting, based on percentile performance of Total shareholder return in the calendar year of grant.

No definition available.

Name:	omcl_PsuSharesEligibleForVestingBasedOnActualShareholderReturn
Namespace Prefix:	omcl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Share-based Compensation Arrangement by Share-based Payment Award, First Year Share Vesting Rate

No definition available.

Name:	omcl_ShareBasedCompensationArrangementByShareBasedPaymentAwardFirstYearShareVestingRate
Namespace Prefix:	omcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Share-based Compensation Arrangement By Share-based Payment Award, Number Of Shares Eligible For Vesting

No definition available.

Name:	omcl_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesEligibleForVesting
Namespace Prefix:	omcl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

share-based compensation arrangement by share-based payment award, number of shares vested for the period

No definition available.

Name:	omcl_Sharebasedcompensationarrangementbysharebasedpaymentawardnumberofsharesvestedfortheperiod
Namespace Prefix:	omcl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Trading days considered in shareholder return calc = the number of trading days considered for the beginning point and ending point for the calendar year Total Shareholder return calcualtion

No definition available.

Name:	omcl_TradingDaysConsideredInShareholderReturnCalc
Namespace Prefix:	omcl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

No definition available.

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901