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

Period for remaining award to vest semi-annually = after first year cliff vesting, the remaining period over which vesting will occur in semi-annual tranches through the end of the required service period.

No definition available.

Name:	omcl_PeriodForRemainingAwardToVestSemiAnnually
Namespace Prefix:	omcl_
Data Type:	us-types:durationStringItemType
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, Percent Vested in First Year = Cliff vesting after 12 months for the first year of service under the award

No definition available.

Name:	omcl_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentVestedInFirstYear
Namespace Prefix:	omcl_
Data Type:	num:percentItemType
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.