Share-Based Compensation Arrangement By Share-Based Payment Award, Non-Option Equity Instruments, Purchased

No definition available.

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

- Definition

Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Purchased In Period, Weighted Average Price

+ References

No definition available.

+ Details

Name:	omcl_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsPurchasedInPeriodWeightedAveragePrice
Namespace Prefix:	omcl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-Based Payment Arrangement, Award, Excluding Option, Cost Not Yet Recognized, Amount

+ References

No definition available.

+ Details

Name:	omcl_ShareBasedPaymentArrangementAwardExcludingOptionCostNotYetRecognizedAmount
Namespace Prefix:	omcl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

+ Details

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

- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

+ References

+ Details

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

- Definition

The cash outflow to reacquire common stock during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

Name:	us-gaap_PaymentsForRepurchaseOfCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

+ Details

Name:	us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=omcl_A2016and2014ShareRepurchaseProgramsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=omcl_The2016RepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=omcl_OneTimeStockRepurchaseSeptember2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=omcl_A2009PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=omcl_A1997EmployeeStockPurchasePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefits and Share-Based Compensation - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 17, 2020	Aug. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate purchase price for repurchased shares				$ 53,035,000	$ 0
2016 and 2014 Share Repurchase Programs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining value of shares authorized for repurchase under stock repurchase programs	$ 54,900,000	$ 54,900,000		$ 54,900,000
Number of shares repurchased (in shares)		0	0	0	0
The 2016 Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares authorized for repurchase under stock repurchase programs							$ 50,000,000.0
One-Time Stock Repurchase Transaction
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of shares authorized for repurchase under stock repurchase programs						$ 75,000,000.0
Number of shares repurchased (in shares)	749,300
Average price of repurchased shares (in dollars per share)	$ 70.78
Aggregate purchase price for repurchased shares	$ 53,000,000.0
2009 Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of options granted (in dollars per share)		$ 23.75	$ 21.59	$ 25.30	$ 23.41
Intrinsic value of options exercised		$ 4,100,000	$ 2,700,000	$ 16,500,000	$ 27,000,000.0
Unrecognized compensation cost of unvested stock options	50,400,000	50,400,000		$ 50,400,000
Weighted average period of compensation cost not yet recognized (in years)				2 years 10 months 24 days
2009 Plan \| RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of compensation cost not yet recognized (in years)				3 years 1 month 6 days
Unrecognized compensation cost	40,300,000	40,300,000		$ 40,300,000
2009 Plan \| RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of compensation cost not yet recognized (in years)				7 months 6 days
Unrecognized compensation cost	900,000	900,000		$ 900,000
2009 Plan \| PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of compensation cost not yet recognized (in years)				1 year 2 months 12 days
Unrecognized compensation cost	4,400,000	4,400,000		$ 4,400,000
1997 Plan \| ESPP shares available for future issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of compensation cost not yet recognized (in years)				1 year 6 months
Shares purchased under ESPP (in shares)				333,000	374,000
Weighted-average price of shares purchased (in dollars per share)				$ 48.77	$ 41.44
Unrecognized compensation cost	$ 6,200,000	$ 6,200,000		$ 6,200,000