Long-Term Obligations Line of Credit Pricing (Details)	12 Months Ended
Dec. 31, 2017
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate Terms	In general, borrowing under the Credit Facility (other than Swingline loans) bears interest, at our option, based on the Base Rate plus applicable margin or the London Interbank Offered Rate ("LIBOR") rate plus applicable margin, as defined below:
Pricing Level I [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage	0.15%
LIBOR Basis Spread on Variable Rate	1.25%
Debt Instrument, Basis Spread on Variable Rate	0.25%
Pricing Level II [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage	0.20%
LIBOR Basis Spread on Variable Rate	1.50%
Debt Instrument, Basis Spread on Variable Rate	0.50%
Pricing Level III [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage	0.25%
LIBOR Basis Spread on Variable Rate	1.75%
Debt Instrument, Basis Spread on Variable Rate	0.75%
Pricing Level IV [Member] [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage	0.30%
LIBOR Basis Spread on Variable Rate	2.00%
Debt Instrument, Basis Spread on Variable Rate	1.00%

LIBOR Basis Spread on Variable Rate

No definition available.

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Namespace Prefix:	icui_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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- 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

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- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=icui_PricingLevelIIMemberMember
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- Details

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- Details

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