Software Development Costs Schedule of Software Development Costs, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule of Software Development Costs [Line Items]
Capitalized Computer Software, Gross	$ 3,226,672	$ 2,995,644
Capitalized Computer Software, Accumulated Amortization	2,226,315	1,986,295
Capitalized Computer Software, Net	1,000,357	1,009,349
Software to sold, leased or marketed [Member]
Schedule of Software Development Costs [Line Items]
Capitalized Computer Software, Gross	2,751,960	2,610,476
Capitalized Computer Software, Accumulated Amortization	1,985,051	1,788,019
Software delivered exclusively as a service [Member]
Schedule of Software Development Costs [Line Items]
Capitalized Computer Software, Gross	474,712	385,168
Capitalized Computer Software, Accumulated Amortization	$ 241,264	$ 198,276

[Line Items] for Schedule of Software Development Costs [Table]

No definition available.

Name:	cern_ScheduleofSoftwareDevelopmentCostsLineItems
Namespace Prefix:	cern_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

+ Details

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

- Definition

Amount before accumulated amortization of capitalized costs for computer software, including but not limited to, acquired and internally developed computer software.

+ References

+ Details

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

- Definition

The carrying amount of capitalized computer software costs net of accumulated amortization as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

+ Details

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

- Details

Name:	cern_SoftwareClassificationAxis=cern_SoftwaretosoldleasedormarketedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	cern_SoftwareClassificationAxis=cern_SoftwaredeliveredexclusivelyasaserviceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: