XML 80 R63.htm IDEA: XBRL DOCUMENT
v3.21.2

Acquisitions - Summary Of Briefly Describe the Company's Acquisition Activity (Parenthetical) (Detail) € in Millions, $ in Millions |  |  |  |  |  |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 18, 2020 USD ($) | Dec. 01, 2020 USD ($) | Sep. 01, 2020 USD ($) | Mar. 31, 2020 USD ($) | Mar. 31, 2020 EUR (€) | Oct. 31, 2019 USD ($) | Oct. 31, 2019 EUR (€) | Jul. 19, 2019 USD ($) | Jul. 19, 2019 EUR (€) | Jul. 09, 2019 USD ($) | Oct. 31, 2018 USD ($) | Oct. 31, 2018 EUR (€) | Jun. 30, 2021 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired |  |  |  |  |  |  |  |  |  |  |  |  | $ 290.1 | $ 55.7 | $ 9.1
SunNuclear |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition | Dec. 18, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired | $ 258.1 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dosimetrics |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  | Dec. 01, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired |  | $ 3.0 |  |  |  |  |  |  |  |  |  |  |  |  |
Biodex |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  | Sep. 01, 2020 |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired |  |  | $ 26.9 |  |  |  |  |  |  |  |  |  |  |  |
AWST |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  |  | Mar. 31, 2020 | Mar. 31, 2020 |  |  |  |  |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  |  |  | 100.00% | 100.00% |  |  |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired |  |  |  | $ 26.9 | € 24.5 |  |  |  |  |  |  |  |  |  |
Selmic |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  |  |  |  | Oct. 31, 2019 | Oct. 31, 2019 |  |  |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  |  |  |  |  | 100.00% | 100.00% |  |  |  |  |  |  |  |
Purchase consideration, net of cash acquired |  |  |  |  |  | $ 10.2 | € 9.1 |  |  |  |  |  |  |  |
Premium Analyse |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  |  |  |  |  |  | Jul. 19, 2019 | Jul. 19, 2019 |  |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  |  |  |  |  |  |  | 100.00% | 100.00% |  |  |  |  |  |
Purchase consideration, net of cash acquired |  |  |  |  |  |  |  | $ 8.9 | € 7.9 |  |  |  |  |  |
Capintec |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  |  |  |  |  |  |  |  | Jul. 09, 2019 |  |  |  |  |
Business acquisition, Percentage of voting interests acquired |  |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |
Purchase consideration, net of cash acquired |  |  |  |  |  |  |  |  |  | $ 14.5 |  |  |  |  |
NRG Dosimetry Services Group |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, Effective date of acquisition |  |  |  |  |  |  |  |  |  |  | Oct. 31, 2018 | Oct. 31, 2018 |  |  |
Business acquisition, Percentage of voting interests acquired |  |  |  |  |  |  |  |  |  |  | 100.00% | 100.00% |  |  |
Purchase consideration, net of cash acquired |  |  |  |  |  |  |  |  |  |  | $ 9.1 | € 7.8 |  |  |

X
- Definition Date when the acquirer obtains control of the acquiree, in YYYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=123586518&loc=d3e848-128460 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=123586518&loc=d3e845-128460 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionEffectiveDateOfAcquisition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- 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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_SunnuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_DosimetricsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_BiodexMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_AwstMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_SelmicMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_PremiumAnalyseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_CapintecMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=mir_NrgDosimetryServicesGroupMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |