XML 61 R49.htm IDEA: XBRL DOCUMENT
v3.22.4

Notes Payable - Components of Notes Payable (Parenthetical) (Detail) | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Jun. 16, 2021 | Mar. 17, 2021
Series C senior notes [Member] | 3.84% Series C senior notes due in 2022 [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Senior Notes, interest rate | 3.84% | 3.84% |  |
Senior Notes, year of maturity | 2022 | 2022 |  |
Series E senior notes [Member] | 2.35% Series E senior notes due in 2026 [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Senior Notes, interest rate | 2.35% | 2.35% | 2.35% |
Senior Notes, year of maturity | 2026 | 2026 |  |
Series D senior notes [Member] | 2.57% Series D senior notes due in 2028 [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Senior Notes, interest rate | 2.57% | 2.57% |  | 2.57%
Senior Notes, year of maturity | 2028 | 2028 |  |

X
- Definition Debt instrument maturity year. + References No definition available. + Details
Name: | mgrc_DebtInstrumentMaturityYear
Namespace Prefix: | mgrc_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=mgrc_SeriesCSeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mgrc_ThreePointEightFourPercentDueTwoThousandTwentyTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=mgrc_SeriesESeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mgrc_TwoPointThreeFivePercentDueTwoThousandTwentySixMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=mgrc_SeriesDSeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mgrc_TwoPointFiveSevenPercentDueTwoThousandTwentyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |