XML 24 R32.htm IDEA: XBRL DOCUMENT v3.20.1

Dividends (Narrative) (Details) - $ / shares			3 Months Ended		6 Months Ended
	Jan. 16, 2020	Oct. 17, 2019	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock			$ 0.165	$ 0.165	$ 0.33	$ 0.33
Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock			$ 0.150	$ 0.150	$ 0.30	$ 0.30
Dividend I [Member]
Dividends Payable [Line Items]
Dividend payment date					Oct. 17, 2019
Dividend record date					Oct. 10, 2019
Dividend I [Member] | Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock		$ 0.165
Dividend I [Member] | Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock		$ 0.15
Dividend II [Member]
Dividends Payable [Line Items]
Dividend payment date					Jan. 16, 2020
Dividend record date					Jan. 09, 2020
Dividend II [Member] | Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock	$ 0.165
Dividend II [Member] | Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock	$ 0.15

X

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: 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=27012166&loc=d3e187085-122770

+ Details

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

X

- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DividendsAxis=imkta_Dividend1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DividendsAxis=imkta_Dividend2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: