Related Party Transaction (Details)	Jul. 20, 2018 USD ($)
Related Party Transactions [Abstract]
Fees reimbursed	$ 750,000

Related Party Transaction, Reimbursement Of Fees From The Family

No definition available.

Name:	calm_RelatedPartyTransactionReimbursementOfFeesFromTheFamily
Namespace Prefix:	calm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant