Fair Value Measures (Narrative) (Details) $ in Thousands	Jun. 01, 2019 USD ($)
Fair Value Disclosures [Abstract]
Adverse effect on fair value of debt from 1% change in interest rate	$ 23

Fair Value Sensitivity To One Percentage Change In Interest Rates

No definition available.

Name:	calm_FairValueSensitivityToOnePercentageChangeInInterestRates
Namespace Prefix:	calm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant