Note 6 - Loss Per Share (Details Textual) - shares	Dec. 31, 2018	Jun. 30, 2018
Options and Warrants Outstanding	0	35,625

Represents the number of options and warrants to purchase common stock, as of the balance sheet date.

No definition available.

Name:	ctgo_OptionsAndWarrantsOutstanding
Namespace Prefix:	ctgo_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant