Investments - Contract Maturity of The Available-for-sale Securities (Details)	9 Months Ended
Sep. 30, 2022
Investments [Abstract]
One year or less	100.00%
After one year but within two years	0.00%
Total	100.00%

Debt Securities, Available For Sale, Noncurrent, Percent

No definition available.

Name:	xcur_DebtSecuritiesAvailableForSaleNoncurrentPercent
Namespace Prefix:	xcur_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration