ACCRUED EXPENSES OTHER CURRENT LIABILITIES (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
ACCRUED EXPENSES OTHER CURRENT LIABILITIES [Abstract]
Reduction in Certain Accrued Expense and Accounts Payable	$ 0.1	$ 0.1

Reduction in Certain Accrued Expense and Accounts Payable

No definition available.

Name:	prpo_ReductionInCertainAccruedExpenseAndAccountsPayable
Namespace Prefix:	prpo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration