Share-Based Compensation - Schedule of Restricted Stock Units to be Settled in Cash (Detail) shares in Thousands	3 Months Ended
Mar. 31, 2020 shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning balance of Outstanding, Restricted Stock Units to be Settled in Cash	82
Restricted Stock Units to be Settled in Cash, Vested	(82)

The number of non-vested equity-based payment instruments which are to be settled in cash, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

No definition available.

Name:	prdo_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonVestedNumberSettledInCash
Namespace Prefix:	prdo_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant