SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Guaranteed Living Withdrawal Benefits (Details) $ in Millions	Dec. 31, 2017 USD ($)
Guaranteed living withdrawal benefits (GLWB)
Guaranteed Minimum Withdrawal Benefits
Guaranteed living withdrawal benefits liability held, net	$ 15.5

Represents the amount of expected guaranteed benefits in short of the projected account balances for minimum guaranteed benefit contracts, net of reinsurance recoverables, as of the balance sheet date.

No definition available.

Name:	plico_LiabilitiesForGuaranteesOnLongDurationContractsGuaranteedBenefitAssetNet
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant