COMMERCIAL MORTGAGE LOANS - Schedule of Commercial Mortgage Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Allowance for Credit Loss
Allowance for credit losses	$ (173,186)	$ (4,884)
Total Commercial Loans
Total commercial mortgage loans	9,545,793	$ 9,379,401
Commercial Mortgage Loans
Amortized Cost
2020	591,896
2019	2,545,699
2018	1,625,965
2017	1,368,660
2016	961,861
Prior	2,624,898
Amortized cost	9,718,979
Allowance for Credit Loss
2020	(10,132)
2019	(36,008)
2018	(48,449)
2017	(24,083)
2016	(23,702)
Prior	(30,812)
Allowance for credit losses	(173,186)
Total Commercial Loans
2020	581,764
2019	2,509,691
2018	1,577,516
2017	1,344,577
2016	938,159
Prior	2,594,086
Total commercial mortgage loans	9,545,793
Commercial Mortgage Loans \| Debt Service Coverage Ratio, Less than 1.20x
Amortized Cost
2020	567,319
2019	2,271,803
2018	1,227,831
2017	1,102,631
2016	705,564
Prior	2,071,033
Amortized cost	7,946,181
Commercial Mortgage Loans \| Debt Service Coverage Ratio, 1.00x to 1.20x
Amortized Cost
2020	24,577
2019	272,789
2018	295,053
2017	212,063
2016	196,169
Prior	372,406
Amortized cost	1,373,057
Commercial Mortgage Loans \| Debt Service Coverage Ratio, Less than 1.00x
Amortized Cost
2020	0
2019	1,107
2018	103,081
2017	53,966
2016	60,128
Prior	181,459
Amortized cost	399,741
Commercial Mortgage Loans \| Loan-to-Value Ratio, Less than 75%
Amortized Cost
2020	31,134
2019	39,776
2018	106,759
2017	52,056
2016	6,648
Prior	6,121
Amortized cost	242,494
Commercial Mortgage Loans \| Loan-to-Value Ratio, 50% to 75%
Amortized Cost
2020	467,822
2019	1,653,459
2018	1,030,908
2017	1,032,967
2016	794,766
Prior	1,400,615
Amortized cost	6,380,537
Commercial Mortgage Loans \| Loan-to-Value Ratio, Less Than 50%
Amortized Cost
2020	92,940
2019	852,464
2018	488,298
2017	283,637
2016	160,447
Prior	1,218,162
Amortized cost	3,095,948
Performing \| Commercial Mortgage Loans
Amortized Cost
2020	591,896
2019	2,545,699
2018	1,625,965
2017	1,368,660
2016	961,861
Prior	2,624,898
Amortized cost	9,718,979
Non-performing \| Commercial Mortgage Loans
Amortized Cost
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Amortized cost	$ 0

Financing Receivable, after Allowance for Credit Loss, Originated, More than Five Years before Current Fiscal Year

No definition available.

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

- Definition

Financing Receivable, after Allowance for Credit Loss, Year Five, Originated, Four Years before Current Fiscal Year

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, after Allowance for Credit Loss, Year Four, Originated, Three Years before Current Fiscal Year

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, after Allowance for Credit Loss, Year One, Originated, Current Fiscal Year

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, after Allowance for Credit Loss, Year Three, Originated, Two Years before Current Fiscal Year

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, after Allowance for Credit Loss, Year Two, Originated, Fiscal Year before Current Fiscal Year

+ References

No definition available.

+ Details

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

- Definition

Financing Receivable, after Allowance for Credit Losses

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAfterAllowanceForCreditLossesAbstract
Namespace Prefix:	plico_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing Receivable, Allowance for Credit Loss

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForCreditLossAbstract
Namespace Prefix:	plico_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Originated, More than Five Years before Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Year Five, Originated, Four Years before Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesYearFiveOriginatedFourYearsBeforeCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Year Four, Originated, Three Years before Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesYearFourOriginatedThreeYearsBeforeCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Year One, Originated, Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesYearOneOriginatedCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Year Three, Originated, Two Years before Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Allowance For Loans And Lease Losses, Year Two, Originated, Fiscal Year before Current Fiscal Year

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAllowanceForLoansAndLeaseLossesYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear
Namespace Prefix:	plico_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Amortized Cost

+ References

No definition available.

+ Details

Name:	plico_FinancingReceivableAmortizedCostAbstract
Namespace Prefix:	plico_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121581245&loc=d3e21338-158488

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of financing receivable originated more than five years prior to current fiscal year.

+ References

+ Details

Name:	us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable originated four years prior to current fiscal year.

+ References

+ Details

Name:	us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable originated in current fiscal year.

+ References

+ Details

Name:	us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable originated in fiscal year prior to current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919232-210447

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 79
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448

+ Details

Name:	us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable originated three years prior to current fiscal year.

+ References

+ Details

Name:	us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of financing receivable originated two years prior to current fiscal year.

+ References

+ Details

Name:	us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(c))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before allowance for credit loss, of financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 79
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922352-210448

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919230-210447

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 55
-Paragraph 80
-URI http://asc.fasb.org/extlink&oid=121647567&loc=SL82922355-210448

+ Details

Name:	us-gaap_NotesReceivableGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	plico_DebtServiceCoverageAxis=plico_DebtServiceCoverageRatioLessThan120xMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	plico_DebtServiceCoverageAxis=plico_DebtServiceCoverageRatio100xTo120xMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	plico_DebtServiceCoverageAxis=plico_DebtServiceCoverageRatioLessThan100xMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanToValueAxis=plico_DebtToValueRatioLessThan75Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanToValueAxis=plico_DebtToValueRatio50To75Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanToValueAxis=plico_DebtToValueRatioLessThan50Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: