- Definition

Represents the number of reinsurers to which the entity has ceded a specified percentage of the aggregate face value of life insurance in-force.

+ References

No definition available.

+ Details

Name:	pl_LifeInsuranceInForceConcentrationOfReinsurersNumber
Namespace Prefix:	pl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the stated amount that is the upper retention limit per entity policy, before revision.

+ References

No definition available.

+ Details

Name:	pl_ReinsuranceRetentionPolicyAmountRetainedBeforeRevision
Namespace Prefix:	pl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the amount of insurance retained by the entity on the life of any one person for certain traditional and universal life products.

+ References

No definition available.

+ Details

Name:	pl_ReinsuranceRetentionPolicyAmountRetainedCertainTraditionalAndUniversalLifeProducts
Namespace Prefix:	pl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Stated amount that is the upper retention limit per entity policy.

+ References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceRetentionPolicyAmountRetained
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceRetentionPolicyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of risk reinsured on insurance products per entity policy.

+ References

No definition available.

+ Details

Name:	us-gaap_ReinsuranceRetentionPolicyReinsuredRiskPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ReinsurancePolicyTypeAxis=pl_SingleInsuredLifeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_ReinsurerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

REINSURANCE - Additional Information (Details)	12 Months Ended
REINSURANCE - Additional Information (Details)	Dec. 31, 2017 insurer	Dec. 31, 2016 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2005 USD ($)
REINSURANCE
Percentage of the face value of life insurance in-force reinsured	38.00%
Single insured life
REINSURANCE
Amount of insurance retained before revision - certain newly issued traditional life products				$ 500,000
Amount of insurance retained - certain newly issued traditional life products			$ 2,000,000	$ 1,000,000
Amount of insurance retained - certain traditional and universal life products		$ 5,000,000
Reinsurer Concentration Risk
REINSURANCE
Percentage of the face value of life insurance in-force reinsured	16.00%
Life insurance in-force reinsured, concentrated number of reinsurers \| insurer	3