Equity (With Allowance and All Other Net Unrealized Investment Gains (Losses) in AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	$ 428,612
Ending Balance	1,533,059	$ 428,612
Accumulated Other Comprehensive Income (Loss) Related to Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	429,546	(323,295)	$ (90,117)
Cumulative effect of adoption of ASU 2016-01			(3)
Cumulative effect of adoption of ASU 2018-02			(36,712)
Ending Balance	1,533,767	429,546	(323,295)
All Other \| Accumulated Net Unrealized Investment Gain (Loss) Pre Tax All Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	722,621	(413,575)	(71,723)
Net unrealized investment gains (losses) on investments arising during the period		1,139,167	(405,264)
Reclassification adjustment for (gains) losses included in net income		(3,023)	63,175
Reclassification adjustment for OTTI losses excluded from net income(1)		52	241
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs		0	0
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities		0	0
Cumulative effect of adoption of ASU 2016-01			(4)
Cumulative effect of adoption of ASU 2018-02			0
Ending Balance		722,621	(413,575)
All Other \| Deferred Costs Policy Acquisition and Other Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(154,976)	8,505	(82,212)
Net unrealized investment gains (losses) on investments arising during the period		0	0
Reclassification adjustment for (gains) losses included in net income		0	0
Reclassification adjustment for OTTI losses excluded from net income(1)		0	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs		(163,481)	90,717
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities		0	0
Cumulative effect of adoption of ASU 2016-01			0
Cumulative effect of adoption of ASU 2018-02			0
Ending Balance		(154,976)	8,505
All Other \| Future Policy Benefits and Other Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(35,864)	1,113	(16,997)
Net unrealized investment gains (losses) on investments arising during the period		0	0
Reclassification adjustment for (gains) losses included in net income		0	0
Reclassification adjustment for OTTI losses excluded from net income(1)		0	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs		0	0
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities		(36,977)	18,110
Cumulative effect of adoption of ASU 2016-01			0
Cumulative effect of adoption of ASU 2018-02			0
Ending Balance		(35,864)	1,113
All Other \| Deferred Income Tax (Liability) Benefit
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	(111,572)	85,156	72,932
Net unrealized investment gains (losses) on investments arising during the period		(239,496)	85,105
Reclassification adjustment for (gains) losses included in net income		636	(13,267)
Reclassification adjustment for OTTI losses excluded from net income(1)		(11)	(51)
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs		34,369	(19,049)
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities		7,774	(3,803)
Cumulative effect of adoption of ASU 2016-01			1
Cumulative effect of adoption of ASU 2018-02			(36,712)
Ending Balance		(111,572)	85,156
All Other \| Accumulated Other Comprehensive Income (Loss) Related to Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	420,209	(318,801)	(98,000)
Net unrealized investment gains (losses) on investments arising during the period		899,671	(320,159)
Reclassification adjustment for (gains) losses included in net income		(2,387)	49,908
Reclassification adjustment for OTTI losses excluded from net income(1)		41	190
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs		(129,112)	71,668
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities		(29,203)	14,307
Cumulative effect of adoption of ASU 2016-01			(3)
Cumulative effect of adoption of ASU 2018-02			(36,712)
Ending Balance		420,209	(318,801)
With Allowance and All Other \| Accumulated Net Unrealized Investment Gain (Loss) Pre-Tax with Allowance [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	0	0	0
Reclassification due to implementation of ASU 2016-13	0
Net unrealized investment gains (losses) on investments arising during the period	59	0	0
Reclassification adjustment for (gains) losses included in net income	3	0	0
Reclassification adjustment for OTTI losses excluded from net income(1)		0	0
Reclassification due to allowance for credit losses recorded during period	(60)
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	0	0	0
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	0	0	0
Cumulative effect of adoption of ASU 2016-01			0
Cumulative effect of adoption of ASU 2018-02			0
Ending Balance	2	$ 0	$ 0
With Allowance and All Other \| Accumulated Net Unrealized Investment Gain (Loss) Pre Tax All Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification due to implementation of ASU 2016-13	14,309
Net unrealized investment gains (losses) on investments arising during the period	1,623,552
Reclassification adjustment for (gains) losses included in net income	8,565
Reclassification due to allowance for credit losses recorded during period	60
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	0
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	0
Ending Balance	2,369,107
With Allowance and All Other \| Deferred Costs Policy Acquisition and Other Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification due to implementation of ASU 2016-13	(1,199)
Net unrealized investment gains (losses) on investments arising during the period	0
Reclassification adjustment for (gains) losses included in net income	0
Reclassification due to allowance for credit losses recorded during period	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	(207,254)
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	0
Ending Balance	(363,429)
With Allowance and All Other \| Future Policy Benefits and Other Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification due to implementation of ASU 2016-13	(119)
Net unrealized investment gains (losses) on investments arising during the period	0
Reclassification adjustment for (gains) losses included in net income	0
Reclassification due to allowance for credit losses recorded during period	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	0
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	(27,176)
Ending Balance	(63,159)
With Allowance and All Other \| Deferred Income Tax (Liability) Benefit
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification due to implementation of ASU 2016-13	(3,654)
Net unrealized investment gains (losses) on investments arising during the period	(341,050)
Reclassification adjustment for (gains) losses included in net income	(1,800)
Reclassification due to allowance for credit losses recorded during period	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	43,613
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	5,709
Ending Balance	(408,754)
With Allowance and All Other \| Accumulated Other Comprehensive Income (Loss) Related to Net Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification due to implementation of ASU 2016-13	9,337
Net unrealized investment gains (losses) on investments arising during the period	1,282,561
Reclassification adjustment for (gains) losses included in net income	6,768
Reclassification due to allowance for credit losses recorded during period	0
Impact of net unrealized investment (gains) losses on deferred policy acquisition costs and other costs	(163,641)
Impact of net unrealized investment (gains) losses on future policy benefits and other liabilities	(21,467)
Ending Balance	$ 1,533,767

Cumulative effect of adoption of ASU 2016-01

No definition available.

Name:	cik881453_CumulativeEffectOfAdoptionOfASU201601
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Cumulative effect of adoption of ASU 2018-02

+ References

No definition available.

+ Details

Name:	cik881453_CumulativeEffectOfAdoptionOfASU201802
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Noncredit portion of impairment losses on debt securities reclassified to OCI for those securities that meet the criteria to have impairment losses bifurcated between net income (credit losses) and OCI (noncredit losses).

+ References

No definition available.

+ Details

Name:	cik881453_NonCreditPortionOfOtherThanTemporaryImpairmentsOfDebtReclassificationRecognizedInOtherComprehensiveIncome
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Other Comprehensive Income for Unrealized Investment Gain Loss related to Policyholder's account balance Arising during the Period Net of Tax

+ References

No definition available.

+ Details

Name:	cik881453_OtherComprehensiveIncomeForUnrealizedInvestmentGainLossRelatedToPolicyholdersAccountBalanceArisingDuringPeriodNetOfTax
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Other Comprehensive Income for Unrealized Investment (Gain) Loss related to deferred policy acquisition costs, deferred sales inducements and valuation of business acquired Arising during the Period Net of Tax

+ References

No definition available.

+ Details

Name:	cik881453_OtherComprehensiveIncomeUnrealizedInvestmentGainLossOnDeferredCostsPolicyAcquisitionAndSalesInducementsAndValuationOfBusinessAcquiredArisingDuringPeriodNetOfTax
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reclassification due to allowance for credit losses recorded during period

+ References

No definition available.

+ Details

Name:	cik881453_ReclassificationDueToAllowanceForCreditLossesRecordedDuringPeriod
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Reclassification due to implementation of ASU 2016-13

+ References

No definition available.

+ Details

Name:	cik881453_ReclassificationDueToImplementationOfASU201613
Namespace Prefix:	cik881453_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30)(a)(4))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(a)(3))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 40
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-URI http://asc.fasb.org/extlink&oid=121370832&loc=SL117420844-207641

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e681-108580

+ Details

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

- Definition

Amount after tax of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e689-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL34724391-108580

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount, after tax and before adjustment, of unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

+ Details

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

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=cik881453_OtherNetUnrealizedInvestmentGainsAndLossesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=cik881453_AccumulatedNetUnrealizedInvestmentGainLossPreTaxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=cik881453_DeferredCostsPolicyAcquisitionAndSalesInducementsAndValuationOfBusinessAcquiredPreTaxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=cik881453_PolicyholdersAccountBalancesPreTaxMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=cik881453_DeferredIncomeTaxLiabilityBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=cik881453_NetUnrealizedInvestmentGainsAndLossesOnAvailableForSaleFixedMaturitySecuritiesOnWhichAnAllowanceForCreditLossesHasBeenRecognizedAndAllOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AociGainLossDebtSecuritiesAvailableForSaleWithAllowanceForCreditLossParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: