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.

No definition available.

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- Definition

The carrying value as of the balance sheet date of the estimated valuation allowance to reduce gross premiums receivable to net realizable value.

+ References

Reference 1: 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(5))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5074-111524

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- Definition

The carrying amount as of the balance sheet date due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, net of the allowance for doubtful accounts.

+ 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.(a),5)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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- Definition

Gross amount, as of the balance sheet date, due the entity from (a) agents and insureds, (b) uncollected premiums and (c) others, before deducting the allowance for doubtful accounts.

+ 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 210.7-03.5)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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Premiums Receivable - Premiums Receivable and Agents' Balances (Details) - USD ($) $ in Millions	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	$ 4,697	$ 4,529	$ 4,529
Premium Receivable, Allowance for Credit Loss	(139)	(122)	(145)
Premiums receivable and agents' balances (net of ACL of $139 and $145)	4,558	4,407	4,384
Premiums Receivable, Due in One Year or Less, Excluding Receivables for Loss within a Deductible and Retrospectively-Rated Policy Premiums [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	4,074
Premium Receivable, Allowance for Credit Loss	(98)	(83)	(85)
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	623
Premium Receivable, Allowance for Credit Loss	(41)	$ (39)	$ (60)
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| AAA
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	0
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| AA
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	150
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| A
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	71
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| BBB
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	216
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| BB
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	112
Premiums Receivable, Loss Within a Deductible and Retrospectively-Rated Policy Premiums [Member] \| Below BB
Financing Receivable, Credit Quality Indicator [Line Items]
Premiums Receivable, Gross	$ 74