Terms of insurance policies and contracts.

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Summary of significant accounting policies.

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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No definition available.

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- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

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The increase (decrease) during the reporting period in the value of expenditures made during the current reporting period for benefits that will be received over a period of years. Deferred charges differ from prepaid expenses in that they usually extend over a long period of time and may or may not be regularly recurring costs of operation.

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The increase (decrease) during the reporting period in the account that represents the temporary difference that results from Income or Loss that is recognized for accounting purposes but not for tax purposes and vice versa.

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The increase (decrease) during the reporting period, excluding the portion taken into income, in the liability reflecting revenue yet to be earned for which cash or other forms of consideration was received or recorded as a receivable.

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)			3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 01, 2018	Oct. 02, 2015	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Summary Of Significant Accounting Policies [Line Items]
Cash proceeds from sale of business						$ 0	$ 0	$ 2,317,000,000
Gain on sale of commercial finance business						0	0	197,000,000
Embedded derivatives			$ 0			0	0
Increase in deferred tax assets						$ 2,578,000,000	$ 3,000,000	$ (531,000,000)
Effective income tax rate reconciliation, at federal statutory income tax rate, percent			21.00%	35.00%		31.60%	35.00%	35.00%
Scenario, Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Effective income tax rate reconciliation, at federal statutory income tax rate, percent					21.00%
Accounting Standards Update 2014-05 [Member] \| Subsequent Event [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of adoption of the guidance, reduction in retained earnings	$ 110,000,000
Increase in unearned revenue	219,000,000
Increase in deferred expenses	73,000,000
Increase in deferred tax assets	$ 36,000,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Insurance Policy Term						3 months
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Insurance Policy Term						120 months
Sale of Commercial Finance Business [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash proceeds from sale of business		$ 2,300,000,000
Gain on sale of commercial finance business		$ 197,000,000
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Finance Operations [Member] \| California [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						22.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Finance Operations [Member] \| Texas [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						11.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Finance Operations [Member] \| New York [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						8.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Finance Operations [Member] \| New Jersey [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						5.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Insurance Operations [Member] \| California [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						26.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Insurance Operations [Member] \| New York [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						6.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Insurance Operations [Member] \| New Jersey [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						5.00%
Geographic Concentration Risk [Member] \| Sales Revenue, Net [Member] \| Insurance Operations [Member] \| Maryland [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration Percentage						5.00%