Equity - Regulatory Capital Requirements, Additional Information (Details)	Dec. 31, 2017	Dec. 31, 2016
Property and Casualty Insurance Subsidiaries
Statutory Accounting Practices [Line Items]
RBC company action level	300.00%	300.00%
Health, life and annuity subsidiaries
Statutory Accounting Practices [Line Items]
RBC company action level	300.00%	300.00%

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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