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Fair Value Measurements - Unobservable inputs used in determining fair value of embedded derivatives (Details) - Embedded derivatives | 12 Months Ended
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Dec. 31, 2017
Unobservable inputs used by management in determining fair value of embedded derivatives |
Risk margin for uncertainty in cash flows | 0.70%
Minimum |
Unobservable inputs used by management in determining fair value of embedded derivatives |
Adjustment for insurance subsidiary's credit risk | 0.20%
Surrenders | 3.00%
Partial surrenders | 2.00%
Annuitizations | 0.10%
Deaths | 1.60%
Budgeted option costs | 2.40%
Maximum |
Unobservable inputs used by management in determining fair value of embedded derivatives |
Adjustment for insurance subsidiary's credit risk | 2.00%
Surrenders | 23.00%
Partial surrenders | 10.00%
Annuitizations | 1.00%
Deaths | 8.00%
Budgeted option costs | 3.60%

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- Definition Risk associated with risk of default, credit spread risk and downgrade risk, expressed as a percentage, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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