Equity (Reclassification out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total net unrealized investment gains (losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	$ (54,472)	$ (2,549)	$ (26,998)
Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	(54,472)	(2,549)	(26,998)
Amounts reclassified from AOCI \| Total net unrealized investment gains (losses)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	54,472	2,549	(26,998)
Amounts reclassified from AOCI \| Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from AOCI	54,472	2,549	(26,998)
Amounts reclassified from AOCI \| Net unrealized investment gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized Gain (Loss) on Investments	46,738	(13,340)	28,101
Amounts reclassified from AOCI \| Currency/Interest Rate \| Cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized Gain (Loss) on Investments	$ 7,734	$ 15,889	$ (1,103)

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
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-Publisher FASB
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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 230
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