Accumulated Other Comprehensive Income Level 4 Reclassification of AOCI (Details) - USD ($)	5 Months Ended	7 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized capital gains (losses)	$ (107,000,000)	$ 149,000,000	$ (46,000,000)	$ (135,000,000)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	101,000,000	468,000,000	376,000,000	356,000,000
Income Tax Expense (Benefit)	7,000,000	59,000,000	422,000,000	74,000,000
Net Income (Loss) Attributable to Parent	94,000,000	409,000,000	(46,000,000)	282,000,000
Net Investment Income	520,000,000	509,000,000	1,281,000,000	1,373,000,000
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	3,000,000	(25,000,000)	122,000,000	74,000,000
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized capital gains (losses)	(2,000,000)	(32,000,000)	153,000,000	89,000,000
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(2,000,000)	(32,000,000)	153,000,000	89,000,000
Income Tax Expense (Benefit)	0	(7,000,000)	54,000,000	31,000,000
Net Income (Loss) Attributable to Parent	(2,000,000)	(25,000,000)	99,000,000	58,000,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	6,000,000	0	36,000,000	24,000,000
Income Tax Expense (Benefit)	1,000,000	0	13,000,000	8,000,000
Net Income (Loss) Attributable to Parent	5,000,000	0	23,000,000	16,000,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Interest Rate Swap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other net realized capital gains (losses)	0	0	(1,000,000)	1,000,000
Net Investment Income	8,000,000	0	26,000,000	25,000,000
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Gain (Loss) on Investments [Member] | Cash Flow Hedging [Member] | Currency Swap [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(2,000,000)	0	11,000,000	$ (2,000,000)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Gain (Loss) on Investments [Member] | Cash Flow Hedging [Member] | Currency Swap [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ (2,000,000)	$ 0	$ 11,000,000