Business Dispositions and Discontinued Operations - Reconciliation of the Major Line Items Constituting Pretax Profit (Loss) of Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Benefits, losses and expenses
Income (loss) from discontinued operations, net of tax	$ 322	$ (2,869)	$ 283
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Revenues
Earned premiums	39	106	114
Fee income and other	382	912	931
Net investment income	519	1,289	1,384
Net realized capital losses	(68)	(53)	(158)
Total revenues	872	2,254	2,271
Benefits, losses and expenses
Benefits, losses and loss adjustment expenses	535	1,416	1,390
Amortization of DAC	58	45	146
Insurance operating costs and other expenses	157	368	378
Total benefits, losses and expenses	750	1,829	1,914
Income before income taxes	122	425	357
Income tax expense (benefit)	2	37	74
Income from operations of discontinued operations, net of tax	120	388	283
Discontinued Operation, Amount of Adjustment to Prior Period Gain (Loss) on Disposal, Net of Tax	202	(3,257)	0
Income (loss) from discontinued operations, net of tax	$ 322	$ (2,869)	$ 283