Consolidated Variable Interest Entities - Effect of Consolidating FG VIE's on Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Variable Interest Entity [Line Items]
Net earned premiums	$ 162	$ 214	$ 326	$ 397
Net investment income	101	98	223	197
Net realized investment gains (losses)	15	10	47	(3)
Fair value gains (losses) on FG VIEs	12	4	22	22
Loss and LAE	(72)	(102)	(131)	(192)
Income (loss) before income taxes	150	201	522	266
Less: tax provision (benefit)	(3)	55	52	61
Net income (loss)	153	146	470	205
Net cash flows provided by (used in) operating activities			198	(47)
Effect on shareholders' equity (decrease) increase	6,750		6,750		$ 6,504
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Net earned premiums	(4)	(3)	(8)	(8)
Net investment income	(1)	(2)	(2)	(7)
Net realized investment gains (losses)	0	0	0	1
Fair value gains (losses) on FG VIEs	12	4	22	22
Loss and LAE	2	(2)	4	4
Income (loss) before income taxes	9	(3)	16	12
Less: tax provision (benefit)	3	(1)	6	4
Net income (loss)	6	(2)	10	8
Net cash flows provided by (used in) operating activities	5	$ (1)	10	$ 5
Effect on shareholders' equity (decrease) increase	$ 2		$ 2		$ (9)