INVESTMENTS - Other Investments (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Investment [Line Items]
Other investments	[1]	$ 3,402	$ 1,450
Transitional real estate loans
Investment [Line Items]
Other investments		1,235	0
Commercial mortgage loans
Investment [Line Items]
Other investments		908	855
Middle market loans
Investment [Line Items]
Other investments		859	319
Policy loans
Investment [Line Items]
Other investments		210	184
Short-term investments
Investment [Line Items]
Other investments		57	89
Other Investments
Investment [Line Items]
Other investments		$ 133	$ 3

[1] Includes $2,341 in 2017 and $819 in 2016 of loan receivables and limited partnerships from consolidated variable interest entities