FAIR VALUE MEASUREMENTS (Details - Quantitative Information about Level 3 Fair Value Measurements, Assets)) - Discounted cash flow - Level 3 - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Corporate debt
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 1,638	$ 1,086
Corporate debt | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.74%	3.26%
Corporate debt | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	13.88%	12.22%
Corporate debt | Weighted-average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	9.31%	7.74%
Residential mortgage-backed securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 15,679	$ 16,156
Residential mortgage-backed securities | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	2.99%	2.73%
Constant prepayment rate	3.71%	3.97%
Loss severity	40.73%	43.15%
Constant default rate	3.23%	3.31%
Residential mortgage-backed securities | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	5.33%	5.19%
Constant prepayment rate	12.82%	13.42%
Loss severity	75.96%	77.15%
Constant default rate	8.25%	8.30%
Residential mortgage-backed securities | Weighted-average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.16%	3.96%
Constant prepayment rate	8.27%	8.69%
Loss severity	58.34%	60.15%
Constant default rate	5.74%	5.80%
Certain CDO/ABS
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 5,200	$ 5,254
Certain CDO/ABS | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	3.69%	3.38%
Certain CDO/ABS | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.99%	4.78%
Certain CDO/ABS | Weighted-average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.34%	4.08%
Commercial mortgage backed securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 456	$ 487
Commercial mortgage backed securities | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	2.82%	2.22%
Commercial mortgage backed securities | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	6.34%	7.77%
Commercial mortgage backed securities | Weighted-average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.58%	4.99%
Obligations of states, municipalities and political subdivisions
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 1,571	$ 1,620
Obligations of states, municipalities and political subdivisions | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	3.82%	3.55%
Obligations of states, municipalities and political subdivisions | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.51%	4.32%
Obligations of states, municipalities and political subdivisions | Weighted-average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Yield	4.16%	3.94%