SHORT-TERM AND LONG-TERM DEBT - Schedule Short-term and Long-term Debt (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Short-term and Long-term debt		$ 566	$ 513
Total Short-term and Long-term debt	[1]	$ 769	513
Mortgage debt | 4.1% Non-recourse mortgage debt
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		4.10%
Long-term debt		$ 82	0
Mortgage debt | 3.9% Non-recourse mortgage debt
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		3.90%
Long-term debt		$ 121	0
Revolving credit facility
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		2.40%
Short-term and Long-term debt		$ 75	$ 0
Commercial Paper
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		1.60%	0.90%
Short-term and Long-term debt		$ 491	$ 513

[1] See Note 2 for details of balances with variable interest entities.