SIGNIFICANT ACCOUNTING POLICIES - Impact of New Accounting Pronouncements (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 8,824		$ 9,010	$ 5,978
Noncontrolling interest	$ 3,088		$ 3,095	$ 3,046
Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Equity securities, fair value		$ 13
Difference Between Revenue Guidance In Effect Before And After Topic 606 | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		8
Noncontrolling interest		25
Noncontrolling interest, cumulative contributions received		78
Noncontrolling interest, cumulative contributions paid		$ 43