NEW ACCOUNTING PRONOUNCEMENTS AND POLICIES - U.S. TAX REFORM (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2018
Income Tax Expense (Benefit)	$ 1,472	$ 695	$ 2,353	$ 1,558
U.S. Tax Cuts and Jobs Act, Effective 2018
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	135
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Base Rate, Percent							21.00%
Income Tax Expense (Benefit)	628
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	3,800
Deferred Federal Income Tax Expense (Benefit)	$ 3,200
U.S. Tax Cuts and Jobs Act, Effective 2018 | Scenario, Forecast
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					21.00%	28.00%