POLICY LIABILITIES - Changes in Liability for Unpaid Policy Claims (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Liability for Unpaid Claims and Claims Expenses
Net balance, beginning of period			$ 4,045
Less claims paid during the period on claims incurred during:
Net balance, end of period	$ 4,281		4,281
Total liability for unpaid policy claims	4,281	$ 4,259	4,281	$ 4,259
Health insurance
Liability for Unpaid Claims and Claims Expenses
Unpaid supplemental health claims, beginning of period	3,854	3,710	3,707	3,548
Less reinsurance recoverables	30	28	27	26
Net balance, beginning of period	3,824	3,682	3,680	3,522
Add claims incurred during the period related to:
Current year	1,772	1,790	3,520	3,498
Prior years	(138)	(81)	(260)	(229)
Total incurred	1,634	1,709	3,260	3,269
Less claims paid during the period on claims incurred during:
Current year	1,220	1,266	1,721	1,748
Prior years	400	412	1,461	1,469
Total paid	1,620	1,678	3,182	3,217
Effect of foreign exchange rate changes on unpaid claims	4	198	84	337
Net balance, end of period	3,842	3,911	3,842	3,911
Add reinsurance recoverables	30	30	30	30
Total liability for unpaid policy claims	3,872	3,941	3,872	3,941
Life insurance
Less claims paid during the period on claims incurred during:
Total liability for unpaid policy claims	$ 409	$ 318	$ 409	$ 318