SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions								3 Months Ended		6 Months Ended
	Aug. 02, 2018	Jul. 31, 2018	Jul. 18, 2018	Jun. 28, 2018	Mar. 29, 2018	Jun. 28, 2017	Mar. 29, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Dividends declared per common share								$ 0.32	$ 0.32	$ 0.64	$ 0.64
Date of Shareholders of Record				Jun. 14, 2018	Mar. 15, 2018	Jun. 14, 2017	Mar. 15, 2017
Future policy benefits for life and accident and health insurance contracts								$ 44,608		$ 44,608			$ 45,432
Liability for unpaid losses and loss adjustment expenses								76,713	$ 76,422	76,713	$ 76,422	$ 78,098	$ 78,393	$ 76,050	$ 77,077
Assumed Reinsurance [Member] | DSA Reinsurance Company, Ltd. [Member]
Subsequent Event [Line Items]
Future policy benefits for life and accident and health insurance contracts								31,000		31,000
Liability for unpaid losses and loss adjustment expenses								$ 5,000		$ 5,000
Subsequent event
Subsequent Event [Line Items]
Dividends declared per common share	$ 0.32
Date Dividends Declared	Aug. 02, 2018
Date Dividends To Be Paid	Sep. 28, 2018
Date of Shareholders of Record	Sep. 17, 2018
Subsequent event | Validus Holdings, Ltd. [Member]
Subsequent Event [Line Items]
Payments to Acquire Business			$ 5,500
Subsequent event | TC Group Cayman [Member] | Fortitude Group Holdings, LLC [Member]
Subsequent Event [Line Items]
Interest acquisition		19.90%
Subsequent event | Fortitude Group Holdings, LLC [Member] | DSA Reinsurance Company, Ltd. [Member]
Subsequent Event [Line Items]
Percentage of common stock held after closing of transaction		100.00%
Subsequent event | American International Group, Inc. [Member] | Fortitude Group Holdings, LLC [Member]
Subsequent Event [Line Items]
Percentage of common stock held after closing of transaction		80.10%