INVESTMENTS (OTTI Recognized in Earnings by Asset Class) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Gain (Loss) on Securities [Line Items]
Total OTTI recognized in net income	$ 1,458	$ 5,546	$ 6,328	$ 7,634
Non-U.S. government
Gain (Loss) on Securities [Line Items]
Total OTTI recognized in net income	30	4,426	90	4,448
Corporate debt
Gain (Loss) on Securities [Line Items]
Total OTTI recognized in net income	1,428	1,079	6,238	3,145
CMBS
Gain (Loss) on Securities [Line Items]
Total OTTI recognized in net income	$ 0	$ 41	$ 0	$ 41