DERIVATIVE FINANCIAL INSTRUMENTS - Realized Investment Gains and Losses for the Modco Trading Portfolio that is Included in Realized Investment Gains (Losses) - All Other Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Realized investment gains (losses) - all other investments
Modco trading portfolio	$ 18,552	$ 78,154