Investments - Net Investment Gains (Losses) By Transaction Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Impairment write-downs	$ (1,105)	$ 0	$ (1,778)
Change in intent write-downs	(275)	(1,530)	(10,842)
Net OTTI losses recognized in earnings	(1,380)	(1,530)	(12,620)
Sales and other, net	151,495	3,491	7,756
Change in fair value - equity securities	7,308	(18,323)	0
Change in fair value and gains realized on settlements - derivatives	(4,083)	3,819	1,458
Total	$ 153,340	$ (12,543)	$ (3,406)