CONSOLIDATED CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 73,965	$ 142,098
Other comprehensive income (loss):
Change in net unrealized gains (losses) on investments, net of income tax: (2020 - $(391,653); 2019 - $300,430)	(1,473,362)	1,130,190
Reclassification adjustment for investment amounts included in net income, net of income tax: (2020 - $2,651; 2019 - $(419))	9,972	(1,576)
Change in net unrealized gains (losses) for which a credit loss has been recognized in operations, net of income tax: (2020 - $(1,735))	(6,529)
Change in net unrealized gains (losses) relating to other-than-temporary impaired investments for which a portion has been recognized in earnings, net of income tax: (2019 - $2,337)		8,792
Change in accumulated (loss) gain - derivatives, net of income tax: (2020 - $(1,232); 2019 - $(522))	(4,636)	(1,966)
Reclassification adjustment for derivative amounts included in net income, net of income tax: (2020 - $253; 2019 - $58)	951	220
Total other comprehensive income (loss)	(1,473,604)	1,135,660
Total comprehensive income (loss)	$ (1,399,639)	$ 1,277,758