CONSOLIDATED CONDENSED STATEMENTS OF SHAREOWNER'S EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect Adjustment	Preferred Stock	Common Stock	Additional Paid-In-Capital	Retained Earnings	Retained Earnings Cumulative Effect Adjustment	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2018	$ 7,042,788	$ (50,804)	$ 2	$ 5,000	$ 7,410,537	$ 1,031,465	$ (50,804)	$ (1,404,216)
Increase (decrease) in shareowner's equity
Net income	142,098					142,098
Other comprehensive income (loss)	1,135,660							1,135,660
Comprehensive income (loss)	1,277,758
Ending Balance at Mar. 31, 2019	8,269,742		2	5,000	7,410,537	1,122,759		(268,556)
Beginning Balance at Dec. 31, 2018	7,042,788	(50,804)	2	5,000	7,410,537	1,031,465	(50,804)	(1,404,216)
Increase (decrease) in shareowner's equity
Net income	296,512
Other comprehensive income (loss)	2,138,551
Comprehensive income (loss)	2,435,063
Ending Balance at Jun. 30, 2019	10,277,047		2	5,000	8,260,537	1,277,173		734,335
Beginning Balance at Mar. 31, 2019	8,269,742		2	5,000	7,410,537	1,122,759		(268,556)
Increase (decrease) in shareowner's equity
Net income	154,414					154,414
Other comprehensive income (loss)	1,002,891							1,002,891
Comprehensive income (loss)	1,157,305
Capital contributions from parent	850,000				850,000
Ending Balance at Jun. 30, 2019	10,277,047		2	5,000	8,260,537	1,277,173		734,335
Beginning Balance at Dec. 31, 2019	11,206,826	(138,100)	2	5,000	8,260,537	1,533,645	(138,100)	1,407,642
Increase (decrease) in shareowner's equity
Net income	73,965					73,965
Other comprehensive income (loss)	(1,473,604)							(1,473,604)
Comprehensive income (loss)	(1,399,639)
Ending Balance at Mar. 31, 2020	9,669,087		2	5,000	8,260,537	1,469,510		(65,962)
Beginning Balance at Dec. 31, 2019	11,206,826	$ (138,100)	2	5,000	8,260,537	1,533,645	$ (138,100)	1,407,642
Increase (decrease) in shareowner's equity
Net income	239,070
Other comprehensive income (loss)	808,827
Comprehensive income (loss)	1,047,897
Ending Balance at Jun. 30, 2020	12,116,623		2	5,000	8,260,537	1,634,615		2,216,469
Beginning Balance at Mar. 31, 2020	9,669,087		2	5,000	8,260,537	1,469,510		(65,962)
Increase (decrease) in shareowner's equity
Net income	165,105					165,105
Other comprehensive income (loss)	2,282,431							2,282,431
Comprehensive income (loss)	2,447,536
Ending Balance at Jun. 30, 2020	$ 12,116,623		$ 2	$ 5,000	$ 8,260,537	$ 1,634,615		$ 2,216,469