CONSOLIDATED CONDENSED STATEMENTS OF SHAREOWNER'S EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In-Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2017	$ 8,324,285	$ 2	$ 5,000	$ 7,378,496	$ 916,971	$ 23,816
Increase (decrease) in shareowner's equity
Net income	18,275				18,275
Other comprehensive income (loss)	(571,748)					(571,748)
Total comprehensive income (loss)	(553,473)
Ending Balance at Mar. 31, 2018	7,682,218	2	5,000	7,378,496	857,204	(558,484)
Beginning Balance at Dec. 31, 2017	8,324,285	2	5,000	7,378,496	916,971	23,816
Increase (decrease) in shareowner's equity
Net income	149,067
Other comprehensive income (loss)	(1,196,998)
Total comprehensive income (loss)	(1,047,931)
Ending Balance at Sep. 30, 2018	7,187,760	2	5,000	7,378,496	987,996	(1,183,734)
Beginning Balance at Mar. 31, 2018	7,682,218	2	5,000	7,378,496	857,204	(558,484)
Increase (decrease) in shareowner's equity
Net income	52,268				52,268
Other comprehensive income (loss)	(426,552)					(426,552)
Total comprehensive income (loss)	(374,284)
Ending Balance at Jun. 30, 2018	7,307,934	2	5,000	7,378,496	909,472	(985,036)
Increase (decrease) in shareowner's equity
Net income	78,524				78,524
Other comprehensive income (loss)	(198,698)					(198,698)
Total comprehensive income (loss)	(120,174)
Ending Balance at Sep. 30, 2018	7,187,760	2	5,000	7,378,496	987,996	(1,183,734)
Beginning Balance at Dec. 31, 2018	7,042,788	2	5,000	7,410,537	1,031,465	(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
Total 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	2	5,000	7,410,537	1,031,465	(1,404,216)
Increase (decrease) in shareowner's equity
Net income	486,936
Other comprehensive income (loss)	2,962,999
Total comprehensive income (loss)	3,449,935
Ending Balance at Sep. 30, 2019	11,291,919	2	5,000	8,260,537	1,467,597	1,558,783
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
Total 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
Increase (decrease) in shareowner's equity
Net income	190,424				190,424
Other comprehensive income (loss)	824,448					824,448
Total comprehensive income (loss)	1,014,872
Ending Balance at Sep. 30, 2019	$ 11,291,919	$ 2	$ 5,000	$ 8,260,537	$ 1,467,597	$ 1,558,783