CONSOLIDATED STATEMENTS OF SHAREOWNER'S EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings (Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2015	$ 5,187,477	$ 2	$ 5,000	$ 6,274,169	$ 154,697	$ (1,246,391)
Increase (decrease) in shareowner's equity
Net income	352,608				352,608
Other comprehensive income	591,351					591,351
Comprehensive income	943,959
Dividends paid to the parent company	(540,000)				(540,000)
Capital contributions	1,148,238			1,148,238
Balance at Dec. 31, 2016	6,739,674	2	5,000	7,422,407	(32,695)	(655,040)
Increase (decrease) in shareowner's equity
Net income	1,182,417				1,182,417
Other comprehensive income	705,194					705,194
Comprehensive income	1,887,611
Cumulative effect adjustments	0				26,338	(26,338)
Dividends paid to the parent company	(259,089)				(259,089)
Return of capital	(43,911)			(43,911)
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	193,927				193,927
Other comprehensive income	(1,417,480)					(1,417,480)
Comprehensive income	(1,223,553)
Cumulative effect adjustments						(10,552)
Prior period adjustment	32,041			32,041
Balance at Dec. 31, 2018	$ 7,042,788	$ 2	$ 5,000	$ 7,410,537	$ 1,031,465	$ (1,404,216)