CONSOLIDATED STATEMENTS OF SHAREOWNER'S EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In- Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total shareowners' equity
Balance (Predecessor) at Dec. 31, 2014		$ 44,388	$ 606,125	$ (185,705)	$ 3,082,000	$ 1,418,076	$ 4,964,884
Increase (decrease) in shareowners' equity
Net income | Predecessor	$ 1,509				1,509		1,509
Other comprehensive income (loss) | Predecessor	465,968					465,968	465,968
Total comprehensive income (loss) | Predecessor	467,477						467,477
Stock-based compensation | Predecessor	1,550		1,550				1,550
Balance (Predecessor) at Jan. 31, 2015		44,388	607,675	(185,705)	3,083,509	1,884,044	$ 5,433,911
Balance at Jan. 31, 2015	5,554,059	0	5,554,059	0	0	0
Increase (decrease) in shareowners' equity
Net income	268,299				268,299
Other comprehensive income (loss)	(1,241,134)					(1,241,134)
Total comprehensive income (loss)	(972,835)
Stock-based compensation	0
Balance at Dec. 31, 2015	4,581,224	0	5,554,059	0	268,299	(1,241,134)
Increase (decrease) in shareowners' equity
Net income	393,029				393,029
Other comprehensive income (loss)	586,611					586,611
Total comprehensive income (loss)	979,640
Stock-based compensation	0
Dividends to parent	(89,343)				(89,343)
Balance at Dec. 31, 2016	5,471,521	0	5,554,059	0	571,985	(654,523)
Increase (decrease) in shareowners' equity
Net income	1,106,532				1,106,532
Other comprehensive income (loss)	692,994					692,994
Total comprehensive income (loss)	1,799,526
Cumulative effect adjustments	0				25,775	(25,775)
Stock-based compensation	0
Dividends to parent	(143,848)				(143,848)
Balance at Dec. 31, 2017	$ 7,127,199	$ 0	$ 5,554,059	$ 0	$ 1,560,444	$ 12,696