CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2014
Successor
Net income		$ 268,299	$ 393,029
Other comprehensive income (loss):
Change in net unrealized gains (losses) on investments, net of income tax: (Successor 2016 - $326,838; 2015 - $(680,634)); (Predecessor 2015 - $259,738; 2014 - $531,439)		(1,264,034)	606,985
Reclassification adjustment for investment amounts included in net income, net of income tax: (Successor 2016 - $(5,094); 2015 - $9,349); (Predecessor 2015 - $(2,244); 2014 - $(24,387))		17,362	(9,460)
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: (Successor 2016 - $(3,652); 2015 - $(212)); (Predecessor 2015 - $(131); 2014 - $1,883)		(393)	(6,782)
Change in accumulated (loss) gain—derivatives, net of income tax: (Successor 2016 - $370; 2015 - $(45)); (Predecessor 2015 - $5; 2014 - $(1))		(86)	688
Reclassification adjustment for derivative amounts included in net income, net of income tax: (Successor 2016 - $21; 2015 - $45); (Predecessor 2015 - $13; 2014 - $622)		86	39
Change in postretirement benefits liability adjustment, net of income tax: (Successor 2016 - $(2,616); 2015 - $3,194); (Predecessor 2015 - $(6,475); 2014 - $(12,013))		5,931	(4,859)
Total other comprehensive income (loss)		(1,241,134)	586,611
Total comprehensive income (loss)		$ (972,835)	$ 979,640
Predecessor
Net income	$ 1,509			$ 384,875
Other comprehensive income (loss):
Change in net unrealized gains (losses) on investments, net of income tax: (Successor 2016 - $326,838; 2015 - $(680,634)); (Predecessor 2015 - $259,738; 2014 - $531,439)	482,370			986,958
Reclassification adjustment for investment amounts included in net income, net of income tax: (Successor 2016 - $(5,094); 2015 - $9,349); (Predecessor 2015 - $(2,244); 2014 - $(24,387))	(4,166)			(45,290)
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: (Successor 2016 - $(3,652); 2015 - $(212)); (Predecessor 2015 - $(131); 2014 - $1,883)	(243)			3,498
Change in accumulated (loss) gain—derivatives, net of income tax: (Successor 2016 - $370; 2015 - $(45)); (Predecessor 2015 - $5; 2014 - $(1))	9			(2)
Reclassification adjustment for derivative amounts included in net income, net of income tax: (Successor 2016 - $21; 2015 - $45); (Predecessor 2015 - $13; 2014 - $622)	23			1,155
Change in postretirement benefits liability adjustment, net of income tax: (Successor 2016 - $(2,616); 2015 - $3,194); (Predecessor 2015 - $(6,475); 2014 - $(12,013))	(12,025)			(22,309)
Total other comprehensive income (loss)	465,968			924,010
Total comprehensive income (loss)	$ 467,477			$ 1,308,885