Consolidated Statements of Total Comprehensive Income - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Net premiums earned	$ 25,836	$ 43,152	$ 56,719	$ 90,765
Net investment income:
Securities available-for-sale and short-term	61,742	80,943	172,293	154,093
Other investments	4,920	4,217	4,609	12,626
Total net investment income	66,662	85,160	176,902	166,719
Other-than-temporary impairment losses:
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	(1,010)	(1,763)	(1,351)	(22,917)
Portion of other-than-temporary impairment recognized in other comprehensive income	(4)	0	38	17,212
Net other-than-temporary impairments	(1,014)	(1,763)	(1,313)	(5,705)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	47,148	4,180	52,010	(716)
Change in fair value of credit derivatives:
Gain (Loss) on Sale of Derivatives	91	1,134	197	1,333
Unrealized gains (losses)	(308)	5,490	(760)	6,343
Net change in fair value of credit derivatives	(217)	6,624	(563)	7,676
Net gains (losses) on interest rate derivatives	9,149	34,068	34,686	32,554
Net realized gains (losses) on extinguishment of debt	6	2,179	3,121	4,920
Other Operating Income (Expense), Net	2,491	720	1,982	778
Income (loss) on variable interest entities	577	(1,219)	1,151	2,482
Total revenues	150,638	173,101	324,695	299,473
Expenses:
Losses and loss expenses (benefit)	32,579	66,100	(214,816)	201,111
Insurance intangible amortization	23,242	33,471	51,878	70,996
Operating expenses	26,063	31,304	62,497	59,428
Interest expense	62,446	28,234	110,519	59,806
Total expenses	144,330	159,109	10,078	391,341
Pre-tax income (loss)	6,308	13,992	314,617	(91,868)
Provision for income taxes	1,995	6,882	4,600	26,463
Net income (loss)	4,313	7,110	310,017	(118,331)
Net income (loss) attributable to common stockholders	4,313	7,110	310,017	(118,331)
Other comprehensive income (loss), after tax:
Net income (loss)	4,313	7,110	310,017	(118,331)
Unrealized gains (losses) on securities, net of income tax provision (benefit) of $1,122, $0, $(586) and $0	575	12,649	122,879	33,984
Gains (losses) on foreign currency translation, net of income tax provision (benefit) of $0, $0, $0 and $0	(52,989)	29,292	(20,933)	41,885
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax	(906)		208
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax and Reclassification Adjustment, Attributable to Parent		0		0
Changes to postretirement benefit, net of income tax provision (benefit) of $0, $0, $0 and $0	(302)	(338)	(1,161)	1,949
Total other comprehensive income (loss), net of income tax	(53,622)	41,603	100,993	77,818
Total comprehensive income (loss)			411,010	(40,513)
Less: comprehensive (gain) loss attributable to the noncontrolling interest:
Total comprehensive income (loss) attributable to common stockholders	$ (49,309)	$ 48,713	$ 411,010	$ (40,513)
Earnings Per Share, Basic	$ 0.09	$ 0.16	$ 6.80	$ (2.61)
Earnings Per Share, Diluted	$ 0.09	$ 0.16	$ 6.73	$ (2.61)