Consolidated Statements of Total Comprehensive Income - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
AMPS Exchange Loss Based on Carry Value	$ 81,686		$ 81,686
Revenues:
Net premiums earned	25,640	$ 52,989	82,359	$ 143,754
Net investment income:
Securities available-for-sale and short-term	49,985	80,999	222,278	235,092
Other Investment Income	8,347	6,178	12,956	18,804
Total net investment income	58,332	87,177	235,234	253,896
Other-than-temporary impairment losses:
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	(266)	(25,664)	(1,617)	(48,581)
Portion of other-than-temporary impairment recognized in other comprehensive income	0	12,154	38	29,366
Net other-than-temporary impairments	(266)	(13,510)	(1,579)	(19,215)
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	30,201	6,150	82,211	5,434
Change in fair value of credit derivatives:
Gain (Loss) on Sale of Derivatives	99	134	296	1,467
Unrealized gains (losses)	151	45	(609)	6,388
Net change in fair value of credit derivatives	250	179	(313)	7,855
Net gains (losses) on interest rate derivatives	17,333	3,984	52,019	36,538
Net realized gains (losses) on extinguishment of debt	0	0	3,121	4,920
Other Operating Income (Expense), Net	694	329	2,676	1,107
Income (loss) on variable interest entities	1,831	(4,049)	2,982	(1,567)
Total revenues	134,015	133,249	458,710	432,722
Expenses:
Losses and loss expenses (benefit)	33,501	209,806	(181,315)	410,917
Insurance intangible amortization	26,421	45,690	78,299	116,686
Operating expenses	28,368	34,074	90,865	93,502
Interest expense	65,673	29,145	176,192	88,951
Total expenses	153,963	318,715	164,041	710,056
Pre-tax income (loss)	(19,948)	(185,466)	294,669	(277,334)
Provision for income taxes	2,211	5,439	6,811	31,902
Net income (loss)	(22,159)	(190,905)	287,858	(309,236)
Net income (loss) attributable to common stockholders	(103,845)	(190,905)	206,172	(309,236)
Other comprehensive income (loss), after tax:
Net income (loss)	(22,159)	(190,905)	287,858	(309,236)
Unrealized gains (losses) on securities, net of income tax provision (benefit) of $(625), $0, $(1,211) and $0	60,807	(434)	183,686	33,550
Gains (losses) on foreign currency translation, net of income tax provision (benefit) of $0, $0, $0 and $0	(8,873)	24,624	(29,806)	66,509
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, after Tax	340		548
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	(303)	(338)	(1,464)	1,611
Total other comprehensive income (loss), net of income tax	51,971	23,852	152,964	101,670
Total comprehensive income (loss)	29,812	(167,053)	440,822	(207,566)
Less: comprehensive (gain) loss attributable to the noncontrolling interest:
Total comprehensive income (loss) attributable to common stockholders	$ (51,874)	$ (167,053)	$ 359,136	$ (207,566)
Earnings Per Share, Basic	$ (2.27)	$ (4.20)	$ 4.52	$ (6.82)
Earnings Per Share, Diluted	$ (2.27)	$ (4.20)	$ 4.43	$ (6.82)