Consolidated Statements of Cash Flows - Successor [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income attributable to common shareholders	$ (309,236)	$ 169,536
Net gain (loss)	0	328
Net income (loss)	(309,236)	169,208
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	766	920
Amortization of bond premium and discount	(133,901)	(102,956)
Share-based compensation	3,362	4,228
Deferred income taxes	210	(469)
Current income taxes	4,441	11,848
Unearned premiums, net	(137,127)	(210,722)
Losses and loss expenses, net	282,317	666,196
Ceded premiums payable	(3,936)	(9,983)
Investment income due and accrued	5,874	(145)
Premium receivables	62,205	126,047
Accrued interest payable	27,295	45,201
Amortization of insurance intangible assets	116,686	134,456
Net mark-to-market (gains) losses	(6,388)	(17,843)
Net realized investment gains	(5,434)	(27,748)
Other-than-temporary impairment charges	19,215	19,628
(Gain) loss on extinguishment of debt	(4,920)	(4,845)
Variable interest entity activities	1,567	16,119
Increase (Decrease) in Derivative Assets and Liabilities	(211,659)	81,517
Other, net	9,932	(75,125)
Net cash provided by (used in) operating activities	(278,731)	825,532
Cash flows from investing activities:
Proceeds from sales of bonds	1,523,182	457,423
Proceeds from matured bonds	669,979	940,948
Purchases of bonds	(1,560,024)	(2,085,939)
Proceeds from sales of other invested assets	312,699	132,437
Purchases of other invested assets	(274,445)	(250,727)
Change in short-term investments	(285,775)	94,651
Loans, net	(6,230)	693
Change in cash collateral receivable	103,255	(51,986)
Other, net	(8,524)	(10,714)
Net cash provided by (used in) investing activities	474,117	(773,214)
Cash flows from financing activities:
Paydowns of a secured borrowing	(24,666)	(25,306)
Proceeds from warrant exercises	0	2
Payments for Repurchase of Warrants	0	2,104
Warrants Purchased During Period Dollars	0
Payments for investment agreement draws	(82,358)	(17,964)
Payments for extinguishment of long-term debt	(69,499)	(19,550)
Payments Related to Tax Withholding for Share-based Compensation	(1,268)	0
Net cash used in financing activities	(177,791)	(64,922)
Effect of Exchange Rate on Cash and Cash Equivalents	(1,602)	(1,922)
Net cash flow	15,993	(14,526)
Cash and cash equivalents at beginning of period	91,025	35,744
Cash and cash equivalents end of period	107,018	21,218
Supplemental disclosure of cash flow information:
Income taxes	29,556	10,098
Decrease in long-term debt as a result of an exchange for investment securities	55,426	0
Long-term Debt [Member]
Supplemental disclosure of cash flow information:
Interest Paid	$ 38,325	$ 3,749