Income Taxes Income Taxes - Effective Tax Rates Differing From Prevailing Federal Corporate Income Tax Rates (Details) - Successor [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Effective Tax Rates [Line Items]
Tax on income from continuing operations at statutory rate	$ (99,488)	$ 36,759	$ 178,521
Tax on income from continuing operations at statutory rate,tax rate	35.00%	35.00%	35.00%
Tax-exempt interest	$ (6,004)	$ (1,561)	$ (1,454)
Tax-exempt interest, tax rate	2.10%	(1.50%)	(0.30%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Amount	$ 0	$ 0	$ 180,079
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Percent	0.00%	0.00%	35.30%
Derivative, Gain (Loss) on Derivative, Net	$ (76,257)	$ (545,731)	$ 270,917
Valuation allowance	$ 127,675	$ 139,584	$ (340,133)
Valuation allowance, tax rate	(44.90%)	132.90%	(66.70%)
Foreign taxes	$ (17,742)	$ 26,183	$ 288
Foreign taxes, tax rate	6.20%	24.90%	0.10%
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	$ 36,124	$ (171,687)	$ 0
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Percent	(12.70%)	(163.50%)	0.00%
Other, net	$ 2,013	$ 1,431	$ 63
Other, net, tax rate	(0.70%)	1.40%	0.00%
Income tax expense (benefit)	$ 44,464	$ 30,709	$ 17,364
Effective Income Tax Rate Reconciliation, Percent	(15.60%)	29.20%	3.40%
Income Tax Reconciliation Tax Bankruptcy Adjustments		$ 1,886	$ 0	$ 0
Effective income Tax Reconciliation Tax Bankruptcy Adjustments		(0.70%)	0.00%	0.00%
Financial Services Derivatives Products [Member] | Derivative Products [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ 59,565	$ (50,273)	$ (42,544)
Futures Contracts [Member] | Derivative Products [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	10,695	(191)	(1,367)
Credit Derivatives [Member] | Net Change in Fair Value of Credit Derivatives [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	16,372	20,106	41,701
Interest Rate Swaps [Member] | Derivative Products [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	48,870	(50,082)	(41,177)
Variable Interest Entity, Primary Beneficiary [Member] | Income Loss On Variable Interest Entities [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(152,194)	(515,564)	271,760
Variable Interest Entity, Primary Beneficiary [Member] | Currency Swaps [Member] | Income Loss On Variable Interest Entities [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	(25,530)	58,990	103,757
Variable Interest Entity, Primary Beneficiary [Member] | Interest Rate Swaps [Member] | Income Loss On Variable Interest Entities [Member]
Reconciliation of Effective Tax Rates [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$ (126,664)	$ (574,554)	$ 168,003