Derivative Instruments - Summary of Location and Amount of Gains and Losses of Derivative Contracts (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	$ 30,775	$ (18,447)	$ 39,861	$ (235,409)
Net Change in Fair Value of Credit Derivatives [Member] | Credit Derivatives [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	6,624	3,955	7,676	16,821
Derivative Products [Member] | Interest Rate Swap [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	37,141	(33,326)	37,249	(110,433)
Derivative Products [Member] | Futures Contracts [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(3,073)	(3,005)
Derivative Products [Member] | Other Contracts [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total			(4,695)	(9,322)
Derivative Products [Member] | ERROR in label resolution.
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	34,068	(36,331)	32,554	(119,755)
Income Loss On Variable Interest Entities [Member] | Variable Interest Entity [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(9,917)	13,929	(369)	(132,475)
Income Loss On Variable Interest Entities [Member] | Interest Rate Swap [Member] | Variable Interest Entity [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	34	(437)	14,530	(158,780)
Income Loss On Variable Interest Entities [Member] | Currency Swaps [Member] | Variable Interest Entity [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	$ (9,951)	$ 14,366	$ (14,899)	$ 26,305