Derivative Instruments - Summary of Location and Amount of Gains and Losses of Derivative Contracts (Detail) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2013	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Successor [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		$ 802,462	$ 270,917	$ (585,038)
Predecessor [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	$ (297,855)
Net Change in Fair Value of Credit Derivatives [Member] | Successor [Member] | Credit Derivatives [Member] | Financial Guarantee [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		192,869	41,701	23,906
Net Change in Fair Value of Credit Derivatives [Member] | Predecessor [Member] | Credit Derivatives [Member] | Financial Guarantee [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(60,384)
Derivative Products [Member] | Successor [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		114,771	(42,544)	(181,087)
Derivative Products [Member] | Successor [Member] | Interest Rate Swaps [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		103,846	(41,177)	(173,615)
Derivative Products [Member] | Successor [Member] | Currency Swaps [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total			0	0
Derivative Products [Member] | Successor [Member] | Futures Contracts [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		10,925	(1,367)	(7,472)
Derivative Products [Member] | Predecessor [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(33,735)
Derivative Products [Member] | Predecessor [Member] | Interest Rate Swaps [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(30,602)
Derivative Products [Member] | Predecessor [Member] | Futures Contracts [Member] | Financial Services Derivatives Products [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(3,133)
Other Income [Member] | Successor [Member] | Call Options on Long-Term Debt [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		0
Other Income [Member] | Predecessor [Member] | Call Options on Long-Term Debt [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	0
Income Loss On Variable Interest Entities [Member] | Successor [Member] | Variable Interest Entity [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total		494,822	271,760	(427,857)
Income Loss On Variable Interest Entities [Member] | Successor [Member] | Interest Rate 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		495,712	168,003	(452,434)
Income Loss On Variable Interest Entities [Member] | Successor [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		$ (890)	$ 103,757	$ 24,577
Income Loss On Variable Interest Entities [Member] | Predecessor [Member] | Variable Interest Entity [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Derivative instruments, gain (loss) recognized in income, net, Total	(203,736)
Income Loss On Variable Interest Entities [Member] | Predecessor [Member] | Interest Rate 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	(203,620)
Income Loss On Variable Interest Entities [Member] | Predecessor [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	$ (116)