Fair Value Measurements - Information about Valuation Inputs for Variable Interest Entity Assets and Liabilities Classified as Level 3 (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	Dec. 31, 2012
Successor [Member] | Corporate Debt Securities [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs Coupon Rate				0.345%
Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	$ 15,170,359	$ 14,253,705	$ 11,497,098	$ 13,845,454
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		(417,184)	(545,308)	1,221,057
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		955,046	(739,919)	(822,098)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0	359,193	124,013
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		(4,528)		(59,878)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		(42,381)	(344,865)	(403,576)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		(220,649)	(752,334)	188,241
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		365,046		3,888
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		(1,552,004)	(325,123)	(659,898)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		(565,205)	(607,235)	1,207,070
Fair Value, Inputs, Level 3 [Member] | Successor [Member] | Investments [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	69,412	67,783	488,884	198,201
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		1,870	30,083	11,057
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		7,184	(73,559)	(541)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0	359,193	54,013
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		(4,528)		(59,878)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		(6,428)	(25,034)	(62,266)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		273	0	188,241
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		0		(208)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		0	0
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		0
Fair Value, Inputs, Level 3 [Member] | Successor [Member] | Other Assets [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	14,061	13,384	8,696	12,036
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		(677)	(1,635)	(1,348)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		0	(1,705)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		0	0
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		(677)	(1,635)	(1,348)
Fair Value, Inputs, Level 3 [Member] | Successor [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	(415,360)	(186,934)	(99,192)	(215,346)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		217,666	16,571	(45,392)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		10,760	11,365	16,980
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		0	88,218
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		0	0
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		91,436	(25,980)	(53,509)
Fair Value, Inputs, Level 3 [Member] | Predecessor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	15,170,359				$ 14,416,488
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Additions Of Consolidated Vies	(409,300)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	1,057,181
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss	(776,014)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements	(716,488)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three	0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three	1,598,492
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	1,053,758
Fair Value, Inputs, Level 3 [Member] | Predecessor [Member] | Investments [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	69,412				60,402
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	(33)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss	12,329
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements	(3,286)
Fair Value, Inputs, Level 3 [Member] | Predecessor [Member] | Other Assets [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	14,061				14,557
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	(496)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	(496)
Fair Value, Inputs, Level 3 [Member] | Predecessor [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	(415,360)				(322,337)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	(88,546)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements	(4,477)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	(92,002)
Loan Origination Commitments [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies			325,123
Long-term Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies			0
Investment Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies			0
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		(655,964)	$ (579,620)	$ 1,261,927
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | European ABS Transactions [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs Coupon Rate			1.38%	0.30%
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | US Commercial ABS Transaction [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Inputs Coupon Rate			5.88%	5.88%
Variable Interest Entity, Primary Beneficiary [Member] | Predecessor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	1,146,256
Variable Interest Entity, Primary Beneficiary [Member] | Loan Origination Commitments [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	14,752,053	13,398,895	$ 11,690,324	$ 12,371,177
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		(455,231)	569,617	1,118,084
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		873,986	(612,941)	(726,827)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0		70,000
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		(219,909)	(312,406)	(792,186)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		(1,552,004)		(696,789)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		(475,152)	589,634	1,119,219
Variable Interest Entity, Primary Beneficiary [Member] | Loan Origination Commitments [Member] | Fair Value, Inputs, Level 3 [Member] | Predecessor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	14,752,053				15,359,073
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	956,402
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss	(849,833)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements	(713,589)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	956,402
Variable Interest Entity, Primary Beneficiary [Member] | Long-term Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	(1,750,372)	(1,514,605)	(3,180,170)	(1,263,664)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		(2,490)	(1,152,681)	(290,457)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		(79,063)	93,812	66,515
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		173,196	(17,085)	433,896
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		(220,922)	(840,552)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		365,046		4,096
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		0		36,891
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		(2,490)	(1,161,991)	(286,405)
Variable Interest Entity, Primary Beneficiary [Member] | Long-term Debt [Member] | Fair Value, Inputs, Level 3 [Member] | Predecessor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	(1,750,372)				(2,956,501)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Additions Of Consolidated Vies	(409,300)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	(138,914)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss	150,987
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements	4,864
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three	0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three	1,598,492
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	(138,914)
Variable Interest Entity, Primary Beneficiary [Member] | Investment Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Successor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	2,500,565	2,475,182	2,588,556	2,743,050
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings		(178,322)	(7,263)	429,113
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss		152,939	(147,231)	(161,245)
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Purchases		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Issues		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Sales		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Settlements		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Into Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Transfers Out Of Level Three		0
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Deconsolidation Of Vies		0
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held		$ (178,322)	$ (7,263)	$ 429,113
Variable Interest Entity, Primary Beneficiary [Member] | Investment Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Predecessor [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability	2,500,565				$ 2,261,294
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Earnings	328,768
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Or Liability Gain Loss Included In Other Comprehensive Income Loss	(89,497)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	$ 328,768