Fair Value Measurements - Summary of Gains and Losses (Realized and Unrealized) Relating to Level 3 Assets and Liabilities Included in Earnings (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Variable Interest Entity [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period			$ (206,797)	$ 701,824
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held			(196,107)	707,011
Net Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	$ 8,429	$ 835	21,066	1,676
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	0	0	0	0
Realized Gains Or (Losses) and Other Settlements On Credit Derivative Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	1,693	596	2,519	2,088
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	0	0	0	0
Unrealized Gains Or (Losses) On Credit Derivative Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	35,259	6,820	42,227	11,491
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	4,594	6,761	4,025	10,074
Interest Rate Swaps [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	(16,879)	(3,532)	(24,106)	(49,903)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	(16,879)	(3,532)	(24,106)	(49,903)
Income Loss On Variable Interest Entities [Member] \| Variable Interest Entity [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	24,274	297,183
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	34,964	304,365
Other Income or (Loss) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	(382)	(381)	(1,009)	(983)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	$ (382)	$ (381)	$ (1,009)	$ (983)