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		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held			$ (231,071)	$ 402,646
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	$ 6,908	$ 422	12,637	841
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	407	717	826	1,492
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	9,886	(1,936)	6,968	4,671
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	9,886	(2,544)	5,294	4,056
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	4,195	(24,740)	(7,227)	(46,371)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	4,195	(24,740)	(7,227)	(46,371)
Income Loss On Variable Interest Entities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Total gains or losses included in earnings for the period	(594,120)	218,011	(231,071)	404,641
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	(594,120)	218,011
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	(332)	(340)	(627)	(602)
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held	$ (332)	$ (340)	$ (627)	$ (602)