Derivative Instruments - Summary of Gross Fair Values of Individual Derivative Instruments (Detail) - Successor [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	$ 139,581	$ 137,124
Gross Amounts of Recognized Liabilities, Derivative Liabilities	381,125	405,487
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	61,839	52,129
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	61,839	52,129
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	77,742	84,995
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	319,286	353,358
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Assets	0	0
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	156,925	176,386
Net Amount, Derivative Assets	77,742	84,995
Net Amount, Derivative Liabilities	162,361	176,972
Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	80,407	36,862
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,078,601	1,965,265
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	36,862
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	36,862
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	80,407	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,078,601	1,928,403
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Assets	0	0
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	0	0
Net Amount, Derivative Assets	80,407	0
Net Amount, Derivative Liabilities	2,078,601	1,928,403
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	139,045	137,015
Gross Amounts of Recognized Liabilities, Derivative Liabilities	365,776	370,944
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	61,839	52,129
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	61,839	52,129
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	77,206	84,886
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	303,937	318,815
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	156,925	176,386
Net Amount, Derivative Assets	77,206	84,886
Net Amount, Derivative Liabilities	147,012	142,429
Interest Rate Swaps [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,078,601	1,965,265
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,078,601	1,965,265
Net Amount, Derivative Liabilities	2,078,601	1,965,265
Futures Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	536	109
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	0
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	536	109
Net Amount, Derivative Assets	536	109
Credit Derivatives [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	15,349	34,543
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	0
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	15,349	34,543
Net Amount, Derivative Liabilities	15,349	34,543
Currency Swaps [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	80,407	36,862
Gross Amounts of Recognized Liabilities, Derivative Liabilities		0
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	36,862
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0	36,862
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	80,407	0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities		(36,862)
Net Amount, Derivative Assets	$ 80,407	0
Net Amount, Derivative Liabilities		$ (36,862)