Derivative Instruments - Summary of Gross Fair Values of Individual Derivative Instruments (Detail) - Successor [Member] - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	$ 79,778	$ 139,581
Gross Amounts of Recognized Liabilities, Derivative Liabilities	92,280	381,125
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	731	61,839
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	731	61,839
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	79,047	77,742
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	91,549	319,286
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	81,129	156,925
Net Amount, Derivative Assets	79,047	77,742
Net Amount, Derivative Liabilities	10,420	162,361
Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	65,507	80,407
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,064,071	2,078,601
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	65,507	80,407
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,064,071	2,078,601
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	65,507	80,407
Net Amount, Derivative Liabilities	2,064,071	2,078,601
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	76,667	139,045
Gross Amounts of Recognized Liabilities, Derivative Liabilities	83,274	365,776
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	731	61,839
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	731	61,839
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	75,936	77,206
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	82,543	303,937
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	81,129	156,925
Net Amount, Derivative Assets	75,936	77,206
Net Amount, Derivative Liabilities	1,414	147,012
Interest Rate Swap [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,064,071	2,078,601
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,064,071	2,078,601
Net Amount, Derivative Liabilities	2,064,071	2,078,601
Futures Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	3,111	536
Gross Amounts of Recognized Liabilities, Derivative Liabilities	0
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	3,111	536
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	0
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	0
Net Amount, Derivative Assets	3,111	536
Net Amount, Derivative Liabilities	0
Credit Derivatives [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	9,006	15,349
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	9,006	15,349
Net Amount, Derivative Liabilities	9,006	15,349
Currency Swaps [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	65,507	80,407
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	0
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	65,507	80,407
Net Amount, Derivative Assets	$ 65,507	$ 80,407