Derivative Instruments - Summary of Gross Fair Values of Individual Derivative Instruments (Detail) - Successor [Member] - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	$ 77,108	$ 139,581
Gross Amounts of Recognized Liabilities, Derivative Liabilities	246,946	381,125
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	2,711	61,839
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	2,711	61,839
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	74,397	77,742
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	244,235	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	81,151	156,925
Net Amount, Derivative Assets	74,397	77,742
Net Amount, Derivative Liabilities	163,084	162,361
Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	75,459	80,407
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,064,105	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	75,459	80,407
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,064,105	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	75,459	80,407
Net Amount, Derivative Liabilities	2,064,105	2,078,601
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	77,108	139,045
Gross Amounts of Recognized Liabilities, Derivative Liabilities	232,013	365,776
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	2,711	61,839
Gross Amounts Offset in the Consolidated Balance Sheet, Derivative Assets / Liabilities	2,711	61,839
Net Amounts of Assets Presented in the Consolidated Balance Sheet, Derivative Assets	74,397	77,206
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	229,302	303,937
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	80,714	156,925
Net Amount, Derivative Assets	74,397	77,206
Net Amount, Derivative Liabilities	148,588	147,012
Interest Rate Swap [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	2,064,105	2,078,601
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	2,064,105	2,078,601
Net Amount, Derivative Liabilities	2,064,105	2,078,601
Futures Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets		536
Gross Amounts of Recognized Liabilities, Derivative Liabilities	437
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
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet, Derivative Liabilities	437
Gross Amount of Collateral Received/Pledged Not Offset in the Consolidated Balance Sheet, Derivative Liabilities	437
Net Amount, Derivative Assets		536
Net Amount, Derivative Liabilities	0
Credit Derivatives [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities, Derivative Liabilities	14,496	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	14,496	15,349
Net Amount, Derivative Liabilities	14,496	15,349
Currency Swaps [Member] | Variable Interest Entities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets, Derivative Assets	75,459	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	75,459	80,407
Net Amount, Derivative Assets	$ 75,459	$ 80,407