Derivative Instruments - Summary of Notional for VIE Derivatives Outstanding (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	$ 1,447,939	$ 1,529,759
Successor [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	1,447,939	1,529,759
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | Interest Rate Swaps [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	1,726,477	1,710,344
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | Interest Rate Swaps-Pay-Fixed/Receive-Variable [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	3,181,823	3,152,090
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | Currency Swaps [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	731,492	724,656
Variable Interest Entity, Primary Beneficiary [Member] | Successor [Member] | Credit Derivatives [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Derivative, Notional Amount	$ 17,217	$ 18,278