Special Purpose Entities, Including Variable Interest Entities - Supplemental Information about Loans Held as Assets and Long-Term Debt Associated with Consolidated Variable Interest Entities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entities [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ 14,830,828	$ 15,085,685
Variable Interest Entities [Member] \| Successor [Member]
Variable Interest Entities [Line Items]
Loans, Estimated fair value	12,183,061	12,371,177
Long-term debt, Estimated fair value	12,791,012	12,882,076
Loans, Unpaid principal balance	9,446,235	10,236,695
Long-term debt, Unpaid principal balance	$ 11,366,061	$ 11,925,499

Special Purpose Entities, Including Variable Interest Entities - Supplemental Information about Loans Held as Assets and Long-Term Debt Associated with Consolidated Variable Interest Entities (Detail) - USD ($)
$ in Thousands

Sep. 30, 2015

Dec. 31, 2014

Variable Interest Entities [Line Items]

Variable Interest Entity, Consolidated, Carrying Amount, Liabilities

$ 14,830,828

$ 15,085,685

Variable Interest Entities [Member] | Successor [Member]

Variable Interest Entities [Line Items]

Loans, Estimated fair value

12,183,061

12,371,177

Long-term debt, Estimated fair value