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	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entities [Line Items]
Loans, Unpaid principal balance	$ 4,873	$ 6,205
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	13,235,425	14,259,776
Variable Interest Entities [Member] | Successor [Member]
Variable Interest Entities [Line Items]
Loans, Estimated fair value	10,658,963	11,690,324
Long-term Debt, Fair Value	11,155,936	12,327,960
Loans, Unpaid principal balance	7,641,756	9,182,284
Long-term debt, Unpaid principal balance	$ 8,854,530	$ 11,069,070