Special Purpose Entities, Including Variable Interest Entities - Summary of Fair Value of Fixed Income Securities, by Asset-Type, Held by Consolidated Variable Interest Entities (Detail) - Successor [Member] - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Investments:
Fixed income securities	$ 5,124,394	$ 5,150,018
Variable Interest Entities [Member]
Investments:
Fixed income securities	2,747,181	2,743,050
Corporate Obligations [Member]
Investments:
Fixed income securities	$ 2,747,181	$ 2,743,050