Fair Value Measurements - Information about Valuation Inputs for Fixed Income Securities Classified as Level 3 (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments Measured at NAV as a Practical Expedient [Member] | Successor [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other investments	$ 336,513	$ 239,516