Fair Value Measurements - Summary of Information about Described Model Inputs Used to Determine Fair Value of Each Class of Credit Derivatives (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Notional outstanding	$ 737,380	$ 970,883
Fair Value Measurement Process Description For Credit Derivatives Revised Relative Change Ratio	73.20%
Successor [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Notional outstanding	$ 737,380	970,883
Successor [Member] | CLO [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Notional outstanding	$ 123,052	$ 295,253
Weighted average reference obligation price	$ 99.5	$ 98.4
Weighted average life (WAL) in years	1 year 9 months	1 year 1 month
Weighted average credit rating	AA	AA
Weighted average relative change ratio	36.60%	36.30%
CVA percentage	7.47%	8.34%
Fair value of derivative liabilities	$ 213	$ 1,837
Successor [Member] | Other [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Notional outstanding	$ 614,328	$ 617,148
Weighted average reference obligation price	$ 92.3	$ 85.2
Weighted average life (WAL) in years	5 years 11 months	6 years 1 month
Weighted average credit rating	A-	BBB+
Weighted average relative change ratio	30.60%	33.30%
CVA percentage	11.19%	23.34%
Fair value of derivative liabilities	$ 15,136	$ 32,697
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurement Process Description For Credit Derivatives Base Relative Change Ratio	25.00%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurement Process Description For Credit Derivatives Revised Hypothetical Fee With Credit Down Grade	35.00%
Internal Credit Assessment [Domain] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurement Process Description For Credit Derivatives Revised Relative Change Ratio		33.00%
Internal Credit Assessment [Domain] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Measurement Process Description For Credit Derivatives Full Relative Change Ratio		100.00%
Credit Derivatives [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
CVA percentage	11.10%	22.70%