Investments - Summary of Net Investment Income (Detail) - Successor [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Investment [Line Items]
Net Realized and Unrealized Gain (Loss) on Trading Securities	$ 1,419	$ 3,211	$ 10,042	$ 5,205
Trading Securities, Realized Gain (Loss)	3,069	(6)	5,453	(431)
Fixed income securities	64,627	78,554	130,213	149,539
Short-term investments	60	865	101	1,168
Loans	93	175	225	292
Investment expense	(2,502)	(2,712)	(4,929)	(5,310)
Securities available-for-sale and short-term	62,278	76,882	125,610	145,689
Other investments	2,475	3,211	12,126	5,205
Total net investment income	64,753	80,093	137,736	150,894
Gains (losses) on securities held as of reporting date [Member]
Investment [Line Items]
Other investments	$ (1,650)	$ 3,217	$ 4,589	$ 5,636