Summary of Net Investment Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended				9 Months Ended
	Sep. 30, 2012 Successor [Member]		Sep. 30, 2012 Successor [Member]		Mar. 19, 2012 Predecessor [Member]		Sep. 30, 2011 Predecessor [Member]		Sep. 30, 2011 Predecessor [Member]
Investment income:
Amortization of premium or discount on fixed-maturity	$ (507)		$ (1,263)		$ (523)		$ (613)		$ (1,912)
Investment income on fixed-maturity securities	2,113		5,377		2,467		3,150		9,953
Interest income on cash and equivalents	58		87		3		6		45
Realized net gain (loss) from sale of investment	2,345		2,617		176		357		1,543
Unrealized (losses) gains on trading securities held at period end	(867)		(594)		1,049		(2,498)		(3,251)
Net investment income	$ 3,142	[1]	$ 6,224	[1]	$ 3,172	[1]	$ 402	[1]	$ 6,378	[1]

[1] Please refer to Note 3 and Note 4 for explanation of "Successor" and "Predecessor" Presentation.