Investment Securities - Summary of Net Investment Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended	3 Months Ended
Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Mar. 19, 2012
Successor [Member]
Investment income (loss):
Amortization of premium or discount on fixed-maturity securities	$ (1,837)	$ (1,663)	$ (2,309)
Investment income on fixed-maturity securities	7,232	3,369	6,588
Interest income on cash and equivalents	161	11	10
Realized net gain (loss) from sale of investments	2,747	436	(1,575)
Unrealized (losses) gains on trading securities held at period end	(1,410)	(774)	(3,492)
Net investment income (loss)	6,893	1,379	(778)
Predecessor [Member]
Investment income (loss):
Amortization of premium or discount on fixed-maturity securities				(523)
Investment income on fixed-maturity securities				2,467
Interest income on cash and equivalents				3
Realized net gain (loss) from sale of investments				176
Unrealized (losses) gains on trading securities held at period end				1,049
Net investment income (loss)				$ 3,172

The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

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-Topic 225

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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Amount of accretion (amortization) of purchase discount (premium) on nonoperating securities.

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Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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Investment income on fixed-maturity securities.

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