This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting.

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Comprehensive Income - Schedule of Amounts Reclassed Out of Each Component of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2013	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Predecessor [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)	$ (755)
Successor [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)		$ (7,514)	$ (17,364)	$ (9,557)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(28,634)	(33,778)
Successor [Member] \| Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net realized investment gains			(27,754)	(32,962)
Net of tax and noncontrolling interest			(27,754)	(32,962)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(27,754)	(32,962)
Successor [Member] \| Other Postretirement Benefit Plan, Defined Benefit [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(880)	(816)
Successor [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax and noncontrolling interest			(28,634)	(33,778)
Successor [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member] \| Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)			0	0
Successor [Member] \| Reclassification out of Accumulated Other Comprehensive Income [Member] \| Other Postretirement Benefit Plan, Defined Benefit [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)			0	0
Prior service cost			(666)	(664)
Actuarial gains (losses)			(214)	(152)
Total before tax			(880)	(816)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			$ (880)	$ (816)