Comprehensive Income - Schedule of Changes in Balances of Each Component of Accumulated Other Comprehensive 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
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ 169,329	$ 104,417	$ 220,283	$ 11,661
Other comprehensive income before reclassifications	(80,117)	196,431	(80,042)	295,291
Amounts reclassified from accumulated other comprehensive income	6,150	5,480	44,879	(624)
Net current period other comprehensive income	(73,967)	201,911	(124,921)	294,667
Ending Balance	95,362	306,328	95,362	306,328
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	193,245	46,812	210,693	(41,910)
Other comprehensive income before reclassifications	(120,209)	179,479	(86,655)	274,101
Amounts reclassified from accumulated other comprehensive income	6,370	5,684	44,632	216
Net current period other comprehensive income	(113,839)	185,163	(131,287)	273,885
Ending Balance	79,406	231,975	79,406	231,975
Other Postretirement Benefit Plan, Defined Benefit [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	10,004	10,643	10,031	10,847
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	(220)	(204)	247	408
Net current period other comprehensive income	(220)	(204)	(247)	(408)
Ending Balance	9,784	10,439	9,784	10,439
Accumulated Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(33,920)	46,962	(441)	42,724
Other comprehensive income before reclassifications	40,092	16,952	6,613	21,190
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Net current period other comprehensive income	40,092	16,952	6,613	21,190
Ending Balance	$ 6,172	$ 63,914	$ 6,172	$ 63,914