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, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ 58,012	$ 169,329	$ 15,215	$ 220,283
Other comprehensive income before reclassifications	471	(80,117)	34,252	(80,042)
Amounts reclassified from accumulated other comprehensive income	(7,708)	6,150	1,308	(44,879)
Net current period other comprehensive income	(7,237)	(73,967)	35,560	(124,921)
Ending Balance	50,775	95,362	50,775	95,362
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	110,754	193,245	50,963	210,693
Other comprehensive income before reclassifications	55,623	(120,209)	107,185	(86,655)
Amounts reclassified from accumulated other comprehensive income	(7,453)	6,370	776	(44,632)
Net current period other comprehensive income	48,170	(113,839)	107,961	(131,287)
Ending Balance	158,924	79,406	158,924	79,406
Other Postretirement Benefit Plan, Defined Benefit [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	10,131	10,004	9,344	10,031
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	(255)	(220)	532	(247)
Net current period other comprehensive income	(255)	(220)	532	(247)
Ending Balance	9,876	9,784	9,876	9,784
Accumulated Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(62,873)	(33,920)	(45,092)	(441)
Other comprehensive income before reclassifications	(55,152)	40,092	(72,933)	6,613
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Net current period other comprehensive income	(55,152)	40,092	(72,933)	6,613
Ending Balance	$ (118,025)	$ 6,172	$ (118,025)	$ 6,172