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, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ (2,775)	$ 58,012	$ (38,990)	$ 15,215
Other comprehensive income before reclassifications	44,362	471	69,455	34,252
Amounts reclassified from accumulated other comprehensive income	(2,759)	(7,708)	8,363	1,308
Net current period other comprehensive income	41,603	(7,237)	77,818	35,560
Ending Balance	38,828	50,775	38,828	50,775
Income Tax Expense (Benefit)	6,882	3,156	26,463	6,595
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	140,198	110,754	118,863	50,963
Other comprehensive income before reclassifications	15,070	55,623	27,570	107,185
Amounts reclassified from accumulated other comprehensive income	(2,421)	(7,453)	6,414	776
Net current period other comprehensive income	12,649	48,170	33,984	107,961
Ending Balance	152,847	158,924	152,847	158,924
Accumulated Translation Adjustment [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(154,627)	(62,873)	(167,220)	(45,092)
Other comprehensive income before reclassifications	29,292	(55,152)	41,885	(72,933)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Net current period other comprehensive income	29,292	(55,152)	41,885	(72,933)
Ending Balance	(125,335)	(118,025)	(125,335)	(118,025)
Other Postretirement Benefits Plan [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	11,654	10,131	9,367	9,344
Other comprehensive income before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income	(338)	(255)	1,949	532
Net current period other comprehensive income	(338)	(255)	1,949	532
Ending Balance	11,316	9,876	11,316	9,876
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Income Tax Expense (Benefit)	0	0	0	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Other Postretirement Benefits Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	(241)	(167)	(482)	(333)
Changes In Accumulated Other Comprehensive Income [Roll Forward]
Amounts reclassified from accumulated other comprehensive income	(338)	(255)	1,949	532
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	97	88	(2,431)	(865)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(338)	(255)	1,949	532
Income Tax Expense (Benefit)	$ 0	$ 0	$ 0	$ 0