Income Taxation - Tax Expense for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Domestic (Bermuda)									$ 0	$ 0	$ 0
Foreign									18,433	(3,632)	10,299
Total current tax expense									18,433	(3,632)	10,299
Deferred:
Domestic (Bermuda)									0	0	0
Foreign									(13,996)	(2,492)	(16,694)
Total deferred tax expense									(13,996)	(2,492)	(16,694)
Total income tax expense (benefit) on continuing operations	$ (22,427)	$ 14,597	$ 7,518	$ 4,749	$ (10,688)	$ 746	$ 3,646	$ 172	$ 4,437	$ (6,124)	$ (6,395)