Taxation - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Income Tax Examination [Line Items]
Effective income tax rate (percent)	12.10%	16.70%
Increase in deferred tax asset valuation allowance	$ 900,000
Unrecognized tax benefits	$ 0		$ 0
Bermuda
Income Tax Examination [Line Items]
Effective income tax rate (percent)		0.00%