Distribution of Total Assets by Geographical Area (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	[1]
Segment Reporting Information [Line Items]
Assets	$ 1,796,135	$ 1,717,209
Ireland
Segment Reporting Information [Line Items]
Assets	734,612	663,060
Rest Of Europe
Segment Reporting Information [Line Items]
Assets	356,787	343,733
United States
Segment Reporting Information [Line Items]
Assets	636,751	641,769
Rest of World
Segment Reporting Information [Line Items]
Assets	$ 67,985	$ 68,647

[1] The December 31, 2015 Balance Sheet has been retrospectively restated as required to reflect the requirements of new guidance in respect of the presentation of debt issue costs.