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Business Segment and Geographical Information - Distribution of Income Tax Charge by Geographical Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Income tax charge	$ 41,958	$ 46,569	$ 37,993
Ireland
Segment Reporting Information [Line Items]
Income tax charge	29,096	20,345	24,215
Rest of Europe
Segment Reporting Information [Line Items]
Income tax charge	(434)	1,921	5,528
U.S.
Segment Reporting Information [Line Items]
Income tax charge	3,761	14,772	8,381
Other
Segment Reporting Information [Line Items]
Income tax charge	$ 9,535	$ 9,531	$ (131)

X

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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