Leases - Narrative (Details)	1 Months Ended
Feb. 28, 2017	Jan. 31, 2017
Camberley, United Kingdom
Leased Assets [Line Items]
Term of lease	11 years
Corporate Headquarters \| Morrisville, North Carolina
Leased Assets [Line Items]
Term of lease		12 years

Term of the lessee's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LesseeLeasingArrangementsOperatingLeasesTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration