Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019 USD ($) lease	Sep. 30, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Right-of-use asset impairment charge \| $	$ 1.4	$ 1.4
U.K.
Lessee, Lease, Description [Line Items]
Number of operating leases impaired \| lease	2

Amount of loss from impairment of right-of-use asset from operating lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 25
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=77888369&loc=SL77918431-209957

Name:	us-gaap_OperatingLeaseImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration