Amount of operating lease expense. Excludes sublease income.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918638-209977

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

Commitments and Contingencies - Sublease Agreement (Details) £ in Thousands, $ in Thousands		12 Months Ended
	Jul. 11, 2019 GBP (£)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Other Commitments [Line Items]
Rent expense \| £	£ 20
Standish Management, LLC
Other Commitments [Line Items]
Rent expense \| $		$ 523	$ 321