Summary of Significant Accounting Policies - Summary of Non-Current Assets by Geographical Area (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Operation By Geographical [Line Items]
Non current assets	$ 22,242,698	$ 14,379,105
United States
Operation By Geographical [Line Items]
Non current assets	454,568	436,463
United Kingdom
Operation By Geographical [Line Items]
Non current assets	$ 21,788,130	$ 13,942,642

Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 41
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e9038-108599

Name:	us-gaap_NoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant