The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_CommonStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Subsequent Events - Additional Information (Detail) - shares	May 09, 2019	Mar. 31, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Common stock, shares authorized		20,000,000	20,000,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, shares authorized	40,000,000