CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Minimum [Member]
Stock issued for cash, net (in dollars per share)	$ 3.00	$ 4.00	$ 3.00
Maximum [Member]
Stock issued for cash, net (in dollars per share)	$ 4.89	$ 5.69	$ 5.05

Per share or per unit amount of equity securities issued.

No definition available.

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant