11. Fair Value Measurements (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Text Block [Abstract]
Available-for-sale, at fair value	$ 5,144,707	$ 5,578,159

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

No definition available.

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