9. Fair Value of Financial Instruments (Tables)
|6 Months Ended|
Jun. 30, 2019
|Fair Value Disclosures [Abstract]|
|Valuation of financial instruments at fair value||
The following schedule summarizes the valuation of financial instruments at fair value on a recurring basis in the balance sheets as of June 30, 2019 and December 31, 2018:
Tabular disclosure of input and valuation technique used to measure fair value and change in valuation approach and technique for each separate class of asset and liability measured on recurring and nonrecurring basis.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef