Short Term Investments
|6 Months Ended|
Jun. 30, 2018
|Investments, Debt and Equity Securities [Abstract]|
|Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]||
The following table summarizes the available-for-sale investments heldas of
June 30, 2018. There were no available-for-sale investments in prior periods.
The amortized cost of the available-for-sale investments is adjusted for amortization of premiums and accretion of discounts to maturity. There were no material realized gains or losses recognized on the sale or maturity of available-for-sale investments during the three or six months ended June 30, 2018
The entire disclosure for investments in certain debt and equity securities.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef