Short-term Investments	3 Months Ended
	Mar. 31, 2019
Investments Schedule [Abstract]
Short-term Investments	SHORT-TERM INVESTMENTSShort-term investments at March 31, 2019 consisted of U.S. Treasury Bills totaling $24.8 million, consisting of $10.9 million maturing on June 6, 2019, $4.9 million maturing on June 20, 2019 and $9.0 million maturing on September 12, 2019, respectively. The interest rates on the U.S. Treasury Bills held on March 31, 2019 that are maturing on June 6, 2019, June 20, 2019, and September 12, 2019 were 2.4%, 2.3%, and 2.3%, respectively. Short-term investments at December 31, 2018 consisted of U.S. Treasury Bills totaling $24.8 million, consisting of $9.0 million that matured on March 14, 2019, $10.9 million maturing on June 6, 2019, and $4.9 million maturing on June 20, 2019. The interest rates on the U.S. Treasury Bills held on December 31, 2018 that matured on March 14, 2019 and that are maturing on June 6, 2019 and June 20, 2019 were 2.2%, 2.4%, and 2.3%, respectively. The investments are classified as held-to-maturity and recorded at cost plus accrued interest, which approximates fair value. We do not intend to sell these investments, and it is not more likely than not that we will be required to sell the investments before we recover their amortized cost bases.