6. Stockholders' Equity	12 Months Ended
Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Our Board of Directors has at various times authorized repurchases of our stock in open-market or privately-negotiated transactions at such times and at such prices as management may from time to time determine. On May 21, 2015 our Board of Directors adopted a stock repurchase program authorizing the repurchase of up to 250,000 shares of our common stock in open-market or privately-negotiated transactions. This program has no expiration date but may be terminated by the Board of Directors at any time. As of December 31, 2018, there remained 231,765 shares available for repurchase under this program. There were no stock repurchases during 2018 and 2017. We repurchased 3,427 shares under this program during 2016. We increased our quarterly cash dividend payments in September of each of the past three years. The quarterly dividend was increased to $1.05 per share in September 2016, to $1.20 per share in September 2017 and to $1.35 per share in September 2018. Holders of our stock units earned non-cash dividend equivalents of $25,000 in 2018, $27,000 in 2017 and $40,000 in 2016.

6. Stockholders' Equity

12 Months Ended

Dec. 31, 2018

Our Board of Directors has at various times authorized repurchases of our stock in open-market or privately-negotiated transactions at such times and at such prices as management may from time to time determine. On May 21, 2015 our Board of Directors adopted a stock repurchase program authorizing the repurchase of up to 250,000 shares of our common stock in open-market or privately-negotiated transactions. This program has no expiration date but may be terminated by the Board of Directors at any time. As of December 31, 2018, there remained 231,765 shares available for repurchase under this program. There were no stock repurchases during 2018 and 2017. We repurchased 3,427 shares under this program during 2016.

We increased our quarterly cash dividend payments in September of each of the past three years. The quarterly dividend was increased to $1.05 per share in September 2016, to $1.20 per share in September 2017 and to $1.35 per share in September 2018. Holders of our stock units earned non-cash dividend equivalents of $25,000 in 2018, $27,000 in 2017 and $40,000 in 2016.