	Shares of common stock
	Class A		Class B
	Issued and outstanding		Issued and outstanding

Balance at December 31, 2016		2,419,107		10,000,000
Issued		7,000		—
Balance at December 31, 2017		2,426,107		10,000,000
Share conversion		10,000,000		(10,000,000	)
Issued		9,450		—
Balance at December 31, 2018		12,435,557		—
Issued		7,500		—
Balance at December 31, 2019		12,443,057		—

Class A and Class B common stock. At our 2018 annual meeting of stockholders held May 23, 2018, our stockholders approved our second amended and restated certificate of incorporation, which among other things added a right for each holder of shares of our Class B common stock, at its option, to convert any or all of those shares into the same number of shares of our Class A common stock. Previously, shares of our Class B common stock were convertible into the same number of Class A common shares only under certain specified conditions. The shares of our Class A and Class B common stock were otherwise identical in all respects, except for certain voting rights in which holders of our shares of Class B common stock were entitled to ten votes per share for election of our directors and one vote per share on all other matters presented to our stockholders for their approval. Holders of our shares of Class A common stock are entitled to one vote per share on all matters. Our second amended and restated certificate of incorporation became effective on July 17, 2018 when we filed such certificate with the Delaware Secretary of State. Immediately after such effectiveness, NL, which owned all of the 10,000,000 issued and outstanding shares of our Class B common stock, converted such Class B shares into 10,000,000 shares of our Class A common stock. This conversion eliminated the dual-class voting structure with respect to election of our directors, providing for equal voting rights with respect to the election of directors for all shares of common stock and providing for uniform and equivalent corporate governance rights to all holders of our common stock. The rights of holders of Class A common stock were not otherwise affected, and the conversion did not affect the calculation of our earnings per share and had no impact on our consolidated financial position, results of operations or liquidity. The second amended and restated certificate of incorporation did not permit the reissuance or resale of any of the shares of Class B common stock which were converted. On November 5, 2018, upon the filing of a Certificate of Retirement with respect to the shares of Class B common stock with the Delaware Secretary of State, the shares of Class B common stock were retired, and our second amended and restated certificate of incorporation was amended to eliminate all references to the Class B common stock. Following the conversion and subsequent retirement of our shares of Class B common stock, our authorized capital stock consists of 20,000,000 shares of Class A common stock and 1,000 shares of preferred stock.

Share repurchases and cancellations. Prior to 2017, our board of directors authorized various repurchases of shares of our Class A common stock in open market transactions, including block purchases, or in privately-negotiated transactions at unspecified prices and over an unspecified period of time. We may repurchase our common stock from time to time as market conditions permit. The stock repurchase program does not include specific price targets or timetables and may be suspended at any time. Depending on market conditions, we may terminate the program prior to its completion. We will generally use cash on hand to acquire the shares. Repurchased shares will be added to our treasury and cancelled. We made no treasury purchases during 2017, 2018 or 2019 and at December 31, 2019, approximately 678,000 shares were available for purchase under these authorizations.

Incentive compensation plan. We have a share based incentive compensation plan pursuant to which an aggregate of up to 200,000 shares of our common stock can be awarded to non-employee members of our board of directors. All of the Class A common shares we issued in 2017, 2018 and 2019 were issued under this plan. At December 31, 2019, 149,050 shares were available for award under this plan.

Dividends. We paid regular quarterly dividends of $.05 per share during 2017 and 2018 and $0.07 per during 2019. Declaration and payment of future dividends and the amount thereof, if any, is discretionary and dependent upon our results of operations, financial condition, cash requirements for our businesses, contractual requirements and restrictions and other factors deemed relevant by our board of directors.