Stock awards, which include shares of restricted stock, restricted stock units and performance stock units, are awarded from time to time to executive officers and certain key employees of the Company. Stock award compensation is recorded based on the award date fair value and charged to expense ratably through the requisite service period. The forfeiture of unvested restricted stock, restricted stock units and performance stock units causes the reversal of all previous expense recorded as a reduction of current period expense.

Expense associated with stock awards was $7.0 million, $6.8 million and $9.0 million in 2019, 2018 and 2017, respectively. Unrecognized pre-tax expense of $9.6 million related to stock awards is expected to be recognized over the weighted average remaining service period of 1.8 years for awards outstanding at December 31, 2019.

Deferred stock units are generally awarded to directors of the Company and represent the Company’s obligation to transfer one share of the Company’s common stock to the grantee at a future date. Historically, awards were fully vested, and fully expensed, on the date of grant. Beginning in April 2019, as a result of the amendment and restatement of the 2016 Director Plan discussed above, the expense related to the issuance of deferred stock units is based on the award date fair value and charged to expense ratably through the requisite service period, which is generally one year. The forfeiture of unvested deferred stock units causes the reversal of all previous expense to be recorded as a reduction of current period expense.

Expense associated with awards of deferred stock units was $0.7 million, $1.1 million and $1.1 million in 2019, 2018 and 2017, respectively. Unrecognized pre-tax expense of $0.4 million related to deferred stock unit awards is expected to be recognized over the weighted average remaining service period of 0.3 years for awards outstanding at December 31, 2019.

Stock Options

Stock options on the Company’s common stock are awarded from time to time to executive officers and certain key employees of the Company. Stock options granted generally have a term of seven to ten years and an exercise price equal to the market value of the underlying common stock on the date of grant.

A summary of stock option activity is as follows:

	Years Ended December 31,
	*2019*					*2018*					*2017*
	*Shares*			*Weighted Average Exercise Price*		*Shares*			*Weighted Average Exercise Price*		*Shares*			*Weighted Average Exercise Price*
Outstanding, beginning of year		52,783		$	18.11		126,680		$	23.06		170,253		$	21.99
Exercised		(52,783	)		18.11		—			—		(43,573	)		18.87
Canceled/Expired		—			—		(73,897	)		26.60		—			—
Outstanding, end of year		—		$	—		52,783		$	18.11		126,680		$	23.06

Exercisable, end of year		—		$	—		52,783		$	18.11		126,680		$	23.06

In 2019, 2018 and 2017, there were no expenses related to stock options as all issued stock options were fully vested.

Financial data for stock option exercises are summarized in the following table (in thousands):

	Years Ended December 31,
	*2019*		*2018*			*2017*
Amount received from stock option exercises	$	956	$	—		$	823
Total intrinsic value of stock option exercises ⁽¹⁾		129		—			370
Tax expense (benefit) of stock option exercises recorded in income tax expense		312		(1,556	)		(63	)
Aggregate intrinsic value of outstanding stock options		—		—			386
Aggregate intrinsic value of exercisable stock options		—		—			386

⁽¹⁾ Calculations based on a weighted average market price of the Company’s stock at the time of exercise of $20.55 and $27.35 for the years ended December 31, 2019 and 2017, respectively.