Note 4. Stock-Based Compensation

The Company accounts for all share-based payments in accordance with ASC Topic 718, “Compensation—Stock Compensation”. Stock‑based compensation expense included in operating expenses for the thirteen and twenty-six-week periods ended March 2, 2019 and March 3, 2018 was as follows:


	Thirteen Weeks Ended				Twenty-Six Weeks Ended
	March 2,		March 3,		March 2,		March 3,
	2019		2018		2019		2018
Stock options	$	1,121	$	1,128	$	2,326	$	2,322
Restricted share awards		338		670		870		1,572
Restricted stock units		2,364		1,821		4,729		3,575
Associate Stock Purchase Plan		81		76		153		120
Total		3,904		3,695		8,078		7,589
Deferred income tax benefit		(980)		(1,083)		(2,028)		(2,224)
Stock-based compensation expense, net	$	2,924	$	2,612	$	6,050	$	5,365

Stock options

The fair value of each option grant is estimated on the date of grant using the Black‑Scholes option pricing model with the following assumptions:


	Twenty-Six Weeks Ended
	March 2,		March 3,
	2019		2018
Expected life (in years)	4.0		4.0
Risk-free interest rate	2.98	%	1.87	%
Expected volatility	23.13	%	22.13	%
Expected dividend yield	2.70	%	2.30	%
Weighted-average grant-date fair value	$14.05		$12.25

A summary of the Company’s stock option activity for the twenty-six-week period ended March 2, 2019 is as follows:


	Options	Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding on September 1, 2018	1,760	$	72.96
Granted	398		83.21
Exercised	(191)		75.85
Canceled/Forfeited	(32)		77.66
Outstanding on March 2, 2019	1,935	$	74.71	4.6	$	17,655
Exercisable on March 2, 2019	899	$	72.49	3.5	$	10,197

The unrecognized share‑based compensation cost related to stock option expense at March 2, 2019 was $10,405 and will be recognized over a weighted average period of 2.5 years. The total intrinsic value of options exercised, which represents the difference between the exercise price and market value of common stock measured at each individual exercise date, during the twenty-six-week periods ended March 2, 2019 and March 3, 2018 was $1,617 and $5,283, respectively.

Restricted share awards

A summary of the non‑vested restricted share award (“RSA”) activity under the Company’s 2005 Omnibus Incentive Plan and 2015 Omnibus Incentive Plan for the twenty-six-week period ended March 2, 2019 is as follows:


	Shares	Weighted-Average Grant-Date Fair Value
Non-vested restricted share awards at September 1, 2018	63	$	81.98
Granted	—		—
Vested	(39)		82.38
Canceled/Forfeited	(1)		82.47
Non-vested restricted share awards at March 2, 2019	23	$	81.30

The fair value of each RSA is the closing stock price on the NYSE of the Company’s Class A common stock on the date of grant. Upon vesting, a portion of the RSA award may be withheld to satisfy the statutory income tax withholding obligation. The remaining RSAs will be settled in shares of the Company’s Class A common stock when vested. The unrecognized share-based compensation cost related to RSAs at March 2, 2019 was $978 and will be recognized over a weighted average period of 0.7 years.

Restricted stock units

A summary of the Company’s non-vested Restricted Stock Unit (“RSU”) award activity for the twenty-six-week period ended March 2, 2019 is as follows:


	Shares	Weighted-Average Grant-Date Fair Value
Non-vested restricted stock unit awards at September 1, 2018	377	$	73.18
Granted	171		83.01
Vested	(98)		72.54
Canceled/Forfeited	(17)		77.08
Non-vested restricted stock unit awards at March 2, 2019	433	$	77.05

The fair value of each RSU is the closing stock price on the NYSE of the Company’s Class A common stock on the date of grant. Upon vesting, a portion of the RSU award may be withheld to satisfy the statutory income tax withholding obligation. The remaining RSUs will be settled in shares of the Company’s Class A common stock when vested. These awards accrue dividend equivalents on outstanding units (in the form of additional stock units) based on dividends declared on the Company’s Class A common stock and these dividend equivalents convert to unrestricted common stock on the vesting dates of the underlying RSUs. The dividend equivalents are not included in the RSU table above. The unrecognized share-based compensation cost related to the RSUs at March 2, 2019 was $29,243 and is expected to be recognized over a weighted average period of 3.4 years.