Note 3. Stock-Based Compensation

The Company accounts for all share-based payments in accordance with ASC Topic 718, "Compensation—Stock Compensation" ("ASC 718"). Stock‑based compensation expense included in operating expenses for the thirteen and thirty-nine-week periods ended June 2, 2018 and June 3, 2017 was as follows:


	Thirteen Weeks Ended				Thirty-Nine Weeks Ended
	June 2,		June 3,		June 2,		June 3,
	2018		2017		2018		2017
Stock options	$	1,132	$	1,088	$	3,455	$	3,275
Restricted share awards		658		998		2,230		3,332
Restricted stock units		1,827		1,286		5,401		3,561
Associate Stock Purchase Plan		68		78		189		207
Total		3,685		3,450		11,275		10,375
Deferred income tax benefit		(1,080)		(1,311)		(3,304)		(3,943)
Stock-based compensation expense, net	$	2,605	$	2,139	$	7,971	$	6,432

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:


	Thirty-Nine Weeks Ended
	June 2,		June 3,
	2018		2017
Expected life (in years)	4.0		4.1
Risk-free interest rate	1.87	%	1.16	%
Expected volatility	22.13	%	20.50	%
Expected dividend yield	2.30	%	2.40	%
Weighted-average grant-date fair value	$12.25		$9.29

A summary of the Company’s stock option activity for the thirty-nine-week period ended June 2, 2018 is as follows:


	Options	Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding on September 2, 2017	1,743	$	70.88
Granted	436		79.60
Exercised	(325)		71.20
Canceled/Forfeited	(65)		72.32
Outstanding on June 2, 2018	1,789	$	72.90	4.7	$	33,628
Exercisable on June 2, 2018	682	$	73.77	3.5	$	12,219

The unrecognized share‑based compensation cost related to stock option expense at June 2, 2018 was $8,734 and will be recognized over a weighted average period of 2.4 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 thirty-nine-week periods ended June 2, 2018 and June 3, 2017 was $7,234 and $9,232, 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 thirty-nine-week period ended June 2, 2018 is as follows:


	Shares	Weighted-Average Grant-Date Fair Value
Non-vested restricted share awards at September 2, 2017	160	$	80.49
Granted	—		—
Vested	(90)		79.36
Canceled/Forfeited	(4)		82.40
Non-vested restricted share awards at June 2, 2018	66	$	81.75

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 June 2, 2018 was $2,632 and will be recognized over a weighted average period of 1.2 years.

Restricted stock units

A summary of the Company’s non-vested Restricted Stock Unit (“RSU”) award activity for the thirty-nine-week period ended June 2, 2018 is as follows:


	Shares	Weighted-Average Grant-Date Fair Value
Non-vested restricted stock unit awards at September 2, 2017	313	$	66.66
Granted	169		81.13
Vested	(80)		66.68
Canceled/Forfeited	(22)		71.44
Non-vested restricted stock unit awards at June 2, 2018	380	$	72.81

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 June 2, 2018 was $22,998 and is expected to be recognized over a weighted average period of 3.4 years.