9. Stock-Based Compensation

Pursuant to the 2011 Incentive Plan, we grant stock options, SOSARs, restricted stock units (“RSUs”), or performance/market based restricted stock units (“PSUs”) to employees and non-employee directors. We issue shares of common stock upon the exercise of SOSARs and the vesting of RSUs and PSUs.

Under the 2011 Incentive Plan, 6,830 shares of common stock have been authorized and reserved for issuance to eligible participants, of which 2,626 shares were authorized for issuance but not issued or subject to outstanding awards at December 31, 2018. For purposes of calculating the available shares remaining under the 2011 Incentive Plan, each share issuable pursuant to outstanding full value awards, such as RSUs and PSUs, counts as two shares, and each share underlying a stock option or SOSAR count as one share. The 2011 Incentive Plan is administered by the Compensation Committee of the Board of Directors, which has the authority to select the individuals to whom awards will be granted or to delegate its authority under the plan to make grants (subject to certain legal and regulatory restrictions), to determine the type of awards and when the awards are to be granted, the number of shares to be covered by each award, the vesting schedule and all other terms and conditions of the awards. The exercise price for stock awards granted under the 2011 Incentive Plan cannot be less than fair market value at the date of grant.

Stock-based compensation expense recognized in the consolidated financial statements was as follows:



	Year ended December 31,
	2018		2017		2016
Stock-based compensation expense	$	69,947	$	66,396	$	65,112
Stock-based compensation expense, net of tax	$	51,544	$	40,370	$	35,974
Stock-based compensation expense recognized as capitalized development	$	783	$	1,141	$	946
Excess tax benefit (deficit) on stock-based compensation recognized in provision for income taxes	$	(6,162)	$	448	$	-

SOSARs

SOSAR activity under the 2011 Stock Incentive Plan (in thousands, except years and per share data) was as follows:



	2018			2017			2016
	Shares	Weighted-Average Exercise Price Per Share		Shares	Weighted-Average Exercise Price Per Share		Shares	Weighted-Average Exercise Price Per Share
Outstanding, beginning of year	1,999	$	480.09	1,917	$	490.06	1,694	$	490.70
Granted	741	$	396.66	304	$	426.70	460	$	457.77
Exercised	(408)	$	353.98	(35)	$	307.83	(124)	$	315.87
Forfeited or cancelled	(180)	$	489.14	(187)	$	527.53	(113)	$	559.25
Expired	(1)	$	437.62	-	$	-	-	$	-
Outstanding, end of year	2,151	$	474.51	1,999	$	480.09	1,917	$	490.06



	Shares	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Years of Contractual Life	Aggregate Intrinsic Value
Outstanding as of December 31, 2018	2,151	$	474.51	3.8	$	49,160
Vested and expected to vest as of December 31, 2018	2,107	$	476.09	3.7	$	47,427
Exercisable as of December 31, 2018	1,047	$	538.93	2.3	$	10,627

No SOSARs that included performance conditions were granted during 2018, 2017, or 2016, but in previous years, we granted SOSARs that included such conditions. As of December 31, 2018, 253 SOSARs with performance conditions were outstanding, and all were determined to have met the performance conditions.

The total intrinsic value of SOSARs exercised during the years ended December 31, 2018, 2017 and 2016 was $35,907, $4,296, and $15,946, respectively. Unrecognized stock-based compensation expense for SOSARs as of December 31, 2018 was $34,826 and is expected to be recognized over a weighted average period of 1.7 years.

The weighted average assumptions utilized in the Black-Scholes option-pricing model to estimate the fair value of SOSAR awards granted each year were as follows:



	2018			2017			2016
Risk-free interest rate		2.4	%		1.6	%		1.0	%
Expected life (years)		3.9			3.7			3.5
Expected dividend yield		0.0	%		0.0	%		0.0	%
Volatility		32.2	%		29.9	%		32.2	%
Weighted-average Black-Scholes fair value per share at date of grant	$	77.61		$	105.97		$	117.48

The risk-free interest rate is based on U.S. Treasury rates for instruments with similar terms, and the expected life assumption is based on our historical data. We have not paid dividends to date and do not plan to pay dividends in the near future. The volatility assumption is based on our historical data and implied volatility.

Non-Vested Stock Awards (RSUs)

A summary of non-vested stock award activity under the 2011 Stock Incentive Plan is as follows (in thousands, except per share data):



	2018			2017			2016
	Shares	Weighted Average Grant Date Fair Value Per Share		Shares	Weighted Average Grant Date Fair Value Per Share		Shares	Weighted Average Grant Date Fair Value Per Share
Outstanding, beginning of year	213	$	519.62	125	$	606.24	116	$	511.88
Granted	141	$	305.00	127	$	436.36	90	$	509.05
Vested	(39)	$	732.65	(8)	$	454.84	(7)	$	605.83
Forfeited or cancelled	(91)	$	473.64	(31)	$	502.46	(74)	$	529.54
Expired	-	$	-	-	$	-	-	$	-
Outstanding, end of year	224	$	373.32	213	$	519.62	125	$	606.24

There were 141 non-vested stock awards with a weighted average grant date fair value per share of $305 that were vested and expected to vest as of December 31, 2018. Unrecognized stock-based compensation expense for non-vested stock awards we have determined are probable of vesting was $33,113 as of December 31, 2018, and is expected to be recognized over a weighted average period of 1.6 years. The fair value of shares earned as of the vesting date during the years ended December 31, 2018, 2017, and 2016 was $13,509, $3,524, and $2,787, respectively.

Non-Vested Performance Stock Awards (PSUs)

As of December 31, 2018, 70 of the outstanding non-vested stock awards were subject to performance and/or market conditions, in addition to service vesting conditions. During the year ended December 31, 2018, we awarded 29 performance shares that are subject to service and performance vesting conditions. The shares had a weighted-average grant date fair value was $328.74 per share and vest based on our growth in comparable restaurant sales and average restaurant margin over defined periods. The quantity of shares that will vest range from 0% to 300% of the targeted number of shares. If the defined minimum targets are not met, then no shares will vest.

During the year ended December 31, 2017, we awarded 36 performance shares that are subject to service, market and performance vesting conditions. Two-thirds of the shares had a grant date fair value of $485.53 per share and have vesting criteria based on the price of our common stock reaching certain targets for a consecutive number of days during the three-year period starting on the grant date, with the quantity of shares that vest ranging from 0% to 350% of the targeted number of shares. The remaining one-third of the shares had a grant date fair value of $427.61 and have vesting criteria based on reaching certain comparable restaurant sales increases during the three-year period starting on January 1, 2017, with the quantity of shares that vest ranging from 0% to 300% of the targeted number of shares. If the defined minimum targets are not met, then no shares will vest.

During the year ended December 31, 2016, we awarded 73 performance shares, net of cancellations, that are subject to both service and market vesting conditions. The quantity of shares that vest will range from 0% to 400% of a targeted number of shares, and will be determined based on the price of our common stock reaching certain targets for a consecutive number of days during the three-year period starting on the grant date. If the minimum defined stock price target is not met, then no shares will vest.

During the year ended December 31, 2018, 62 stock awards that were subject to service and performance or market conditions were forfeited.

We adjusted our estimates of the non-vested stock awards expected to vest, which had the following reduction on our expense and earnings per share (dollars in thousands, except per share data) in each of the following years:



	Year ended December 31,
	2018		2017		2016
Cumulative change in expense	$	(79)	$	(1,410)	$	(6,031)
Net of tax impact from cumulative change in expense	$	(58)	$	(857)	$	(3,332)
Impact on basic earnings per share	$	-	$	0.03	$	0.11
Impact on diluted earnings per share	$	-	$	0.03	$	0.11

No stock awards with market conditions were granted during the year ended December 31, 2018. Measurement of the grant date fair value of stock awards with market conditions in prior years included a Monte Carlo simulation model, which incorporates into the fair value determination the possibility that the market condition may not be satisfied, using the following assumptions:



	2018		2017			2016
Risk-free interest rate		N/A		1.5	%		0.9	%
Expected life (years)		N/A		3.0			3
Expected dividend yield		N/A		0.0	%		0.0	%
Volatility		N/A		29.9	%		31.4	%

The assumptions are based on the same factors as those described for SOSARs, except that the expected life is based on the contractual performance period for the stock awards.

In May 2018, as a result of the transition of employees in connection with the corporate restructuring described in Note 5. “Corporate Restructuring Costs”, we reduced our estimate of the number of certain SOSAR and RSU awards that we expect to vest, resulting in a cumulative adjustment to reduce expense of $5,360. In July 2018, we modified service requirements for certain SOSAR and RSU awards for approximately 340 employees, resulting in additional expense of approximately $6,900, of which $6,705 has been recognized during the year ended December 31, 2018. We expect to incur additional expense of $200 in 2019.