Note 3. Share-Based Compensation

The following table summarizes share-based compensation expense:

	Three Months Ended
	March 31,
(in thousands)	2018			2017
Performance unit incentive plan (“PUP”)	$	194		$	1,316
Restricted stock		503			623
Restricted stock units		20			60
Share-based compensation before income tax benefit		717			1,999
Income tax benefit		(181	)		(744	)
Share-based compensation, net of income tax benefit	$	536		$	1,255

We did not record any share-based compensation expense through restructuring expense during the three months ended March 31, 2018 or 2017.

The following table summarizes the activity of the outstanding share-based compensation awards:

	PUP Awards					Restricted Stock					Restricted Stock Units
	Shares			Weighted-Average Grant Date Fair Value		Shares			Weighted-Average Grant Date Fair Value		Shares			Weighted-Average Grant Date Fair Value
Balance at December 31, 2017		239,338		$	32.80		206,899		$	33.16		12,750		$	30.94
Granted		71,625		$	52.15		41,457		$	52.15		3,669		$	52.28
Vested		(75,761	)	$	27.29		(54,458	)	$	27.35		(4,300	)	$	27.35
Forfeited		—		$	—		(1,156	)	$	36.37		(258	)	$	37.69
Balance at March 31, 2018		235,202		$	40.46		192,742		$	38.87		11,861		$	38.70

Viad Corp Omnibus Incentive Plan

We grant share-based compensation awards to our officers, directors, and certain key employees pursuant to the 2017 Viad Corp Omnibus Incentive Plan (the “2017 Plan”). The 2017 Plan has a 10-year life and provides for the following types of awards: (a) incentive and non-qualified stock options; (b) restricted stock and restricted stock units; (c) performance units or performance shares; (d) stock appreciation rights; (e) cash-based awards; and (f) certain other stock-based awards. In June 2017, we registered 1,750,000 shares of common stock issuable under the 2017 Plan. As of March 31, 2018, there were 1,672,566 shares available for future grant under the 2017 Plan.

PUP Awards

The vesting of PUP award shares is based upon achievement of certain performance-based criteria. The performance period of the shares is three years.

During the three months ended March 31, 2018, we granted $3.7 million PUP awards of which $1.6 million are payable in shares. Liabilities related to PUP awards were $5.1 million as of March 31, 2018 and $11.0 million as of December 31, 2017. In March 2018, PUP awards granted in 2015 vested and we distributed cash payouts of $5.9 million. In March 2017, PUP awards granted in 2014 vested and we distributed cash payouts of $3.7 million.

Restricted Stock

As of March 31, 2018, the unamortized cost of outstanding restricted stock awards was $4.1 million, which we expect to recognize over a weighted-average period of approximately 1.5 years. We repurchased 16,362 shares for $0.9 million during the three months ended March 31, 2018 and 25,642 shares for $1.2 million during the three months ended March 31, 2017 related to tax withholding requirements on vested share-based awards.

Restricted Stock Units

Aggregate liabilities related to restricted stock units were $0.3 million as of March 31, 2018 and $0.5 million as of December 31, 2017. In February 2018, the 2015 restricted stock units vested and we distributed cash payouts of $0.2 million. In February 2017, portions of the 2012 and 2014 restricted stock units vested and we distributed cash payouts of $0.3 million.

Stock Options

The following table summarizes stock option activity:

	Shares			Weighted-Average Exercise Price
Options outstanding and exercisable at December 31, 2017		63,773		$	16.62
Exercised		(5,084	)	$	16.62
Options outstanding and exercisable at March 31, 2018		58,689		$	16.62