We issue equity-based awards to our employees pursuant to the 2017 Omnibus Incentive Plan (“2017 Employee Plan”) and our non-employee directors pursuant to the 2017 Stock Plan for Non-Employee Directors (“2017 Director Plan”). The 2017 Employee Plan provides that a maximum of 8,000,000 shares of our common stock may be issued, and as of September 30, 2019, 5,496,016 shares of common stock remain available for future issuance. The 2017 Director Plan provides that a maximum of 450,000 shares of our common stock may be issued, and as of September 30, 2019, 297,344 shares of common stock remain available for future issuance. For both the three months ended September 30, 2019 and 2018, we recognized $4 million of share-based compensation expense, and $12 million for both the nine months ended September 30, 2019 and 2018. As of September 30, 2019, unrecognized compensation expense was $20 million, which is expected to be recognized over a weighted-average period of 1.4 years.

Restricted Stock Awards (“RSAs”) generally vest in annual installments between one and three years from each grant date. The following table provides a summary of RSAs for the nine months ended September 30, 2019:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested at January 1, 2019		585,106		$	26.89
Granted		298,329			31.31
Vested		(308,094	)		27.00
Forfeited		(12,615	)		29.96
Unvested at September 30, 2019		562,726		$	29.10

Performance Stock Units (“PSUs”) generally vest at the end of a three-year performance period and are subject to the achievement of a market condition based on a measure of our total shareholder return relative to the total shareholder return of the companies that comprise the FTSE Nareit Lodging Resorts Index (that have a market capitalization in excess of $1 billion as of the first day of the applicable performance period). The number of PSUs that may become vested ranges from zero to 200% of the number of PSUs granted to an employee, based on the level of achievement of the foregoing performance measure. The following table provides a summary of PSUs for the nine months ended September 30, 2019:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested at January 1, 2019		537,936		$	31.16
Granted		314,858			34.28
Vested		(277,325	)		31.25
Forfeited		(672	)		42.05
Unvested at September 30, 2019		574,797		$	32.82

The grant date fair values of these awards were determined using a Monte Carlo simulation valuation model with the following assumptions:

Expected volatility⁽¹⁾	19.5% - 21.5%
Dividend yield⁽²⁾		—
Risk-free rate	1.8% - 2.4%
Expected term	3 years