Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Restricted Stock Awards ("RSAs")

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 years ended December 31, 2019, 2018 and 2017:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested at January 1, 2017		—		$	—
Granted		594,213			26.52
Vested		(106,795	)		26.85
Forfeited		(25,779	)		26.22
Unvested at December 31, 2017		461,639			26.47
Granted		367,463			27.34
Vested		(214,208	)		26.67
Forfeited		(29,788	)		27.48
Unvested at December 31, 2018		585,106			26.89
Granted		302,506			31.24
Vested		(312,462	)		26.99
Forfeited		(17,905	)		29.58
Unvested at December 31, 2019		557,245		$	29.10

Schedule of Performance Stock Units ("PSUs")

The following table provides a summary of PSUs for the years ended December 31, 2019, 2018 and 2017:

	Number of Shares			Weighted-Average Grant Date Fair Value
Unvested at January 1, 2017		—		$	—
Granted		387,642			31.95
Vested		—			—
Forfeited		(16,085	)		31.73
Unvested at December 31, 2017		371,557			31.96
Granted		179,774			29.47
Vested		—			—
Forfeited		(13,395	)		30.48
Unvested at December 31, 2018		537,936			31.16
Granted		314,858			34.28
Vested		(277,325	)		31.25
Forfeited		(672	)		42.05
Unvested at December 31, 2019		574,797		$	32.82

Schedule of Grant Date Fair Values of Awards Using Monte Carlo Simulation Valuation Model

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

	Year Ended December 31,
	2019		2018		2017
Expected volatility⁽¹⁾	19.5% - 21.5%		20.0% - 24.0%		25.5% - 29.5%
Dividend yield⁽²⁾		—		—		—
Risk-free rate	1.8% - 2.4%		2.4% - 2.7%		1.2% - 1.5%
Expected term	3 years		3 years		2 - 3 years

⁽¹⁾

Due to limited trading history of our common stock, we used the historical and implied volatilities of our peer group in addition to our historical and implied volatilities over the performance period to estimate appropriate expected volatilities. For the years ended December 31, 2019, 2018 and 2017, the weighted average expected volatility was 20.5%, 24.0% and 28.4%, respectively.

⁽²⁾	Dividends are assumed to be reinvested in shares of our common stock and dividends will not be paid unless shares vest.