Equity-based Compensation (Tables)

A summary of unvested Holdings Unit activity is presented below:

	Holdings Units			Weighted average grant date fair value		Weighted average remaining contractual term (years)		Aggregate intrinsic value
Unvested outstanding at January 1, 2016		1,805,783		$	1.52
Units granted		—
Units forfeited		(126,482	)	$	1.52
Units vested		(654,285	)	$	1.52
Unvested outstanding at December 31, 2016		1,025,016		$	1.52		1.4	$	20,603

A summary of stock option activity for the year ended December 31, 2016:

	Stock Options			Weighted average exercise price		Weighted average remaining contractual term (years)		Aggregate intrinsic value
Outstanding at January 1, 2016		108,270		$	16.15
Granted		309,683		$	17.90
Exercised		(8,483	)	$	16.00
Forfeited		(5,000	)	$	16.00
Outstanding at December 31, 2016		404,470		$	17.49		9.2	$	1,055
Vested or expected to vest at December 31, 2016		392,755		$	17.47		9.2	$	1,032
Exercisable at December 31, 2016		17,324		$	16.23		8.6	$	67

	Stock Options			Weighted average fair value		Weighted average remaining contractual term (years)		Aggregate intrinsic value
Unvested at January 1, 2016		8,160		$	18.38
Granted		2,447		$	20.43
Vested		(2,720	)	$	18.38
Unvested outstanding at December 31, 2016		7,887		$	19.02		1.0	$	159

Valuation assumptions:

	Year ended December 31, 2014
Expected term (years)		1.70
Expected volatility		36.8	%
Risk-free interest rate		0.4	%
Dividend yield		—

The fair value of stock option awards granted were determined on the grant date using the Black-Scholes valuation model based on the following assumptions:

	Year ended December 31,
	2016		2015
Expected term (years) ⁽¹⁾		6.25		6.25
Expected volatility ⁽²⁾	33.2% - 34.4%			35.4	%
Risk-free interest rate ⁽³⁾	1.31% - 1.76%		1.70% - 1.82%
Dividend yield ⁽⁴⁾		—		—

(1)	Expected term represents the estimated period of time until an award is exercised and was determined using the simplified method.

(2)	Expected volatility is based on the historical volatility of a selected peer group over a period equivalent to the expected term.

(3)	The risk-free rate is an interpolation of yields on U.S. Treasury securities with maturities equivalent to the expected term.

(4)	Based on an assumed a dividend yield of zero at the time of grant.