The following table summarizes activities related to the Company’s stock options:

				Weighted-
			Weighted-	Average
			Average	Remaining	Aggregate
		Number of	Exercise	Contractual	Intrinsic
(in thousands, except per share data)		Options	Price	Term (Years)	Value
	Outstanding as of December 31, 2016	1,197	$ 19.51
	Exercised	(582)	19.28
	Forfeited or expired	(19)	19.76
	Outstanding as of December 31, 2017	596	19.72
	Exercised	(200)	18.21
	Forfeited or expired	(22)	22.99
	Outstanding as of December 31, 2018	374	20.35
	Exercised	(100)	21.21
	Forfeited or expired	(4)	21.29
	Outstanding as of December 31, 2019	270	$ 20.02	3.49	$	3,878

	Exercisable as of December 31, 2019	270	$ 20.02	3.49	$	3,878

The following table summarizes the activities related to the Company’s performance-based restricted stock units:

			Weighted-
			Average
		Number of	Grant Date
(in thousands, except per share data)		Units	Fair Value
	Non-vested units outstanding as of December 31, 2016	227	$ 21.43
	Granted⁽¹⁾	172	31.60
	Forfeited	(53)	18.81
	Non-vested units outstanding as of December 31, 2017	346	26.88
	Granted⁽¹⁾	120	29.60
	Forfeited	(147)	24.06
	Non-vested units outstanding as of December 31, 2018	319	$ 29.19
	Granted⁽¹⁾	198	27.45
	Vested	(57)	31.40
	Forfeited	(76)	21.23
	Non-vested units outstanding as of December 31, 2019	384	$ 28.89

⁽¹⁾Represents target number of units that can vest based on the achievement of the performance goals.