Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Non-Qualified Stock Options, Activity

A summary of activity and weighted average exercise prices related to the NSOs is as follows:

	Three Months Ended   March 31, 2019
	Shares		Weighted Avg. Exercise Price
Outstanding, beginning of period	2,431,397		$	36.54
Exercised	(220,792	)	31.74
Forfeited	(44,740	)	33.10
Cancelled	(1,860	)	50.49
Outstanding, end of period	2,164,005		$	37.09
Vested and exercisable, end of period	1,508,539		$	39.02

Restricted Stock Units Activity

A summary of activity and weighted average fair values related to the RSUs is as follows:

	Three Months Ended   March 31, 2019
	Shares		Weighted Avg. Fair Value
Outstanding, beginning of period	1,123,554		$	35.46
Granted	467,430		46.03
Dividend equivalent units granted	6,376		46.04
Vested	(369,339	)	34.48
Dividend equivalent units vested	(22,281	)	37.51
Forfeited	(29,245	)	36.55
Dividend equivalent units forfeited	(1,227	)	38.45
Outstanding and nonvested, end of period	1,175,268		$	39.96

Unrestricted Stock Award Activity

A summary of activity and weighted average fair values related to the restricted stock awards is as follows:

	Three Months Ended   March 31, 2019
	Shares	Weighted Avg. Fair Value
Outstanding, beginning of period	27,812	$	36.84
Outstanding and nonvested, end of period	27,812	$	36.84

Performance-based Units Activity

A summary of activity and weighted average fair values related to the PSUs and Supplemental PSUs is as follows:

	Three Months Ended   March 31, 2019
	Shares		Weighted Avg. Fair Value
Outstanding, beginning of period	161,515		$	37.30
Granted (1)	49,342		46.43
Dividend equivalent units granted	1,487		40.95
Vested	(119,282	)	36.60
Dividend equivalent units vested	(6,548	)	37.19
Outstanding and nonvested, end of period	86,514		$	42.06

(1) Represents shares of PSUs for which performance targets have been established and which are deemed granted under U.S. GAAP.

Unrecognized Compensation Cost, Nonvested Awards

As of March 31, 2019, the Company had not yet recognized compensation cost on nonvested awards as follows (dollars in thousands):

	Unrecognized Compensation Cost		Weighted Avg. Remaining Recognition Period
Nonvested awards	$	50,268	2.6