Stock-Based Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2019

Share-based Payment Arrangement, Noncash Expense [Abstract]

A summary of the Company's stock option activity for the six months ended June 30, 2019 and June 30, 2018 is presented below:



Stock Options	Common Shares		Weighted Average Strike Price		Remaining Contractual Term⁽¹⁾	Intrinsic Value ⁽²⁾ ($000)
Outstanding at January 1, 2019	795,014		$	42.25
Granted	—		—
Exercised	(94,767	)	38.00
Forfeited or canceled	—		—
Outstanding at June 30, 2019	700,247		$	42.83	2.7	$	21,239
Exercisable at June 30, 2019	685,127		$	42.80	2.7	$	20,802



Stock Options	Common Shares		Weighted Average Strike Price		Remaining Contractual Term ⁽¹⁾	Intrinsic Value ⁽²⁾ ($000)
Outstanding at January 1, 2018	1,084,756		$	41.98
Granted	—		—
Exercised	(231,902	)	41.65
Forfeited or canceled	(4,361	)	40.87
Outstanding at June 30, 2018	848,493		$	42.07	3.5	$	38,164
Exercisable at June 30, 2018	650,494		$	42.24	3.2	$	29,147


(1)	Represents the remaining weighted average contractual life in years.

(2)

Aggregate intrinsic value represents the total pre-tax intrinsic value (i.e., the difference between the Company's stock price on the last trading day of the quarter and the option exercise price, multiplied by the number of shares) that would have been received by the option holders if they had exercised their options on the last day of the quarter. Options with exercise prices above the stock price on the last trading day of the quarter are excluded from the calculation of intrinsic value. The intrinsic value will change based on the fair market value of the Company's stock.

Summary Of Plans' Restricted Share And Performance-Vested Stock Award Activity

A summary of the Plans' restricted share activity for the six months ended June 30, 2019 and June 30, 2018 is presented below:



	Six months ended June 30, 2019				Six months ended June 30, 2018
Restricted Shares	Common Shares		Weighted Average Grant-Date Fair Value		Common Shares		Weighted Average Grant-Date Fair Value
Outstanding at January 1	143,263		$	60.80	127,787		$	53.33
Granted	11,121		72.01		24,888		87.44
Vested and issued	(13,401	)	76.29		(9,725	)	56.33
Forfeited or canceled	(1,158	)	78.36		(982	)	55.39
Outstanding at June 30	139,825		$	60.06	141,968		$	59.09
Vested, but not issuable at June 30	91,148		$	52.08	90,105		$	51.80

A summary of the Plans' performance-based stock award activity, based on the target level of the awards, for the six months ended June 30, 2019 and June 30, 2018 is presented below:



	Six months ended June 30, 2019				Six months ended June 30, 2018
Performance-based Stock	Common Shares		Weighted Average Grant-Date Fair Value		Common Shares		Weighted Average Grant-Date Fair Value
Outstanding at January 1	396,855		$	67.71	359,196		$	54.37
Granted	174,187		71.58		129,479		88.26
Vested and issued	(94,288	)	41.00		(82,307	)	44.39
Forfeited	(6,590	)	72.96		(10,343	)	56.28
Outstanding at June 30	470,164		$	74.43	396,025		$	67.47
Vested, but deferred at June 30	33,570		$	42.84	21,432		$	43.32