Stock Options and Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Activity with respect to these plans is as follows:

	2019	2018	2017
Shares under option January 1	18,940	29,340	62,390
Options canceled	—	—	150
Options exercised	6,990	10,400	32,900
Shares under option at December 31	11,950	18,940	29,340
Options exercisable at December 31	11,950	18,940	29,340

The weighted average exercise price is as follows:

	2019	2018	2017
Shares under option January 1	$17.87	$18.40	$18.28
Options canceled	—	—	20.63
Options exercised	16.06	19.38	18.16
Shares under option December 31	18.93	17.87	18.40
Options exercisable December 31	18.93	17.87	18.40

Schedule of Executive Management Share-based Compensation Activity

As of December 31, 2019, there were 1,115,472 shares of Company stock authorized for the payment of awards under these plans. Information with respect to these plans is presented below:

	Number of shares	Weighted average grant date value per share	Year-end intrinsic value (000's)
Shares potentially payable at January 1, 2017	189,418	$36.90	$6,989
Forfeitures	—	—
Payments	(75,545)	$36.35
Shares accrued based on 2017 performance	43,532	$48.26

Shares potentially payable at December 31, 2017	157,405	$40.30	$6,343
Forfeitures	—
Payments	(79,762)	$39.90
Shares accrued based on 2018 performance	34,822	$70.59

Shares potentially payable at December 31, 2018	112,465	$49.96	$5,619
Forfeitures	—	—
Payments	(45,689)	$36.74
Shares accrued based on 2019 performance	14,936	$92.12

Shares potentially payable at December 31, 2019	81,712	$65.06	$5,316

Schedule of Other Management Share-based Compensation Activity

The determination of compensation expense for other management share-based compensation plans is based on the number of outstanding share units, the end-of-period share price, and Company performance. Information with respect to these plans is presented below:

	Number of shares	Weighted average value per share	Cash paid for share based liabilities (000's)
Share units potentially payable at January 1, 2017	261,145

Grants	96,505
Changes due to performance	(11,891)
Payments	(89,190)	$46.64	$4,160
Forfeitures	(20,473)
Share units potentially payable at December 31, 2017	236,096

Grants	65,370
Changes due to performance	14,343
Payments	(75,545)	$62.69	$4,736
Forfeitures	(12,963)
Share units potentially payable at December 31, 2018	227,301

Grants	58,878
Changes due to performance	21,740
Payments	(69,912)	$70.67	$5,528
Forfeitures	(22,935)
Share units potentially payable at December 31, 2019	215,072