Stock Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2018

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

Schedule of information relating to options

The following table sets forth information relating to such options during 2018, 2017, and 2016.

Stock Option Activity	Number Of Shares		Average Exercise Price		Weighted- Average Grant Date Fair Value
Balance, December 31, 2015	2,320,687		$	71.01
Options exercised	(745,938	)	36.97
Options forfeited	(9,458	)	73.40
Options terminated	(2,426	)	67.06
Options granted	377,920		68.32		$	12.90
Balance, December 31, 2016	1,940,785		66.83
Options exercised	(386,300	)	45.21
Options forfeited	(34,545	)	72.97
Options terminated	(23,320	)	75.60
Options granted	316,830		71.37		13.00
Balance, December 31, 2017	1,813,450		72.04
Options exercised	(243,502	)	61.92
Options forfeited	(90,862	)	69.82
Options terminated	(33,481	)	75.07
Options granted	428,190		67.36		12.30
Balance, December 31, 2018	1,873,795		72.34

Schedule of summary of non-vested option activity for the period

The following is a summary of nonvested option activity for the year ended December 31, 2018.

Stock Option Activity	Number Of Shares		Weighted- Average Grant Date Fair Value
Nonvested options outstanding at beginning of year	719,027		$	15.47
Granted	428,190		12.30
Vested	(358,511	)	18.14
Forfeited	(124,343	)	14.99
Nonvested options outstanding at end of year	664,363		12.88

Schedule of stock options outstanding and exercisable by exercise price range

A summary of our stock options outstanding and exercisable at December 31, 2018, follows:

Exercise Price Range	Number Outstanding	Number Exercisable	Outstanding Weighted- Average Remaining Contractual Life (Years)	Exercisable Weighted- Average Exercise Price
$60 - $70	710,321	226,938	3.23	68.27
$70 - $80	1,139,369	958,389	1.46	75.72
$80 - $90	24,105	24,105	0.16	80.76
	1,873,795	1,209,432

Schedule of the assumptions used for estimating the fair value of stock options granted during the period

The following summarizes the weighted average assumptions used for estimating the fair value of stock options granted during 2018, 2017 and 2016, respectively.

	2018	2017	2016
Expected volatility	22.9% - 24.4%	23.8% - 25.1%	26.2% - 27.5%
Weighted average expected volatility	23.7%	24.8%	26.6%
Expected term	3.00 - 6.50 years	3.00 - 4.00 years	3.00 - 4.00 years
Risk-free rate	2.55%	1.66%	1.01%
Dividend yield	1.4%	1.2%	1.0%