Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

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

Schedule of assumptions used in estimating fair value of stock options using Black-Scholes option pricing model

In determining the estimated fair value of our stock options as of the date of grant, we used the Black-Scholes option pricing model with the following assumptions:

	2018	2017		2016
Risk-free interest rate	N/A	1.69-1.87%		0.93-1.27%
Dividend yield	N/A	6.00	%	5.50	%
Volatility factors of the expected market price for our common stock	N/A	21.5-21.6%		19.1-20.6%
Weighted average expected life of options	N/A	4.0 years		4.0 years

Summary of stock option activity

The following is a summary of stock option activity in 2018:

	Shares (000’s)		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Intrinsic Value ($000’s)
Outstanding as of December 31, 2017	5,025		$	58.57
Options granted	—		—
Options exercised	(201	)	43.53
Options forfeited	(35	)	59.49
Options expired	(5	)	58.93
Outstanding as of December 31, 2018	4,784		59.20		6.4	$	13,566
Exercisable as of December 31, 2018	4,196		58.89		6.3	$	13,521

Summary of status of nonvested restricted stock and restricted stock units and changes during the year

A summary of the status of our non-vested restricted stock and restricted stock units as of December 31, 2018, and changes during the year ended December 31, 2018 follows:

	Restricted Stock (000’s)		Weighted Average Grant Date Fair Value		Restricted Stock Units (000’s)		Weighted Average Grant Date Fair Value
Nonvested at December 31, 2017	319		$	58.36	414		$	62.01
Granted	161		50.77		331		53.44
Vested	(182	)	59.35		(104	)	61.47
Forfeited	(22	)	53.94		(14	)	58.29
Nonvested at December 31, 2018	276		53.64		627		57.70