Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

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

Fair Value Assumptions

The following table summarizes the assumptions we used for the six months ended June 30, 2018 and 2017:

	For the Six Months Ended June 30,
	2018	2017
Risk-free rate of return	2.73%	1.83%
Expected dividend yields	1.87%	1.68%
Expected award life (years)	4.49	4.48
Expected volatility	18.13%	18.64%

Summary of Restricted Share Activity

A summary of restricted share activity as of June 30, 2018 and changes during the six months ended is as follows:

	Shares		Weighted-Average Grant Date Fair Value
Outstanding at January 1, 2018	767,140		$	42.91
Granted	319,134		$	47.57
Vested and issued	(199,193	)	$	42.99
Expired or forfeited	(85,003	)	$	44.74
Outstanding at June 30, 2018	802,078		$	44.55

Summary of Stock-Settled SARs Activity

A summary of stock-settled SARs activity as of June 30, 2018 and changes during the six months ended is as follows:

	Shares		Weighted-Average Exercise Price
Outstanding at January 1, 2018	1,494,458		$	30.85
Exercised	(464,807	)	$	27.07
Expired or forfeited	(14,947	)	$	36.25
Outstanding at June 30, 2018	1,014,704		$	32.50

Summary of Cash-Settled SARs Activity

A summary of cash-settled SARs activity as of June 30, 2018 and changes during the six months ended is as follows:

	Shares		Weighted-Average Exercise Price
Outstanding at January 1, 2018	189,568		$	28.95
Exercised	(68,955	)	$	28.56
Expired or forfeited	(2,568	)	$	21.23
Outstanding at June 30, 2018	118,045		$	29.35