Share-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2016

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

Summary of share-based compensation expense

A summary of share-based compensation expense included in net income is as follows:

	Year Ended December 31,
	2016			2015			2014
	(In thousands)
Grants of common shares and options	$	11,227		$	12,074		$	12,941
Capitalized share-based compensation	(1,310		)	(868		)	(1,188		)
Share-based compensation expense	$	9,917		$	11,206		$	11,753

Summary of weighted average assumptions used to value options granted

The following table provides a summary of the weighted-average assumption used to value options granted in 2016:

Volatility	18.8	%
Expected dividend yield	2.8	%
Expected term (in years)	6.0
Risk free interest rate	1.5	%

Summary of option activity

The following table provides a summary of option activity for 2016:

	Shares Under Option		Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value
					(In years)	(In thousands)
Outstanding at December 31, 2015	313,802		$	60.93
Granted	682		152.34
Exercised	(55,365	)	82.03
Forfeited or expired	—		—
Outstanding at December 31, 2016	259,119		$	56.66	1.7	$	22,148
Exercisable at December 31, 2016	258,437		$	56.41	1.7	$	22,148

Summary of restricted share activity

The following table provides a summary of restricted share activity for 2016:

	Shares		Weighted-Average Grant-Date Fair Value
Unvested at December 31, 2015	177,214		$	118.68
Granted	153,450		152.70
Vested	(94,774	)	116.62
Forfeited	(18,537	)	129.08
Unvested at December 31, 2016	217,353		$	142.70

Schedule of common shares awarded under various compensation plans

Subsequent to December 31, 2016, common shares were awarded under various compensation plans as follows:

Date	Award		Vesting Term	Beneficiary
January 3, 2017	4,751	Shares	Immediate	Trustees
February 7, 2017	101,009	Restricted shares	3-4 years	Officers and key employees