Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Restricted Stock Units Valuation Assumptions

The total fair value of the Time-Based RSUs is based on the Company's closing share price on the NYSE on the respective fair valuation dates as detailed in the table below:



	2016 Time-Based RSU Grant		2015 Time-Based RSU Grant
Service vesting period	January 28, 2016 - January 5, 2019		January 27, 2015 - January 5, 2018
Fair value on valuation date (in millions)	$	7.1	$	6.4
Fair value per share	$	56.23	$	75.34
Date of fair valuation	January 28, 2016		January 27, 2015

As a result, the number of RSUs earned as of that date based on the FFO per share performance, excluding the impact of forfeitures, was as follows:



	2016 Performance-Based RSU Grant	2015 Performance-Based RSU Grant
Service vesting period	January 28, 2016 - January 5, 2019	January 27, 2015 - January 5, 2018
Target RSUs granted	168,077	127,657
Estimated RSUs earned based on FFO per share performance condition	241,438	185,510
Date of fair valuation	January 28, 2016	January 27, 2015

The following table summarizes the assumptions utilized in the Monte Carlo simulation pricing models:



	2016 Award Fair Value Assumptions	2015 Award Fair Value Assumptions
Valuation date	January 28, 2016	January 27, 2015
Fair value per share on valuation date	$57.08	$78.55
Expected share price volatility	26.00%	20.00%
Risk-free interest rate	1.13%	0.92%
Remaining expected life	2.9 years	2.9 years

Summary of Nonvested Restricted Stock

A summary of our nonvested restricted stock activity from January 1, 2016 through December 31, 2016 is presented below:



	Nonvested Restricted Stock		Weighted-Average Grant Date Fair Value Per Share
Outstanding at January 1, 2016	60,797		$	47.32
Vested ⁽¹⁾	(24,262	)	46.39
Outstanding as of December 31, 2016	36,535		$	47.93

_______________


(1)	The total shares vested includes 12,661 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested. We accept the return of shares at the current quoted closing share price of the Company’s common stock to satisfy tax withholding obligations.

Summary of Nonvested and Vested Restricted Stock Activity

A summary of our nonvested and vested restricted stock activity for years ended December 31, 2016, 2015 and 2014 is presented below:



	Shares Granted			Shares Vested
Years ended December 31,	Nonvested Shares Issued	Weighted-Average Grant Date Fair Value Per Share		Vested Shares		Total Fair Value at Vest Date⁽¹⁾ (in thousands)
2016	—	$	—	(24,262	)	$	1,527
2015	—	—		(24,264	)	1,725
2014	213	51.35		(25,899	)	1,323

_______________


(1)	Total fair value of shares vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the date of vesting.

Schedule of Stock Options Valuation Assumptions



	February 2012 Option Grant
Fair value of options granted per share	$9.20
Expected stock price volatility	33.00%
Risk-free interest rate	1.35%
Dividend yield	3.80%
Expected life of option	6.5 years

Summary of Stock Options Activity

A summary of our stock option activity related to the February 2012 grant from January 1, 2016 through December 31, 2016 is presented below:



	Number of Options		Exercise Price		Intrinsic Value (in millions) ⁽¹⁾
Outstanding at December 31, 2015	610,000		$	42.61	$	12.6
Exercised	(286,500	)	42.61		8.4
Forfeited	(9,000	)	42.61		0.1
Outstanding at December 31, 2016 ⁽²⁾	314,500		$	42.61	$	9.6

Options exercisable at December 31, 2016 ⁽³⁾	50,500		$	42.61	$	1.5

_______________


(1)	The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of an option. The fair value of the underlying stock was determined by using the closing share price on the NYSE on the date of exercise, forfeiture or respective period end.


(2)	As of December 31, 2016, the average remaining life of stock options outstanding was 5.1 years


(3)	As of December 31, 2016, the average remaining life of stock options exercisable was approximately 5.1 years.

Market measure-based Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Restricted Stock Units Award Activity

A summary of our market-measure based RSU activity from January 1, 2016 through December 31, 2016 is presented below:



	Nonvested RSUs				Vested RSUs		Total RSUs
	Amount		Weighted-Average Fair Value Per Share ⁽¹⁾		Vested RSUs		Total RSUs
Outstanding at January 1, 2016	425,452		$	67.68	—		425,452
Granted	258,393		57.36		—		258,393
Vested	(36,914	)	43.53		36,914		—
Settled ⁽²⁾					(36,914	)	(36,914	)
Issuance of dividend equivalents ⁽³⁾	12,120		65.50		—		12,120
Outstanding as of December 31, 2016 ⁽⁴⁾	659,051		$	64.95	—		659,051

_______________


(1)	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant, which was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014, as an insufficient number of shares were available to settle these RSUs upon initial grant on January 29, 2014.

(2)

Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 19,264 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.


(3)	Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.

(4)

Outstanding RSUs as of December 31, 2016 represent the achievement of the maximum performance conditions and assumed target levels for the market conditions. The number of restricted stock units ultimately earned is subject to change based upon actual performance over the three-year vesting period. Dividend equivalents earned will vest along with the underlying award and are also subject to changes based on the number of RSUs ultimately earned for each underlying award.

A summary of our market-measure based RSU activity for years ended December 31, 2016, 2015 and 2014 is presented below:



	RSUs Granted			RSUs Vested
Years ended December 31,	Non-Vested RSUs Granted	Weighted-Average Fair Value Per Share ⁽¹⁾		Vested RSUs		Total Vest-Date Fair Value (in thousands)
2016	258,393	$	57.36	(36,914	)	$	2,788
2015	191,483	79.25		—		—
2014	183,365	64.86		(16,338	)	1,092

_______________


(1)	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant, which was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014, as an insufficient number of shares were available to settle these RSUs upon initial grant on January 29, 2014.

Time-Based Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of Restricted Stock Units Award Activity

A summary of our time-based RSU activity from January 1, 2016 through December 31, 2016 is presented below:



	Nonvested RSUs				Vested RSUs		Total RSUs
	Amount		Weighted Average Fair Value Per Share ⁽¹⁾		Vested RSUs		Total RSUs
Outstanding at January 1, 2016	318,449		$	58.91	951,360		1,269,809
Granted	173,747		58.29		—		173,747
Vested	(130,784	)	57.91		130,784		—
Settled ⁽²⁾					(72,148	)	(72,148	)
Issuance of dividend equivalents⁽³⁾	5,027		65.78		23,243		28,270
Canceled ⁽⁴⁾					(4,489	)	(4,489	)
Outstanding as of December 31, 2016	366,439		$	59.07	1,028,750		1,395,189

_______________


(1)	Represents the grant-date fair value for all awards, excluding the 2014 Performance-Based RSU Grant, which was re-measured upon stockholder approval of the amended 2006 Plan on May 22, 2014, as an insufficient number of shares were available to settle these RSUs upon initial grant on January 29, 2014.

(2)

Represents vested RSUs that were settled in shares of the Company’s common stock. Total shares settled include 23,087 shares that were tendered in accordance with the terms of the 2006 Plan to satisfy minimum statutory tax withholding requirements related to the RSUs settled. We accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy tax obligations.


(3)	Represents the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.


(4)	For shares vested but not yet settled, we accept the return of RSUs at the current quoted closing share price of the Company’s common stock to satisfy minimum statutory tax-withholding requirements related to either the settlement or vesting of RSUs in accordance with the terms of the 2006 Plan.

A summary of our time-based RSU activity for the years ended December 31, 2016, 2015 and 2014 is presented below:



	RSUs Granted			RSUs Vested
Year ended December 31,	Non-Vested RSUs Issued	Weighted-Average Grant Date Fair Value Per Share		Vested RSUs		Total Vest-Date Fair Value ⁽¹⁾ (in thousands)
2016	173,747	$	58.29	(130,784	)	$	8,438
2015	98,802	74.49		(107,541	)	7,528
2014	155,016	59.89		(116,447	)	6,675

_______________


(1)	Total fair value of RSUs vested was calculated based on the quoted closing share price of the Company’s common stock on the NYSE on the day of vesting. Excludes the issuance of dividend equivalents earned on the underlying RSUs. The dividend equivalents vest based on terms specified under the related RSU award agreement.