Long-term Equity-based Compensation (Tables)

The assumptions used in the Black-Scholes pricing model for Tandem Awards granted during the years ended December 31, 2017, 2016 and 2015 are presented below.



	2017					2016					2015
RANGE OF VALUATION ASSUMPTIONS
Expected Volatility	26.17	%	-	30.39	%	25.85	%	-	42.19	%	21.31	%	-	41.65	%
Risk-free Interest Rate	1.59		-	2.25		0.77		-	2.01		1.08		-	1.96
Expected Dividend Yield	1.39		-	2.43		2.22		-	3.41		2.37		-	2.62
WEIGHTED-AVERAGE EXPECTED LIFE IN YEARS
Employee Grants	4		-	6.5		1		-	6.5		4		-	7
Director Grants	N/A					N/A					5.5

activity for the year ended December 31, 2017 is presented below.



	Shares Subject to Awards		Weighted- average Exercise Price Per Share ($)		Weighted- average Remaining Contractual Life (in Years)	Aggregate Intrinsic Value ($ In Millions)
Outstanding at Beginning of the Year	1,306,123		$	36.35
Granted	444,339		43.72
Exercised	(377,811	)	35.60
Forfeited or Expired	(360,372	)	43.14
Outstanding at December 31, 2017	1,012,279		37.45		7.85	$	31.8
Vested and Expected to Vest at December 31, 2017	959,899		$	37.40	7.81	$	30.2
Exercisable at December 31, 2017	470,946		$	35.49	6.92	$	15.7

Information pertaining to Tandem Awards outstanding at December 31, 2017 is presented below.



					Outstanding				Exercisable
Range of Exercise Prices ($)					Shares Subject to Awards	Weighted- average Exercise Price Per Share ($)		Weighted- average Remaining Contractual Life (in Years)	Shares Subject to Awards	Weighted- average Exercise Price Per Share ($)
$	15.00	-	$	20.00	4,000	$	16.48	1.35	4,000	$	16.48
20.01		-	25.00		2,000	22.33		1.94	2,000	22.33
25.01		-	30.00		205,469	27.82		7.36	108,813	27.92
30.01		-	35.00		124,127	31.84		6.90	83,141	32.03
35.01		-	40.00		198,515	37.40		7.03	124,428	37.20
40.01		-	45.00		463,637	42.58		8.70	148,564	42.24
45.01		-	50.00		—	—		0.00	—	—
50.01		-	55.00		734	54.50		9.76	—	—
55.01		-	60.00		—	—		0.00	—	—
60.01		-	65.00		6,221	64.30		9.84	—	—
65.01			70.00		7,576	68.65		9.92	—	—
15.00		-	70.00		1,012,279	37.45		7.85	470,946	35.49

Activity related to DSU awards for the year ended December 31, 2017 is presented below.



	Number of DSUs	Weighted- average Grant-date Fair Value Per DSU
Vested Balance at Beginning of the Year	21,520	$	32.68
Granted and Vested	23,040	38.20
Vested Balance at December 31, 2017	44,560	$	35.54

Activity related to nonvested RSUs for the year ended December 31, 2017 is presented below.



	Time-based Restricted Stock Awards				Time-based Restricted Stock Unit Awards
	Number of Shares		Weighted- average Grant-date Fair Value Per Share		Number of Restricted Stock Units		Weighted- average Grant-date Fair Value Per Unit
Nonvested Balance at Beginning of the Year	16,000		$	34.69	158,361		$	33.56
Granted	—		—		84,331		44.70
Vested	(14,000	)	34.13		(57,016	)	33.65
Forfeited	(2,000	)	38.59		(55,429	)	34.46
Nonvested Balance at December 31, 2017	—		$	—	130,247		$	40.34

Activity related to nonvested PSU awards for the year ended December 31, 2017 is presented below.



	PSU Awards
	Number of PSUs		Weighted- average Grant-date Fair Value Per PSU
Nonvested Balance at Beginning of the Year	227,584		$	34.55
Granted	100,620		44.32
Forfeited	(102,221	)	38.96
Nonvested Balance at December 31, 2017	225,983		$	36.90