Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

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

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The following table summarizes the assumptions used in estimating the fair value of these awards issued in 2014:

	Stock Price on Measurement Date		Dividend Yield		Expected Volatility		Risk Free Interest Rate		Expected Term	Weighted Avg. Grant Date Fair Value
2014	$	106.44	2.1	%	22.7	%	1.0	%	3 Years	$	95.96

Schedule of Activity Related to Employee and Non-Employee Restricted Stock

Activity related to both employee and non-employee restricted stock for the year ended December 31, 2014 is as follows (in thousands, except per share amounts):

	Shares		Weighted Average Grant Date Fair Value/Share
RESTRICTED STOCK AT DECEMBER 31, 2013	167		$	91.17
Shares granted	87		105.35
Shares vested	(83	)	83.73
Shares forfeited	(4	)	76.28
RESTRICTED STOCK AT DECEMBER 31, 2014	167		$	102.22

Summary of Stock Appreciation Rights

Activity related to SARs for the year ended December 31, 2014 is as follows (in thousands, except per share amounts):

	Number of Rights		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
OUTSTANDING AT DECEMBER 31, 2013	1,531		$	69.68
Granted	251		106.73
Exercised	(314	)	57.16
Forfeited	(3	)	95.63
OUTSTANDING AT DECEMBER 31, 2014	1,465		$	78.64	7.4 Years	$	41,601
EXERCISABLE AT DECEMBER 31, 2014	947		$	65.79	6.4 Years	$	38,950

Summary of the Weighted-Average Assumption Used in Estimating Fair Value of Stock Appreciation Rights

The following table summarizes the weighted-average assumptions used in estimating the fair value of the SARs granted during the years 2014, 2013, and 2012:

	Expected Dividend Yield		Expected Volatility		Risk Free Interest Rate		Expected Term	Weighted Avg. Grant Date Fair Value of 1 SAR
2014	2.0	%	21.8	%	1.6	%	5.3 Years	$	18.42
2013	1.9	%	28.3	%	1.6	%	5.4 Years	$	24.58
2012	2.0	%	29.4	%	0.7	%	5.5 Years	$	18.13

Summary of Performance Shares Valuation

The following table summarizes the related assumptions used to determine the fair values of the performance share awards granted during the years 2014, 2013, and 2012:

	Stock Price on Measurement Date		Dividend Yield		Expected Volatility		Risk Free Interest Rate		Expected Term	Weighted Avg. Grant Date Fair Value
2014	$	106.44	2.1	%	22.7	%	1.0	%	3 Years	$	117.55
2013	$	107.87	1.9	%	33.8	%	0.6	%	3 Years	$	130.33
2012	$	83.73	2.0	%	27.3	%	0.4	%	3 Years	$	100.77

Summary of Stock Option Activity

Stock option activity for the year ended December 31, 2014 is set forth below (in thousands, except per share amounts):

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
OUTSTANDING AT DECEMBER 31, 2013	51		$	47.95
Exercised	(51	)	47.95
OUTSTANDING AT DECEMBER 31, 2014	—		$	—	—	$	—
EXERCISABLE AT DECEMBER 31, 2014	—		$	—	—	$	—