Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

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

Details of Grants of Stock-based Compensation

The following are the details of grants of stock-based compensation during the three months ended March 31, 2015 and 2014.

	2015		2014
Grant Details	Shares	Fair Value	Shares	Fair Value
Stock options	291,586	$53.96	357,781	$43.05
Restricted stock units	91,075	$228.08	116,989	$179.21
Contingent shares (a)	31,654	$236.24	38,756	$187.06

(a) The number of contingent shares represents the target value of the award.

The following are the details of grants of stock-based compensation during the three months ended March 31, 2015 and 2014.

	2015		2014
Grant Details	Shares	Fair Value	Shares	Fair Value
Stock options	291,586	$53.96	357,781	$43.05
Restricted stock units	91,075	$228.08	116,989	$179.21
Contingent shares (a)	31,654	$236.24	38,756	$187.06

Weighted Average Assumptions Used in Calculating the Fair Value of Stock Option

The fair value of the stock option grants issued in the three months ended March 31, 2015 was calculated with the following weighted average assumptions:

Weighted average exercise price	$236.24
Risk-free interest rate	1.9	%
Expected life of option in years	6.5
Expected dividend yield	2.7	%
Expected volatility	29.2	%