Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

Share-based Compensation [Abstract]

Assumptions to Estimate Fair Value of Option Grant on Date of Grant Using Black Scholes Option Pricing Model

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

	Six months ended June 30,
	2016			2015
Dividend yield	1.70		%	1.60		%
Volatility - stock option plans	24 - 25%			31		%
Risk free interest rates	1.31		%	1.79		%
Expected life (years) - stock option plans	5.50 - 6.50			6.41 - 7.47
Weighted average fair value of stock options granted during the period	$	9.57		$	13.42

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs

Total stock compensation expense and the total related tax benefit recognized are as follows:

	Three months ended				Six months ended
	June 30,				June 30,
	2016		2015		2016		2015
Stock compensation expense	$	12,957	$	11,663	$	23,788	$	21,570
Recognized tax benefit	$	2,049	$	1,491	$	3,779	$	2,734