Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2011

Notes to Financial Statements [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 with the following assumptions:

	Six months ended June 30,
	2011			2010
Dividend yield	0.97		%	1.08		%
Volatility - stock option plans	38 - 40 %			38 - 40 %
Risk free interest rates	2.17 - 2.84%			2.18 - 2.86%
Expected life (years) - stock option plans	5.50 - 7.11			5.44 - 6.90
Weighted average fair value of stock options granted during the period	$	19.35		$	14.51

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,
	2011		2010		2011		2010
Stock compensation expense	$	10,236	$	11,003	$	20,708	$	22,201
Recognized tax benefit	$	39	$	52	$	77	$	109