Stock Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2012

Stock Compensation Plans [Abstract]

Summary of stock-based compensation expense

The following table is a summary of the stock-based compensation expense recognized for the three months ended March 31, 2012 and 2011 (in thousands of dollars):

	Three Months Ended
	March 31,
	2012			2011
Stock-based compensation expense	$	1,619		$	871
Tax benefit		(599	)		(322	)
Stock-based compensation expense, net of tax	$	1,020		$	549

Stock option valuation assumptions

There were no option grants during the first three months of 2012.  The fair value of each option grant during the first three months of 2011 was estimated on the date of grant using the Black-Scholes option-pricing model, based on the following assumptions:

	2011
Expected dividend yield		0.80	%
Expected stock price volatility		48.6% - 57.6	%
Risk free interest rate		0.86% - 2.39	%
Expected life options	2 - 5 years
Weighted-average fair value per share at grant date	$	24.31

Summary of stock options activity

A summary of stock option activity under the plans during the three months ended March 31, 2012, is presented below:

						Weighted-
				Weighted-		Average		Aggregate
				Average		Remaining		Intrinsic
				Exercise		Contractual		Value
Options	Shares			Price		Term		($000's)
Outstanding at January 1, 2012		1,504,311		$	42.26
Granted		-			-
Exercised		(50,051	)		30.64
Forfeited or expired		(6,750	)		42.46
Outstanding at March 31, 2012		1,447,510		$	42.66		7.7	$	55,196
Exercisable at March 31, 2012		702,437		$	34.91		6.6	$	32,216