Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Summary of Share-Based Compensation Expense

The following table summarizes the share-based compensation expense recognized for the periods presented:

	Year Ended December 31,
	2011		2010		2009
Stock option plans	$	5,477	$	5,828	$	6,602
Common, deferred, restricted and restricted unit plans		1,953		1,983		2,525
	$	7,430	$	7,811	$	9,127

Fair Value of Each Option Award Estimated on Date of Grant Using Black-Scholes-Merton Option-Pricing Formula

The fair value of each option award is estimated on the date of grant using the Black-Scholes-Merton option-pricing formula that uses the assumptions noted in the following table. Expected volatilities are based on historical changes in the market value of our stock. Separate groups of employees that have similar historical exercise behavior are considered separately to estimate expected lives. Options granted have a maximum term of ten years. We base the risk-free interest rate on the U.S. Treasury rate for the week of the grant having a term equal to the expected life of the option.

2011

2010

2009

Expected volatility

61.7% to 71.9%

59.5% to 67.6%

51.7% to 64.9%

Dividend yield

1.25% to 2.25%

0.90% to 1.20%

1.25% to 1.49%

Expected life

3.5 to 4.6 years

Risk-free interest rate

0.39% to 2.18%

0.68% to 2.30%

1.23% to 1.84%

Activity of Awarded Options

The following table summarizes activity for our most recent fiscal year with respect to awarded options:

						Weighted-
						Average
				Weighted-		Remaining
	Shares Under			Average		Contractual		Aggregate
	Options			Exercise Price		Term		Intrinsic Value
Outstanding at beginning of year		2,144,357		$	24.70
Granted		830,021			16.98
Exercised		(95,516	)		11.89
Forfeited		(403,788	)		23.26
Outstanding at end of year		2,475,074		$	22.84		7.4	$	67
Exercisable at end of year		1,352,273		$	26.74		6.4	$	12

Status of Nonvested Restricted Stock

The following table summarizes activity for our most recent fiscal year with respect to awarded nonvested restricted stock:

	Nonvested			Weighted-Average
	Restricted			Grant Date
	Stock			Fair Value
Balance at beginning of year		5,957		$	42.27
Vested		(5,957	)		42.27
Balance at end of year		-		$	-

Activity of Awarded Deferred Common Stock Units

The following table summarizes activity for our most recent fiscal year with respect to awarded deferred common stock units:

	Deferred		Weighted-Average
	Common Stock		Grant Date
	Units		Fair Value
Balance at beginning of year		103,256	$	26.76
Granted		105,527		8.31
Balance at end of year		208,783	$	17.34

Activity of Awarded Restricted Stock Units

The following table summarizes activity for our most recent fiscal year with respect to awarded restricted stock units:

				Weighted-Average
	Restricted Stock			Grant Date
	Units			Fair Value
Balance at beginning of year ¹		72,215		$	18.77
Granted		78,763			17.14
Vested		(51,152	)		18.38
Balance at end of year ¹		99,826		$	18.10

¹ Excludes 61,344 units at both the beginning and end of year that have vested due to retirement eligibility, but have not yet been settled or converted to common shares.