Share-Based Compensation (Details) (Restricted Stock [Member], USD $) In Thousands, except Share data	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Restricted Stock [Member]
Summary of Nonvested Shares
Outstanding at January 1, 2011 , Shares	50,032
Outstanding at January 1, 2011, Weighted Average Grant Date Fair Value Per Share	$ 58.40
Granted, Non-Vested Shares	68,727		3,239
Granted, Weighted Average Grant Date Fair Value Per Share	$ 37.83		$ 30.88
Vested, Shares	(9,474)	[1]	(16,358)
Vested, Weighted Average Grant Date Fair Value Per Share	$ 56.76
Outstanding as of September 30, 2011, Shares	109,285
Outstanding as of September 30, 2011, Weighted Average Grant Date Fair Value Per Share	$ 45.61
Summary of Granted and Vested Shares
Granted, Non-Vested Shares	68,727		3,239
Granted, Weighted Average Grant Date Fair Value Per Share	$ 37.83		$ 30.88
Vested, Shares	(9,474)	[1]	(16,358)
Vested shares, total fair value	$ 370	[2]	$ 474	[2]

[1] The total shares vested include 2,198 shares that were tendered to satisfy minimum statutory tax withholding requirements related to the restricted shares that have vested in accordance with the terms of the 2006 Plan. We accept the return of shares at the current quoted closing share price of the Company's common stock to satisfy tax obligations.

[2] Total fair value of shares vested was calculated based on the quoted closing share price of the Company's common stock on the NYSE on the day of vesting.