Stock-Based Compensation (Details 2) (SOSARs [Member], USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
SOSARs [Member]
Summary of stock option activity
Outstanding at January 1,	2,121,454	2,298,288
Granted	361,923	371,812
Exercised	(40,986)	(65,637)
Canceled/ forfeited	(23,920)	(10,000)
Outstanding at March 31,	2,418,471	2,594,463
Weighted Average Exercise Price, Outstanding at Jan 1	$ 12.93	$ 12.35
Weighted Average Exercise Price, Granted	$ 18.36	$ 15.61
Weighted Average Exercise Price, Exercised	$ 13.90	$ (10.57)
Weighted Average Exercise Price, Cancelled	$ 15.61	$ (14.96)
Weighted Average Exercise Price, Outstanding at March 31	$ 13.70	$ 12.85
Weighted average grant date fair value per share	$ 5.64	$ 4.98
Aggregate grant date fair value	$ 2,042	$ 1,850
Black-Scholes Assumptions
Dividend yield	2.18%	2.31%
Risk free rate of return	0.99%	1.05%
Volatility	39.62%	41.51%
Expected Life	6 years	6 years

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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The range of expected volatilities used and the weighted-average expected volatility for an entity using a valuation technique with different volatilities during the contractual term.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Gross number of share options (or share units) granted during the period.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees can acquire the shares reserved for issuance on stock options awarded.

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Number of share options (or share units) exercised during the current period.

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