Share-Based Compensation (Stock Option Activity) (Details) (USD $)	6 Months Ended	12 Months Ended
Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010
Options
Outstanding, beginning balance	125,034	138,766
Granted	0	0
Exercised	0	0
Expired	0	(13,732)
Forfeited	0	0
Outstanding, ending balance	125,034	125,034	138,766
Exercisable	125,034	125,034
Weighted Average Exercise Price
Outstanding, beginning	$ 22.43	$ 22.09
Granted	$ 0.00	$ 0.00
Exercised	$ 0.00	$ 0.00
Expired	$ 0.00	$ 19.00
Forfeited	$ 0.00	$ 0.00
Outstanding, ending	$ 22.43	$ 22.43	$ 22.09
Exercisable	$ 22.43	$ 22.43
Weighted Average Remaining Contractual Life (Years)
Outstanding	1 year 3 months	1 year 9 months	2 years 9 months
Exercisable	1 year 3 months	1 year 9 months

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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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.

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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 remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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 could have acquired the underlying shares with respect to stock options of the plan that expired.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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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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