Share-based Compensation (Details 1) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Market-based performance condition [Member]
Summary of award information associated with market and non-market-based performance condition awards
Grant Date Fair Value	$ 13.78
Estimated Number of PSUs to be Issued	100
Maximum Number of PSUs that could Potentially be Issued	246
Non-market-based performance condition [Member]
Summary of award information associated with market and non-market-based performance condition awards
Grant Date Fair Value	$ 10.02
Estimated Number of PSUs to be Issued	187
Maximum Number of PSUs that could Potentially be Issued	246