Other Assets (Amortization Expense Of Perpetual License) (Details) (Perpetual License [Member], USD $) In Thousands, unless otherwise specified	7 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	May 31, 2010	May 31, 2009
Perpetual License [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense of perpetual license	$ 875	$ 1,500	$ 1,500	$ 689