Other Assets (Details 2) (USD $) In Thousands, unless otherwise specified		12 Months Ended		12 Months Ended
	Dec. 31, 2009	Dec. 31, 2010 2012 Notes, 6.25% interest, due 2012	Dec. 31, 2011 2012 Notes, 6.25% interest, due 2012	Dec. 31, 2010 Term loan facilities under the Credit Agreement	Dec. 31, 2011 August 25, 2011 Amendment to credit agreement
Deferred financing fees
Write-off of unamortized deferred financing fees		$ 1,300		$ 700	$ 4,200
Debt Instrument, interest rate, stated percentage	0.75%		6.25%