Debt Convertible Notes (Details) (USD $) In Thousands, except Share data, unless otherwise specified			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Convertible Notes due December 15, 2017 [Member]
Debt Instrument [Line Items]
Stock price, per share, exceeded at least 20 or last 30 days of quarter			$ 13.36
Period Of Trading Days			20 days
Period of Consecutive Trading Days			30 days
Estimated Cash, Surrender of Convertible Notes, Value			$ 57,500
Convertible Notes Principal Amount	$ 57,500	$ 57,500
Estimated Common Stock, Surrender of Convertible Notes, Shares			2,224