Debt Convertible Notes (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified			3 Months Ended		3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 Convertible Notes Due in 2017 [Member]	Dec. 15, 2011 Convertible Notes Due in 2017 [Member]	Mar. 31, 2014 Minimum Convertible Notes Due in 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date			Dec. 15, 2017
Debt Instrument, Interest Rate, Stated Percentage				7.00%
Stock price, per share, exceeded at least 20 of 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			1,644