Notes Payable - Schedule of Debt (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 7.50% Notes [Member]	Dec. 31, 2013 7.50% Notes [Member]	Mar. 31, 2014 4.50% Notes [Member]	Dec. 31, 2013 4.50% Notes [Member]	Mar. 31, 2014 7.50% Senior Exchange Convertible Notes Member [Member]	Dec. 31, 2013 7.50% Senior Exchange Convertible Notes Member [Member]
Debt Instrument [Line Items]
Outstanding debt			$ 55,481	$ 55,500	$ 5,402	$ 5,402	$ 44,500	$ 44,500
Interest payments	$ 3,749	$ 3,935