Fair Value Disclosures - Carrying and Fair Values of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 4.50% Notes [Member]	Dec. 31, 2013 7.50% Notes [Member]	Dec. 31, 2013 7.5% Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 Carrying Amount [Member] 4.50% Notes [Member]	Dec. 31, 2012 Carrying Amount [Member] 4.50% Notes [Member]	Dec. 31, 2013 Carrying Amount [Member] Notes and Senior Exchange Convertible Notes [Member]	Dec. 31, 2012 Carrying Amount [Member] Notes and Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] 4.50% Notes [Member]	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] 4.50% Notes [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Notes and Senior Exchange Convertible Notes [Member]	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Notes and Senior Exchange Convertible Notes [Member]
Fair Value Disclosures [Abstract]
Impairment of Real Estate	$ 958
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notes Payable, Fair Value Disclosure					$ 5,402	$ 5,402	$ 100,000	$ 100,000	$ 5,425	$ 5,343	$ 111,775	$ 101,500
Notes, mortgage notes and other debt [Abstract]
Stated interest rate (percent)		4.50%	7.50%	7.50%