Fair Value Disclosures - Carrying and Fair Values of Financial Instruments (Details) (USD $)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Minimum [Member]	Sep. 30, 2014 Maximum [Member]	Sep. 30, 2014 4.50% Notes [Member]	Mar. 31, 2014 4.50% Notes [Member]	Dec. 31, 2013 4.50% Notes [Member]	Sep. 30, 2014 7.50% Notes [Member]	Mar. 31, 2014 7.50% Notes [Member]	Dec. 31, 2013 7.50% Notes [Member]	Sep. 30, 2014 7.5% Senior Exchange Convertible Notes [Member]	Mar. 31, 2014 7.5% Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 7.5% Senior Exchange Convertible Notes [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] 4.50% Notes [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] 4.50% Notes [Member]	Sep. 30, 2014 Estimate of Fair Value, Fair Value Disclosure [Member] Notes and Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Notes and Senior Exchange Convertible Notes [Member]	Sep. 30, 2014 Carrying Amount [Member]	Dec. 31, 2013 Carrying Amount [Member]	Sep. 30, 2014 Carrying Amount [Member] 4.50% Notes [Member]	Dec. 31, 2013 Carrying Amount [Member] 4.50% Notes [Member]	Sep. 30, 2014 Carrying Amount [Member] Notes and Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 Carrying Amount [Member] Notes and Senior Exchange Convertible Notes [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notes Payable, Fair Value Disclosure													$ 198,000,000	$ 0	$ 0	$ 5,425,000	$ 102,960,000	$ 111,775,000	$ 200,000,000	$ 0	$ 0	$ 5,402,000	$ 99,981,000	$ 100,000,000
Contingent Consideration, Fair Value													2,500,000	0					2,500,000	0
Notes, mortgage notes and other debt [Abstract]
Stated interest rate (percent)				4.50%	4.50%	4.50%	7.50%	7.50%	7.50%	7.50%	7.50%	7.50%
Fair Value Assumptions, Borrowing Costs	7.00%
Fair Value Assumptions, Expected Volatility Rate, Remainder of Year	5.00%
Fair Value Assumptions, Expected Volatility Rate, Next Twelve Months	15.00%
Fair Value Assumptions, Market Risk Premium	6.00%
Fair Value Assumptions, Asset Beta	1.2	0.50	1.50
Fair Value Assumptions, Expected Volatility Rate		5.00%	25.00%
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, Low		2,428,000
Business Combination, Contingent Consideration Arrangements, Change in Range of Outcomes, Contingent Consideration, Liability, Value, High			$ 2,642,000