Notes, Mortgage Notes and Other Debt (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended		12 Months Ended			9 Months Ended			9 Months Ended	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Oct. 13, 2008	Sep. 30, 2011 4.50 % Convertible Senior Notes [Member]	Sep. 30, 2012 4.50 % Convertible Senior Notes [Member]	Sep. 30, 2011 4.50 % Convertible Senior Notes [Member]	Dec. 31, 2009 4.50 % Convertible Senior Notes [Member]	Dec. 31, 2008 4.50 % Convertible Senior Notes [Member]	Apr. 30, 2011 4.50 % Convertible Senior Notes [Member]	Sep. 30, 2012 4.50 % Convertible Senior Notes [Member]	Dec. 31, 2011 JEN Transaction Notes 1 [Member]	Dec. 31, 2011 JEN Transaction Notes 2 [Member]	Sep. 30, 2012 JEN Trasnsaction Notes [Member]	Sep. 30, 2012 7.50% Senior Convertible Notes [Member]	Sep. 30, 2011 7.50% Senior Convertible Notes [Member]	Sep. 30, 2012 7.50% Senior Convertible Notes [Member]	Sep. 30, 2011 7.50% Senior Convertible Notes [Member]	Dec. 31, 2011 Real Estate Notes [Member]	Sep. 30, 2012 7.5% Senior Exchange Convertible Notes [Member]	Sep. 30, 2012 7.5% Senior Exchange Convertible Notes [Member]
Debt Instrument [Line Items]
Outstanding debt												$ 120,000,000	$ 6,000,000	$ 6,000,000		$ 100,000,000		$ 100,000,000		$ 3,000,000
Stated interest rate (in hundredths)	7.50%	4.50%	7.50%	4.50%	4.50%							4.50%	6.00%	6.00%		7.50%		7.50%			7.50%	7.50%
Maturity Date of debt																		Jan. 31, 2016				Feb. 15, 2016
Proceeds from convertible debt			0	100,000,000								95,373,000
Underwriter's discount (in hundredths)												4.25%
Debt issuance costs			(1,683,000)	(4,627,000)																	1,683,000	377,000
Non Cash Charges Related to Amortization of Underwriting Fees and Expenses																174,000	394,000	945,000	1,041,000		111,000	111,000
Debt Instrument, convertible, number of equity instruments (in shares)												19.0006						33.3333				55.5555
Principal conversion standard base unit (in dollars per share)												$ 1				$ 1		$ 1			$ 1,000	$ 1,000
Debt Instrument, Convertible, Conversion Price (in dollars per share)												$ 52.63				$ 30.00		$ 30.00			$ 18.00	$ 18.00
Financial covenants: [Abstract]
Minimum cash and cash equivalents per financial covenants																20,000,000		20,000,000
Maximum indebtedness per financial covenants																150,000,000		150,000,000
Maximum indebtedness per financial covenants excluding for purposes of the covenant																50,000,000		50,000,000
Redemption right [Abstract]
Number of trading days the entity may redeem outstanding Notes												20 days						20 days
Number of consecutive trading days												30 days						30 days
Convertible conversion price percentage (in hundredths)												120.00%						130.00%				130.00%
Principal amount of debt retired							5,000,000		14,076,000	35,920,000						44,500
Remaining principal amount of debt after exchange												5,402,000						55,500
Business Day Period												5 days
Consecutive trading days the trading price per principal amount was less												5 days
Minimum closing price of common stock as a percentage of conversion price (in hundredths)												98.00%
Number of note payable agreements															2
Interest incurred	2,229,000	2,549,000	6,912,000	7,560,000
Interest capitalized	(326,000)	(112,000)	(656,000)	(330,000)
Interest expense	1,903,000	2,437,000	6,256,000	7,230,000
Interest payments			7,473,000	5,552,000
Debt Conversion [Line Items]
Debt Conversion, Original Debt, Amount							200,000
Debt Conversion, Converted Instrument, Shares Issued							3,800
Extinguishment of Debt, Amount							5,000,000		14,076,000	35,920,000						44,500
Amount of principal owners exercised right for the company to repurchase											41,637,000
Repurchase price percentage (in hundredths)							100.00%
Amortization of debt discount						$ 0		$ 293,000