Mortgages and Notes Payable (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				15 Months Ended		3 Months Ended		12 Months Ended	3 Months Ended		12 Months Ended			3 Months Ended
	Mar. 31, 2010	Mar. 31, 2012 Line of Credit [Member]	Jan. 13, 2012 Secured Term Loan [Member]	Mar. 31, 2012 Secured Term Loan 1 [Member]	Mar. 31, 2012 Secured Term Loan 2 [Member]	Jan. 13, 2012 Secured Revolving Credit Facility [Member]	Mar. 31, 2012 6.00% Convertible Guaranteed Note [Member]	Mar. 31, 2011 6.00% Convertible Guaranteed Note [Member]	Dec. 31, 2011 6.00% Convertible Guaranteed Note [Member]	Mar. 31, 2012 5.45% Exchangeable Guaranteed Note [Member]	Mar. 31, 2011 5.45% Exchangeable Guaranteed Note [Member]	Dec. 31, 2011 5.45% Exchangeable Guaranteed Note [Member]	Dec. 31, 2007 5.45% Exchangeable Guaranteed Note [Member]	Jan. 31, 2012 5.45% Exchangeable Guaranteed Note [Member]	Mar. 31, 2012 Other Debt Obligations [Member]	Mar. 31, 2011 Other Debt Obligations [Member]	Jan. 13, 2012 Condition One [Member] Secured Term Loan [Member]	Jan. 13, 2012 Condition One [Member] Secured Revolving Credit Facility [Member]	Jan. 13, 2012 Condition Four [Member] Secured Term Loan [Member]	Jan. 13, 2012 Condition Four [Member] Secured Revolving Credit Facility [Member]	Mar. 31, 2012 Secured Revolving Credit Facility, Expiring January 2015 [Member] Secured Term Loan [Member]	Jan. 13, 2012 Secured Revolving Credit Facility, Expiring January 2015 [Member] Secured Term Loan [Member]	Jan. 13, 2012 Secured Revolving Credit Facility, Expiring January 2015 [Member] Secured Revolving Credit Facility [Member]	Jan. 13, 2012 Secured Revolving Credit Facility, Expiring January 2014 [Member] Secured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt From Continuing Operations					$ 1,578								$ 44
Debt Instrument, Maturity Date							Jan. 31, 2030
Line of Credit Facility, Amount Outstanding		20,000																				161,000
Letters of Credit Outstanding, Amount		3,744
Line of Credit Facility, Remaining Borrowing Capacity		276,256																			54,000
Debt Instrument, Face Amount			215,000	25,000	35,551		115,000	115,000	115,000	0		62,150	450,000										300,000	300,000
Debt Instrument, Basis Spread on Variable Rate																	2.00%	1.625%	2.85%	2.375%
Unamortized discount							(9,367)		(9,851)	0		(48)
Debt Instrument, Interest Rate, Stated Percentage			1.578%										5.45%
Percent Of Notes Required To Be Repurchased At The Option Of The Holders On Set Dates	100.00%
Debt Instrument, Convertible, Conversion Ratio							142.6917
Debt Instrument, Convertible, Conversion Price							$ 7.01
Extinguishment of Debt, Gain (Loss), Net of Tax															(27)	19
Carrying amount of debt component							105,633		105,149	0		62,102
Carrying amount of equity component							13,134		13,134	0		20,293
Effective interest rate							8.10%		8.10%	0.00%		7.00%
Aggregate if-converted value in excess of aggregate principal amount							32,522		7,907	0		0
Coupon interest							1,725	1,725		188	847
Discount amortization							484	484		34	166
Interest Expense							2,209	2,209		222	1,013
Debt Instrument, Prepaid Amount												387,850
Debt Instrument, Repurchased and Satisfied Amount														62,150
Debt Instrument, Increase in Credit Facility						225,000
Debt Instrument, Aggregate Credit Facility Amount						$ 525,000