Senior Notes Payable and Other Debt (Details 1) (USD $) In Thousands	Jun. 30, 2011		Dec. 31, 2010
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations [Abstract]
2011	$ 250,837
2012	367,005
2013	593,776
2014	218,948
2015	600,886
Thereafter	2,589,922
Total maturities	4,621,374		2,926,954
Principal Amount Due at Maturity [Member]
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations [Abstract]
2011	230,700
2012	185,684
2013	558,075
2014	186,740
2015	575,377
Thereafter	2,436,484
Total maturities	4,173,060
Unsecured Revolving Credit Facilities [Member]
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations [Abstract]
2011	0	[1]
2012	139,500	[1]
2013	0	[1]
2014	0	[1]
2015	0	[1]
Thereafter	0	[1]
Total maturities	139,500	[1]
Scheduled Periodic Amortization [Member]
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations [Abstract]
2011	20,137
2012	41,821
2013	35,701
2014	32,208
2015	25,509
Thereafter	153,438
Total maturities	$ 308,814

[1] June 30, 2011, we had $26.7 million of unrestricted cash and cash equivalents, for $112.8 million of net borrowings outstanding under our unsecured revolving credit facilities.