SENIOR NOTES PAYABLE AND OTHER DEBT (Details 2) (USD $)	1 Months Ended					9 Months Ended				1 Months Ended
	Oct. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2013 Unsecured revolving credit facilities	Dec. 31, 2012 Unsecured revolving credit facilities	Sep. 30, 2013 Mortgage loans and other	Dec. 31, 2012 Mortgage loans and other	Oct. 31, 2013 Mortgage loans and other Subsequent Event	Sep. 30, 2013 6.90% Senior Notes due 2037	Dec. 31, 2012 6.90% Senior Notes due 2037	Sep. 30, 2013 6.59% Senior Notes due 2038	Dec. 31, 2012 6.59% Senior Notes due 2038	Sep. 30, 2013 Principal Amount Due at Maturity	Sep. 30, 2013 Unsecured Revolving Credit Facility	Sep. 30, 2013 Scheduled Periodic Amortization
Scheduled maturities of borrowing arrangements and other provisions excluding capital lease obligations
2013		$ 90,813,000													$ 77,497,000	$ 0	$ 13,316,000
2014		322,943,000													273,050,000	0	49,893,000
2015		1,546,514,000													1,057,536,000	447,970,000	41,008,000
2016		994,917,000													960,917,000	0	34,000,000
2017		949,337,000													927,243,000	0	22,094,000
Thereafter		5,454,494,000													5,292,084,000	0	162,410,000
Total		9,359,018,000	8,186,315,000			447,970,000	540,727,000	2,811,766,000	2,880,609,000		52,400,000	52,400,000	22,973,000	22,973,000	8,588,327,000	447,970,000	322,721,000
Interest rate (as a percent)											6.90%	6.90%	6.59%	6.59%
Unrestricted cash and cash equivalents		54,672,000	67,908,000	58,530,000	45,807,000
Amount outstanding, net of cash and cash equivalents						393,300,000
Line of credit facility optional extension period						1 year
Repayments of Debt	$ 40,900,000									$ 40,900,000