CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investment in real estate
Land	$ 6,319,353	$ 4,554,912
Depreciable property	19,966,235	15,711,944
Projects under development	500,829	387,750
Land held for development	577,676	353,823
Cash and cash equivalents	56,087	612,590
Investments in unconsolidated entities	193,338	17,877
Deposits - restricted	147,515	250,442
Escrow deposits - mortgage	39,535	9,129
Deferred financing costs, net	71,229	44,382
Other assets	358,136	170,372
Total assets	23,795,158	17,201,000
Liabilities:
Mortgage notes payable	6,380,424	3,898,369
Notes, net	5,379,890	4,630,875
Lines of credit	395,000	0
Accounts payable and accrued expenses	104,836	38,372
Accrued interest payable	88,518	76,223
Other liabilities	401,225	304,518
Security deposits	72,669	66,988
Distributions payable	150,751	260,176
Total liabilities	12,973,313	9,275,521
Commitments and contingencies
Redeemable Noncontrolling Interests - Operating Partnership	386,757	398,372
Shareholders' equity:
Preferred Shares of beneficial interest, $0.01 par value; 100,000,000 shares authorized; 1,000,000 shares issued and outstanding as of September 30, 2012 and 1,600,000 shares issued and outstanding as of December 31, 2011	50,000	50,000
Common Shares of beneficial interest, $0.01 par value; 1,000,000,000 shares authorized; 302,674,716 shares issued and outstanding as of June 30, 2012 and 297,508,185 shares issued and outstanding as of December 31, 2011	3,601	3,251
Paid in capital	8,492,845	6,542,355
Retained earnings	1,759,990	887,355
Accumulated other comprehensive (loss)	(182,508)	(193,148)
Total shareholders' equity	10,123,928	7,289,813
Noncontrolling Interests:
Operating Partnership	205,230	159,606
Noncontrolling Interests - Partially Owned Properties	105,930	77,688
Total Noncontrolling Interests	311,160	237,294
Total equity	10,435,088	7,527,107
Total liabilities and equity	$ 23,795,158	$ 17,201,000