Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
ASSETS:
Investment properties, at cost	$ 34,386,654	$ 34,252,521
Less - accumulated depreciation	9,297,731	9,068,388
Investment properties, net	25,088,923	25,184,133
Cash and cash equivalents	829,966	1,184,518
Tenant receivables and accrued revenue, net	454,110	521,301
Investment in unconsolidated entities, at equity	2,001,506	2,108,966
Investment in Klepierre, at equity	1,991,533	2,016,954
Deferred costs and other assets	1,520,085	1,570,734
Total assets	31,886,123	32,586,606
LIABILITIES:
Mortgages and unsecured indebtedness	22,572,615	23,113,007
Accounts payable, accrued expenses, intangibles, and deferred revenues	1,231,298	1,374,172
Cash distributions and losses in partnerships and joint ventures, at equity	825,220	724,744
Other liabilities	246,300	303,588
Total liabilities	24,875,433	25,515,511
Commitments and contingencies
Preferred units, at liquidation value, and noncontrolling redeemable interests in properties	187,411	178,006
Partners' Equity
Preferred units, 796,948 units outstanding. Liquidation value of $39,847	44,636	44,719
General Partner, 310,047,871 and 309,903,824 units outstanding, respectively	5,800,890	5,865,884
Limited Partners, 52,309,016 and 51,952,554 units outstanding, respectively	978,684	983,363
Total partners' equity	6,824,210	6,893,966
Nonredeemable noncontrolling deficit interests in properties, net	(931)	(877)
Total equity	6,823,279	6,893,089
Total liabilities and equity	$ 31,886,123	$ 32,586,606