Investments in Partially Owned Entities (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Feb. 27, 2013 USD ($)
Partially Owned Property Balance Sheet Schedule
Properties	308		308
Apartment Units	78,826		78,826
ASSETS
Investment in real estate	$ 25,361,243,000		$ 25,361,243,000		$ 25,182,352,000
Accumulated depreciation	(5,255,965,000)		(5,255,965,000)		(4,905,406,000)
Investment in real estate, net	20,105,278,000		20,105,278,000		20,276,946,000
Cash and cash equivalents	517,586,000	$ 37,366,000	517,586,000	$ 37,366,000	42,276,000	$ 40,080,000
Investments in unconsolidated entities	60,911,000		60,911,000		68,101,000
Deposits – restricted	129,569,000		129,569,000		55,893,000
Other assets	421,406,000		421,406,000		428,899,000
Total assets	21,297,744,000		21,297,744,000		23,110,196,000
LIABILITIES AND EQUITY
Secured Debt	4,138,301,000		4,138,301,000		4,685,134,000
Accounts payable & accrued expenses	199,795,000		199,795,000		187,124,000
Accrued interest payable	69,441,000		69,441,000		85,221,000
Other Liabilities	353,605,000		353,605,000		366,387,000
Security deposits	64,060,000		64,060,000		77,582,000
Total liabilities	10,517,051,000		10,517,051,000		11,847,058,000
Noncontrolling Interests – Partially Owned Properties/Partners' equity	4,194,000		4,194,000		4,608,000
Total liabilities and equity	21,297,744,000		21,297,744,000		$ 23,110,196,000
Partially Owned Property Income Statement Schedule
Operating revenue	606,074,000	696,289,000	1,820,311,000	2,041,772,000
Property management	19,517,000	20,094,000	64,003,000	64,651,000
General and administrative/other	12,395,000	15,197,000	47,408,000	50,618,000
Depreciation	179,230,000	196,059,000	528,242,000	584,862,000
Operating income	209,373,000	257,594,000	632,016,000	722,180,000
Interest and other income	5,509,000	256,000	65,092,000	6,906,000
Other expenses	(10,420,000)	(1,139,000)	(14,480,000)	(2,839,000)
Interest:
Expense incurred, net	(86,352,000)	(114,298,000)	(386,316,000)	(333,946,000)
Amortization of deferred financing costs	(2,261,000)	(2,607,000)	(10,000,000)	(7,734,000)
Income before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations	115,849,000	139,806,000	286,312,000	384,567,000
Income and other tax (expense) benefit	(426,000)	(329,000)	(1,189,000)	(698,000)
Income (loss) from investments in unconsolidated entities	7,750,000	(1,041,000)	5,846,000	14,388,000
Net income	217,492,000	205,456,000	$ 4,177,723,000	694,298,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Disposed Properties			92
Apartment Units			28,167
Net gain on sales of real estate properties	$ 90,036,000	$ 66,939,000	$ 3,870,871,000	$ 295,692,000
Consolidated VIE
Partially Owned Property Balance Sheet Schedule
Properties	18		18
Apartment Units	3,471		3,471
ASSETS
Investment in real estate	$ 668,656,000		$ 668,656,000
Accumulated depreciation	(220,216,000)		(220,216,000)
Investment in real estate, net	448,440,000		448,440,000
Cash and cash equivalents	19,499,000		19,499,000
Investments in unconsolidated entities	47,521,000		47,521,000
Deposits – restricted	336,000		336,000
Other assets	26,655,000		26,655,000
Total assets	542,451,000		542,451,000
LIABILITIES AND EQUITY
Secured Debt	318,427,000		318,427,000
Accounts payable & accrued expenses	2,944,000		2,944,000
Accrued interest payable	1,085,000		1,085,000
Other Liabilities	625,000		625,000
Security deposits	1,913,000		1,913,000
Total liabilities	324,994,000		324,994,000
Noncontrolling Interests – Partially Owned Properties/Partners' equity	4,194,000		4,194,000
Company equity/General and Limited Partners' Capital	213,263,000		213,263,000
Total equity/capital	217,457,000		217,457,000
Total liabilities and equity	$ 542,451,000		542,451,000
Partially Owned Property Income Statement Schedule
Operating revenue			70,123,000
Operating Expenses			17,183,000
Net operating income			52,940,000
Property management			2,476,000
General and administrative/other			50,000
Depreciation			16,161,000
Operating income			34,253,000
Interest and other income			47,000
Other expenses			(7,000)
Interest:
Expense incurred, net			(11,073,000)
Amortization of deferred financing costs			(289,000)
Income before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations			22,931,000
Income and other tax (expense) benefit			(44,000)
Income (loss) from investments in unconsolidated entities			(1,091,000)
Net income			$ 21,796,000
Unconsolidated Non-VIE
Partially Owned Property Balance Sheet Schedule
Properties	2		2
Apartment Units	945		945
ASSETS
Investment in real estate	$ 235,025,000		$ 235,025,000
Accumulated depreciation	(30,246,000)		(30,246,000)
Investment in real estate, net	204,779,000		204,779,000
Cash and cash equivalents	8,203,000		8,203,000
Investments in unconsolidated entities	0		0
Deposits – restricted	262,000		262,000
Other assets	344,000		344,000
Total assets	213,588,000		213,588,000
LIABILITIES AND EQUITY
Secured Debt	145,423,000		145,423,000
Accounts payable & accrued expenses	2,674,000		2,674,000
Accrued interest payable	691,000		691,000
Other Liabilities	255,000		255,000
Security deposits	485,000		485,000
Total liabilities	149,528,000		149,528,000
Noncontrolling Interests – Partially Owned Properties/Partners' equity	60,689,000		60,689,000
Company equity/General and Limited Partners' Capital	3,371,000		3,371,000
Total equity/capital	64,060,000		64,060,000
Total liabilities and equity	213,588,000		213,588,000
Partially Owned Property Income Statement Schedule
Operating revenue			19,917,000
Operating Expenses			6,785,000
Net operating income			13,132,000
Property management			580,000
General and administrative/other			1,000
Depreciation			7,876,000
Operating income			4,675,000
Interest and other income			0
Other expenses			0
Interest:
Expense incurred, net			(6,217,000)
Amortization of deferred financing costs			0
Income before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations			(1,542,000)
Income and other tax (expense) benefit			(13,000)
Income (loss) from investments in unconsolidated entities			0
Net income			(1,555,000)
Unconsolidated Non-VIE | Residual JV [Domain]
ASSETS
Investments in unconsolidated entities	$ (1,400,000)		$ (1,400,000)				$ 147,600,000
Investments In Partially Owned Entities (Textuals) [Abstract]
Business Acquisition, Percentage of Voting Interests Acquired	60.00%		60.00%
Unconsolidated VIE
Partially Owned Property Balance Sheet Schedule
Properties	0		0
Apartment Units	0		0
ASSETS
Investment in real estate	$ 172,995,000		$ 172,995,000
Accumulated depreciation	(43,169,000)		(43,169,000)
Investment in real estate, net	129,826,000		129,826,000
Cash and cash equivalents	17,000		17,000
Investments in unconsolidated entities	0		0
Deposits – restricted	0		0
Other assets	299,000		299,000
Total assets	130,142,000		130,142,000
LIABILITIES AND EQUITY
Secured Debt	0		0
Accounts payable & accrued expenses	133,000		133,000
Accrued interest payable	0		0
Other Liabilities	8,000		8,000
Security deposits	0		0
Total liabilities	141,000		141,000
Noncontrolling Interests – Partially Owned Properties/Partners' equity	86,650,000		86,650,000
Company equity/General and Limited Partners' Capital	43,351,000		43,351,000
Total equity/capital	130,001,000		130,001,000
Total liabilities and equity	$ 130,142,000		130,142,000
Partially Owned Property Income Statement Schedule
Operating revenue			3,927,000
Operating Expenses			1,583,000
Net operating income			2,344,000
Property management			56,000
General and administrative/other			48,000
Depreciation			4,125,000
Operating income			(1,885,000)
Interest and other income			0
Other expenses			0
Interest:
Expense incurred, net			0
Amortization of deferred financing costs			0
Income before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations			(1,885,000)
Income and other tax (expense) benefit			0
Income (loss) from investments in unconsolidated entities			0
Net income			$ (1,885,000)
Partially Owned Properties – Unconsolidated
Partially Owned Property Balance Sheet Schedule
Properties	2		2
Apartment Units	945		945
ASSETS
Investment in real estate	$ 408,020,000		$ 408,020,000
Accumulated depreciation	(73,415,000)		(73,415,000)
Investment in real estate, net	334,605,000		334,605,000
Cash and cash equivalents	8,220,000		8,220,000
Investments in unconsolidated entities	0		0
Deposits – restricted	262,000		262,000
Other assets	643,000		643,000
Total assets	343,730,000		343,730,000
LIABILITIES AND EQUITY
Secured Debt	145,423,000		145,423,000
Accounts payable & accrued expenses	2,807,000		2,807,000
Accrued interest payable	691,000		691,000
Other Liabilities	263,000		263,000
Security deposits	485,000		485,000
Total liabilities	149,669,000		149,669,000
Noncontrolling Interests – Partially Owned Properties/Partners' equity	147,339,000		147,339,000
Company equity/General and Limited Partners' Capital	46,722,000		46,722,000
Total equity/capital	194,061,000		194,061,000
Total liabilities and equity	$ 343,730,000		343,730,000
Partially Owned Property Income Statement Schedule
Operating revenue			23,844,000
Operating Expenses			8,368,000
Net operating income			15,476,000
Property management			636,000
General and administrative/other			49,000
Depreciation			12,001,000
Operating income			2,790,000
Interest and other income			0
Other expenses			0
Interest:
Expense incurred, net			(6,217,000)
Amortization of deferred financing costs			0
Income before income and other taxes, income (loss) from investments in unconsolidated entities, net gain (loss) on sales of real estate properties and land parcels and discontinued operations			(3,427,000)
Income and other tax (expense) benefit			(13,000)
Income (loss) from investments in unconsolidated entities			0
Net income			$ (3,440,000)
Investments In Partially Owned Entities (Textuals) [Abstract]
Disposed Properties			1
Apartment Units			336
Net gain on sales of real estate properties			$ 8,900,000