Investments in Partially Owned Entities - Partially Owned Property Income Statement Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Partially Owned Property Income Statement Schedule
Operating information for the year ended 12/31/17 (at 100%):	$ 2,471,406	$ 2,425,800	$ 2,744,965
Property management	85,493	82,015	86,206
General and administrative	52,224	57,840	64,664
Depreciation	743,749	705,649	765,895
Operating income	847,471	856,086	1,009,238
Interest and other income	6,136	65,773	7,372
Interest:
Expense incurred, net	(383,890)	(482,246)	(444,487)
Amortization of deferred financing costs	(8,526)	(12,633)	(10,801)
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	456,005	416,612	558,380
Income and other tax (expense) benefit	(478)	(1,613)	(917)
Income (loss) from investments in unconsolidated entities	(3,370)	4,801	15,025
Net income	628,381	$ 4,480,104	$ 908,018
Unconsolidated Non-VIE
Partially Owned Property Income Statement Schedule
Operating information for the year ended 12/31/17 (at 100%):	26,898
Operating expenses	8,936
Net operating income	17,962
Property management	784
General and administrative	3
Depreciation	10,633
Operating income	6,542
Interest and other income	0
Interest:
Expense incurred, net	(8,289)
Amortization of deferred financing costs	(1)
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	(1,748)
Income and other tax (expense) benefit	(13)
Income (loss) from investments in unconsolidated entities	0
Net income	(1,761)
Consolidated VIE
Partially Owned Property Income Statement Schedule
Operating information for the year ended 12/31/17 (at 100%):	93,472
Operating expenses	22,412
Net operating income	71,060
Property management	3,401
General and administrative	279
Depreciation	25,505
Operating income	41,875
Interest and other income	77
Interest:
Expense incurred, net	(13,316)
Amortization of deferred financing costs	(270)
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	28,366
Income and other tax (expense) benefit	(27)
Income (loss) from investments in unconsolidated entities	(1,549)
Net income	26,790
Unconsolidated VIE
Partially Owned Property Income Statement Schedule
Operating information for the year ended 12/31/17 (at 100%):	5,243
Operating expenses	2,463
Net operating income	2,780
Property management	75
General and administrative	0
Depreciation	5,501
Operating income	(2,796)
Interest and other income	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	(2,796)
Income and other tax (expense) benefit	0
Income (loss) from investments in unconsolidated entities	0
Net income	(2,796)
Partially Owned Properties – Unconsolidated
Partially Owned Property Income Statement Schedule
Operating information for the year ended 12/31/17 (at 100%):	32,141
Operating expenses	11,399
Net operating income	20,742
Property management	859
General and administrative	3
Depreciation	16,134
Operating income	3,746
Interest and other income	0
Interest:
Expense incurred, net	(8,289)
Amortization of deferred financing costs	(1)
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	(4,544)
Income and other tax (expense) benefit	(13)
Income (loss) from investments in unconsolidated entities	0
Net income	$ (4,557)