Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]

Deferred leasing and other costs at December 31, 2015 and 2014, excluding such costs for properties classified as held-for-sale, were as follows (in thousands):



	2015			2014
Deferred leasing costs	$	302,282		$	301,173
Acquired lease-related intangible assets	289,518			325,294
	$	591,800		$	626,467

Accumulated amortization - deferred leasing costs	$	(106,912	)	$	(104,916	)
Accumulated amortization - acquired lease-related intangible assets	(138,514		)	(133,916		)
Total	$	346,374		$	387,635

Schedule of Future Amortized Expense and Charge to Rental Income

The expected future amortization, or charge to rental income, of acquired lease-related intangible assets is summarized in the table below (in thousands):



Year	Amortization Expense		Charge to Rental Income
2016	$	33,486	$	1,139
2017	28,103		966
2018	21,704		863
2019	17,302		712
2020	12,423		633
Thereafter	32,524		1,149
	$	145,542	$	5,462

Schedule of Earnings Per Share, Basic and Diluted

The following table reconciles the components of basic and diluted net income (loss) per common share or Common Unit (in thousands):



	2015			2014			2013
General Partner
Net income attributable to common shareholders	$	615,310		$	204,893		$	153,044
Less: Dividends on participating securities	(3,081		)	(2,588		)	(2,678		)
Basic net income attributable to common shareholders	612,229			202,305			150,366
Add back dividends on dilutive participating securities	3,081			—			—
Noncontrolling interest in earnings of common unitholders	6,404			2,627			2,094
Diluted net income attributable to common shareholders	$	621,714		$	204,932		$	152,460
Weighted average number of common shares outstanding	345,057			335,777			322,133
Weighted average Limited Partner Units outstanding	3,582			4,308			4,392
Other potential dilutive shares	3,558			361			187
Weighted average number of common shares and potential dilutive securities	352,197			340,446			326,712

Partnership
Net income attributable to common unitholders	$	621,714		$	207,520		$	155,138
Less: Distributions on participating securities	(3,081		)	(2,588		)	(2,678		)
Basic net income attributable to common unitholders	$	618,633		$	204,932		$	152,460
Add back distributions on dilutive participating securities	3,081			—			—
Diluted net income attributable to common unitholders	$	621,714		$	204,932		$	152,460
Weighted average number of Common Units outstanding	348,639			340,085			326,525
Other potential dilutive units	3,558			361			187
Weighted average number of Common Units and potential dilutive securities	352,197			340,446			326,712

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following table summarizes the data that is excluded from the computation of net income (loss) per common share or Common Unit as a result of being anti-dilutive (in thousands):



	2015	2014	2013
General Partner and Partnership
Other potential dilutive shares or units:
Anti-dilutive outstanding potential shares or units under fixed stock option and other stock-based compensation plans	997	1,210	1,373
Anti-dilutive outstanding participating securities	—	3,844	3,871

Reconciliation of Net Income to Taxable Income Before Dividends Paid Deduction

The following table reconciles the General Partner's net income (loss) to taxable income (loss) before the dividends paid deduction, and subject to the 90% distribution requirement, for the years ended December 31, 2015, 2014 and 2013 (in thousands):



	2015			2014			2013
Net income	$	621,861		$	246,455		$	196,549
Book/tax differences	(314,691		)	738			50,127
Taxable income before the dividends paid deduction	307,170			247,193			246,676
Less: capital gains	(294,901		)	(95,797		)	(109,133		)
Adjusted taxable income subject to the 90% distribution requirement	$	12,269		$	151,396		$	137,543

Computation of Dividends Paid Deduction

The General Partner's dividends paid deduction is summarized below (in thousands):



	2015			2014			2013
Total Cash dividends paid	$	307,170		$	255,622		$	251,914
Less: Return of capital	—			(5,479		)	(1,938		)
Dividends paid deduction	307,170			250,143			249,976
Less: Capital gain distributions	(294,901		)	(95,797		)	(109,133		)
Dividends paid deduction attributable to adjusted taxable income subject to the 90% distribution requirement	$	12,269		$	154,346		$	140,843

Summary of Tax Characterization of Dividends Paid

A summary of the tax characterization of the dividends paid by the General Partner for the years ended December 31, 2015, 2014 and 2013 is as follows:



	2015		2014		2013
Common Shares
Ordinary income	4.2	%	59.2	%	52.6	%
Return of capital	—	%	2.5	%	4.4	%
Capital gains	95.8	%	38.3	%	43.0	%
	100.0	%	100.0	%	100.0	%
Preferred Shares
Ordinary income			60.7	%	55.0	%
Capital gains			39.3	%	45.0	%
			100.0	%	100.0	%

Fair Value Measurements, Nonrecurring [Table Text Block]

The table below aggregates the total fair value of these impaired assets as determined during the years ended December 31, 2015, 2014 and 2013, respectively, by the levels in the fair value hierarchy (in thousands):



	2015				2014				2013
	Level 1	Level 2	Level 3		Level 1	Level 2	Level 3		Level 1	Level 2	Level 3
Real estate assets	—	—	$	31,100	—	—	$	146,767	—	—	22,150
Investment in land joint ventures	—	—	$	19,500	—	—	$	—	—	—	—