Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Real estate investments at cost:
Notes receivable	$ 0	$ 15,803
Parent Company [Member]
Real estate investments at cost:
Property, Plant and Equipment, Gross	10,854,283	10,578,430
Properties in development	36,707	314,391
Gross real estate investments at cost	10,890,990	10,892,821
Less: accumulated depreciation	1,474,769	1,339,771
Total Cost Net of Accumulated Depreciation	9,416,221	9,553,050
Investments in real estate partnerships	458,051	386,304
Net real estate investments	9,874,272	9,939,354
Real Estate Held-for-sale	51,892	0
Cash and cash equivalents	40,365	45,370
Restricted cash	4,121	4,011
Tenant and other receivables, net of uncollectible reserves of $14,332 and $12,728 at September 30, 2018 and December 31, 2017, respectively	160,709	170,985
Deferred Costs, Leasing, Net	85,292	80,044
Acquired lease intangible assets, less accumulated amortization of $206,378 and $148,280 at September 30, 2018 and December 31, 2017, respectively	412,653	478,826
Other assets	427,726	427,127
Total assets	11,057,030	11,145,717
Liabilities:
Notes payable	3,008,592	2,971,715
Unsecured credit facilities	708,616	623,262
Accounts payable and other liabilities	236,250	234,272
Acquired lease intangible liabilities, less accumulated amortization of $84,435 and $56,550 at September 30, 2018 and December 31, 2017, respectively	507,341	537,401
Tenants’ security, escrow deposits and prepaid rent	43,988	46,013
Total liabilities	4,504,787	4,412,663
Commitments and contingencies	0	0
Stockholders’ equity/Partners' capital:
Common stock, $0.01 par value per share, 220,000,000 shares authorized; 169,441,714 and 171,364,908 shares issued at September 30, 2018 and December 31, 2017, respectively	1,694	1,714
Treasury stock at cost, 385,652 and 366,628 shares held at September 30, 2018 and December 31, 2017, respectively	(19,550)	(18,307)
Additional paid in capital	7,756,215	7,873,104
Accumulated other comprehensive income (loss)	14,066	(6,289)
Distributions in excess of net income	(1,240,331)	(1,158,170)
Total stockholders’ equity	6,512,094	6,692,052
Noncontrolling interests:
Exchangeable operating partnership units, aggregate redemption value of $22,628 and $24,206 at September 30, 2018 and December 31, 2017, respectively	10,726	10,907
Limited partners’ interests in consolidated partnerships	29,423	30,095
Stockholders' Equity Attributable to Noncontrolling Interest	40,149	41,002
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(6,552,243)	(6,733,054)
Total liabilities and equity	11,057,030	11,145,717
Partnership Interest [Member]
Real estate investments at cost:
Property, Plant and Equipment, Gross	10,854,283	10,578,430
Properties in development	36,707	314,391
Gross real estate investments at cost	10,890,990	10,892,821
Less: accumulated depreciation	1,474,769	1,339,771
Total Cost Net of Accumulated Depreciation	9,416,221	9,553,050
Investments in real estate partnerships	458,051	386,304
Net real estate investments	9,874,272	9,939,354
Real Estate Held-for-sale	51,892	0
Cash and cash equivalents	40,365	45,370
Restricted cash	4,121	4,011
Tenant and other receivables, net of uncollectible reserves of $14,332 and $12,728 at September 30, 2018 and December 31, 2017, respectively	160,709	170,985
Deferred Costs, Leasing, Net	85,292	80,044
Acquired lease intangible assets, less accumulated amortization of $206,378 and $148,280 at September 30, 2018 and December 31, 2017, respectively	412,653	478,826
Other assets	427,726	427,127
Total assets	11,057,030	11,145,717
Liabilities:
Notes payable	3,008,592	2,971,715
Unsecured credit facilities	708,616	623,262
Accounts payable and other liabilities	236,250	234,272
Acquired lease intangible liabilities, less accumulated amortization of $84,435 and $56,550 at September 30, 2018 and December 31, 2017, respectively	507,341	537,401
Tenants’ security, escrow deposits and prepaid rent	43,988	46,013
Total liabilities	4,504,787	4,412,663
Commitments and contingencies	0	0
Stockholders’ equity/Partners' capital:
General partner; 169,441,714 and 171,364,908 units outstanding at September 30, 2018 and December 31, 2017, respectively	6,498,028	6,698,341
Limited partners; 349,902 units outstanding at September 30, 2018 and December 31, 2017	10,726	10,907
Accumulated other comprehensive income (loss)	14,066	(6,289)
Total partners’ capital	6,522,820	6,702,959
Noncontrolling interests:
Limited partners’ interests in consolidated partnerships	29,423	30,095
Total equity	6,552,243	6,733,054
Total liabilities and equity	$ 11,057,030	$ 11,145,717