Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Real Estate Investment Property, at Cost [Abstract]
Real estate assets, at cost	$ 11,082,484	$ 11,101,858
Less: accumulated depreciation	2,047,078	1,994,108
Real estate assets, net	9,035,406	9,107,750
Investments in real estate partnerships	484,425	467,155
Properties held for sale	32,641	33,934
Cash, cash equivalents, and restricted cash, including $2,070 and $2,377 of restricted cash at March 31, 2021 and December 31, 2020, respectively	139,320	378,450
Tenant and other receivables	127,455	143,633
Deferred leasing costs, less accumulated amortization of $113,544 and $113,959 at March 31, 2021 and December 31, 2020, respectively	66,138	67,910
Acquired lease intangible assets, less accumulated amortization of $292,402 and $284,880 at March 31, 2021 and December 31, 2020, respectively	178,784	188,799
Right of use assets, net	285,998	287,827
Other assets	275,821	261,446
Total assets	10,625,988	10,936,904
Less: accumulated depreciation	2,047,078	1,994,108
Real estate assets, net	9,035,406	9,107,750
Liabilities:
Notes payable	3,652,242	3,658,405
Unsecured credit facilities		264,679
Accounts payable and other liabilities	285,320	302,361
Acquired lease intangible liabilities, less accumulated amortization of $152,783 and $145,966 at March 31, 2021 and December 31, 2020, respectively	369,438	377,712
Lease liabilities	219,107	220,390
Tenants’ security, escrow deposits and prepaid rent	56,837	55,210
Total liabilities	4,582,944	4,878,757
Commitments and contingencies
Equity/Capital:
Common stock, $0.01 par value per share, 220,000,000 shares authorized; 169,828,955 and 169,680,138 shares issued at March 31, 2021 and December 31, 2020, respectively	1,698	1,697
Treasury stock at cost, 466,469 and 440,574 shares held at September 30, 2020 and December 31, 2019, respectively	(24,775)	(24,436)
Additional paid-in-capital	7,791,416	7,792,082
Accumulated other comprehensive loss	(12,512)	(18,625)
Distributions in excess of net income	(1,786,196)	(1,765,806)
Total stockholders’ equity	5,969,631	5,984,912
Exchangeable operating partnership units, aggregate redemption value of $43,386 and $34,878 at March 31, 2021 and December 31, 2020, respectively	35,667	35,727
Limited partners’ interests in consolidated partnerships	37,746	37,508
Total noncontrolling interests	73,413	73,235
Total equity	6,043,044	6,058,147
Total equity	6,043,044	6,058,147
Total liabilities and equity	10,625,988	10,936,904
Partnership Interest [Member]
Real Estate Investment Property, at Cost [Abstract]
Real estate assets, at cost	11,082,484	11,101,858
Less: accumulated depreciation	2,047,078	1,994,108
Real estate assets, net	9,035,406	9,107,750
Investments in real estate partnerships	484,425	467,155
Properties held for sale	32,641	33,934
Cash, cash equivalents, and restricted cash, including $2,070 and $2,377 of restricted cash at March 31, 2021 and December 31, 2020, respectively	139,320	378,450
Tenant and other receivables	127,455	143,633
Deferred leasing costs, less accumulated amortization of $113,544 and $113,959 at March 31, 2021 and December 31, 2020, respectively	66,138	67,910
Acquired lease intangible assets, less accumulated amortization of $292,402 and $284,880 at March 31, 2021 and December 31, 2020, respectively	178,784	188,799
Right of use assets, net	285,998	287,827
Other assets	275,821	261,446
Total assets	10,625,988	10,936,904
Less: accumulated depreciation	2,047,078	1,994,108
Real estate assets, net	9,035,406	9,107,750
Liabilities:
Notes payable	3,652,242	3,658,405
Unsecured credit facilities		264,679
Accounts payable and other liabilities	285,320	302,361
Acquired lease intangible liabilities, less accumulated amortization of $152,783 and $145,966 at March 31, 2021 and December 31, 2020, respectively	369,438	377,712
Lease liabilities	219,107	220,390
Tenants’ security, escrow deposits and prepaid rent	56,837	55,210
Total liabilities	4,582,944	4,878,757
Commitments and contingencies
Equity/Capital:
General partner; 169,677,302 and 167,571,218 units outstanding at September 30, 2020 and December 31, 2019, respectively	5,982,143	6,003,537
Limited partners; 765,046 and 746,433 units outstanding at September?30, 2020 and December?31, 2019, respectively	35,667	35,727
Accumulated other comprehensive loss	(12,512)	(18,625)
Total partners’ capital	6,005,298	6,020,639
Limited partners’ interests in consolidated partnerships	37,746	37,508
Total capital	6,043,044	6,058,147
Total capital	6,043,044	6,058,147
Total liabilities and equity	$ 10,625,988	$ 10,936,904