Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Summary information for the reportable segments
Rental and other property revenues	$ 230,235	$ 225,393
Tax credit and transaction revenues	0	22,327
Total revenues	230,235	247,720
Property operating expenses	79,184	78,287
Direct Costs of Leased and Rented Property or Equipment - Asset Management	0	9,195
Depreciation and amortization	93,565	92,548
General and administrative expenses	10,369	11,355
Other operating expenses not allocated to reportable segment (3)	109,637	106,861
Total operating expenses	188,821	194,343
Operating Income (Loss), Property	41,414	53,377
Other Items included in income before gain on dispositions (4)	252,862	7,796
Income before gain (loss) on dispositions	294,276	61,173
Segment Reconciling Items [Member]
Summary information for the reportable segments
Rental and other property revenues		8,236
Total revenues	8,747	8,236
Property operating expenses	8,189	7,726
Total operating expenses	8,189	7,726
Operating Income (Loss), Property	558	510
Income before gain (loss) on dispositions	558	510
Corporate Non-Segment [Member]
Summary information for the reportable segments
Rental and other property revenues		19,582
Tax credit and transaction revenues		22,327
Total revenues	5,959	41,909
Property operating expenses	9,830	12,945
Direct Costs of Leased and Rented Property or Equipment - Asset Management		9,195
Other operating expenses not allocated to reportable segment (3)	109,637	106,861
Total operating expenses	119,467	129,001
Operating Income (Loss), Property	(113,508)	(87,092)
Other Items included in income before gain on dispositions (4)	252,862	7,796
Income before gain (loss) on dispositions	139,354	(79,296)
Same Store [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		168,606
Tax credit and transaction revenues		0
Total revenues	175,719	168,606
Property operating expenses	47,137	46,755
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	47,137	46,755
Operating Income (Loss), Property	128,582	121,851
Income before gain (loss) on dispositions	128,582	121,851
Redevelopment and Development [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		18,077
Tax credit and transaction revenues		0
Total revenues	20,350	18,077
Property operating expenses	7,290	6,499
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	7,290	6,499
Operating Income (Loss), Property	13,060	11,578
Income before gain (loss) on dispositions	13,060	11,578
Acquisition [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		1,580
Tax credit and transaction revenues		0
Total revenues	9,993	1,580
Property operating expenses	2,855	523
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	2,855	523
Operating Income (Loss), Property	7,138	1,057
Income before gain (loss) on dispositions	7,138	1,057
Other Real Estate [Member] | Operating Segments [Member]
Summary information for the reportable segments
Rental and other property revenues		9,312
Tax credit and transaction revenues		0
Total revenues	9,467	9,312
Property operating expenses	3,883	3,839
Direct Costs of Leased and Rented Property or Equipment - Asset Management		0
Total operating expenses	3,883	3,839
Operating Income (Loss), Property	5,584	5,473
Income before gain (loss) on dispositions	$ 5,584	$ 5,473