Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Total Revenues	$ 762,290	$ 755,073	$ 740,340
Expenses:
Rental property operating expenses	258,371	259,461	250,850
Reimbursed expenses	2,024	2,476	1,580
General and administrative expenses	28,319	29,321	27,034
Interest expense	72,537	67,027	60,605
Impairment	0	0	14,829
Depreciation and amortization	295,587	288,092	288,648
Transaction costs	0	0	428
Other	2,134	2,131	2,091
Total costs and expenses	658,972	648,508	646,065
Income from unconsolidated joint ventures	7,700	6,801	7,947
Gain on sales of investments in unconsolidated joint ventures	56,267	13,083	45,767
Gain (loss) on investment property transactions	(9)	152,547	90,125
Gain on extinguishment of debt	169	0	0
Net income	167,445	278,996	238,114
Net income attributable to noncontrolling interests	(652)	(410)	(836)
Net income available to common stockholders	$ 166,793	$ 278,586	$ 237,278
Net income per common share — basic (in usd per share)	$ 1.11	$ 1.87	$ 1.60
Net income per common share — diluted (in usd per share)	$ 1.11	$ 1.87	$ 1.60
Weighted average shares — basic (in shares)	150,113	148,666	148,277
Weighted average shares — diluted (in shares)	150,419	148,891	148,636
Dividends declared per common share (in usd per share)	$ 1.28	$ 1.24	$ 1.20
Rental property revenues
Revenues:
Total Revenues	$ 753,511	$ 739,063	$ 721,883
Fee income
Revenues:
Total Revenues	6,119	15,559	18,226
Other
Revenues:
Total Revenues	$ 2,660	$ 451	$ 231