CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Dividends declared and paid:
Common stock dividends (in dollars per share)	$ 0.5300	$ 0.5200	$ 1.5700	$ 1.5500
Issuance of common stock:
Director compensation (in shares)	7,443	8,865	22,642	25,624
Stock purchase plan (in shares)	1,811	1,908	5,543	6,214
ATM equity program (in shares)		216,373	30,000	1,634,350
Restricted shares, net of forfeitures (in shares)			287,207	263,406
Series F Preferred Stock
Dividends declared and paid:
Preferred stock dividends (in dollars per share)	$ 0.3250	$ 0.3250	$ 0.9750	$ 0.9750