CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Dividends declared and paid:
Common stock dividends (in dollars per share)	$ 0.515	$ 0.500	$ 1.030	$ 1.000
Issuance of common stock:
Director compensation (in shares)	10,647	6,962	16,759	14,969
Stock purchase plan (in shares)	2,829	1,832	4,306	4,156
Restricted shares, net of forfeitures (in shares)			253,406	259,650
ATM equity program (in shares)	1,417,977	1,495,548	1,417,977	1,495,548
Series E Preferred Stock
Dividends declared and paid:
Preferred stock dividends (in dollars per share)		$ 0.356250		$ 0.712500
Series F Preferred Stock
Dividends declared and paid:
Preferred stock dividends (in dollars per share)	$ 0.325000	$ 0.325000	$ 0.650000	$ 0.650000