Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 12,700	$ 10,927
Adjustments to reconcile net earnings to net cash flow provided by operating activities:
Depreciation and amortization expense	7,097	6,099
Impairment charges	1,031	771
(Gain) loss on dispositions of real estate	(869)	51
Deferred rent receivable	(777)	(955)
Amortization of above-market and below-market leases	(108)	(172)
Amortization of investment in direct financing leases	982	827
Amortization of debt issuance costs	260	235
Accretion expense	466	538
Stock-based compensation	732	474
Changes in assets and liabilities:
Accounts receivable	1,461	1,342
Prepaid expenses and other assets	(188)	(765)
Environmental remediation obligations	(2,113)	(1,873)
Accounts payable and accrued liabilities	(2,800)	(2,017)
Net cash flow provided by operating activities	17,874	15,482
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions	(57,321)
Addition to construction in progress	7	(151)
Proceeds from dispositions of real estate	851	77
Deposits for property acquisitions	690	50
(Issuance) of notes and mortgages receivable		(382)
Collection of notes and mortgages receivable	2,691	1,905
Net cash flow (used in) provided by investing activities	(53,082)	1,499
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under credit agreement	65,000	5,000
Repayments under credit agreement		(35,000)
Payment of finance lease obligations	(153)	(127)
Security deposits received (refunded)	63	(242)
Payments of cash dividends	(15,163)	(14,138)
Payments in settlement of restricted stock units	(244)	(115)
Net cash flow provided by (used in) financing activities	49,476	(44,639)
Change in cash, cash equivalents and restricted cash	14,268	(27,658)
Cash, cash equivalents and restricted cash at beginning of period	23,664	48,742
Cash, cash equivalents and restricted cash at end of period	37,932	21,084
Supplemental disclosures of cash flow information Cash paid during the period for:
Interest	6,347	5,759
Income taxes	251	222
Environmental remediation obligations	1,325	1,532
Non-cash transactions:
Dividends declared but not yet paid	15,632	14,555
Issuance of notes and mortgages receivable related to property dispositions	792
ATM Program [Member]
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net	$ (27)	$ (17)