SUPPLEMENTAL CONDENSED COMBINING FINANCIAL INFORMATION - Condensed Combining Statement of Cash Flows (Detail) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2011 Getty Petroleum Marketing [Member]	Sep. 30, 2011 Other Tenants [Member]	Sep. 30, 2011 Corporate [Member]
Cash flows from operating activities:
Net earnings (loss)	$ 6,646,000	$ 31,938,000	$ 19,744,000	$ 24,480,000	$ (12,286,000)
Adjustments to reconcile net earnings (loss) to net cash flow provided by (used in) operating activities:
Depreciation and amortization expense	10,966,000	7,354,000	3,244,000	4,079,000	31,000
Impairment charges	10,552,000	3,094,000	1,544,000	1,550,000
Gain from dispositions of real estate	(3,819,000)	(629,000)	(319,000)	(310,000)
Deferred rental revenue	(2,858,000)	(213,000)	1,390,000	(1,603,000)
Allowance for deferred rent and accounts receivable	16,524,000	11,292,000	11,043,000	249,000
Amortization of above-market and below-market leases	(245,000)	(533,000)		(533,000)
Accretion expense	2,250,000	469,000	459,000	10,000
Stock-based employee compensation expense	547,000	480,000			480,000
Changes in assets and liabilities:
Net investment in direct financing leases		334,000		334,000
Accounts receivable, net	(14,968,000)	(1,177,000)	(200,000)	(977,000)
Other assets	(5,445,000)	547,000	168,000	(140,000)	519,000
Environmental remediation costs	(5,169,000)	(802,000)	(746,000)	(56,000)
Accounts payable and accrued liabilities	(3,254,000)	540,000	74,000	440,000	26,000
Net cash flow provided by (used in) operating activities	12,250,000	52,694,000	36,401,000	27,523,000	(11,230,000)
Cash flows from investing activities:
Property acquisitions and capital expenditures	(2,494,000)	(167,475,000)		(167,474,000)	(1,000)
Proceeds from dispositions of real estate	5,882,000	1,464,000	784,000	680,000
Decrease in cash held for property acquisitions	(3,287,000)	149,000			149,000
Collection of notes and mortgages receivable	1,169,000	483,000		379,000	104,000
Issuance of notes and mortgages receivable		(30,400,000)		(30,400,000)
Net cash flow provided by (used in) investing activities	1,270,000	(195,779,000)	784,000	(196,815,000)	252,000
Cash flows from financing activities:
Borrowings under credit agreement	4,000,000	247,253,000			247,253,000
Repayments under credit agreement		(140,853,000)			(140,853,000)
Repayments under term loan agreement	(585,000)	(585,000)			(585,000)
Cash dividends paid	(4,202,000)	(46,654,000)			(46,654,000)
Credit agreement origination costs	(4,044,000)	(175,000)			(175,000)
Net proceeds from issuance of common stock		91,986,000			91,986,000
Cash consolidation - Corporate			(37,185,000)	169,292,000	(132,107,000)
Net cash flow provided by (used in) financing activities	(4,831,000)	150,972,000	(37,185,000)	169,292,000	18,865,000
Net increase in cash and cash equivalents	8,689,000	7,887,000			7,887,000
Cash and cash equivalents at beginning of period	7,698,000	6,122,000			6,122,000
Cash and cash equivalents at end of period	$ 16,387,000	$ 14,009,000			$ 14,009,000