Supplemental Condensed Combining Financial Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2011 Getty Petroleum Marketing [Member]	Jun. 30, 2011 Getty Petroleum Marketing [Member]	Jun. 30, 2011 Other Tenants [Member]	Jun. 30, 2011 Other Tenants [Member]	Jun. 30, 2011 Corporate [Member]	Jun. 30, 2011 Corporate [Member]	Dec. 31, 2011 Corporate [Member]
Cash flows from operating activities:
Net earnings (loss)	$ 3,626	$ 15,202	$ 10,111	$ 26,588	$ 10,900	$ 21,201	$ 6,875	$ 14,146	$ (2,573)	$ (8,759)
Adjustments to reconcile net earnings to net cash flow provided by (used in) operating activities:
Depreciation and amortization expense			7,474	4,530		1,963		2,546		21
Impairment charges	2,783		3,146	2,507		994		1,513
Gains from dispositions of real estate			(3,241)	(319)		(319)
Deferred rental revenue, net of allowance			(1,379)	(184)		812		(996)
Allowance for deferred rent and accounts receivable			16,739	215				215
Amortization of above-market and below-market leases			(211)	(262)				(262)
Accretion expense			1,584	296		290		6
Stock-based employee compensation expense			372	311						311
Changes in assets and liabilities:
Net investment in direct financing leases				211				211
Accounts receivable, net			(14,876)	(150)		(236)		86
Other assets			(3,334)	75				(100)		175
Environmental remediation costs			(3,811)	(110)		(108)		(2)
Accounts payable and accrued liabilities			(2,480)	1,616		92		2,168		(644)
Net cash flow provided by operating activities			10,436	35,324		24,689		19,531		(8,896)
Cash flows from investing activities:
Property acquisitions and capital expenditures			(2,465)	(166,594)				(166,594)
Proceeds from dispositions of real estate			5,013	784		784
Decrease in cash held for property acquisitions			(2,016)	60						60
Collection of notes and mortgages receivable			928	307				187		120
Issuance of notes and mortgages receivable			(1,011)	(30,640)				(30,400)		(240)
Net cash flow provided by (used in) investing activities			449	(196,083)		784		(196,807)		(60)
Cash flows from financing activities:
Borrowings under credit agreement			4,000	231,253						231,253
Repayments under credit agreement				(122,553)						(122,553)
Repayments under term loan agreement			(390)	(390)						(390)
Payments of cash dividends				(30,543)						(30,543)
Payment of loan origination costs			(3,701)	(175)						(175)
Net proceeds from issuance of common stock				91,986						91,986
Cash consolidation - Corporate						(25,473)		177,276		(151,803)
Net cash flow provided by (used in) financing activities			(91)	169,578		(25,473)		177,276		17,775
Net increase in cash and cash equivalents			10,794	8,819						8,819
Cash and cash equivalents at beginning of period			7,698	6,122						6,122	7,698
Cash and cash equivalents at end of year	$ 18,492	$ 14,941	$ 18,492	$ 14,941					$ 14,941	$ 14,941	$ 7,698