Supplemental Condensed Combining Financial Information - Supplemental Condensed Combining Statement of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings	$ 12,447	$ 12,456	$ 51,700
Adjustments to reconcile net earnings to net cash flow provided by operating activities:
Depreciation and amortization expense	13,700	10,336	9,738
Impairment charges	13,942	20,226
Gains on dispositions of real estate	(6,866)	(968)	(1,705)
Deferred rent receivable, net of allowance	(4,368)	(453)	96
Allowance for deferred rent and accounts receivable	15,903	28,879	229
Allowance for accounts receivable			229
Amortization of above-market and below-market leases	(285)	(685)	(1,260)
Amortization of credit agreement origination costs	3,396	207	304
Accretion expense	3,174	899	775
Stock-based employee compensation expense	757	643	480
Changes in assets and liabilities:
Accounts receivable, net	(15,848)	(14,890)	(189)
Prepaid expenses and other assets	(8,004)	151	(379)
Environmental remediation obligations	(9,009)	(1,981)	(2,512)
Accounts payable and accrued liabilities	(3,054)	5,935	(213)
Net cash flow provided by operating activities	15,885	60,755	57,064
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions and capital expenditures	(4,148)	(167,495)	(4,725)
Proceeds from dispositions of real estate	9,855	2,317	2,858
(Increase) decrease in cash held for property acquisitions	(1,615)	(750)	2,665
Amortization of (accretion in) investment in direct financing leases	728	505	(323)
Issuance of notes and mortgages receivable	(2,972)	(30,400)
Collection of mortgages receivable, net	1,703	2,679	158
Net cash flow provided by (used in) investing activities	3,551	(193,144)	633
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowing under credit agreement	4,000	247,253	163,500
Repayments under credit agreement	(1,410)	(140,853)	(273,400)
Repayments under term loan agreement	(780)	(780)	(780)
Payments of capital lease obligations	(152)	(59)
Payments of cash dividends	(8,404)	(63,436)	(52,332)
Payments of loan origination costs	(4,144)	(175)
Security deposits received	650	29	182
Net proceeds from issuance of common stock		91,986	108,205
Net cash flow provided by (used in) financing activities	(10,258)	133,965	(54,625)
Net increase in cash and cash equivalents	9,178	1,576	3,072
Cash and cash equivalents at beginning of year	7,698	6,122	3,050
Cash and cash equivalents at end of year	16,876	7,698	6,122
Getty Petroleum Marketing [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings		(5,506)	43,520
Adjustments to reconcile net earnings to net cash flow provided by operating activities:
Depreciation and amortization expense		5,024	4,229
Impairment charges		18,676
Gains on dispositions of real estate		(641)	(1,685)
Deferred rent receivable, net of allowance		1,463	1,580
Allowance for deferred rent and accounts receivable		28,879
Accretion expense		879	758
Changes in assets and liabilities:
Accounts receivable, net		(14,851)	(15)
Environmental remediation obligations		(1,304)	(3,062)
Accounts payable and accrued liabilities		3,040	42
Net cash flow provided by operating activities		35,659	45,367
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from dispositions of real estate		1,604	2,623
Net cash flow provided by (used in) investing activities		1,604	2,623
CASH FLOWS FROM FINANCING ACTIVITIES:
Cash consolidation - Corporate		(37,263)	(47,990)
Net cash flow provided by (used in) financing activities		(37,263)	(47,990)
Other Tenants [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings		34,992	21,353
Adjustments to reconcile net earnings to net cash flow provided by operating activities:
Depreciation and amortization expense		5,266	5,472
Impairment charges		1,550
Gains on dispositions of real estate		(327)	(20)
Deferred rent receivable, net of allowance		(1,916)	(1,484)
Allowance for accounts receivable			229
Amortization of above-market and below-market leases		(685)	(1,260)
Accretion expense		20	17
Changes in assets and liabilities:
Accounts receivable, net		(39)	(174)
Prepaid expenses and other assets		(68)	467
Environmental remediation obligations		(677)	550
Accounts payable and accrued liabilities		692	(455)
Net cash flow provided by operating activities		38,808	24,695
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions and capital expenditures		(167,471)	(4,629)
Proceeds from dispositions of real estate		1,781	235
Amortization of (accretion in) investment in direct financing leases		505	(323)
Issuance of notes and mortgages receivable		(30,400)
Collection of mortgages receivable, net		2,415
Net cash flow provided by (used in) investing activities		(193,170)	(4,717)
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments of capital lease obligations		(59)
Security deposits received		29	182
Cash consolidation - Corporate		154,362	(20,160)
Net cash flow provided by (used in) financing activities		154,932	(19,978)
Corporate [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net earnings		(17,030)	(13,173)
Adjustments to reconcile net earnings to net cash flow provided by operating activities:
Depreciation and amortization expense		46	37
Amortization of credit agreement origination costs		207	304
Stock-based employee compensation expense		643	480
Changes in assets and liabilities:
Prepaid expenses and other assets		219	(846)
Accounts payable and accrued liabilities		2,203	200
Net cash flow provided by operating activities		(13,712)	(12,998)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property acquisitions and capital expenditures		(24)	(96)
Proceeds from dispositions of real estate		(1,068)
(Increase) decrease in cash held for property acquisitions		(750)	2,665
Collection of mortgages receivable, net		264	158
Net cash flow provided by (used in) investing activities		(1,578)	2,727
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowing under credit agreement		247,253	163,500
Repayments under credit agreement		(140,853)	(273,400)
Repayments under term loan agreement		(780)	(780)
Payments of cash dividends		(63,436)	(52,332)
Payments of loan origination costs		(175)
Net proceeds from issuance of common stock		91,986	108,205
Cash consolidation - Corporate		(117,129)	68,150
Net cash flow provided by (used in) financing activities		16,866	13,343
Net increase in cash and cash equivalents		1,576	3,072
Cash and cash equivalents at beginning of year		6,122	3,050
Cash and cash equivalents at end of year		$ 7,698	$ 6,122