Investment in Unconsolidated and Consolidated Joint Ventures - Condensed Statements of Operations and Balance Sheet Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Statement of Operations
Revenues			$ 54,295	$ 61,354
Total revenues	$ 6,849	$ 7,000	19,802	23,633
Net income (loss)			5,569	4,695
Net (loss) income	(728)	377	467	1,978
Partner’s share of net income (loss)			2,272	1,889
Net income attributable to parent	(688)	406	521	2,023
Equity in earnings (loss)			3,297	2,806
Equity in earnings of unconsolidated joint ventures, net	1,842	$ 1,656	3,297	2,806
Balance Sheet Information
Current assets	23,940		23,940		$ 20,046
Current assets, consolidated	52,316		52,316		48,893
Real Estate	136,564		136,564		135,459
Real Estate, consolidated	45,819		45,819		44,469
Other assets	18,870		18,870		20,275
Long-term debt	(76,359)		(76,359)		(77,255)
Long-term debt, consolidated	(85,089)		(85,089)		(74,215)
Other liabilities	(4,083)		(4,083)		(4,071)
Net assets	98,932		98,932		94,454
Petro Travel Plaza Holdings
Statement of Operations
Revenues			48,052	55,180
Net income (loss)			5,129	4,583
Partner’s share of net income (loss)			2,052	1,833
Equity in earnings (loss)			3,077	2,751
Balance Sheet Information
Current assets	14,433		14,433		12,013
Real Estate	54,763		54,763		52,296
Other assets	170		170		264
Long-term debt	(14,500)		(14,500)		(14,973)
Other liabilities	(3,027)		(3,027)		(2,890)
Net assets	51,839		51,839		46,710
Five West Parcel LLC
Statement of Operations
Revenues			1,484	1,856
Net income (loss)			549	472
Partner’s share of net income (loss)			274	236
Equity in earnings (loss)			275	236
Balance Sheet Information
Current assets	2,533		2,533		3,277
Real Estate	13,358		13,358		13,704
Other assets	313		313		297
Long-term debt	(10,520)		(10,520)		(10,725)
Other liabilities	(122)		(122)		(340)
Net assets	5,562		5,562		6,213
18-19 West LLC
Statement of Operations
Revenues			4	13
Net income (loss)			(72)	(59)
Partner’s share of net income (loss)			(36)	(30)
Equity in earnings (loss)			(36)	(30)
Balance Sheet Information
Current assets	61		61		23
Real Estate	4,617		4,617		4,617
Other assets	0		0		0
Long-term debt	0		0		0
Other liabilities	0		0		0
Net assets	4,678		4,678		4,640
TRCC/Rock Outlet Center
Statement of Operations
Revenues			4,755	4,305
Net income (loss)			(37)	(301)
Partner’s share of net income (loss)			(18)	(150)
Equity in earnings (loss)			(19)	(151)
Balance Sheet Information
Current assets	6,913		6,913		4,733
Real Estate	63,826		63,826		64,842
Other assets	18,387		18,387		19,714
Long-term debt	(51,339)		(51,339)		(51,557)
Other liabilities	(934)		(934)		(841)
Net assets	36,853		36,853		36,891
Rental income			5,800	5,400
Non-cash tenant allowance amortization			1,000	1,100
Centennial-VIE | Primary Beneficiary
Statement of Operations
Total revenues			72	205
Net (loss) income			(225)	(175)
Net income attributable to parent			(54)	(45)
Equity in earnings of unconsolidated joint ventures, net			0	$ 0
Balance Sheet Information
Current assets, consolidated	46		46		230
Real Estate, consolidated	84,284		84,284		81,742
Other assets, consolidated	5		5		9
Long-term debt, consolidated	0		0		0
Other liabilities, consolidated	(1,483)		(1,483)		(754)
Net assets	$ 82,852		$ 82,852		$ 81,227